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Cooling system overhaul tips and tricks (E39)

177K views 60 replies 47 participants last post by  Bmwe39528i 
#1 ·
COOLING System Overhaul Info for V8 folks

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Last year I wrote the Cooling Overhaul Tips for Inline 6-cylinder engine (1998 528i):

http://www.bimmerboard.com/forums/posts/199986

For V8 engine, it is very similar in concept in belts layout, see this diagram that I just prepared for you folks with V8 engine. When combined above link and this picture, V8 folks should be able to do cooling overhaul themselves

cn90
98 528i 5sp 95K
 

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#33 ·
Is there a beltdrive layout for an '02 530iA? I couldn't find one here using the search function.
 
#34 ·
To the best of my knowledge the belt layout is the same as above which is like my 540i. BTW I just changed my water pump out and would like to thank those here who've put the time in tell us what to expect.

I had absolutely no issue getting my fan off. However mine was still intact as I had caught it early. All I did was put the 32mm wrench on the nut and then take a hammer and strike the wrench end about 7 times firmly. The pulley would turn some but the force of the strike broke it free and that was without using WD40 or the like. The fan shouldn't be torqued down at all since the direction the belt travels constantly tightens it. Another note: be careful to separate the pipes behind the pump without pulling them out from where that attach in the rear. I hear they can be a bitch to get back in.

Anyway thanks again for all the write ups folks! For my next trick I think I'm going to tackle my clutch!!!!:yikes:
 
#35 ·
I had the great luck of being on the side of I-75 in Atlanta last night during a snowstorm because something went wrong with my coolant system. While driving I saw steam escaping out the back of the car. At first it seemed like just exhaust escaping in cold weather but then it increased in seconds to a cloud of steam. I quickly darted over to the side of the road and turned off the car. Then, when I checked under the hood I saw a splitting belt and a bit of melting rubber around the waterpump/fan clutch. So, I was pretty sure it was the Waterpump, but on hindsight I question the fan clutch too.

But neither bothered me as much as the dealership-recommended tow truck driver who decided it was best to DRIVE my car onto the flatbed. I was in shock, but realized it was like screaming at the chef before he's done making your meal. You could make it worse. So I drove quietly with him to the dealership biting my lip the whole time and thinking "at least he only has to coast it down off the back now." Oh no, he decided once he had it lowered that it was blocking another car, so HE STARTS IT UP AGAIN AND DRIVES ROUND THE CORNER TO A PARKING SPOT.

At this point I was furious and laid into him while the front desk assistants from the now-closed BMW service area watched. I made certain of this because I needed witnesses. He was originally rude, then 10 minutes later called to apologize. I'm a fair man, so right now I am going to describe to the service area what he did, but not yet go into detail on how he acted. But if anything else was impacted by this I'm gonna go nuts on this guy and the dealership for recommending him.
 
#36 · (Edited)
Resurrecting this thread for advice specific to the waterpump. Planning on completing my overhaul with the water pump, belts and hoses in the next couple of weeks. Was curious, my indy just did the coolant flush in February 2010 and since I've never done a flush would prefer to leave that piece of the puzzle alone.

So, I know that once I pull the waterpump out, coolant will come gushing out, but can I just put the new pump in, fill and bleed the system to top off the coolant and be done with it, or will I need to do a complete system flush as called for in the DIY?
 
#40 · (Edited)
I just overhauled my entire cooling system on my 2001 530i. It went pretty well...no leaks thus far. For this car, I noted some differences from cn90's most excellent write-up:

Regarding the reservoir and its small hose that attaches to the opposite side of the radiator: I found attaching this hose to the reservoir first was significantly easier than any other method. I didn't have the room to attach the hose to the reservoir (with it attached to the radiator first) because the length of the hose was too short and the shroud was in the way. I used a stick to keep the shroud raised up to allow me to attach the other end of the hose to the radiator second...MUCH EASIER. :)

Also, pick up two "BMW" hose clamps for the reservoir hose. The ones we typically get at the auto/hardware store just can't take what I feel is the required torque to cinch these hoses down good. I went to my dealer and it took him some time to locate the screw type that was roughly the same size as the original crimp style that came from the factory. Here is the part number: 07 12 9 952 104 from the fuel filter diagram (http://www.realoem.com/bmw/showparts.do?model=DT53&mospid=47587&btnr=13_0918&hg=13&fg=10). Yeah, they were a tad pricey at the dealer at around $3 each but worth it for no leaks, right?! :thumbup:

