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Discussion Starter · #1 ·
2000 528i 140k miles. very clean car, no CarFax indications of problems at all.

background:

I'm 2nd owner bought in November 2010

When buying, seller stated the following replacements, work done by him;

Thermostat
A/C Condenser Fan
Clutch Fan
Water Cooler
]Expansion Tank
Radiator


During test drive, pulled over to lift the hood to inspect engine compartment. a loud whirring sound began, increasing in speed. located source: front aux fan. Sound was WAYYYYY to loud for comfort.

Upon return, seller said it is supposed to sound like that, as BMWs require considerable circulating air etc. I mentioned that I was aware this model has a reputation for cooling problems, and is that why he'd replaced the cooling system, more or less. He nodded and said everything is fine, but I didn't have problems before, I did this prophylactically.

He told me he'd been in touch the garage who'd serviced the vehicle the entire lifetime of the first owner, and arranged to purchase parts to do the work at a discount etc.

I also noticed a marked odor of coolant in the cabin at the end of the test drive. When inspecting the engine compartment, i noticed a bit of coolant coming from the safety valve located in the hose that goes from the right side of radiator to the thermostat. just a bit of leakage, nothing remarkable i suppose.

Seller indicated he'd just "polished" the cabin clean air intake filters with a cleaning solution, and that was the smell I encountered.

Now, the symptoms the vehicle is experiencing:

  • temperature gauge fluctuates rapidly for no apparent reason.
  • mostly indicates high temperatures only during cold weather (-30 F)
  • when overheats, pull car over immediately, lift hood and no indication of actually extreme temperature at all.
  • often, after 15 mins temp gauge normalizes (dead center) within minutes (2-3)
  • sometimes when driving at, say, 50MPH, neutral outside temperature (50F), needle will fluctuating between neutral and almost redline within 30 seconds. then back and forth a few times.
  • consistently now, cold start, temp gauge is dead center immediately.
  • after a few months of these symptoms, engine starts as though only 2 cylinders or less than 6. very rough. numerous restarts within 30 seconds takes about 4 attempts to get clean smooth start. no problems for remainder of driving, until next cold start (longer than 8 hours duration)
  • check coolant level often, rarely needs topping up, but if so, less than 8-12 ounces needed
  • seems to always be some leakage out of pressure release valve on coolant hose, but not excessive
  • aux fan continued high-rev noise for months, usually when outside temperature reached 60 degree or more
  • but now, it clunks loudly. upon further inspection, it is obvious the bearings are loose somehow allowing the blades or blade circle to hit the shroud intermittently.

I checked with service garage (EuroCar - Roswell, GA) to see if the seller had, in fact, purchased the parts he indicated - the answer is "some." in particular, the auxiliary fan. person on phone indicated the original owner sold car because it started showing coolant issues and didn't want to deal with it any longer.

So, the seller misrepresented his knowledge of problems existing with the car. and, as far as i can tell, the thermostat does not appear to be new, there are marks on the enter bold for the water pump, perhaps he did replace that. the aux fan DOES NOT look new, but i could be wrong. even so, it is obviously defective (or old)

I would appreciate any sage-like insight here. my thinking is there is an electrical problem somehow either misreading the temperature gauge thus mis-controlling the thermostat (which might be defective as well.)

adding to all of this, the heating does not work at all, except sometimes if you push the defog setting for 5 minutes, but not always.

i am exploring possibility of fraudulent misrepresentation of the vehicles working condition,a s the seller does not respond or reply to any emails or phone calls. none of which have been threatening, rather to ask for helping determine exactly what work has been done so far.

thanks in advance!!!
 

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I don't think these cars have an "AC Condensor Fan" or "Water Cooler." If the electric auxiliary fan is running, it's probably not defective; your problem sounds like the cooling system was only partially replaced and not properly bled to remove any air pockets inside. Start searching here, go to the Best Links section at the top of the forum. Welcome to Bimmerfest.

You refer to a pressure release valve. There are two bleeder screws that can be opened to bleed the air out of the system when coolant is being replaced. They are not valves and should not be leaking at all when closed. I'd recommend you not drive this car until you get the cooling system issues cleared up. Overheat this car and you will need a new engine.

The auxiliary fan is the electric fan in front of the radiator, behind the grille. The engine fan is the one inside the shroud in the engine compartment, and mounted on the water pump. My guess is you mean the engine fan. If blades are hitting the shroud, the water pump is probably off-axis too, and you are about to experience a catastrophic cooling system failure. Do not drive the car.
 

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Older than old school
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Even though I have the V-8, which theoretically makes more of a demand on the cooling system, I don't think my auxiliary fan has come on in the two months I've owned the car, and the temperature has been rock steady. And the smell of coolant sets off the "gong" chime in my head.

