So unfortunately my R32 developed a new problem this weekend, when the car is up to temp and driving it's fine. However on idle it's started blowing white smoke out the back, a lot of it and it hangs in the air, smells plasticy/oily. Now there is no goo in the radiator, just fresh coolant, a little bit of oil in the hot pipe of the turbo pre intercooler. Ran a compression test today, results as follows: 1) 140 2) 142 3) 130 4) 120 5) 140 6) 141 Looks like a problem with cylinders 3 & 4 perhaps? Did a leak down test too, percentage leak as well as main leak location below: 1) 18% - Dipstick 2) 15% - Dipstick 3) 30% - Cylinder #2 4) 28% - Cylinder #3 5) 20% - Dipstick 6) 7% - Dipstick I'd like to think its not a problem with the head gasket as I put a new one on 6 months ago, had the head skimmed at the same time as well so everything was flat. Also used ARP studs and followed the torquing procedure. There is also no creamy stuff in the radiator so again I don't think this is a head gasket issue. So I think its one of the following: Turbo oil seals CCV (Unlikely as both cam covers go to a catch can) Valve stem seals Any help would be greatly appreciated!
You're on the right track, but the test results are pointing at either cylinder 3 and 4 with worn rings. To lose that much on a leakdown it's probably rings, unless the valves aren't seated right after you did the headgasket. What oil are you using? Sometimes a thicker oil can help stop the seepage past the seals. Only downside is that you need to take more care with warming it up before using it
I'm wondering why the rings would go suddenly though? I'm using 5W-40 at the moment, did an oil change this weekend, exact same oil that came out went back in, same viscosity, same manufacturer. Is there any possibility this could be an oil issue in the turbo? I'll drop the downpipe next time I'm working on the car, if it is a turbo oil issue I assume the downpipe will have oil residue in it? Obviously changing a turbo is easier than changing the rings..... Cheers
Indeed, but your results aren't pointing towards turbo. The leakdown is identifying issues on cylinders 3 and 4. During the leakdown, could you determine if it was coming out of the dipstick or the intake? Dipstick points to rings, intake points to valve seats. Were the tests done at cold or warm? If it was warm (as it should be) then i would say try the Castrol GTX 15W-50 High Mileage or something similar and restest. RB20's are getting long in the tooth and contrary to common belief they don't run forever sadly. 5W-40 is a little light on the cold vicoscity. I would tend towards a 10W or 15W
Good point! Test was done cold, so I can retest when up to temp and see if the results change. If they don't, might be time to replace the rings then?
I'm going the RB20 route too so will be good to see what your issue is. Might take some precautions accordingle
Well those are damn good results for a cold test tbh! If it was me, i wouldn't be worried. I compression tested my RB25 recently and came back much worse. I would redo the leakdown once it's warmed up to give the oil a chance to help improve the ring seal. Due to it puffing a bit of white smoke on idle once warm i'd say this isn't going to change much If cylinders 3 & 4 are still above 20% then do an oil change and bump up the viscosity and restest at warm again. I'm anticipating this to have the biggest affect If it still hasn't improved then start planning for a ring replacement in the distant future when you want to wind more fun into it. But don't worry, it'll still run absolutely fine as is Other things to look into is checking the the oil drain from the turbo isn't kinked or partially blocked. Also, is the PCV valve from the cam cover to the intake still hooked up? Try blocking this and see if it improves it - or running it to a catch can if you don't have one already.
I compression tested this again cold and still got the same results and to be honest I think the piston rings are still slightly worn. However being that the smoke from the exhaust was the main concern I dropped the downpipe which was coated in oil, elbow was coated in oil and you guessed it, back of the turbo was oily. Based on this I'm going to say turbo oil seal, I've since replaced the turbo and initially haven't seen any smoke from the exhaust when hot. Will update if it starts again but for now, looks like the turbo was at fault for the smoke.
So you didn't retest it once warmed up? Interesting to see if it smokes with the new turbo, but it gave you a reason to upgrade and that's got to be a good thing And if it does still smoke, then you can sell the factory turbo as mint condition lol