I did not bother filling the system with new fluid until everything was done and completed...it was just easier. I was able to put 11.1 quarts of fluid in relatively easily. I filled the system VERY SLOWLY through the bleeder screw hole on the upper radiator hose...agonizingly slowly. I was hoping if I did this that I wouldn't trap air. I left the reservoir cap and its bleeder screw there open the whole time and air was bubbling out as I slowly filled. After that, it was a matter of running the engine, heater on high set to 90F, and then keep checking the fluid level off and on and after a cycle or two of this over a couple hours, I had all 11.1 quarts into the system. I suggest you keep careful track of the amount so that you are sure.

Finally, attached is a pic of a cheap plumber's tool that will aid you in knocking the fan bolt loose in 10 s...along with a 1 1/4" wrench if you don't have a 32 mm one. :D
 

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#44 · (Edited)
attaching this hose to the reservoir first
This is a great hint!

two "BMW" hose clamps for the reservoir hose... 07 12 9 952 104 from the fuel filter diagram
Another great tip.

I'll update the recommended cooling system parts list.

Ågent99 said:
cheap plumber's tool
For the life of me, I can't figure out HOW you're gonna use THAT tool ... but if it works, all the power to you. I added it to the counterhold tools thread.

PS: Someone take a picture of that tool in use so we can see how it works!

 
#45 ·
Well, I don't plan to visit the cooling system again for at least another 100k miles but I'll try to use words to describe how to use the strainer wrench to hold the pulley while wrenching on it.

Simply hook the notched end of the tool on a nut on the pulley and the swing arm gets hooked on the opposite nut. That is it...you can now hold the pulley in place and knock the nut loose with a wrench.

This plumber's tool is made for removing large diameter locking rings (i.e. large plastic "nuts") on sink drains and what not. Some of those are quite large in diameter and the swing arm makes the tool universal for many different sizes.
 
#46 · (Edited)
I did my full cooling system overhaul a couple weeks ago. 2002 530i Automatic, 75,000 miles. Tips, I agree with everyone here, do it all at once. Use the best parts and rest easy after.
My radiator split causing this need.
I did not have a tool for the fan clutch but taking a long 15mm box end wrench I put the box end over one of the four 10mm fan pulley mounting bolts and rotated the wrench till the shaft contacted the hub center.
This worked as a lever to hold the water pump firmly in place while I hit the long 1 1/4 wrench with a rubber mallet to losen the fan clutch. One hard whack had it loose. ( 1 1/4 worked and fit perfectly, I did not have a 32mm open end ) It spun off fine. I did use anti-seize on the new water pump hub so the clutch would not be an issue should I ever have to revisit.
I read the posts about quickly installing the fan clutch back on the water pump. I tried once to see how hard it might be and it went on with no issue or strain. I was prepared for using the string trick but did not need it. I had the radiator out for replacement so I had extra room.

I found an oil leak behind the Oil filter housing and pulled it for a clean and new gasket. No more leaks!
Pulled the PS tank hose and replaced the clamp, no more leak.
Found a rats nest in my Air Filter box, removed it, that should help air flow.

Two hoses on the 530i were hard to find.
Part number WO133-1792583 Engine to Heater Control Valve 31.94
Part number WO133-1792584 Heater core to Radiator Tank return line 35.94
My 530i has the 3 heater inlet/outlet ports on the drivers side of the engine compartment side by side. Most photo's I saw only show 2 with the third hose bib on the pass side. 540i design maybe?

These are in addition to all the Hoses included in most of the kits.
Radiator to Thermostat, upper and lower.
Exp tank to the aux pump
Exp tank to Heater core, this is the first half, a second goes actually to the core.
Two more heater hoses, Valve to heater core Left and Right
Aux pump to engine
 
#47 ·
I successfully completed most of the overhault (skipped rollers and hoses) about 2 weeks ago and haven't had any issues since. For the record I am NOT a DIY expert and prior to owning my BMW (bought 3 months ago) I had never even changed oil on a car. That said, despite being intimidated at first, this was really not all that bad. I completed my overhaul in 3 nights working maybe 2 hours at a time and being very very careful about everything.

