S52 Excessive oil Burning

[ZEKTI]

Hi all, Have an oddish issue. OBD1 S52 I got was torn down but rotating assembly left alone. No idea if it did this prior. However there is a nice blue cloud under de acceleration. I will be having a leak down test done on it as well. What I assume is the intake was not installed correctly as the drain to pan was never hooked up. Before I tear down into it more does anyone have suggestions outside of my diag thinking? 1 - Perform leakdown test 2 - Clean intake manifold as I can feel oil where the ICV connects 3 - if poor leak down install new valve stem seals Here are the plugs after about 1K and ICV. Is that a “normal” amount of oil. Sent from my iPhone using Tapatalk Pro

[dmanb2b]

I am going similar issue, except it's mainly front three cyl and it's smelling like oil at idle. Waiting on valve stem seals to be delivered from Achilles Motorsports

[ZEKTI]

They have nice products, I saw their upgraded valvle stem seals but OE/Corteco will work fine for the application. I will say the upgraded race chain kit they sell is nice. Going to have the intake off and looked and then a leak down test to see some idea of the health of the engine.

[ZekeTheSneak]

I had to break out my computer for this response....

I am on my second s52 that smokes on deceleration. Both with higher miles around 150k. First thing I found was that it was worse with no crank case vacuum, ie no intake air pulling vacuum from the crank case. This helps seal the rings. I first had the obd1 crank case vent system which does not filter out the oil. Excess oil vapor was being drawn up through the valve cover and pooling into the intake via the CCV system. I thought I found the problem. So unplugged the Valve cover and cleaned out the intake. Same problem but a bit worse from lack of Vacuum.

Frustrated I installed a catch can, Cheap one to test with. Thing filled up very fast and Still smoked, Intake was clean though. I then ordered all the parts to run the full stock obd2 CCV system. With air/oil seperator. I purchased the turner motorsport intake manifold adapter and while expensive, made all of this very neat and tidy. This fixed the oil in my intake. Bmw put that thing there for a reason and clearly it works.

Ok so what next? I order valve stem seals. Cheap test just a few hours of my life. I made tools to compress the springs/retainers in car and honestly it wasn't very hard. Replaced the stem seals. Couple hundred miles later and same issue. What I have gathered from all this and many hours of research. The s52 has looser tolerances on the rings then say a m52. Many many a forum post on Bimmerfroums talks about the s52 naturally consuming oil from the factory. I'm assuming at this point that the oil control rings wear out later in life and this is the result. Lots of oil burning. If you find an answer I would love to know. I have a shortblock that is probably going to the machine shop to have it fixed once and for all. I'm going to do a leakdown test on my car sometime this week hopefully as well.

[ZEKTI]

Thanks Zeke for the information. I did not know that on an s52 I wonder why they changed it. I also disconnected the entire intake to vent to atmosphere to test and no real changes. I would think, but i'm not an engine builder, that if the rings were bad would each cylinders plugs be all equally as bad? It's going to the shop tomorrow for the leakdown test I have not been able to mess more with the intake. I will follow up on this but it's a bit annoying at this point. My friend has a spare M54 I may use if indeed this is an s52 internal issue.

[ZekeTheSneak]

Yah this is just my finding. The ring thing is a mystery myself, hopefully someone way smarter then I has answers. I could be way off but who knows. I hope you find an answer with the leakdown.

[spiDmang]

Very interesting info, and definitely worth considering for future swappers.

[ZekeTheSneak]

Did yours ever smoke brad?

[wworm]

glad I found this thread, have an s52 with 180k sitting on a stand in my garage that I'm about to start tearing into and was initially going to just get the valves lapped and put new stem seals in. Sounds like I should do rings now as well.

[twright]

More info: I used to own a 1997 M3. It had a notice (on the fuel gage?) That warned you to check your oil level. Oil consumption on those models was a normal situation , even when New.

[ZEKTI]

glad I found this thread, have an s52 with 180k sitting on a stand in my garage that I'm about to start tearing into and was initially going to just get the valves lapped and put new stem seals in. Sounds like I should do rings now as well.

When I had head decked and chains etc I should have just done the rings. One and done kind of deal.

Regarding the oil consumption, I know S motors burn more than their non S counterparts, however this is abnormal amount. There should not be blue clouds roll past me at a stop light.

[dmanb2b]

Well got an update from my shop, at least in my case while my stem seals were shot and gunked from carbon, replacing didn't solve the issue. Looks like the freshly sealed motor is going to be pulled again for new rings...running great too

[ZekeTheSneak]

Make sure the intake isnt drinking oil through the crank case vent. Oil will pool behind the throttle body.

[dmanb2b]

Make sure the intake isnt drinking oil through the crank case vent. Oil will pool behind the throttle body.

My car is set-up with catch can venting to atmosphere after the can.... :<(

[spiDmang]

Did yours ever smoke brad?

I noticed that it consumed oil as well. I had to add a quart every 1500-2k miles. Just depended on how heavy my foot was during that oil interval lol.