528i M52 cooling system bleeding, overhaul, overheating

[e39dream]

thanks dream, appreciated the help a bunch.

peace out, Benji

anytime Benji!

[e39eddie]

e39dream, so if my engine's getting hot at idle, bleed system first and check possible fan clutch failure? I did a complete cooling system overhaul 7 months ago (minus the fan clutch).

[e39dream]

that sounds like a good plan of attack. bleed out air/ top up coolant and if temps continue to rise at idle check your fan clutch and aux electric fan.

[e39eddie]

that sounds like a good plan of attack. bleed out air/ top up coolant and if temps continue to rise at idle check your fan clutch and aux electric fan.

Thanks, I'll give it a shot this weekend.

[m530i]

hey all, im planning on doing my waterpump/themorstat hoses etc.

at oembimmer.com has a great kit, for super cheap.

http://www.oembimmerparts.com/catalo...50/4258853.htm

BMW Inspection II Kit contains the following items. Ordering Tips

• Air Filter
• Oil Filter
• Cabin Air Filter (Pair)
• Water pump (metal impeller)
• Thermostat w/housing
• Upper Radiator Hose
• Lower Radiator Hose
• Fuel Filter w/ Pressure Regulator or without depending on year of production.
• A/C Belt
• Accesory Drive Belt
• Gallon of BMW Coolant (antifreeze)

anyways my question is, does all the diy self info pertain to the m54 e39 530i motor as well? anything diff about doing the install opposed to the m52 528?

[e39dream]

nearly identical process. you will have to add a radiator and expansion tank to that order and you'll replace most common points of failure.

your thermostat housing will have a wire plug coming off of it you have to unplug and your expansion tank will probably have a float type level indicator rather than a see thru tank with a full cold line. just minor differences.

[m530i]

thanks for the super quick reply, just got a complete diy from
Ruben at desertmotorworks.com
great guy, helped me very quickly and went out of his way for a stranger..

thanks every 1

ill post it once i convert it..if any 1 wants to see..

[iamkhanz]

is this setup for the 528 cooling system same as 540 system? also if not is there a write up for the removal of the radiator on the 540i? I am trying to remove radiator but I am not sure if the fan MUST be removed or not? I'd prefer to do w/o removing fan if possilbe..
Input is appreciated.

[e39dream]

yeah- the fan must come off. The 540 is actually easier to work on believe it or not. The Inline 6 engines are long and skinny so they take more space up front. The 540i water pump is pretty simple.

[e39dream]

haha- it used to be. Quick links my ass.

[brandon5069]

This is great...

Good for you E39dream. I second the sticky creation request.

+100000000000000

[mjdh530i]

This has been such a helpful thread. I have reviewed random threads all over the place about cooling issues, but this one put everything in one place with illustrations and links. I don't have any issues myself (yet), but this is obviously a common problem area so I was getting VERY stressed out. I'm not now that I know a lot more about it and how to handle the replacements.

Thank you very much, e39dream, and everyone else who has contributed with your problems, fixes, and suggestions.

This could help a ton of folks out there apparently. Instead of requesting that this be made a sticky, and no one has officially responded to these multiple requests a single time throughout the five pages of posts, I'd like to try a different angle: Why, oh why is this NOT a sticky? I'd like a publicly stated reason from a Forum Moderator, please. Thanks for your consideration, time, and for providing these Forums in the first place.

[JackEatsEmoKids]

So far no one has posted this yet, when you overhaul ANYTHING on the cooling system, when you go to bleed it and turn on the car...turn off your ac and put it to full HEAT, so the coolant also runs though the heater core.

I've had a few trainnies' at work overheat M52 and M54s because of that(cars came back 70 miles later overheated and warpped heads/blocks).

[e39dream]

excellent point Jack- I forgot that.

[brandon5069]

If you guys want the thread parked PM Kevlar, it's out of my hands.

PM sent.

[tdawg183]

This is a sore subject to me. If you guys want the thread parked PM Kevlar, it's out of my hands.

