Oil on top of piston after rebuild

[tom04841]

I just completed a rebuild on my 6 bolt. Reman'd head w/ new valve seals, comp head gasket w/ arp studs, all new gaskets every where, new rod/main bearings, piston rings, timing belt and components, new water pump, and bs elim. Cyls were checked for round and got a fresh hone.

Where is the oil coming from that is pooling on top of the pistons? I can see it when i pull the plugs. Smokes pretty bad, but runs great. Poor ring seal? I don't recall the endgaps, but they were all within specs.....yes, i measured every one.

Any suggestions?

 

[T9S1i]

how many miles on the rebuild? There will be oil on top of the cyl's until the rings have seated, but i wouldnt describe it at "pools". How much is it smoking? When is it smoking?

 

[tom04841]

how many miles on the rebuild?

Maybe 20 miles.

There will be oil on top of the cyl's until the rings have seated, but i wouldnt describe it at "pools".

Well, maybe not pools, but when i pull the plugs, i can see some oil.

How much is it smoking? When is it smoking?

At first it was smoking alot at idle and while driving (on and off boost). I took it out for a spirited run after work....using the motoman method. The smoking has calmed down a bit.
A little at idle, but still quite a bit under boost. I don't really notice much while cruising.

 

[Spool'n Spyder]

How many miles on the turbo? Has it been rebuilt as well? It could be oil blowing by the seals on the turbo.

 

[tom04841]

Turbo has 500 mile on it. I checked the lower ic pipe....its clean. Its not part of the problem. My exhaust manifold wasn't as tight as it should have been, and oil was coming out from between it and the head, so i know it is coming from the combustion chamber. It SHOULDN'T be valve seals, as they are brand new with the reman'd head

I am going to inspect my pcv valve later.

 

[tom04841]

Well, i unhooked the pcv valve...no help.

Decided to do a compression check. 100 across the board. Engine at operating temp, and throttle plate wide open.

Someone please tell me this isn't normal. I have done quite a few rebuilds and none have smoked this bad, nor had this low of compression.

 

[95 'clipse RS]

did you do the break in procedure to seat the piston rings? also did you re-torque the head studs after the engine coming to operating temp? and did you position the piston ring end gaps to the correct positions?

 

[T9S1i]

i wouldnt worry about oil on top of the pistons after 20 miles. Excessive oil out the exhaust doesnt sound too good, but the rings havent seated after 20 miles. Dont drive the car too hard, well you can break in the motor however you want b/c its your money, but i did a very soft break in for my skat/weisco 8.3 build that i just did.
Remember to do engine breaking and decelleration as much as possible. After 300 miles my pistons were dry and i had 180 compression across the board. Im still at low boost 4500 miles later... 10psi to be exact. I didnt give the motor more than 5psi for the first 300 miles (i didnt even get to 10psi until about 500 miles ago, but that wasnt my choice, my damn internal 38mm wastegate broke and was stuck open!)

Questions for you. Who did the rebuild? Did you assemble it? You said that the cyl's were just rehoned, so your using stock sized pistons? Are you using stock pistons or forged pistons?
If it were me, id give it till at least 200 miles and if it isnt fixed by then id go back to the machinist. Let the machinist know the situation now and ask him how long they think it will take for the rings to seal, tell them that the problem has been there since 0 miles and tell them that you are giving it more time for the rings to seal. I dont think i would ever do a rebuild without going .20 over and boring each cyl to the specific piston going in.

One last thing, im pretty sure if the turbo seals are bad the oil will work its way out the exhaust side too, so no oil on the intake tract doesnt necessairly mean the turbo is ok. But dont quote me on this b/c i havent had a turbo blow on me before.

 

[tom04841]

I did the rebuild. I have a friend that is a machinist, and he checked the cyls for round, and said it just needed to be honed. I am using stock pistons.

This isn't my first rebuild, but it is the first time with this kind of smoking issue.

 

[Devilsown]

Sounds like your rings are not seated.
compression is sounds low but i am not the most familiar with dsm.

