Where exactly do we look on the E39 radiator for telltale cracks?

I have become very aware of cooling system problems with this model since being on this forum ,my old e28's used to leak @ the plastic side tanks seals after huge mileage and in many cases it was no more than a small weep.
I have really enjoyed this post(cheers to bluebee and others), would I be right in saying the failures of parts are restricted to certain models? my car has had thermostat housing and vuscious fan done and so far no probs on 208,000kms.
When I purchased my thermostat housing the seller who has a lot of experience servicing bmw's told me this part is a big seller due to the fact they are made from new with recycled plastic from the factory,he went on to say he had no returns on his part as it was made from virgin plastic (aftermarket),your comments please.
Our car does a huge mileage every week on long open roads any evidence of this being better for a cooling system?

Originally Posted by E39 touring

would I be right in saying the failures of parts are restricted to certain models?

While the valley pan gasket leaks happen only on the V8, most seem to say the E39 V8 runs hotter than the E39 I6 & therefore has a few additional heat-related/pressure-related problems ... but overall ... since this is one of the (if not the) weakest systems in the vehicle ... my bet is that most would suggest the difference doesn't really matter.

They both stink.

As for failures, here's yet another related failure posted just today (although this may have been due to road debris):
- So I found what made a horrendous noise in my engine the other day..

Originally Posted by Brandon540/6M

Driving on the Freeway stopped in traffic, there was this LOUD grinding noise, like metal bearings ripping apart. Startled me, but then it went away. Came back again just a minute later, more chunks being shredded, and then gone.. heard some bits and pieces like falling through the car. I looked and I couldn't find anything wrong though, and the noise never came back! (it was odd too because it was RPM independent, and I was stopped...) Yesterday, I heard an odd grinding noise again, could finally see where it was coming from. Looked a lil closer and noticed my AUX fan was decimated, and I look inside my bumper to see some foreign piece of metal that clearly pierced the grate in my bumper. Looks like I hit some road debris, and it exploded my AUX fan! Can see some pics.. I fished more chunks of fan out since then..

For the record, today a 540i owner found his "cooling system voltage regulator" broken:
- E39 (1997 - 2003) > BMW repairs, identify part

Originally Posted by idofgrahf

Hi, new to the forum. I got a quick question, my mechanic was putting my bmw back together after a timing rail and chain change and as he was doing so a part broke. The problem is I have no idea what this part is or where to find a replacement for it. I've attached several pictures. Do any of you guys know what this thing is, called, and where I can buy another? Thanks.

Originally Posted by idofgrahf

I figured it out, its a cooling system voltage regulator thats found on 535, 540 and 740's made after 1998.

Yet another disintegrating fan blade situation:
- E39 (1997 - 2003) > Broken fan blades

Why did the fan disintegrate?

1. Did the water pump fail?
2. Or did the viscous fan clutch seize?
3. Or, was the plastic fan itself developing cracks?
4. Or, are the rubber motor or tranny mounts bad?

The solution for the first three is the same: COMPLETE COOLING SYSTEM OVERHAUL.

Mine cracked on the way home from work Fri when I decided to go around someone in a deep cell call doing 30 in a 45. After I passed him, I looked back and noticed that the 540 now had a smoke screen. Pulled into a parking lot and had AAA flatbed it 3 miles to home. Replaced the radiator tonight and had only lost 1.75 gals of coolant. I will be replacing the rest of the poopy coolant system this spring.

This little SOB was replaced this past Sept. As you can see, no cracks.



And here is the crack...


The replacement(Behr/Hella) was $187 shipped next day UPS to my house through http://www.blunttech.com as they are local, but did not have it in stock. It did come with this coolant hose elbow which surprised me...


And here's the one from BMW back in Sept that I managed to get out of the old radiator without breaking it. Just a little difference...


I found it much easier to remove/replace the radiator through the bottom, not pulling it upwards, even with the fan left in. I did have to unscrew the brake ducts for a little more room.

Originally Posted by bluebee

I'm above 80K so I'm worried but I'm still a bit confused. Did I mark the right spot below on the composite diagram where to look for the classic crack?

(If not, I supplied a blank composite for someone to correct where I err.)

The red arrow is where my radiator seems to be leaking!

For the crosslinked record, this thread today shows how a German-made Behr expansion tank failed:
> E39 (1997 - 2003) > BEHR expansion tank leaks after 5000 miles

Many miles on my 523i touring (135,000 @last count) have done top plastic pipe (thermostat housing) viscous fan coupling and I check the gauge and system for problems as often as possible,look around the refill tank and the hoses,the top plastic pipe fails early in life mine did as did the viscous fan.
The top hose mounting in the radiator is a failure point,but don't run around waiting to replace your whole cooling system untill you have problems if you are on a budget,not all the problems on this forum happen all the time or to your car ,just watch your temp gauge.