Some notes for future DIY-ers include:
1. Fan clutch nut on my 2001 525i apparently had a more difficult seize than many others. As a result the BMW 1703 tool was extremely useful and much more successful than the screwdriver method in the DIY. My seize was so hard that I actually had to resort to setting up the 1703 and bracing it against a maglite in the engine bay and striking the 32mm wrench clockwise with a rubber hammer a few times. After at least an hour of fussing with it this was the only way I was able to break the seize. I bought my 1703 on ebay for about $30 but neglected to check if Autozone and the like had it available for loan.

2. Rethreading said fan clutch was somewhat frustrating. You have to set it on the nut "just so" where it won't fall off at all, spin it clockwise, and hope that it doesn't slip. I bet this took at least 20 minutes.

3. I happen to have mechanical tensioners on my bimmer and it is important to note that these required a T50 TORX screw rather than an 8mm Hex screw as noted in the guide. I very strongly recommend anyone with mechanical tensioners, who are not replacing them, to buy a T50 bit or a set of them instead of the Torx keys. It would be extremely difficult to release the tension using a key. I bought a large set of Torx bits for about $10 at Autozone.

4. Water pumps, at least at the time I did my overhaul, seem to have gone up considerably in price. Even the OEM one is over $100 everywhere I checked and I've heard bad things about the Graf. I picked up a Bosch 96101 on Amazon.com for only about $50 and feel really good about it. Compared to the OEM Behr part it was almost identical save for the *****colored (brass?) impeller. It came with the gasket, too, so no need to order a new one. I couldn't find much info on if this unit was good or not but I optimistically took it as a good sign since enthusiasts regularly complain about the subpar parts. Even if it fails in the near future, at 1/3 of the price of most OEM-quality models, I think I'll be satisfied with it.

5. As far as the coolant goes, I would recommend just buying BMW coolant. I bought the yellow Prestone extended life coolant for CHEAP ($12-5 MIR!!!) and ended up returning it after doing a lot of research. There just isn't a definitive answer from other enthusiasts on a suitable alternative for BMW coolant and I decided not to risk it. The coolant in my car at the time was also not OEM since it was a bright green color (Peak maybe?) and that also spurred my decision to only use the real thing. $21.95 per gallon at the local dealer (I used about 1.25 gallons myself). A lot more spendy than the practically free Prestone but a cheap investment for peace of mind.

A couple of great resources that also helped me out during the overhaul include:

1. Pelican Parts 3 series cooling system DIY.
Can't find the link for this one but it was for an e39 or e346. Almost identical to procedure on e39 and includes some really good pictures.

2.
Great video for cooling system bleeding which is something I was paranoid about doing incorrectly. I followed this procedure exactly and had 0 problems with air bubbles, etc.
 
#48 · (Edited)
I just did this overhaul over the weekend to my wife's '97 528i. Thank you all so much for the information! Here are a few things I ran into and the alternative steps I had to take:

* The cheapest place I could find all of the parts in the correct brands and free shipping was here:
http://www.perfectimportparts.com
* I ordered this wrench (due to the low price) from Amazon for the clutch nut removal:
http://www.amazon.com/gp/product/B004QO9I2W
Unfortunately, the wrench was too wide to fit without sticking. The fix...using a bench grinder, I ground off about 1-2mm off of each side of the open end. It fits perfectly now.
* I wasn't able to find a clutch holding tool for rent/loan from an auto parts vendor, so I ended up making my own. I took a very old steel square edge and drilled two holes for the bolt heads. After this, I grinded again with the wheel to create the arch between the holes for the center of the water pump shaft. This tool also came in quite handy when removing the bolts from the water pump pulley. I'll try to add a picture of the tool, if I can ever remember. :)
* Our 528i has a mechanical tensioner for the water pump/alt/PS pump belt, and there is a hydraulic one for the A/C belt. The hydraulic tensioner pulley did not want to break loose. At first I wondered if maybe I'd done something wrong. After reading, they just like to be stubborn. Thus, a nice long persuasion pipe on the end of my ratchet did the trick. :D

Just thought I'd throw out this info, in case it might help someone. :thumbup:

