discussion E92 335i build guide

[N3RD91_WP]

Hi everyone,

Recently got back into the bmw scene after my old 240. Purchased a e92 335i with DCT box, been my favorite shape of all the series that coupled with the DCT and the spec of the car.

Items i have done so far, full service as well as replacing the tappet cover with an OEM one just for preventative.

Car had no issues, however a month or 2 after the service. Im noticing quite a bit of smoke on cold start, its not billowing or blowing smoke, its just cold start smoke and then its gone. Nothing on idle, nothing on WOT only a little bit on downshifting and on first cold start of the day.
I have also had to add 2l of oil into the car and 1l of coolant since the service.

Now i know the issue could be anything from blown headgasket to valve stem seals to the turbo being the issue.

Just wanted to see if anyone here had suggestions on where to start, or if it would be better to just go into a full engine rebuild. I dont mind doing this, as this is probably a car i am going to keep in my stable for a really really long time.

Do the valve stem seals and replace thermostate and oil pressure regulator as a first? Or look into forged pistons. And if forged pistons is the route, could anyone point me in the direction of where to get the correct size pistons, rings, bearings and rods from? As well as recommendations on where to send my turbo in for rebuild.

End goal of the car is not to have a race car, its not to make 1000whp. Its to have a daily "reliable" car, yes im using the word reliable loosely here, N55. But i want to use the car daily and not have it be a race car.

 

[VinceM]

Hi

What colour is the smoke?


Sent from my iPhone using Tapatalk Pro

 

[N3RD91_WP]

Hi

What colour is the smoke?


Sent from my iPhone using Tapatalk Pro

Its light grey from what i can tell, smells like oil. I should also add, under throttle the engine still feels smooth and no ticking or rattling sounds.

 

[VinceM]

Below are the common smoke colours:

- Blue Smoke - Oil burning (valve stems seals could be the culprit)

- Black Smoke - Over fuelling (running too rich, possible injector problems, vacuum somewhere)

- White Smoke - Coolant issues (could also be cracked cylinder head)

Let’s see if someone can share light on the grey smoke, I think might be best to have someone check it for you.

 

[AudiDriver]

That sounds like valve stem seals, especially if it smokes on cold start (after standing, some oil leaks through seals into cylinders) and on overrun / deceleration. My track car has the same issue, but I haven't bothered to have it fixed. My car also breathes more oil than normal through PCV, which is another tell tale sign of guides and seals needing replacement.


Sent from my iPhone using Tapatalk

 

[N3RD91_WP]

That sounds like valve stem seals, especially if it smokes on cold start (after standing, some oil leaks through seals into cylinders) and on overrun / deceleration. My track car has the same issue, but I haven't bothered to have it fixed. My car also breathes more oil than normal through PCV, which is another tell tale sign of guides and seals needing replacement.


Sent from my iPhone using Tapatalk

Alright then I'll start with the valve stem seals and go from there

 

[Teezoh]

Same car that was on Niyaaz YT for the upcoming build journey?

 

[N3RD91_WP]

Same car that was on Niyaaz YT for the upcoming build journey?

Yeah. I wanted to do a series around the daily ownership of a 335. But the partnership was not what I expected. So no more series 🤷.

I might create a video of my own just to discuss what happened with the purchase and the maintenance etc.
But this smoking just started suddenly when I came back from a work trip, car had been standing for 3 weeks

 

[DarrylvanNiekerk]

Alright then I'll start with the valve stem seals and go from there

Might be an idea to do some preventative maintenence when you have the head off - good idea to check valve stem guides for movement of valves.

Check lifters for wear and replace vacuum pump seals.

 

[N3RD91_WP]

Might be an idea to do some preventative maintenence when you have the head off - good idea to check valve stem guides for movement of valves.

Check lifters for wear and replace vacuum pump seals.

Was also just going to check oil pressure and high pressure fuel pump pressure while I'm at it. But yes might as well do the stem guides and lifters since the head will be off

 

[osiris]

After parking the car let it sit for around 4 hours then pull the spark plugs and check if any of them are wet and if they smell of fuel. If they are wet and don't smell of fuel, then you got problems. Either head gasket or cracked cylinder/head. Take a small torch with a narrow beam and look inside the cylinder through the spark plug hole when you remove the plug and check if the head of the cylinder is dry or wet, they should all be bone dry.

My car was recently smoking too but it was mostly when coming to a stop at a traffic light or stop street and it was 100% due to one of the turbos. I replaced the turbos three weeks back and no more smoke.

A leaking injector can also cause light grey smoke, I found this out after doing some research, it won't smell like oil or coolant but obviously rather fuel...smoke caused by fuel isn't always black.

Valve stem seals also don't just suddenly start to cause smoking issues, it will be graduel.

Other things can be a cracked valve cover, however you said you replaced the valve cover. Then PCV valve can cause smoking too.

 

[N3RD91_WP]

After parking the car let it sit for around 4 hours then pull the spark plugs and check if any of them are wet and if they smell of fuel. If they are wet and don't smell of fuel, then you got problems. Either head gasket or cracked cylinder/head. Take a small torch with a narrow beam and look inside the cylinder through the spark plug hole when you remove the plug and check if the head of the cylinder is dry or wet, they should all be bone dry.

My car was recently smoking too but it was mostly when coming to a stop at a traffic light or stop street and it was 100% due to one of the turbos. I replaced the turbos three weeks back and no more smoke.

A leaking injector can also cause light grey smoke, I found this out after doing some research, it won't smell like oil or coolant but obviously rather fuel...smoke caused by fuel isn't always black.