My car has 142k miles on the original radiator and expansion tank. No leaks, no overheating.
I don't like replacing everything without having a reason. These parts look o.k. I check these and also the belts every few thousand miles.

Is there anyone here having the original rad + exp tank with more mileage than my one?

I saw horrible failures in this topic but I don't have an objective picture what is the average life time of a radiator. Many owners are not reading bimmerfest and many of the readers have no issues with the radiator, so they don't post here.

Originally Posted by acoste

My car has 142k miles on the original radiator and expansion tank. No leaks, no overheating.
I don't like replacing everything without having a reason. These parts look o.k. I check these and also the belts every few thousand miles.

Is there anyone here having the original rad + exp tank with more mileage than my one?

I saw horrible failures in this topic but I don't have an objective picture what is the average life time of a radiator. Many owners are not reading bimmerfest and many of the readers have no issues with the radiator, so they don't post here.

I would wager that the average is much less than 142K. I didn't have any leaks or overheating either until the tstat housing exploded as it idled in my driveway. During the tear-down the upper rad hose and the connector nipple at the radiator came off in one piece. It wasn't leaking either.
Consider that if any part of this already weakly designed system fails, it very well could mean the end of your engine. I was very fortunate that it happened where it did. The car was packed for a 400 mile trip and we were ready to take off when it let loose. We took the Camry (you know, the sensible, reliable brand)and when we got home I just pushed it into the garage and did the repair.

As if we didn't have enough places to look for leaks, RDL posted today that his plastic bleed screw leaked up the middle!
- -> E39 (1997 - 2003) > Leaking Bleed Screw

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!


Note: I last replaced my Behr expansion tank in 2010 as noted by the markings on the side.

You know, there's just no excuse for that substandard plastic garbage. It makes me so mad to think about it. I'm on my third one and I know my number will come up again sometime. Any thoughts about switching over to the Evans NPG product?

Originally Posted by dms540i

You know, there's just no excuse for that substandard plastic garbage

It does make me mad if the leak I obviously have turns out to be the expansion tank ... because that tank is only two years old and it's from one of the most trusted sponsors on this forum.

I'll have to dig though to see exactly where the leak is coming from (it could be the small drain hose, for example). I won't know 'till I disassemble.

Yet another crack in the neck ...

Originally Posted by ndncdntxn

Hi All,
I noticed this morning on my drive to work that I had a low coolant message show up on my dash. Checked when I got back in the evening and saw it was low and figured I would wait for the engine to cool off and I would top it off. Came back after 2 hours and noticed something was leaking. I backed the car up and noticed there was a huge patch of brownish liquid. It didn't look like oil. Could it possibly be old coolant (is blue when I pour it in)?
I then topped off and drove the car around for 10 minutes to get it circulating. When I got back I popped the hood and noticed a leak right by the radiator (see pic). Looked like coolant was spraying out at a very small rate. Does this look like a crack in the radiator or in the hose? Anyone seen something similar?

Thanks in advance,
Vik

Originally Posted by bluebee

Yet another crack in the neck ...

Thanks for posting my story Bluebee! I was about to add my $0.02.
Just an update, I found a radiator shop close by that replaced the radiator and the upper and lower hoses for about $500. Only had it a day so far but it seems to be good. I agree that if you replace the radiator go ahead and get the hoses changed. My upper one was okay but the lower hose was softer than a sponge.
My car is around 84k miles as well but has spent the past 4 years in HUMID Texas heat which I'm sure played a role.

Originally Posted by ndncdntxn

Just an update,

Thank you for the update. So few people do that - but - it's very useful - especially for the newbie (we all were once) to see how others handled the same issues they're seeing, years later.

We all stand on the shoulders of others!

There are pics of zip-tie fixes of broken radiator fan shrouds in this thread today:
-> E39 (1997 - 2003) > Fan Shroud ?

Originally Posted by cn90

That link you saw above (MacGyver) is from May 2006.

Since then I have modified my ziptie thingy a bit so it looks more elegant LOL....

- Tip the reservoir toward the engine a bit to expose fan shroud.
- Use a Nail (because there is no room for a drill bit) and gently make 2 holes for ziptie.
- Then feed the ziptie through the holes you just made.
- Re-position the reservoir.
- Bring the ziptie around the reservoir.