-Ben
 
#50 ·
E39 Water Pump Removal reccomendations

Go buy or build a tool to hold the pump pulley wheel AND get a 32mm wrench (thin). Both are available on Ebay for about $45 including shipping. I built the pulley holding tool many years ago for my 1970 BMW2002 and have been using it ever since. My tool just broke on my 540i so I had to rebuild it by drilling two 7/16" holes 38mm apart and a C-shaped cutout between the two bolt holes whose circular diameter is 38mm as well. I bought a piece of iron bar about 2' long and 3/16" thick with a width of about 1". Alternatively, you can take out 1 bolt on the pulley and bolt on a tool with a 6mm (1/4") hole at one end of the same bar dimensions given. Do not expect to be able to undo the 32mm bolt with your normal human stregth alone; you need to use an impact technique to loosen the bolt. This is done using a hammer on the wrench to loosen the bolt while holding the homemade tool (or purchased one). REMEMBER THAT THE BOLT LOOSENS IN THE CLOCKWISE DIRECTION ON THE WATER PUMP PULLEY! Sometimes the bolt has been on way too tight and it took a lot of hammering to get it off. My 540i bolt was way overtightened.
Next. on the California and I assume other US cars, there is an exaust air pipe that goes around the entire front of the engine. A bolt on each side of this air pipe lets it be taken off prior to removing the water pump. The bolts are just an inch or two behind the front plane of the engine on either side of the engine. There are two small o-ring type gaskets on this pipe that must be present upon re-installation.
Before pulling off the water pump, make sure the two metal pipes exiting the rear of the water pump stay in their positions and are not pulled free from their rear connections. I used a channel lock wrench to attempt to hold the smaller pipe in but was unsuccessful. The larger pipe stayed in. I would recommend using two hose clamps mounted on the pipes to provide a place for a screwdriver to be able to keep them back while the water pump is extracted from it's position.
Now, I am waiting for parts...
 
#51 ·
I was tricked by Sears today - the website said they had the fan clutch wrench and the tool in stock at my store. i walked two miles to the store abd they didn't have ANY 32mm wrenches of any sort whatsoever, much less the other tool. I was SOL and needed to do this today, so I picked up the thinnest adjustable wrench I could find. I wanted a slide wrench, which would have made it even thinner, buy they had nothing that opened to 32mm (there was a tag that said "see sales associate" but the sales associate said that means its out of stock - she even suggested I order it... why would I go to a store to order something online? I could have done that in my underwear at home!)

ANYWAYS...

All they had that was thin enough was a 10 inch adjustable wrench. I said some prayers and placed it in the fan clutch nut and began to apply pressure. It slid in without touching the surrounding components, I heard the nut break free and that was it - fan is coming off! I imagine it would be even easier with a longer wrench - I had just enough room to get mu two fore fingers and thumb on it. The wrench cost me 18 bucks. Maybe if you aready have a thin wrench it might not be necessary to buy a special tool - just make sure your not forcing it in the space.
 
#52 ·
So these tips and tricks don't get lost, here's one posted today:

Two weeks ago I did a cooling overhaul for my 530i with 123,000 miles on it. I bought a bundle from OEMBimmerparts.com that included:

Nissens Radiator
Expansion Tank
Graf Water Pump w/Metal Impeller
Wahler Thermostat and Housing
Upper and Lower Rad Hoses
Cooling Temp Sensor
a small washer in its own bag

This bundle cost around $430. I spent an evening pricing things out from different suppliers, figuring out what the cost individually would be, etc. It looked like I could have saved about $10 if I sourced all the parts separately, but I was happy to the extra $5 for the convenience of having everything put together and shipped at the same time. In addition, most of the best individual prices that I found were on eBay which is always a bit of a crapshoot.

The day of my fix, I also decided that I should change the Serpentine Belt. This part costs $30 online, but since it was day-of I went to the stealer and paid $61.86. Oh well, better than worrying about it.

I primarily used cn90's excellent DIY for the fix, which can be found here: http://www.bimmerboard.com/forums/posts/199986"]. Besian also has good information about the fan shroud removal at http://www.beisansystems.com/procedures/vanos_procedure.htm. I have heard that Pelican Parts has a good DIY as well but I did not use it. Because there are such great resources out there for this fix, I will not go into it step by step, but will put down a few details that I ran into. I also did the double Vanos during this fix, but I will put my specific experiences on that in a different post.

I recommend getting the serpentine belt and A/C belt if you are going to do this fix. If you plan ahead (unlike I did) you can have both for around $40, and again, peace of mind is why we do these fixes. You will be removing both of these during the course of the work, so it is no extra effort to replace with new.

Another item is the catch pan for coolant. I wasn't sure what size I needed. I ended up using a Rubbermade 3 gallon rectangular container. I only ended up draining about 1.5 gallons of coolant, but to be fair a good amount ended up on the garage floor. I also cleaned this puppy thoroughly after use. Since I had an issue with my fix I had to open everything up again, and having a clean container meant that I could re-use the new coolant when I had to drain it for the second time.

