Strange Overheating Issues

Probably my first post on this forum. Recently purchased a very nice 1998 528i w/136k. Tight as a drum and runs great. That is until I probably caused a problem.

To begin with, after owning it two weeks, I decided to add Water Wetter to the coolant. Have been used to using it from days gone, by taking my long-gone MINI to trackdays. Figured I wasn't going to need the heat lowering benefit, but liked the idea that it lubricates the system. Forgot it also has some cleaning capabilities.

So Norm, how did that $10 additive work out for you? Let's see, so far we flushed it 4 times, then changed the thermostat. Still problems. Intake hose hot, outgoing hose cold. Next the radiator, water pump and expansion tank (BMW dealer). Still problems. In -- hot. Out -- cold. Getting to be a very expensive bottle of additive.

The AC fan is also not working. checking fuses out mechanic's shop. Don't know where we stand on this one at the moment. Of course, this shouldn't effect the apparent "plug" in the system flow.

Did some searching, and realized we haven't done anything with the fan clutch, but again, that shouldn't effect the complete lack of flow, should it?

So, that's where we are. Any ideas are appreciated.

You need to change all the cooling system hoses. And bleed the air out of the system. Check if the electric pump is working. Replace the a/c fan, you'll need to remove the front bumper. It's an easy diy.

Sent from my MB860 using Bimmer App

Hopw long after adding the water wetter did symptoms appear? And what were they? Was the coolant level topped up before adding the stuff? Did you see any sludge in the coolant when you drained it?

Did you do the flushings only after adding the stuff? Or was there a drain of coolant before?

When you say the outlet hose is cold, is it at ambient temp, or just cooler than the inlet? Note that it s/b colder than the inlet; that's what a radiator is for.

Sounds like an old-fashioned case of air in the system. The six is VERY difficult to bleed, and there are specific bleeding instructions on this forum. Air gets in via a leak. Since you've only owned the car a couple of weeks, you may not have discovered a leak, so this problem may have been brewing for some time.

Thanks for the replies. I'll try to answer/clarify some questions raised.

BTW,most work being done by shop as part of barter for old car.

Added WW one night overheated very next drive in morning after warming up. Four miles. Has continued to do same except run by mechanic after replacing parts mentioned above. Drove away from shop yesterday 4miles later buried needle dead red.

All flushes done after additive and problem arose. Outflow is ambient temp. Exhibits total lack of flow. Haven't done anything on AC fan yet since focus was to get system working first. Hoses looked fairly new but will replace.

Thanks again.

I would bleed it again, with the front end raised up a little, the heater set to *full hot*, and the heater fan ON....

.

Still fighting the air lock (I think). Car in shop all this time, but so have I been, thanks to ankle surgery. However, I'd like to see us both on the road soon.

After replacing radiator, tstat, water pump, cowling and expansion tank (BMW), flushing car three times (last two per instructions, ie raising front end); it is still locking.

Temperature climbs immediately, One hose hot, one cold.

Where should we be looking to find source of air leak. checked hoses, even trimmed ends of some. Running out of ideas.

BTW, did much searching and reading on forums. Think I am more confused, but I tried. Is there one bleed screw on the 98 528, or two like older models?

Thanks, advice very appreciated.

There should be a bleed screw on the thermostat housing and one next to the expansion tank. I always bleed out the air from the t-stat housing first, close, then move to the expansion tank.

Originally Posted by BentValve

There should be a bleed screw on the thermostat housing and one next to the expansion tank. I always bleed out the air from the t-stat housing first, close, then move to the expansion tank.

precisely how i have done it on my vehicle as per tis instructions and this link
http://www.bimmerfest.com/forums/sho...d.php?t=558386

It is not hard to bleed the system if a noob like me can do it then anyone can. If you have followed the correct bleeding procedure and the vehicle is still overheating then there is another issue at hand.

Not to mention the several youtube videos...

Reporting back.

Thanks for the help and I guess we were bleeding the coolant system correctly, as per the instructions that I previously looked up.

Unfortunately, we have found the problem and the mechanic shop and I are livid. It seems the air was entering through the head/gasket (?).

In our first flush, way back when, after I had created the air lock, we got a lot of gunk come up. Thought it was weird, but continued to diagnose and replace parts. First was the radiator, thinking that was where the gunk came from. Then tstat, water pump, etc.

After many of these replacements the coolant system was flushed, Still locking. After the fourth flush, the dam broke open. White smoke and coolant in the oil.