Yet another BMW E39 cooling system engine fan explodes - due to a variety of potential causes:

Originally Posted by racerx8413

Well, my first post isn's as cheery as I was hoping it would be.

I picked up a 97 540i in Texas, with roughly 100k, for what I figure isn't a bad price. Thankfully I made it back up to Denver before this happened a few days later.





It shredded the insulation under the hood, punched through the hood in at least one spot, and destroyed the power steering hose and 2 radiator hoses. Fortunately it didn't appear to have done too much damage to anything else except the fan shroud.

I was curious, if anyone has any experience with Uro parts, or bavauto. I figure the fan can only blow up like this for a couple reasons, crappy parts being one of them, although i'm not ruling out that the original mechanic possible overtightened, installed wrong, or even put the wrong setup on.

Just wanted to share, and see if anyone had any recommendations. I may very well buy my own fan to minimize repair costs. It's sitting at the shop right now, and I know I'm going to have them replace the power steering hose at the minimum. The rest, I can install myself if I can source good parts. I don't want to make the mistake of the original mechanic and put the wrong item, or a junk item on.

I have been happy with EROparts bits they are sold for many brands of euro cars and have used them on my VW's to good result.

This thread today showed nice pictures of the heater hoses which were leaking on a user's V8:

Originally Posted by borahatch

I went down to my indy and picked up a used heater core for $50. It was fairly straight forward to swap the core. There are three coolant hoses attached and two electrical plugs. It did take me a while to get the lowest rear coolant hose connected since space is extremely limited. I suggest putting the core in its resting spot and then attach all the hoses.

My core was leaking from the aux water pump. At first it leaked slowly, I added coolant about once a week. It gradually got worse. It got to the point where I could watch the coolant stream right out of the bottom of the aux water pump.

I did an autopsy on my old core and it looks like a rubber gasket failed. The gasket sits between the water pump and the plastic body of the core. The coolant leaked past the gasket and made its way into the front half of the aux water pump, it then leaked from the hole in the bottom of the pump. I believe I could have easily repaired my core with a new gasket.

Anyhow, my car is no longer leaking ridiculous amounts of coolant. Since everyone loves pics, I've attached a few pics of core. Took it apart and just took random pics of the innards. Thanks again for the help, team. Enjoy.

when my expansion tank cracked, the crack was invisible. I've got great eyes and I couldn't see anything!! It wasnt until I pressurized the system that I would see coolant seeping out of the plastic. It was quite odd, it looked like coolant was magically appearing out of the plastic!!

I purchased a new expansion tank at my local BMW dealership, and they told me that my new part is covered under a 3 year warranty, parts AND LABOR!! Even though I replaced it myself, they said if it fails again within three years, THEY will replace it FOR ME!! Wow!

Originally Posted by acoste

My car has 142k miles on the original radiator and expansion tank. No leaks, no overheating.
I don't like replacing everything without having a reason. These parts look o.k. I check these and also the belts every few thousand miles.

Is there anyone here having the original rad + exp tank with more mileage than my one?

I saw horrible failures in this topic but I don't have an objective picture what is the average life time of a radiator. Many owners are not reading bimmerfest and many of the readers have no issues with the radiator, so they don't post here.

Very true thanks, how often do you read a post saying "my cooling system is fine after XXXXXX miles but you do see the failures (lots) and you have to sort the reality from the real bad situations, many don't fail,don't believe anyone can but a shedule on it.
Besides why rip out parts and change when many of the replacements are not up to the mark.
The one that gets me is the BMW main agents that when you go in for a service say by the way you need to do this and do that,wake up and see they make a good mark-up on the parts and there inflated labour charges thats what its all about.

Another M54 fan explosion today - this one tracked to a bad fan clutch:
> E46 (1999 - 2006) > What the heck happened to my fan???

Originally Posted by christopherr117

Apparently I forgot to give everyone the final results. The cause WAS a faulty fan clutch. The distributor for the shop that I used said the fan clutch was up to spec when it wasn't. The clutch allowed for the fan to wobble and the engine compartment is tight enough to where the fan blades would knock and break off after hitting other parts of the engine, and then causing the damage. Total cost for the repair was just over $1,000!

I have a radiator, expansion tank, fan, fan clutch, and cowl sitting in the garage I would like to get rid of if anyone is interested. I took these out of my 540i6 in 2006, back when my car had about 32000 miles on it and this stuff has been sitting in the garage since. The radiator won't fit my 540iT, so I am unlikely to use thus stuff.

Here is my post from the 2006 Zionsville install:

http://forum.roadfly.com/threads/113...System-Install