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water pump? thermostat?

3K views 19 replies 11 participants last post by  mcsimon 
#1 ·
1998 528i e 39. Yesterday I wasdriving my car and I parked it and left it running after about 10-15 mins I noticed my temp Gage rising I shut the car down and waited for the temp to drop. I started it up and drove about 2-3 miles and it started to overheat so I stoped again and waited for temp to drop ( I know I shouldn't drive it while overheating but I had to get the vehicle home) so I started it again and it was fine sticky thermostate was the first thing that came to mind. But today I got driving it again and the temp Gage is at normal operating temp but I have no heat. Checked antifreeze and it is full. Any ideas. Thanks for the input all love the forums they areextreamly helpful
 
#2 ·
If it only heats up while its not driving eg in idle it might also be your auxiliary fan or fan clutch. When the car moves, outside air cools radiator so temps dont go up. but it doesnt sound like thats your problem. Any lights on? also wats ur coolant level? no leaks correct? best way to check for leaks is to put cooling system under pressure test, which i would recommend doing. when under pressure, u can check for leaks near w/p. might also have crack in radiator that is very small. otherwise it is probably your thermostat. hope i could help, but definately get the system pressure leak checked... :thumbup:
 
#5 ·
No leaks in cooling system, I will try purging this afternoon. After I had more time to sit and rattle the problem around my head for the night. And now that the car is home where I can work on it. I realized that the inlet hose to the radiator was hot hard ( had pressure) and the outlet was cold ( could squeeze hose together with no effort) it is looking like I have a clogged radiator. CORRECT? It will take me a couple weeks to get the parts here but I am going to replace thermostate, water pump, radiator, gaskets and hoses and while I have the front apart with 78000 k. I might as well hit that vamos system to. What do u gentalmen say? Thanks for the input. Matt
 
#6 ·
I would deal with the cooling system first and leave the Vanos for when it gets warmer. The Vanos is a 4-6 hour job by itself. While removing the fan is redundant to both tasks and is often the toughest part of either job. If you put a dab of antiseize on the fan clutch during the cooling job, future removal will be very easy.

Your lack of heat could be anything from air in the system to aux pump motor to heater control valve. Air bubbles are usually due to some cooling related service. If you have had no recent cooling system service, you can eliminate air bubbles as a cause. The overheating is more likely be due to thermostat. Although you have relatively low mileage (78K), it is better to replace the complete cooling system in order to restore 100% confidence against cooling system failures (which can be fatal to engines). If you do it all, don't forget the tensioners and belts.
 
#9 ·
Took car for drive yesterday the heat was blowing and I went about fifteen mins car warmed up stayed at operating temp for about ten mins then started to overheat I got out and I could stop the fan with my fingers deffanately need new fan clutch. I felt the hosesinlet and outlet from radiator and antifreeze is making it thru its cycle my next question is if I should just replace WP and thermostat as well the chassis has 168 k motor has prob about 70-75 k by now being that the motor was replaced by someone named Leroy in pa and only came with 30 day warrenty should I just dump the money and overhaul the cooling system also has anyone ever herd of the radiator clogging because the radiator and hoses all look to be in like new condition and would hate to pay to replace them if it isn't neccesary. Thanks again to everyone. PS I am correct in the assumption that I should not be able to stop my fan from spinning with my fingers correct?
 
#10 · (Edited)
Search forum for "Cooling Overhaul".
You are sitting on a time bomb.


Testing Fan Clutch: if you want to keep your fingers, keep them away from the Fan Blade.
With engine hot and running, hold a piece of paper behind the Fan Blade, it should "flap", indicating that there is adequate air flow.

There are countless people with blown head gaskets b/c of failure to do a cooling overhaul.
In fact, I would not be surprised the #1 cause of death in an E39 is blown head gasket.
 
#11 ·
^Going to say, no way I'm touching the cooling fan with the engine running. Good way to lose your fingers. Check the fan clutch resistance with the engine OFF!!
 
#16 ·
Just because you stopped it with your fingers does not mean its bad. It just means it was not engaged at that time. Machanical fan engages and disengages below 2000 rpm. most common problem with the machanical fan is they engage and wont disengage. Then when you rev to 4-5k rpm its still engaged and they come apart causing catastrophic damage to the hood and all surrounding componants. Your damn lucky you still have 5 fingers:tsk:. Sounds to mean like you need to take your car to someone who knows what there doing:eeps:.
 
#13 ·
Search for and PROPERLY BLEED
You have to do it cold with the engine off but key turned to on position with heater turned up to max so the aux. pump circulates coolant through heater core. Have the front of the car jacked up and fill through the bleeder screw on the thermostat housing. Open bleed valve at the reservoir and fill until no bubbles come out of the reservoir bleeder. Close everything up. Get up to operating temp, let cool down and recheck level in reservoir after complete cool down. Do not open cap when still hot or you may introduce air back into the system.
That's not the only way, but you can search to see alternatives.
 
#17 ·
Regardless I am getting no wind blowing in my face when car is running. So I am assuming fan clutch its 13 degrees here today so no way I am going to bleed te system. Also I cut my money tree down last year hents y I am looking to fix the problem myself. hents y these forums are here. If everyone was like you JASON and told people to take it to someone that knows what they are doing then what the fudge is the point to these forums thanks to the People acctually looking to help
 
#18 ·
mcsimon

Im not trying to attach you so please throttle back:brent:. I am trying to help you, by pointing you in the right direction.

Your right. Thats what these forms are on here for. Everyone has to start somewhere. I just dont want to see you hurt yourself. Sticking your fingers in a running fan on a 200+ lb-ft torque gasoline engine does not strike me as a bright idea.....Im just saying. Been around maintenance for about 30 years now and seen a couple of people lose a finger or 2 from not knowing how things work.

Im no good at sewing, so I dont do it. I take my cloths to a talor. I dont believe everyone should have a car either. I look at it this way. If your not into cars, then your probablly not into driving. If your not into driving then your probably not very good at it, so what are you doing behind the wheel? Not saying this about you.....just my philosophy.


Hope you fix your problem.:wave:
 
#20 ·
First of all I am sorry for freaking out but its not like I just stuck my finger in there I used a peice of rolled up foam and once I saw that that was slowing it down I slowly put my finger along the blades and stooped it but I digress. I believe I have figured out my problem thanks to everyone's help which I am thankful for I believe that it.is a combination of two thing
1. Fan clutch
2 auxiliary fan as well

So that brings me to another question since I am missing my AC button I cannot turn it on to test my auxiliary fan. But I used a screwdriver to try and spin it by hand. It will spin about a half an inch in either direction but then stops. The information I have come across leads me to believe that the fan should b able to spin freely with the car turned off is this correct?


One more thing JASON once again I apoligize for freaking out I just purchased the car a few months ago and since this overheating issue I have been stuck driving my Dodge hemi GETTING 10 MPG and having to drive my girlfriend to work and the kid to school making rediculouse round trips a day wasting money on gas and getting as little as 2 hours of sleep a night because of this. So I was deffanately on edge and just needed to get this problem fixed. But I believe I have the problem figured out now as long as my assumption of the auxiliary fan ( explained above) is correct. Once again my sincere apologies sir thanks for your help and knowledge

Matt
 
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