M42 rad + M50 overheating woes.

[lolcantturn]

I also don't have the top of the t-stat drilled

[trackjunkie21]

Your biggest problem is the M42 radiator and the fact its too small and its a mother Fer to bleed properly.

It's really not that bad, Took me all of a few minutes to bleed properly.

[lolcantturn]

Did you elevate the front end while bleeding it? I'd start there.

the M42 radiator sucksass, but it doesn't suck so much ass that you can't drive the car with it.

Front of the was not lifted

Oh boy this whole bleeding process reminds me of my M20 which is why I sold it. 12hrs bleeding, still overheated haha

[dnick]

how do you like the fan? lol when it does its job

[lolcantturn]

ran it on my last E30 with no problems at all.

[Jafxod]

I have no idea. It's fairly old but came from a known working well never-overheated M20.

lies lol

[Ceeker]

first incline the front end and keep the revs up while bleeding it. You should see a continuous flow of coolant coming out without bubbling. if it is bubbling you still have air in the system no matter how long or how many times you bled it. the possible reason the temp is climbing when the motor is under load is the internal pressure and air temp inside is also climbing causing it to over heat. Air expands when it gets hot creating a air lock. I'd also make sure that your waterpump is working properly. I had the same problem with my m42 years ago. I changed my pump and needed to bleed off the system. Drive it on the highway and then pull over and crack the bleeder open that may release the air due to pressure build up. close it off and drive it again. see if the temp stabilizes.

[cabin]

There is nothing wrong with the m42 radiator. It is plenty sufficient on my s50 and it takes literally 5 minutes to bleed correctly. Unless the radiator has failed, that is not the OP's issue.

[nando]

I bet it's just not fully bled.

[drumad]

Dammit, I just bled my m42 rad for my swap yesterday and now I'm worried.

I don't even have a fan yet and my temp sensor is either not wired appropriately or broken.

[Boosted E30]

M42 rad is fine, ive tracked my s50 swapped car with m42 rad in 30*c weather and it was fine. it ran a little hotter but never overheating.

op you probably have air in the system still.

[Jand3rson]

Your biggest problem is the M42 radiator and the fact its too small and its a mother Fer to bleed properly.

Completely incorrect statement. The M42 has plenty of capacity for an M50 and is not a "mother Fer" to bleed properly. I had mine bled in 15 minutes. I have a 16" Spal fan on the front of mine, and my needle rarely goes just a little past halfway.

[MR E30 325is]

I had the exact same issue.

Scrapped the tiny M42 rad and went with a late model M20 setup and never looked back. Problem free to this day, even in 115 degree AZ summers.

[butters]

+1 for the M42 radiator being fine. I could probably get away with no fan, temps have been rock steady at the 1/2 mark no matter what. parking on a steep incline allowed me to bleed in a matter of moments.

[einstein57]

Pressurize the system with a compression testor or your mouth and open the bleeders one at a time. Fill and repeat. Ususally takes about 5+ times.