'89 318i 6 speed m50b32tu turbo swap build

[ba114]

Couple pics following a bit of a cruise yesterday

[ba114]

just updating as ive been quiet.

The issue was 100% a collapsed PCV. Car runs fine now without smoke.
I'm now having some issues with timing drops at idle once the engine is hot so i've got some investigating to do.

other than that, it's driving well, boost comes on cleanly off just the wastegate spring. Dealing with a little more knock than i'd like so still working through timing and fueling but i'm happy with the progress :)

[ba114]

Still not in the clear yet. Haven't had a chance to take it for a drive and check if it still smokes under load.

I'm optimistic, but at the same time looking for piston and rods to fit on the m52 crank I have leftover from the scrapped m52, for fitting ìn the spare m50 block.

[Northern]

that's some really good news then!

[ba114]

After completely removing the turbo, i found oil in the manifold indicating that it was not infact oil getting through the seal.
After more researching, I diagnosed a potentially faulty pcv valve which could have been sucking oil up through the dipstick.

To test this I cut the drain from the pcv to the dipstick in half and plugged both ends.

After running for about 5-10 minutes the smoke stopped and this is now what remains when I start the car.

https://youtu.be/Fr3n_eJ4yxQ

It seems to confirm that the PCV had indeed failed and was allowing oil to be pulled through the dipstick.

So not an issue with pressurised crankcase, but more an issue of excessive vacuum through the pcv.

[ba114]

Yeh I used the spot that is most commonly used elsewhere. As you can see there is no way to go any higher on the pan.

Timing cover would be difficult to route as I am running A/C...

[pazi88]

I mean, Pazi and I have our drains higher on the block/timing cover, but there are dozens of people on BF.C draining directly back to the pan as you are.

Yes there are. But As I said that depends on a what turbo is used.

[Northern]

That would be under the oil level when the engine is off, but I would find it hard to believe the oil would be anywhere near that height while the engine is running.

Any chance the drain is kinked or otherwise collapsed?

If that's -10 with a -4 feed, and it is clocked near 0deg as the pictures show, I really don't think it should be a problem.

I mean, Pazi and I have our drains higher on the block/timing cover, but there are dozens of people on BF.C draining directly back to the pan as you are.

[pazi88]

That is clearly under oil level and depending on the turbo that could cause broblems. The front cover is very good place to put the oil return.

[ba114]

Oil return is as high up on the pan as I could get it without interference.

[pazi88]

Ba114 how is your turbo oil return? Where is it located? Is it under the oil level or over?

[BaltimoreBimmer]

awesome build and great attitude ba114. this is good stuff!

[ba114]

Definitely not pcv related.

My pcv routes through a catch can, then to the stock pcv valve whilst the engine is under vacuum. My obd1 manifold has been modified to retain the stock obd2 connections for the pcv and iacv.

Under boost the stock pcv setup is then isolated via check valves and instead vacuum is sourced from the turbo inlet (although currently is VTA)

[pandaboo911]

Venting to atmosphere seems to work fine for everyone else (myself included)

True dat, I'm not saying it doesn't work. It's probably the best solution for any boosted engine.

Some people's vents aren't all that great though and pressure might build up. Just noting that pulling vacuum on the crank case would be better if you can get it to work right.

From his pictures it looked like he had the stock OBD2 CCV hose attached, not sure where the other end goes though with the obd1 manifold.

[Northern]

Venting to atmosphere seems to work fine for everyone else (myself included)