It seems that the SOB that sold me the car had use a head sealing additive to disguise the problem and it only appeared after the above.

Will be interesting phone call, that I imagine will lead to court. "Intent to defraud". Oh boy, what fun.

We had done a pre-purchase inspection, including compression test. Car passed with flying colors. Shop mechanic said car was in great shape and had a strong engine. They're pissed at this guy also. Will provide affidavits, etc.

In the meantime, we have to figure out what to do next.

Start tearing down the engine and hope it is a head gasket, is our first best hope. Second is new head. Third, is new/used engine.

We think the bottom end handled a high compression earlier and should be able to withstand any increase a repaired/new top end will produce. However, can never be sure.

Hate to do top end work only to have bottom end go 3 months later. A real quandary. Thinking on taking the chance, since engine was strong before and is lucky it it has been driven 200 miles since I bought it, Very few of those miles were during overheating problem. Stopped quickly and often when problem appeared and babied it back to the shop. Never got far, so didn't have far to go to get back.

Any advice and/or suggestions are appreciated.

If we are looking at a another engine, what are our choices? Car is 1998 528i. It's otherwise in too good of a shape to give up on it.

As for the bills on this, it may be the judge that decides.

Thanks, Norm

On potential rebuilt engine replacements here is what I have found so far:

http://www.woodfins.com/Parts/1998-B...80-Engine.html
Woodfins $1620 3 year warranty, unlimited miles


http://www.bmrparts.com/used_bmw_eng...gine_99-01.htm
Bavarian Auto Recycling startng at $2400 2 year warranty, unlimited miles.

Any comments appreciated.

Your M52 engine has the iron block (unlike the M54 which is aluminum), is less prone to warping and should have withstood the overheating. Hence, replacing the head will be cheaper.

Originally Posted by Norm B

Will be interesting phone call, that I imagine will lead to court. "Intent to defraud".

I've never sued anyone in my life, but I've listened to people's stories.

Two things I've learned:
a) Caveat emptor
b) Fraud is five (or more) things

Do a google search for "the 5 elements of fraud" and make sure that ALL FIVE are there (otherwise, it's not fraud, in most states).

Originally Posted by Norm B

We had done a pre-purchase inspection, including compression test.

I'm not a lawyer, but I can read. The very fact that you thought you needed that PPI, potentially negates your fraud argument in one fell swoop. Why? Because that indicates you didn't trust what the seller said. And, you have to have reason to trust what the seller said for fraud to exist (among the other four elements which all have to simultaneously exist).

Seems to me, the seller may or may not have said 'the head gasket is fine ... I checked it myself" ... but even if the seller did tell you the head gasket is fine and that he didn't put goop in there to hide it ... you didn't have sole reason to trust his spoken word - otherwise you would not have run the PPI. You trusted the PPI, right?

Anyway, don't take it from me. Just read the links to make sure ALL FIVE elements of fraud exist if you're going to successfully claim fraud in court.

Originally Posted by Norm B

In the meantime, we have to figure out what to do next.

This is a good starting point:
- Summary advice to provide users who suspect a major engine repair due to overheating (1)

Originally Posted by Norm B

hope it is a head gasket, is our first best hope. Second is new head. Third, is new/used engine.

Here's a good starting point for engines:
- What E39 engine swaps are most recommended (1) (2) (3) & how to lift & remove the engine (1) & where to obtain a new or rebuilt replacement short block or long block (1) (2)

Originally Posted by Norm B

However, can never be sure.

The folks on this thread can help with testing interpretation:
- How to test an engine for blown head gasket, cracked heads, a warped block, cam seizures, contaminated bearings, coolant hydrolock, or piston, ring, or valve damage (1) (2)

Originally Posted by Fudman

Your M52 engine has the iron block (unlike the M54 which is aluminum), is less prone to warping and should have withstood the overheating.

Here's more information on that:
- Which E39 engines are prone to heat-related damage & why (1)

Originally Posted by Fudman

Hence, replacing the head will be cheaper.

These may help:
- DIY for replacing the I6 M54 head gasket (1) (2) & replacing the V8 M62TU head gasket (1)

Thanks again for the advice. I will research your links.

The time and effort put into your posts is not lost on me. As I get more familiar with the car and the local BMW community, I hope that I will do a better job of searching and/or finding answers. I had a heavily modded MINI that I tracked and over time, I learned my way. Hope to do the same with the BMW.

Especially appreciate your comments and research on fraud. Unfortunately, I think you are correct.