Valve stem seals also don't just suddenly start to cause smoking issues, it will be graduel.

Other things can be a cracked valve cover, however you said you replaced the valve cover. Then PCV valve can cause smoking too.

Just because I replaced the valve cover, doesn't mean it can't be faulty. I'm going to spend some time on the weekend going around the car.


On the note of the smoking, the only time I get smoking is on the first cold start.

 

[Teezoh]

Just because I replaced the valve cover, doesn't mean it can't be faulty. I'm going to spend some time on the weekend going around the car.


On the note of the smoking, the only time I get smoking is on the first cold start.

Spot on, I replaced my cover in December of last year and it only lasted 2 months (give or take). Replaced it again around Feb and a few months ago I was greeted with a PCV whistle again. It originally went away but just last week it came back again. It baffles me that in all this time there is no bypass or fix for this N55 problem. The valve cover just has no lifespan on a tuned N55.

There is an aluminum one available but one thing I can't seem to get verification on is the PCV part of it, if the diaphragm tears is it an easy swap out on only the PCV or are we back to getting the entire cover replaced? Still unsure of it. Regarding the pricing, getting the OEM one is gonna cost me another 10k, take that over the last 11 months and it's been a 30K upkeep sink on only the cover.

Regarding your problems though:

Reach out to Ashley from @Xcede Performance , I can guarantee you will spend much less having him take a look at the car than you and us falling around with possibilities.

 

[N3RD91_WP]

Spot on, I replaced my cover in December of last year and it only lasted 2 months (give or take). Replaced it again around Feb and a few months ago I was greeted with a PCV whistle again. It originally went away but just last week it came back again. It baffles me that in all this time there is no bypass or fix for this N55 problem. The valve cover just has no lifespan on a tuned N55.

There is an aluminum one available but one thing I can't seem to get verification on is the PCV part of it, if the diaphragm tears is it an easy swap out on only the PCV or are we back to getting the entire cover replaced? Still unsure of it. Regarding the pricing, getting the OEM one is gonna cost me another 10k, take that over the last 11 months and it's been a 30K upkeep sink on only the cover.

Regarding your problems though:

Reach out to Ashley from @Xcede Performance , I can guarantee you will spend much less having him take a look at the car than you and us falling around with possibilities.

I was looking at the aluminium one its really not much more than an OEM one from stealership. But like you said can you replace the pcv or is the entire tappet cover needing to be replaced. Luckily I can warranty claim my tappet cover if it is the issue.

Let me give Ashley a call. I want to fix all the issues before I tune. Black Friday is coming up after all

 

[osiris]

Just because I replaced the valve cover, doesn't mean it can't be faulty. I'm going to spend some time on the weekend going around the car.


On the note of the smoking, the only time I get smoking is on the first cold start.

yea thats why I am telling you to check the plugs 4 hours after switching the car off. if it is smoking on first start you will probably find that one of those cylinders have some kind of liquid inside, if it's injector it will be fuel...if it's gasket or cracked block it could be oil or coolant.

 

[Teezoh]

I was looking at the aluminium one its really not much more than an OEM one from stealership. But like you said can you replace the pcv or is the entire tappet cover needing to be replaced. Luckily I can warranty claim my tappet cover if it is the issue.

Let me give Ashley a call. I want to fix all the issues before I tune. Black Friday is coming up after all

Just on a side note, you and Niyaaz had the car by Master M, was that just bait for the next episode or did they have a look at the car? If so, what did they see?

 

[N3RD91_WP]

Just on a side note, you and Niyaaz had the car by Master M, was that just bait for the next episode or did they have a look at the car? If so, what did they see?

No, Master M is a friend of mine.

He does all the service work on all of my cars. He is my go to for all OEM related work. But now that I want to modify and tune slightly different story. Wasn't click bait. I spend most evenings by that workshop talking sh*t with the guys there

 

[Teezoh]

No, Master M is a friend of mine.

He does all the service work on all of my cars. He is my go to for all OEM related work. But now that I want to modify and tune slightly different story. Wasn't click bait. I spend most evenings by that workshop talking sh*t with the guys there

Ok cool, did they have a look at oil leaks though or could they not find anything relating to your problem?

 

[N3RD91_WP]

Ok cool, did they have a look at oil leaks though or could they not find anything relating to your problem?

No leaks that we could find post the initial check. So when I got the car, there was a leak from tappet cover, we replaced that and cleaned the engine bay. We put in new spark plugs, oil, coolant, brake fluid basically full service. And there are no oil leaks since then.

He suspects valve stem seals as well. But I also wanted to get my vanos and injectors inspected which he doesn't have the tools to do.

Master M is basically my alternative to BMW dealership for OEM work

 

[Teezoh]

No leaks that we could find post the initial check. So when I got the car, there was a leak from tappet cover, we replaced that and cleaned the engine bay. We put in new spark plugs, oil, coolant, brake fluid basically full service. And there are no oil leaks since then.

He suspects valve stem seals as well. But I also wanted to get my vanos and injectors inspected which he doesn't have the tools to do.

Master M is basically my alternative to BMW dealership for OEM work

If the valve stem seals are bad you should have missfire though and from what I understand it's only the smoke on cold start? Taking that into account it means the car stands for a while triggering the cold start, giving oil the time to "settle down". If not visible anywhere my first go-to would have been checking inside the chargepipe and downpipe area for oil, if there is it might be turbo seals. Once again only speculating like true keyboard warriors

Keep us posted after getting in touch with Ashley, I'll bet my next tank that he turns into your go-to guy for everything too going forward.