+1 PM sent

[Username in use]

I also have a question on the bleeder valve for a 528, because there appears to be 2. There is one on the thermostat housing, and appears to be another one on the expansion tank (doubles as the screw that locks the expansion tank in place). What one are you supposed to use when? Or is the one on the expansion tank not a bleeder valve at all, but rather simply there to lock the expansion tank in place?

I'm going out to play around with it today, maybe I'll get it figured out, but if someone could post a definite answer in this thread I'm sure it would help a lot of 528 owners.

That answers one of my questions, now for the other:

I'm putting a *cough* Chevy V8 *cough* into an E34 and using the larger 540 E34 radiator. Since the expansion tank for that setup was not compatible with what I'm doing, I found one for a '97 or so 528 E39. I noted it has two openings on the bottom, one with barbs that look like a heater hose type connection, and another with a cap. I'm figuring that is where the coolant level sensor goes.

Looking at the diagram in the first post, the lower hose appears to go to some sort of extra pump. Since I don't have this pump, what should I do with the bottom hose connection? Can it be capped with a rubber cap? The 540 radiator has a barb fitting on it that will connect to the top fitting on the E39 tank, so that is not a problem. Is there an expansion tank for cars w/o the extra pump that does not have this fitting?

Thanks for any help.

[e39dream]

I'd imagine you'll be fine capping it off. On some early 528i it is capped off. I have one expansion tank with a sensor there, but no wiring to connect so the sensor is a plug.

The extra hose goes to a small pump and some e39s have it, some dont.

[Username in use]

Thank you for the information.

EDIT
I found info on another forum that answered this question, so I will repost it here in the event this is found in the course of a later search.

The expansion tank acts as an air removal tool in the cooling system, enhancing efficiency. For those such as myself that are using this in a non-stock setup, the lower outlet must be teed into the low pressure side of the cooling system, i.e. heater core return to water pump.

[528i RetNavy]

Hi everybody I am new on the forum, I bought a 1998 528i in August, it has 125k miles on it, last week all of a sudden the temp gage went to red, I stop immediately and did not use since then. I assumed that the thermostat was bad, I removed the thermostat housing and I noticed that the left side (driverside US) on the housing is very dry it seems like there were no water running in it for a while. I also noticed that the packing between the thermostat housing and the engine block is damaged, the aluminum surface on the engine is rusted. I appreciate any advice especially from E39Dream.

[e39dream]

I removed the thermostat housing and I noticed that the left side (driverside US) on the housing is very dry it seems like there were no water running in it for a while. I also noticed that the packing between the thermostat housing and the engine block is damaged, the aluminum surface on the engine is rusted. I appreciate any advice especially from E39Dream.

http://www.realoem.com/bmw/showparts...46&hg=11&fg=35

replace the gasket for sure, be sure to get all of the old gasket off down to clean metal. replace your thermostat, top off system and bleed out air, see what happens. aluminum does not rust, it may be stained from a coolant leak. Let us know how it goes!

[528i RetNavy]

I ordered aluminum thermostat housing and thermostat at ebay for $57 the seller said the thermostat is OEM.

[e39dream]

let us know how you like that thermostat housing, I've seen those but always been hesitant to buy one.

[David Frette]

This thread is a great thread! Thanks for sharing. The detailed instructions on bimmerboard are great, too. I have my 98 528i cooling system dissassembled, and I'm just awaiting parts. I'm not sure which parts we're getting as I'm waiting to discuss it with my mechanic. I can't believe how easy it is to work on the cooling system and belts.

I took some pictures, but I don't have a high enough post count to post them.

Two questions:.
1) Is there a trick to getting the radiator to slide out? One mine, it catches on something on the sides.
2) A rubber grommet fell to the ground as I tried to lift the radiator out. Anyone recall a diagram pointing to where this grommet goes? I think I know where it came from, but would like to confirm it.

[528i RetNavy]

I did a further investigation with my cooling system today, I removed the water pump, the plastic part is all busted, I'm pretty sure this is the problem, but I might as well replace the thermostat and install an aluminum housing. What I am worrying is there might be some plastic debris from the pump into the system