1991 525i overheating

[kuplo]

I have a 1991 525i that is overheating. This started on Friday all of a sudden. Generally the temp guage on our car has the needle sitting just about 1 needles width above the half way mark and it's been like this forever. But on Friday after being used to put around town, it crept up to the red area within a mile or so, I shut it down, and gave it time to cool off.

I tried it again and it did the same thing so I towed it to the radiator cooling shop near our home. I picked up the vehicle today and they told me that they replaced the fan clutch which looking at it, they indeed DID do.

I drove home which is only about 1.5 miles from the repair shop and I took the car 1 block up the hill from our home and sure enough the needle went up to the red area, so I turned around and went the block home.

So, knowing that they have replaced the fan clutch, I have to take it back tommorrow to see about them fixing it properly but I'd like to go in with some knowledge of what to do.

They told me that the fan clutch wasn't moving any air and that they could stop it with their bare hands while the motor was running, indicating that indeed it could be a bad fan clutch, but Im not sure if I am supposed to pay for this repair or any further repair since it did not fix the overheating problem, nor do I have a clue as to what else it could possibly be.

I'd rather not go in there and have them tell me now that it needs a water pump, thermostat and radiator unless of course it really does.

Is there something specific with this year and model that is known to go bad at a certain time or mileage (mileage is about 148,000 miles)?

Thanks for any information.

[BlueM60]

Water pumps, T stats and radiators are all common items. Make sure you dont allow then engine to enter the red even for a second if possible, as the heads on those engines are basically made of glass. I would check Tstat first, but its very possible the impeller of the water pump has come apart in the block, which Ive seen many times. If you open the coolant res cap while the engine is just above cold, NOT hot, you should see a slight pisser stream of water right at the top of the res. This will let you know the water pump is doing its job, or the T stat has jammed shut. Hope this helps.
-Ben

[kuplo]

Okay, I'll try that in the A.M

I failed to mention too that the upper (and I assume the lower) radiator hose has plenty of pressure in it. I don't know if that makes any difference or not. I've seen cars in the past that when the Tstat fails closed, then they dont have any pressure in their system. Our jeep was like that.

But I dont know if this makes any difference on the BMW or not.

[colo525i]

Sounds like a failed water pump to me (my car won't even come to temperature in 1.5 miles of driving) , and can't hurt to replace the t-stat. The water pump is only $60 from bav auto. The original water pumps on these cars have a plastic impeller that loves to disintegrate for fun, causing overheating and cracked cylinder heads.

[kuplo]

Okay, I'll keep that price in mind when I go back tommorrow, as the fan clutch I think I was over charged for at $180.00 just for the part, then half hour for the labor, the labor part seems fair enough to me, but the fan clutch at 180.00 seems way marked up to me, but what do I know, I only work for a Honda dealership.

Yeah, strange thing is that the car takes it's normal amount of time to get up to temperature but then goes from half way to the red fairly quickly, within 1.5 miles or so, maybe even less.

At first I thought it might just be the sensor, but on friday on my second attempt, I pulled into a parking lot to shut it off and I heard the dreaded "pinging" noise from the engine being too hot, fortunately, it doesnt appear to have done any damage to the head, but it was only at the bottom of the red momentarily before being shut off both times.

[BillionPa]

$180 seems high to me, as the going rate for an M50 clutch is about $100

[Ross]

Ditto!

[kuplo]

Yeah I thought it was high too, but not much I can do except pay it, which is still much lower than my local dealer would charge me for the repair.

It's now at the repair shop all day today, and Im guessing he's replacing the waterpump and the Tstat at the same time, strange that he's had it since 9AM this morning and now it's going on 3PM and I just called him to have him tell me that he's still working on it. I guess he must have been busy today or he's just goofing off. Arrrggghhhh, I hate auto repairs.

[Dave M]

Yeah I thought it was high too, but not much I can do except pay it, which is still much lower than my local dealer would charge me for the repair.

It's now at the repair shop all day today, and Im guessing he's replacing the waterpump and the Tstat at the same time, strange that he's had it since 9AM this morning and now it's going on 3PM and I just called him to have him tell me that he's still working on it. I guess he must have been busy today or he's just goofing off. Arrrggghhhh, I hate auto repairs.

Hmmmm, 6hr @ 80/hour = $480 ;)

I hope he hasn't removed the head, sounds like got it pretty hot.

Good luck with it, hope its just a thermo and pump etc.

[kuplo]

You and me both. Im pretty sure he has'nt done anything drastic like that else I *think* he would have told me on the phone ;)

Plus I don't think I really got it all that hot, it only once went to about half way into the red, the other 2 or 3 times I shut it down before it was able to actually get *into* the red.

[Hansen99]

I have a 1992 535i that had a similar problem. I agree with the other guy, do not let your car go int the red. Had to re-build my baby. My baby had a sticking thermostat. It would be fine then the next thing you knew it was in the red. Good luck. I would make sure they change the thermostat, it is a lot cheaper than a re-build.

[kuplo]

Well, turned out to be the waterpump. Apparently it was still one of the plastic impellar water pumps, the owner of the shop told me that the bearings had gone bad and the impellar was doing nothing but airating the coolant, but it hadn't disintegrated.

So he put in a new waterpump, Tstat, both belts (suprised they hadn't broken yet they were cracked up bad), and then the fan clutch.

Car now runs dead center on the temperature guage.

[fkong777]

good.. @140K on my 525i I went thru 2 water pump. 2 radiator and 1 fan clutch. Its a DIY job if you are handy. only trouble I had was loosing the o ring for the trans oil cooler on one of the radiator change job.