As for the problems you're having, the cooling should never[/I (well, almost never) need topping off. Eight ounces is a significant amount. The question is, where is it going? One possibility is the vent hose connections along the top of the radiator, under the fan shroud. It's also possible, by the way, that the cooling system was never bled properly by the previous owner. Trapped air blocking the flow of coolant could account for the fluctuating temperature gauge.

There are some good links on this board (see the "Very Best Links" sticky) and on You Tube showing how to bleed your cooling system. It's easy and worth a try.
 

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i had the same issue on my car after a purchased it, i had top it off almost with a full cup about 10oz a day or driving for 100 miles, after further inspection i found out the cylinder #3 is getting all the coolant, so i had to take the cylinder head out yesterday and im sending it to get it machined tomorrow.
you can find all this out by doing a cylinder leakage test its simple and quick.
hope this help
02 525i
 

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Freude am Fahren
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My auxiliary fan is broken, and I don't overheat. It should not be running all the time. A faulty coolant temperature sensor fan could be part of the problem. (under the expansion tank)

There is no coolant LEVEL sensor in the 528. Check the level constantly. Fluctuating temperatures can indicate low coolant. Also check for actual coolant content-if someone topped off with water it might be freezing at -30°F! I'd actually recommend draining and filling to be sure, if you can. -30° is colder than I'd like to work in! Edit***8212;WTF, Georgia gets that cold?
 

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There is no coolant LEVEL sensor in the 528. ....... -30° is colder than I'd like to work in! Edit-WTF, Georgia gets that cold?
My '99 has that sensor, plugged into the bottom of the expansion tank and "live."

Georgia might get down below freezing but I'd venture the coldest it ever gets there is in the teens a couple times a year. That minus sign ...... typo?
 

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Mine also has a coolant level sensor. It's at the base of the reservoir. I know it's coolant level sensor because I once got a dashboard warning "low coolant level," and when I checked the reservoir (after the engine had cooled), the little thermometer-looking red stick was nowhere in sight. I've since changed my reservoir and cut off the tip of the vent hose that attaches to the reservoir nipple before reattaching it.
 

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You probably have 2 hopefully unrelated problems. One is the cooling, the other is the rough starts.

The way you describe the rough start, my bet is on vacuum leakage. Do you get any "Check Engine" lights? Regardless, go and have your OBD2 codes read, and write down the error codes that you have there. Again, my bet is on fuel/air mix being out of whack.

Solution: replace all vacuum lines and CCV. Spray clean your MAF.


Cooling:
Loud fan: Does it sound like a fully loaded Boeing 747 trying to take off? If so, then it is normal. That is not a problem.

Crazy temp needle: Usually the result of trapped air bubbles in the cooling system. BAD and Dangerous. Solution: bleed the system via the bleeding screws.

Safety valve: No such thing. Our cooling system is designed to explode. LOL .. What you are looking at, that thing the size of a penny with an X on it IS the bleeding screw. It should not leak. But if it is leaking then the air bubbles were suppose to escape by now. So I don't like what's going on there.

Good news/bad news: There was a recall from BMW to replace 2000 528i thermostat. Call, or go to a BMW dealer and check if your thermostat has been replaced. They'll check their computer for that. If it was not replaced, then they'll replace it for you free of charge. When they do that, they will also replace the liquid and bleed your system. (for free). The only thing that they will charge you, maybe, is to replace that leaking bleeding screw. No big deal.

Do that check with them first. You might get lucky.

Loose fan blades: How do you know that it is loose? If you can move them and they touch the shroud, you can break the fan. If it happens when your hood is open and you are looking inside - it will kill you. If the fan blades break when the hood is closed - they will bend or tear up your hood. That thing is like a bomb. Very dangerous.

Ultimately, what you need in this condition is a complete cooling system overhaul, and a complete vacuum lines overhaul. If you are a DIY kind of of guy, you can do them both for around $600 - $800 total. But check with BMW Dealer first to see if your car deserves the thermostat recall and let them replace whatever they need to replace, and THEN do your own cooling overhaul for the rest of the parts. The good news is that they will probably check and analyze the whole system and will let you know what else is wrong with it - so then you'll know what to fix - by yourself, and save some $$$.

I think you should do it today. Just call the dealer with your VIN number and they'll tell you about the recall. At least put your mind at ease and that little piece of information will determine how you should proceed.

mw
 

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My car is one that had the t-stat replaced under that recall. There's a sticker documenting it on the left (driver-side) strut tower, so if it has been done, check under the hood for that info.
Or remove the sticker and have it replaced again... :bustingup

mw
 

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Discussion Starter · #12 · (Edited)
@Plieiades

yeah, well long day and accidentally typed "water cooler" instead of water pump.

fan i refer to as being noise: electric fan, NOT water pump clutch fan. i've been told this fan is exclusive to cooling the A/C condenser/radiator. this is the fan that is noisy, and YES @matWiz like a fully packed Boeing 747. BUT one that has been sped up to 78RPM(as in vinyl record and turntable)

yes, the "pressure release valve" i named myself, is "leaking" to an extend, but seemingly not a enough to account for the general coolant loss.

checked for sticker indicating warranty replacement thermostat work - not there. might be a good thing.

