balbs

3.5 years ago, my car had a full coolant in the tank. About 2 years ago, I had a thermostat replaced by the dealer under warranty which (I think) involved flushing the system out. I'm pretty sure the coolant was topped off then. For awhile now, I've been noticing that a slight white smoke coming out of my exhaust. I compare it to other cars around me and it seems mine is smoking more than others however, it doesn't look that bad and a figure it could be just the cold morning or evening air. Last February I sent an oil sample to Blackstone labs and the sample came out okay so I felt safe that no coolant was going into the engine.

A couple of weeks ago, I got curious and checked the coolant level and found it to be less than the minimum. I didn't even get an idrive error. I then filled it up with about 24oz of 50/50 coolant/water mix to the full line.

What do you guys think? Is coolant leaking into the engine? If so, is there a DIY that I can look at? Is it just a simple replace the gasket issue? Any advice would be appreciated.

Thanks!

E90dima

How many miles do you have?

balbs

About 74700 miles.

EUAutoHaus

White smoke usually means that you're burning oil. The N52 is probably about due for a valve cover gasket change. Lots of fun on the N52! The coolant level is probably due to a small leak where you are unable to detect it. You did the correct thing by replenishing. Now just keep an eye on it to determine the rate of leak. You may have a small pin-hole leak in a hose or a hairline crack in the lower part of the expansion tank.

pcy

I thought white smoke typically results from coolant leaking in to the engine; and blue smoke results from oil leaking in to the engine.

While valve cover gasket may need to be changed, that has no relevance to white smoke from exhaust.

pcy

If I were you, I'd use a flash light and look around all coolant related hoses/connections, especially the return hose, coolant reservoir, bottom portion of radiator, around the o-ring on coolant temp sensor etc. Very likely, you will find coolant residue on one of those parts.

balbs

That's what I thought too...

I'll do that. Just looking around above the engine bay, I don't see any leaks. Also, my parking spot at home and assigned parking at work is spotless. I'll check under the hood in more detail with a flashlight. However, since I'm getting a white smoke, I'm more worried that the leak is in the engine so I won't see any other leaks outside.

Is the gasket fairly easy to change? If so, which one? Any DIY?

Thanks for the help!

EddieboyS

White smoke means coolant is making it's way to the combustion chamber. A typical cause is a bad head gasket or warped head. Are you aware if the car has ever overheated in a significant fashion? This could certainly result in a warped head or blown head gasket.

balbs

Not to my knowledge. The car runs well otherwise. Is the head gasket the same as the valve cover gasket?

pcy

No, they are different gaskets.
Leak from valve cover gasket results in oil seeping out of the engine (on the top). This is a relatively easy job to replace valve cover gasket.
Leak from head gasket, on the other hand, results in coolant leaking in to the engine. You won't see any visual signs outside except the white smoke from the exhaust. This can get expensive job to replace head gasket.