My E36 Cooling System Overhaul DIY - NOT 56K Friendly!

[crqflier]

Well, if everything is original and you've got 90k miles, you're on borrowed time. Really should replace all components.

For your immediate problem, look all around the engine bay in the AM. Look for dried coolant - it'll be whitish/blue. If you don't see anything, it's very likely not bled correctly. Did you happen to use your heater one morning after the flush?

[david2991]

They parts weren't new. The car has 90k miles and I believe all the cooling system parts are original.

That's exactly why I replaced the entire cooling system on a 95 M3 I just bought. It was at 122,00 when installed. I now have the most beautiful peace of mind concerning the entore cooling system.

[berny2435]

it's very likely not bled correctly. Did you happen to use your heater one morning after the flush?

that may have been the companies mistake on this guys car. They didn't have the heater on and fans blowing at full bore while they did the bleed. It's suprising sometimes what is not common knowledge.

[pDubs]

Will be doing this in the near future. Thanks for the writeup

[MarketMaster]

Have a question. Was not able to get the car up to temp before flushing the radiator at the radiator screw on the bottom. I still see a lot of coolant in the expansion tank. How do I get the rest out? Seems like this is a potential for a HUGE mess later.

[loungin]

Just tried this and had a heck of a time getting the fan clutch nut off even though I bought the eBay holder. If you have difficult google for Bmw fan clutch nut seized. The same problem is endemic to all sorts of older BMWs.

But impact is the way to go, not torque. I bent my holder tool and thin 32mm eBay wrench by using a cheater bar and it still didn't come off. Taking off everything first (eg radiator, thermostat) gave me space to use the holder tool with a real normal thickness 32mm wrench and a 2lb dead blow hammer to get it off. I think pbblaster helped too. Had to hit the thing 100 times.

[Nickco43]

I just picked up a 98 323is with 86k miles. I just got all of my parts for the cooling system overhaul but I read threw all of the replies to the thread and a few things are worrying me. My fan and aluminum thermostat housing are uro parts. I got everything of Turner Motorsport and it did not say they were uro parts. Should I return them and get OEM or will it be fine? Also should I replace tensioner and the pulley?

[BimmerM3inGA]

If it were me, I would not use ÜRO parts. I've had very bad luck with them. And yes, you might as well replace the tensioner pulley "while you're in there".

[poorhouse]

Great write up!

Just did complete cooling system overhaul on my new 97.

This was hugely helpful.

Original radiator and expansion tank at 112k...

[Nickco43]

IMG_20160113_151326[1].jpg

I am getting ready to finally do the cooling system and it turns out the PO replaced at least the thermostat housing. He said he recently replaced the water pump but there weren't any receipts. Is there any way to tell if he replaced it without ripping apart the car?

I also found a leak but I don't know what its leaking.
IMG_20160113_151520[1].jpg

[MarketMaster]

IMG_20160113_151326[1].jpg

I am getting ready to finally do the cooling system and it turns out the PO replaced at least the thermostat housing. He said he recently replaced the water pump but there weren't any receipts. Is there any way to tell if he replaced it without ripping apart the car?

I also found a leak but I don't know what its leaking.
IMG_20160113_151520[1].jpg

Looks like power steering leak?

[BimmerM3inGA]

That's power steering. I've never seen an E36 or E46 that didn't leak power steering fluid. I even replaced ALL the hoses on my M3 with new OEM parts. It was leaking again within 6 months.

[zactastic]

This write up is really great. any updates that anyone can suggests to the parts listed in here...

Im going with the standard Behr or should i get the Z3M s54 Behr?

[zactastic]

From what I read in other threads it seems everyone agrees that the original plastic impeller was faulty, but some questioned the durability of the bearings in the metal impeller replacement design (excluding the high $ stewart). I don't think there has been many problems with the newer composite impeller. I found it interesting that BMW did not stick with the metal impeller design as a replacement but rather now supplies the composite impeller design.

Should i get the remanufactured OE composite impeller or all aluminum? or get the stewart?

[BimmerM3inGA]

OP here. Wow, blast from the past! I would also replace the expansion tank. I skipped it when I did this and it failed a couple of years later. Would've been better to take care of it along with everything else. Unless you track the car, the standard Behr will be fine - that's what I used and it's been in the car for more than 10 years (I still have the car). Same for the water pump. The Stewart is great, but overkill for a stock street car.

[TostitoBandito]

I track my car with the OEM behr radiator. Works fine. I have the Stewart pump as well.

[cmoody]

Should i get the remanufactured OE composite impeller or all aluminum? or get the stewart?

Get the Stewart.

[zactastic]

guess ill go with the Stewart thanks guys, going with the Behr. OP, i really liked this DIY the best, and thats comparing it to like 5 other sources i have. cheers mate!! thanks for all the info and contributions on here

[JBZ4]

Well almost two years later from the last post. I just want shout out my thanks to everyone who contributed to this thread.

I am getting on in age and not the best of shape but this thread and some You Tube video’s really helped me breeze through the cooling upgrade. The part numbers were great also along with the spread sheet.

Thanks again, great community here!

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