The OFFICIAL let's make Erick's M30 stop overheating thread

[LowR3V'in]

Erick, if your water is boiling, you have a leak in your coolant system. Water will not boil if it's under pressure (think pressure-cooker). If the car won't overheat on the ride to my shop, I can run a pressure test for you.

I think that's part of the problem also.
My car sees 210f sometimes when I forget to turn the fan on, and does not boil, just cools right back down to 195f.

[Erick]

Valid point... what could cause that to happen?

[ForcedFirebird]

Radiator cap, for one, slow leak in a hose, ANY little leak to atmosphere in the coolant system will not let it build enough pressure. It takes 13-16psi in the system for water to NOT boil up to about 200*

[Erick]

Radiator cap, for one, slow leak in a hose, ANY little leak to atmosphere in the coolant system will not let it build enough pressure. It takes 13-16psi in the system for water to NOT boil up to about 200*

Radiator cap is brand new. Considering the old radiator cap didn't change the issue, I'm assuming that's clean.

The leak on the hose has got to be beyond minimal.... enough that the motor being warm itself can burn up the water before it leaks. The car can sit on for half an hour without leaving a single drop.

Your pressure tester can find this leak?

- E

[ForcedFirebird]

Radiator cap is brand new. Considering the old radiator cap didn't change the issue, I'm assuming that's clean.

The leak on the hose has got to be beyond minimal.... enough that the motor being warm itself can burn up the water before it leaks. The car can sit on for half an hour without leaving a single drop.

Your pressure tester can find this leak?

- E

This is not good! ANY leak will cause overheating.

The pressure tester set to about 20psi will usually show you where the leak is and NOT blow your hoses up.

Did you use all new hoses etc when you did the swap, or is it JY stuff?

Dammit, Erick, we could have a much faster conversation of you call haha.

[Zacm829]

Has to be a leak to be boiling coolant as everyone else states. Ever thought of a larger aftermarket radiator to up the surface are and cooling? How close are you to be able to run that clutch fan? That would be ideal as I'm sure you now.

[Erick]

Alright, so I finally had the opportunity to meet up with John tonight (ForcedFirebird). I'm sure he'll post up his findings but basically we found nothing conclusive with the pressure test.

We pumped 14psi in the coolant system and it had a very slow leak. Took about half an hour to get down to 10psi, and an hour and a half after that it was holding 6psi. John says that it's really not significant enough to cause the car to behave as it does.

While the coolant system was pressurized, I took the valve cover off and checked the torque of the head studs. Made sure everything was tight at 90ft/lbs after driving about 60 miles. All is good there.

Driving back home, it still drives very much the same way. John went for a ride and the car just keeps warming up as it sits at idle.

So..... any thoughts/suggestions? I honestly don't know where to look anymore. I'm considering trying a fan shroud to help cooling, but thats really not fixing the problem, just trying to help improve cooling enough so that the problem is not as persistent.

But until I can find a way to keep the car running at a set temperature, and have a cooling system that can cool the car down to such temperature after making a drifting run, this car is really of no use to me. :(

Besides a fan shroud... any other ideas?

- E

[ForcedFirebird]

Has to be a leak to be boiling coolant as everyone else states. Ever thought of a larger aftermarket radiator to up the surface are and cooling? How close are you to be able to run that clutch fan? That would be ideal as I'm sure you now.

No room at all, really for a clutch fan.

The radiator should be sufficient since it is the radiator, after all, that comes with the motor, just in a different car.

Erick, remember, I didn't have the cap tightened all the way the first test, but the second test held more than enough. Took quite a while for it to bleed down to 10psi, pretty much the same I see on any car.

What do you think about maybe using a narrow flex fan from another car, or maybe a slim generic one and drilling it to the water pump pattern?

[LowR3V'in]

Does it still keep getting hot if you run water over the rad with a hose?

[slammin.e28]

I may be mistaken as I read this whole thread and it all kinda got jumbled together but I'll just throw this out there...

My e28, 535i with the B34 was exhibiting similar symptoms. Boiling coolant, etc, but the gauge wasn't leaving the blue (stock gauge on cluster). After dicking around with T-stats and rad caps for a while I took all the hoses off, flushed them and inspected all the junctions, etc. I noticed that inside the little nipple on top of the radiator that connects the overflow hose to the overflow tank there was some debris. I removed the debris with a paperclip and voila, no more boiling!

As far as my temp gauge, I'm thinking it gave up on me. The coolant would boil before the gauge even hit 11 o'clock. Haven't really driven the car since I got the boiling taken care of so haven't worried about it.

Also, I've been running straight water too (leaky freeze plug so I don't wanna lose all the coolant and have to keep buying it 'till I fix it), so my theory is that possibly some corrosion from running straight water (distilled), or just the fact my overflow tank was full of shit, could have come loose and made it's way to that nipple, eventually closing it off. Then the coolant will not circulate properly. Check that nipple.

I'm going to do a full flush hardcore on the car after I replace the freeze plug. Also, wouldn't a leaky freeze plug cause a loss in pressure possibly? It is a leak to the atmosphere....

Like I said, just throwing that out there. I read this thread 2x but it all got kinda jumbled together.

Good luck!

[Erick]

Does it still keep getting hot if you run water over the rad with a hose?

Never tried that. I'm assuming that'd say the radiator isn't cooling enough (perhaps pointing towards the fan?)

I may be mistaken as I read this whole thread and it all kinda got jumbled together but I'll just throw this out there... lots of etc etc etc

Good info. I suppose that might be it, although doing the mye28 sticky cooling bleed, I'd assume that the top overflow hose is fine, but I will check it anyways.

Much appreciated for the help. I shall report back later with my findings.

- E

[wildstoats]

So..... any thoughts/suggestions? I honestly don't know where to look anymore. I'm considering trying a fan shroud to help cooling, but thats really not fixing the problem, just trying to help improve cooling enough so that the problem is not as persistent.

- E

I highly doubt this will solve all of your problems but have you tried getting the rubber gasket that Spal sells for their fans? I am running one on mine and I think the tight seal against the core really helps. Like I said, I can't imagine that is the entire problem but it might help. For reference here's a picture of it on my car:

[slammin.e28]

Good info. I suppose that might be it, although doing the mye28 sticky cooling bleed, I'd assume that the top overflow hose is fine, but I will check it anyways.

For me it wasn't the hose itself. It was inside the little nipple that's on top of the rad. Get a light and peer down that hole. It doesn't take much to plug that up.

Sorry if I got a little long winded earlier!:oops:

[Erick]

Its all good boss. No worries with the long explanations. Trust me when I say that at this point, i'm reading all suggestions carefully :p

I will still take a look, although on a new radiator, it's kinda tough to believe it's clogged. I should be able to take a look tomm.

[LowR3V'in]

Do temps go back down if you rev it out or just let it engine brake?

My temps goes down like 5f if let it sit for a while and just do some runs or
some high rpm engine braking. I think it's probably a slow reacting thermostat, or old
water pump.