Fixed vacuum leak - now *lots* of white smoke

[JimmyDee]

My wife's 2001 325CI was running rough.

DTCs said, "bad purge valve" so I replaced that. I also found a vacuum leak between the oil separator portion of the CCV and the dipstick and replaced that hose. It started, idled, and ran "like new," she said.

Then after a short trip and a five minute errand, she called and said it was blowing white smoke. Since she was only a couple minutes away, I said "Bring it home."

It was smoking a little when she got home: wispy white with virtually no odor. We shut it off and let it sit overnight.

Next morning, I checked coolant: still had pressure in the radiator and seemed full. Then I started it: yup, white smoke. It didn't smell like oil or gas. I let it idle for one hour and it cleared-up. I feathered the throttle, it rev-ed up, dropped back to idle -- and started smoking like crazy. Huge, billowing clouds. I've *never* seen this much smoke coming out of an exhaust pipe! It was white and smelled a little bit burnt.

After one minute, it didn't look like it was going to stop so I shut it down.

What's next?

[MarcoZandrini]

White smoke is an indication of coolant getting into one or more cylinders. My suspicion is that the head gasket is bad. This is supported by the statement that the upper radiator hose is firm even when the engine is cold.

has the engine ever been overheated? When was the entire CCV system last replaced?

[flyfishvt]

If it really is white smoke then you've got a head gasket or cylinder head issue. The fact you did a repair on the CCV system 24 hours prior kind of rules that out.

I suspect that your white smoke is actually blue smoke from engine oil. They can appear very similar if you've never experienced both. A failed CCV system can cause oil to be pulled out of the crank case into the intake manifold. In severe cases it will create clouds of smoke so thick you can't see your hand in front of your face. It will have a slight burnt oil smell. While smoke from coolant has a very distinct sweet smell.

When issues like this pop up it's always wise to look at any work that was performed just before the issue started. Start with the CCV system. You could have a failed cyclone separator.

[legoman67]

It always amuses me how quick people are to jump to the worst conclusion. Coolant has a very sweet smell when it is being burnt. Also the next obvious step would be to see if the car is actually losing coolant.

How is this car mostly used? does it get many trips more then 20 minutes in length? Highway driving?

[MIKYZZ4]

Replace CCV System as a kit, not hose by hose.
Here is what you need:https://www.fcpeuro.com/products/bmw...-m54b25coldkit

[dhurley34]

I'll take "What is a CCV system failure" for $200 Alex.