You will need a 32mm wrench for this fix as well. I bought one at a local bike shop for $12. This is also the wrench you will need if you want to fix the headset on your bike. Hooray, double use! I think I saw some posts that said they got away with using a wrench, and while I am sure this is possible, my life was made much easier with the 32mm. Also, if you have a choice of lengths when purchasing this wrench, get the longest one you can find. Mine was a bit short which makes it awkward to smack with a hammer, but even so it is not too bad.

Moving on to the fix, the first item that I was not clear on was how the radiator plug works. It is on the bottom of the radiator on the drivers side, and I guess it is usually blue (mine was). I turned it 90 degrees, as specified, and nothing happened. What you have to do then is pull straight down on it. It will pop out with moderate force, and you will get coolant all over your shirt. Or at least that is what happened with me. If I knew better, I would have positioned myself more out of the way and yanked more firmly. Then I would have only gotten it on my hand. You will get it on your hand.

The second item that gave me a bit of trouble was the hoses themselves. They are held on with a metal clip that is easy to pry up, but even after doing that the hoses can be difficult to dislodge. I wasn't sure if I needed to do something else or not. I did not. Just pull up the clip (half of them will fly off the hoses, but this is no big deal) and start to work that bad boy off. The first hose you take off, the one that connects to the auxiliary water pump, will spray quite a bit of coolant out even after draining the radiator, so be prepared. It comes out with a small amount of pressure so factor that in with your catch pan positioning.

Once you follow the directions and get the fan shroud loose, you get to the dreaded fan removal. I have removed this thing several times now, and it has been different every time. I assume it is because the fan is "clutched", so depending on the clutch position the fan may spin easily or it may not spin much at all. At any rate, the method described is exactly right--put the wrench on and hit is with the hammer. It is reverse threaded so you want to go righty-loosy. A snap of the wrist is better than a wind up power shot. You don't need power, you need pop. Two out of the three times that I removed the fan I popped it and then spun the fan to remove it, but the other time I couldn't spin the fan and had to use the wrench the whole way. It sucked, but it worked. I also had some trouble lining up the threads when I went to put the fan back on. Just keep at it, and know that this part is (normally) the biggest PITA in the whole project.

When I got to the Serpentine belt I was having some trouble removing it. The DIY says to use an allen wrench in the middle of the tensioner pulley to release the tension. I did not have a wrench that would fit. What I did find was a 16mm (I think) bolt head cast into the tensioner arm. I was able to use this to release the tension. It seemed easier to me than working with the rather small hole in the middle of the tensioner pully. The only other detail here is that when you release the tension the instructions are to put a drill bit into the holes that line up above the tensioner pulley to keep the belt slack. This works well, but you definitely want to put in the largest drill bit that will fit in the hole. I started out with a drill bit one or two sizes smaller than the hole, and that half millimeter made it so I couldn't release the belt.

Another issue that I ran into was the coolant temperature sensor that goes on the lower radiator hose. It didn't feel tight when I put it in, and I had this washer in a bag all by itself for which I did not have a purpose. Since the washer fit into the socket for the sensor, I put it in and replaced the sensor. I must have pushed too hard because I broke the housing of the sensor. It didn't leak any more, but I was throwing the code for that sensor--sorry I can't remember what the code was. I ended up buying another sensor and installing it without the washer, and no more code.

My last issue outside of the DIYs was that once I buttoned it all up, I was getting coolant leaking from behind the serpentine belt. I couldn't tell if it was the thermostat or the water pump. I posted a question about it on this forum and got many helpful suggestions, but the reality was that I made a mistake. I have a $20 torque wrench that is a POS. It is one of the beam-style ones. When I was replacing the Vanos during this fix, I broke a post from torquing it too hard, because to my eye the torque wrench had not reached the recommended N/m. Because of this I was way too careful when I installed the thermostat, and didn't bolt it back in strongly enough. When I finally inspected the thermostat I could turn the bolts with my fingers! I torqued this back down and everything was fine.

Based on my experience I strongly suggest getting a digital torque wrench. Sure, it costs $100 or more, but if you are a DIY person, tools don't cost you money, they save you money. Add that onto the fact that you will use this tool with nearly every fix you do, and the $100 seems pretty worth it.