 

[Quasimondo]

One last thing, im pretty sure if the turbo seals are bad the oil will work its way out the exhaust side too, so no oil on the intake tract doesnt necessairly mean the turbo is ok. But dont quote me on this b/c i havent had a turbo blow on me before.

I've had that happen when I killed my turbo. Smoked like crazy, intake side was clean, but the exhaust and O2 housing were coated in oil. Everything else he wrote is spot on. Break the engine in fully and then do another compression test after the rings have been fully seated.

 

[T9S1i]

Thanks for confirming that. I was pretty sure that if oil can work its way out the compressor side then it should be able to work its way out the exhaust side as well. It also makes more sense that it would be smoking if it was leaking on the exhaust half b/c its hard for oil to go all the way through the i/c piping and through the i/c and into the intake manifold to the cyl's then get burned out the exhaust. If oil makes its way out the exhaust it instantly hits the hot turbine housing and will burn right then. Oil in the intake tract is usually from blowby from the pcv/crankcase breather system.

 

[tom04841]

The only reason i don't think it is the turbo seals is because A: It is practically brand new. B: After warming up, i had to retorque the exhaust manifold nuts....i did this because it had oil coming out from between the head and exhaust manifold.

 

[Turbo Shogun]

Oh God, I've been having the same issue with my build.

Did you have excessive oil just completely pouring out of the exhaust ports?

It leaks so bad that it just oozes out between the O^2 housing and the downpipe and leaves a big puddle of sooty oil underneath the car. I thought it was the rings too, but there's just too much oil on the top of the pistons (a 1-2mm skin if you use a screwdriver as a "dipstick").

I pulled the head and found that the intake valves were absolutely drenched in oil. WTF Opening the valves on a workbench would release a floodgate of black, sooty oil.

At first I thought it was the EGR recirculating the oil from the exhaust side back into the intake, so I blocked off the EGR. Cleaned EVERYTHING of oil (exhaust manifold, turbine housing and O^2 housing were absolutely soaked in oil), including the head and the intake manifold.

Started it up and ... What do you know. Same problem.

Head is torqued properly (I even borrowed a digital torque wrench from my dad's shop), I'm running off a Mitsu MLS gasket clamped down by a set of ARPs. Head and block have both been decked with JE's/Crowers in +.020 bores. Balance shafts eliminated.

I'm speculating that the increased oil pressure due to having the balance shafts removed is somehow causing this, but I don't know. This car has been dead for a year as I am a Law student and I have ZERO time to work on this pile.

I don't mean to hijack your thread, but I thought I'd share what I've done so far. Hope you fix yours soon.

- edit -

I took a video of the startup to show you guys the extent of the problem ... Video is in quicktime format, but it's kind of loud. Took it with my cameraphone.

http://media.putfile.com/HOLY-SMOKE-97

 

[Maglin]

Dude. Easy to answer. I pretty much knew the issue after reading your 2nd post in this thread. Your Valve guides are shot. Your valves are also deflecting most likely and probably beat up the valve seats so you are not getting a good valve seal. EGR has not effect on the oil system. PCV does. Exhaust Gas Return only put exhaust gases into the intake to help with emissions, and that is only at cruise light load.

Pull the head and take it to a machine shop. Don't put valve liners in they wear out very fast. Just get a set of bronze/copper valve guides and new valve seals. Also have them check the vavle seats/valves. You want to make sure they are sealing. I had the same problem. Knew about it for a long time but I hate pulling my motor apart. I'm not one to just pull the head. I do a complete tear down and check everything. So I let mine go until the oil was pretty much fouling out plugs very fast. And it was still running mid 11's in this beat up state.

BTW. I only had like 130ish PSI across the board on my stock bottom end. Traded it to a buddy for some parts and with his new head it was 170 PSI across the board. head was milled so that is why it's 5 PSI over new. That is 135K on the pistons and rings. I cleaned my ring lands every time I tore it apart and of course ensured that the rings are always staggered properly which some people that I know just can't seem to grasp.