[jlsm511]

I'm writing this on behalf of my friend, who is an airline pilot and away from home. He has a 2007 E92 335i, and right before he left for training out of state, the car overheated on his way home. At first we thought it was just low on coolant, but then I saw what looked like oil in the coolant reservoir and read that the Oil Filter Housing gasket may be the likely culprit. However, after going through the trouble of fixing this for him, I want to make sure that there might not be some other, secondary cause for this which may have led to the car overheating. It's no longer under warranty (it was a CPO), and I plan on doing the repair myself along with another friend to save costs (pilots dont make as much as you would think hahah). So any tips would be greatly appreciated. Thanks!

[Bartman619]

That does look like oil mixed with coolant. Could be the Head Gasket also. Any steam/white smoke coming our of the exhaust ? Loss of coolant or drop in coolant level ? You may want to do a compression test on it ASAP to isolate the problem.

[E90_831]

looks like you have a blown head gasket.. how long was the vehicle driven overheating..?

[jlsm511]

0 smoke or steam from the exhaust from what I saw and what he has told me. As soon as the engine overheat warning appeared on the cluster, he turned the car off and had it towed home.

[F32Fleet]

Head gasket. Is it tuned?

[jlsm511]

It was purchased CPO, but my friend hasn't done anything to it and I don't see any mods on it.

[Red_Bean_Bun]

I would guess that after the gasket is replaced ... You would flush the radiator and refill it with distilled water and coolant .....

[Bartman619]

As for the overheating, its probably the waterpump and thermostat.

[GMWNashville]

Oil filter housing gasket is leaking engine oil into cooling system. Flush the system with water and dawn(let engine get hot) then just water then coolant/water Mixed. That being said you also need a water pump

[jlsm511]

Thanks for all the suggestions. We are gonna have the car towed to the dealer and see if they can give us a better idea of what is going on. Hopefully it's something minor that can we can repair ourselves.

[jlsm511]

Just to let everyone know, we ended up replacing the thermostat and water pump and that fixed the issue. Car is running good now and is no longer overheating! Thanks for all the help and suggestions!

[123Britt]

Overheating -- yes the Thermo & W/P has corrected the problem -- but has it really?
.
.
From my experience : The 335i starts to over heat due to the Thermostat being contaminated with particulate from the Oil Filter housing gasket / oil cooler gasket. When I removed my (2) gaskets they were both deteriorating around the coolant opening. Thus particles of the gaskets fouled up the thermostat as well as letting oil pass into the coolant.
.
.
With my car (yours possibly) the overheating was a system and not the root cause. After replacing the Thermostat and W/P I found oil in the coolant and proceeded to replace both gaskets and o-rings common to the oil cooler lines. This has eliminated oil in my coolant and hopefully eradicated the root of the problem.
.
So after a week or so of driving -- I would carefully inspect the coolant for oil. The presence of oil would indicate a failing gasket at the oil filter housing or possibly a bad valve cover gasket.

This was my recent experience --- I will now be changing my valve cover gasket next week -- at 90k as preventative maintenance.

[jlsm511]

Originally Posted by 123Britt

Overheating -- yes the Thermo & W/P has corrected the problem -- but has it really?
.
.
From my experience : The 335i starts to over heat due to the Thermostat being contaminated with particulate from the Oil Filter housing gasket / oil cooler gasket. When I removed my (2) gaskets they were both deteriorating around the coolant opening. Thus particles of the gaskets fouled up the thermostat as well as letting oil pass into the coolant.
.
.
With my car (yours possibly) the overheating was a system and not the root cause. After replacing the Thermostat and W/P I found oil in the coolant and proceeded to replace both gaskets and o-rings common to the oil cooler lines. This has eliminated oil in my coolant and hopefully eradicated the root of the problem.
.
So after a week or so of driving -- I would carefully inspect the coolant for oil. The presence of oil would indicate a failing gasket at the oil filter housing or possibly a bad valve cover gasket.

This was my recent experience --- I will now be changing my valve cover gasket next week -- at 90k as preventative maintenance.

Well, I forgot to mention we also replaced the oil filter housing gasket and thoroughly cleaned the coolant housing to make sure no oil further contaminated the coolant. But thanks for the advice!

[3002 tii]

All good info here, and I agree with most of the above. Anyone else reading this, if you're going to do wp & t-stat, may as well do the oil filter housing gasket too since you're doing a coolant flush anyway. The parts are cheap and it's only another hour of your time.