@bobdmac

excellent point. where is the coolant going? nowhere i can determine. i don't see any, and haven't seen any, evidence of leakage. the fan i am referring to is in fact the aux fan, which has a set of blades with a circular, rigid element which connects the tips of the blades accordingly. i know this is loose simply by watching it closely while the fan is running. the tolerance between the fan blade circle fluctuates between. 5 CM and 2mm while rotating. additionally, i can wiggle the fan back and forth a little with my hand (while the engine is turned OFF)... not much, but in truth at 3500+ RPMs, a little can be disastrous i would think.

the hi-rev noise, i must say, is quite bothersome and leads me to believe it is NOT normal. the clunking noise is clearly the fan blade tips/circle, hitting the edge of the shroud while rotating. suggesting an axis that fluctuates somehow.

@bmw_bnoob13

interesting. i have wondered what that connector/sensor is below the expansion tank. the ET was, clearly, replaced by the seller. i suppose this sensor could have been disturbed somehow during that or some other work being done. i shall look into that for sure.

i've been told the 2000 528 can have problematic aux fan relays - a new relay pack is supposed to fix that. and i wondered myself, why should that fan be running at all at > 30º F?

haha! yeah, Georgia gets "THAT" cold. usually >10º once a year, and mostly consistent around 30º for a few days a few times a month for a week.

yes, typo. means > 30ºF was using a cryptic PC keyboard and didn't know how to use the key combos.

i've extensive and crystal clear, close-up photos if anyone is interested.

i shall make a list of recommendations and proceed.

i am eternally grateful for all of your input, really nice to know people give thought to respond to a complete stranger.

as an aside
i am planning on getting a 2005 m3 in june (this is my girlfriend's car). i drove a 2011 e90 series last weekend and was entirely seduced. i don't want to pay for a new car, so i hear the 2005 m3 is mack daddy.
 

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@bobdmac

excellent point. where is the coolant going? nowhere i can determine. i don't see any, and haven't seen any, evidence of leakage.
Well, it's either leaking into the block or the combustion chamber, or out through the hoses or cooling system components.

Do you see any white chalky residue anywhere in the engine compartment.?
 

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yep. limited to the area surrounding the 'flush" outlet, or what i called the "pressure release valve.' the residue can be found nowhere else.
It is very possible that this bleed screw is loose. Take a penny and use it to close it all the way down, but do not force it since it is plastic that you can break if you use too much force. You can try to open it first to take it out to have a look to see if it is broken or something. It should not leak.

If it is in one piece and nothing is broken, then it means that it is loose. So just put it back in and close it all the way.

Do it when the car is cold....

mw
 

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Discussion Starter · #18 ·
i went back and looked at photos i took just after i discovered the problem. much of the white chalky residue has been cleaned up and has not reappeared. however, the area near and underneath the expansion tank seems to have been the other most concentrated area of incidence.

BTW, this is what the clunking aux fan sounds like:

Video on Flickr







 

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I apologize but I didn't read the whole thread.
I loved the nice pictures though!

I'm gonna add them to the thread on cooling system leaks: :)
- Pictorial look at typical E39 cooling system failure modes (1)

Looks like there is white BMW coolant residue EVERYWHERE!

What you need to do, I think, is wash it all off with a garden hose. Let it dry and make sure it's all gone. Then look anew.

ALL of the pictures contain weak points in the BMW cooling system. In fact, ANY picture of the BMW cooling system shows one of the weak points.

Note: Pictures re-included below, only shrunk to 640x480.

This shows the lower radiator hose aux fan thermoswitch. This thermoswitch often leaks at the o-ring if it's replaced. The thermoswitch itself rarely goes bad. Of course, the hose often goes bad, especially if hot oil drips on it from a leaking VCG above it.


Another shot of the auxiliary fan thermoswitch (which actually feeds the DME which then instructs the aux fan to turn on or off).


This is the upper radiator hose bleed screw. The screw itself often breaks, and so does the hose, and so does the plastic thermostat housing connected on one end, and so does the plastic radiator neck on the other end.

TO THE OP: You are missing a tie-wrap on that thermostat/VANOS wiring loom! The danger is that the loom can contact the fan!

See this misplaced thermostat loom thread.



Another view of the upper hose and thermostat/VANOS wiring loom.
 

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i went back and looked at photos i took just after i discovered the problem. much of the white chalky residue has been cleaned up and has not reappeared. however, the area near and underneath the expansion tank seems to have been the other most concentrated area of incidence.

BTW, this is what the clunking aux fan sounds like:

Video on Flickr
That's a lot of coolant residue.

Do what I said with the bleed screw, but do it cold. That screw is about $4 at the dealer, or you can order online made of brass.

What is that white band aid on the hose??? :confused:

If you can make a Youtube, post it. Can't get into the flickr without registering.

mw
 
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