To finish, a quick question: what is that little washer for? While it fits in the temp sensor socket, the bottom of the sensor is pointed rather than flat, so it doesn't seem like it is made for that application. With the new sensor that I put in without the washer I am getting random droplets of coolant leaking out. Not much leakage--maybe 2-3 drops on a 10 mile journey--but it seems the seal is not as good as it should be. Is that actually what the washer is for? Was I just being too much of a boy when I shoved the first sensor in and broke it?

Thanks to everyone for their posts and DIYs. This was a fun fix and I am feeling much better about my cooling system. I am running consistently 93 degrees C on the high cluster and I can just tell my car is much happier.

--Adam
Update: Drat. My cooling system sprung a leak yesterday!

Well, it's 'my' turn again!

I noticed a puddle on my driveway today ...


So I started looking for the telltale white spots:

And, watching for a while, I found the culprit!
http://www.youtube.com/watch?v=S2eqA7vzmww&feature=colike

Note: I last replaced my Behr expansion tank in 2010 as noted by the markings on the side.
 
#53 ·
One note on the picture: V-8s built after September 1998 have a 3d roller outside between the power steering and alternator pulleys. I'm in the process of pricing and ordering parts for a complete (front) overhaul of the cooling system next weekend after discovering a small leak around the expansion tank top.
 
#54 ·
I am having coolant problems as well. I have a 2006 525i with 85K miles. The coolant light started coming on and I was having to top the system weekly. Now it is daily and I was just adding water. I was just advised that water is a no no and I must use coolant. Unfortunately, I just lost my job and there is no cash to make expensive repairs.

Does anyone have any diagnostic tips? Back in the spring,l I had a dealer check it out and they could not locate the problem. However today after speaking with someone at an auto supply store, We looked under the hood and it does appear there are some fluids in the underbody of the vehicle.

Thanks for any assistance you can provide!
 
#55 ·
I just completed a cooling system overhaul on my 01 540. I replaced the water pump, thermostat, belts, tank, hoses, and radiator. I put BMW coolant back in with a mix of distilled water. The car run a little rough on startup now but smooths out. Has anyone had this kind of an issue after a cooling system overhaul or any ideas?
 
#56 · (Edited)
I will be joining the coolant leak club now. I have a 00 540i, that has a mysterious coolant leak. no one can find it. It has been tested hot and cold. all i know is that the leak is leaving residue all on the drivers side of the engine compartment from the upper hose, on the fan side, to all over the oil filter cartridge mounted on the fender. It started out slow but has progressively gotten worse. Still no one can find the leak. i have looked every where my self but again found nothing. The radiator is super clean with no residue. The tips of the fan do look as if they have a slight residue on them. The small puddle that keeps appearing is on the driver's side under the fog light on the ground. Any help that can be offered is greatly appreciated. I, for one, am at a loss. Thanks in advance.... Also any advice in possibly upgrading the entire cooing system, (parts and where to get them, as well as, price if possible) would be a welcomed addition too.
 
#57 ·
Read the thread and check the links...all info is there. As to locating your leak, I suggest cleaning the engine real well and letting it dry thoroughly. Then run it and see if you can located the leak. Have you had a pressure test done? That might help locate the leak as well. All that said, if you have ~100k on your original coolant system parts, just seriously consider having all of them replaced.
 
#58 · (Edited)
Im having overheating issues, I was told by a mechanic that I would need to replace fan clutch, expansion tank, hoses, water pump, thermostat...I'm attempting the repair myself, and replacing a few pulleys. When I was attempting to remove the water pump, one of the two pipes fell out(the smaller one,) the ones that lead all the way to the back of the engine. The pipe is back in at the moment however I am unsure if this will become problematic.

(#5 on the diagram)

http://www.realoem.com/bmw/showparts.do?model=DN62&mospid=47548&btnr=11_1536&hg=11&fg=35

My Qestions:

1) I purchased the o-rings for both sides of each pipe, has anyone had to replace these o-rings and/or would they cause a problem if I did not replace these?

2) My friend who is also a mechanic suggested to flush the system out (back/engine side of the water pump) with a garden hose. Has anyone tried this? _sl_
 
#59 ·
I replaced the O-rings (and the gaskets holding that collector pipe to the back side of the cylinder heads) when I replaced the valley pan last October, all as a precautionary measure while I fixed an oil leak at the oil separator on the back of the intake manifold. I would hate to have an old O-ring crack when it's a cheap part and I already had the pipe off.

Where I live, I wouldn't want to run city water through my engine. Your mileage may vary.
 
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