2001 audi a6 2.7 smoking

[AKBray907]

So I have an 01 a6 2.7 quattro. The original motor had bent a valve and the exhaust was smoking pretty bad, I thought due to the fact the valve wasnt closing, so replaced it with a 2004 2.7 with 67xxx miles on it, had my ko3s rebuilt and balanced and put them on the "new" motor.

Changed the valve covers on the 04 to the earlier style and changed the secondary water pump and knock sensors to the old style as well so I could just plug and play in my car.

Put the engine and transmission in the car, pulled the fuel pump relay , cranked the motor several times to get oil throughout it. Put the relay back in, car starts right up. Sounds great everything looks good. Comes up to temp properly.

However car has the same smoking issue as it did before but with a different motor and turbos. The motor runs great and sounds great, as well do the turbos. But it smokes quite a bit. Looks like white or grayish possibly bluish smoke. Get worse when revved. It also smells sort of rich in the exhaust as well.

I disconnected the the intercooler to throttle body hoses just to rule out somehow bad turbos and am getting and burning oil that way, hoses had a little oil (could feel it if you ran your finger around the inside of the hose) but honestly didn't clean them super well so could be from previous motor. And even with the hoses disconnected and the car running the exhaust still smokes. So I think that eliminates the turbos from being an issue.

Coolant level has not changed and no indication of a headgasket problem. All the cylinders tested fine in a compression test.

Narrowing down things, I reused the previous pcv system. Is there a chance this is cause the issue?

Any insight or help would be much appreciated, kind of beating my head against a wall here. Getting close to just scrapping the car. Motor runs great, no cels, no wierd noises, just smokes

[LINDW4LL]

Under what conditions does it smoke? All the time? Only on cold start, under boost, etc...?

[AKBray907]

It's kind of all over the place and will smoke all the time sometimes, then clear sometimes but seems worse when oil Temps get up and when the car is revved. But I haven't revved the car over 2500 rpm. And without the turbo hoses connected I only revved it to about 1200 and same issue.

The time it seems the best is on a cold start.

[AKBray907]

Bump

[spacecadet]

Do leak down could be valve seals. You ran it without turbo oil feeds ?

[jonboy]

I'm having a very similar issue. 2005 allroad and just did new "k04's", also made a new spider hose setup, removed the sai as the tune eliminates it. My buddy says the pcv on the intake y pipe is shot so I'm wondering if the crankcase pressures is higher than normal and not allowing the oil to drain out of the turbos quickly enough and thus forcing it out the exhaust. Anyone have thoughts on that?

[glennda5id]

I'm having a very similar issue. 2005 allroad and just did new "k04's", also made a new spider hose setup, removed the sai as the tune eliminates it. My buddy says the pcv on the intake y pipe is shot so I'm wondering if the crankcase pressures is higher than normal and not allowing the oil to drain out of the turbos quickly enough and thus forcing it out the exhaust. Anyone have thoughts on that?

High crankcase pressure can cause seals to leak.

For original poster and this poster, these motor commonly leak from the chain tensioner gasket and the valve cover gaskets after 70k - 100k but it can occur earlier due to age. I would say most of these cars are going to be leaking at 10 years regardless of mileage if driven regularly.

The oil leaks onto the turbo and exhaust and smokes once the engine heats up.

[jonboy]

I can't speak for the original poster, but I think he and I have the same issue as far as how the smoke is generating. Which is to say it's "combusting" somewhere rather than the valve cover leak. Which I got to fix and clean when I first got the car lol.
If it is indeed crank case pressure, how long can one expect before it really starts to shit the bed?

[AKBray907]

Do leak down could be valve seals. You ran it without turbo oil feeds ?

Thought it could be valve seals but just seems odd that it's the same issue as the motor before was doing, that's why I was leaning towards pcv.
Absolutely not on the oil feeds, just undid the tubing from the intercooler to the throttle body to help eliminate variables

[AKBray907]

I'm having a very similar issue. 2005 allroad and just did new "k04's", also made a new spider hose setup, removed the sai as the tune eliminates it. My buddy says the pcv on the intake y pipe is shot so I'm wondering if the crankcase pressures is higher than normal and not allowing the oil to drain out of the turbos quickly enough and thus forcing it out the exhaust. Anyone have thoughts on that?

I'm curious if it's pcv too, the system on these motors is pretty stupid if you ask me but i still have a hard time it's making it smoke like it is. Let me know if you have any updates

[AKBray907]

High crankcase pressure can cause seals to leak.

For original poster and this poster, these motor commonly leak from the chain tensioner gasket and the valve cover gaskets after 70k - 100k but it can occur earlier due to age. I would say most of these cars are going to be leaking at 10 years regardless of mileage if driven regularly.

The oil leaks onto the turbo and exhaust and smokes once the engine heats up.

It's not an external leak, new valve cover gaskets and turbos are completely clean and no oil leaking onto them from the outside or on the exhaust.

- - - Updated - - -

I can't speak for the original poster, but I think he and I have the same issue as far as how the smoke is generating. Which is to say it's "combusting" somewhere rather than the valve cover leak. Which I got to fix and clean when I first got the car lol.
If it is indeed crank case pressure, how long can one expect before it really starts to shit the bed?

Sounds like we have the same issue

[AKBray907]

Anybody have any thoughts?

[spacecadet]

what color is smoke? what is result of leak down? what is result of compression test? what is result of hydrocarbons in coolant test?

[LINDW4LL]

Anybody have any thoughts?

My first thought is to change the PCV as to eliminate that variable. Beyond that, there are usually only a few possibilities for burning oil- valve stem seals, piston rings, or turbos. Bad rings seem very unlikely. Valve stem seals rarely go bad (although ironically I'm actually dealing with this on my S4 engine). However, the symptoms still aren't the same as smoke only happens on the first cold start after sitting for awhile, and quickly disappears after a few minutes.

How many miles have you put on the car since the engine swap (or, how long has the new engine been run for)?

[AKBray907]

There a way to eliminate the pcv from the equation without just replacing it? Getting sick of throwing hundreds of dollars everywhere at this car.

Car has been driven about 50 ft. And run for probably a total time of an hr.

Something I noticed yesterday, is it will be fine idling, no smoke, then when put into gear, it will begin to smoke. Makes me think an air/fuel issue or something of that nature. It doesn't like the load on the motor at all.

Also if it matters, the car is piggy piped

[glennda5id]

Where is the smoke coming from? Back of engine, sides, front? How about a video?

[vdubfredvr6]

Maybe bad gas? I had filled up on 93 at a station I always get gas at, 15min. later my Allroad 2.7t started smoking pretty bad. Called the station to see if anybody else called in with issues and come to find out, the delivery guy out diesel in the 93 tank. I wasn't the only one.

[AKBray907]

So I haven't had time to play with the car for a few weeks. But The exhaust and white smoke definitely has a gas smell to it. Could a stuck injector with bad gas cause this? also getting mulitple random misfire code now.

Is there a way to check these injectors? both in VCDS and maybe on the bench?

[AKBray907]

bump

[spacecadet]

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