[Jcklvrsn]

I’m starting to become more familiar with these n54 engines. My 2007 335i has a constant white smoke issues and I can’t seem to wrap my head around what exactly it is and I have a few guesses on what it is but I’d like to see if someone else on here has been through the same issue or not. Before I get more into detail some info on my car
2007 e92 n54
Guy I bought it from says it’s Fbo but it’s missing an intercooler (stock intercooler)
Also supposedly has index 12s
Dual come intakes
Supposedly has 19T turbos with 5k miles
Runs on a e40 tune
Supposedly has a custom tune
Guys says it’s pushing 500whp feels close but I’m not sure. Used to run around 25psi max.
About a month ago my coolant expansion tank blew up while I was just sitting in idle and the water pump had previously been ignored by the owner and I didn’t have time to fix his problems he handed to me, until the other day I finally put a new water pump in and thermostat then I thought my smoke problem would go away and it didn’t so I replaced the valve cover gasket and valve cover and upgraded the PCV valve to a metal one of burger tunings website. Thought that would make my constant white smoke issues go away but it’s almost worse. Usually smokes the worst at stop lights smokes the whole intersection out. Sometimes it’s a constant trail behind me of smoke. I also go through about a quart of oil a week. I’m assuming the water pump hasn’t already gone bad my car runs at about 210-230 after 30 mins of driving. I’m wondering if my turbo seals have gone bad, could be the turbos suffocating because there isn’t enough air flow since I have a stock intercooler and I’m trying to push to much boost for the stock one. Also don’t have any blow by on the oil cap so I wouldn’t think it’s the head gasket. When I open the oil cap there is usually a milkshake as long as my oil catch can looks like a Frappuccino. Someone please help me diagnose my issues before I spend 3k on a single turbo and the issue doesn’t resolve. Thanks

[2sporty]

my dearest condolences, your valve seals are going bad... if they were replaced, they were not installed correctly.

[Jaronbwall]

Originally Posted by 2sporty

my dearest condolences, your valve seals are going bad... if they were replaced, they were not installed correctly.

Very clearly the valve seals and oil consumption. From what you described not much maintenance was completed on this car. I feel for you. Hopefully you knew that full on before buying it. It's time to bring out the check book and tool box if you want to save money.

"Also supposedly has index 12s" - Did you verify the index for the injectors?.... Get under there and read them

[Jcklvrsn]

Jaronbwall
I already replaced the valve cover gasket less than 100 miles ago. I’m guessing it’s turbo seals then?

[trohde78]

Previous comments are referring to the valve stem seals, not the valve cover. Valve seals are a much bigger issue.

[iqraceworks]

The combination of cheap 19t junk turbos + 5K miles at 25psi would make me think your turbo seal(s) are going bad. Those cheap ebay 19t's have a pretty big failure rate. I've seen several guys who have smoking issues with them at well under 5K miles...some as soon as 1K....some right out of the box.

I would pull the downpipes and take a look up inside the turbos....check for oil. If it's smoking as bad as you say it is.....it should be pretty obvious if it's coming from the turbo(s).

I know it can happen....but it seems like valves seal issues on the N54's are much...much less common that leaky turbo seals.