1jz oil consumption quandary

[mattsplat72]

Ok, I am diving into a 1jz that was boosted to 20psi with a malfunctioning meth injection kit. It is leaking/burning oil.

The owner had a comp check done and it was good across the board. The shop that did the comp test said the turbo and pipes were clean. I have not pulled plugs yet as it is final week. Any ideas of where to start looking for potential damage? The owner is leaning towards valve stem deals.

 

[mattsplat72]

He also reports that his garage floor is clean as is mine it has been sitting since Saturday. He states it is burning about a quarter of a quart after an hours drive.

 

[mikejza70]

JEEZ. That's a lot of oil thats disappearing. Definitely check your plugs and do a comp test yourself.

 

[mkiiichip]

Bad valve stem seals almost always cause the car to smoke on cold start. Are you seing any smoke?

 

[mattsplat72]

We will do that, I am just looking for a starting point.

 

[seoul4korea]

Bad valve stem seals almost always cause the car to smoke on cold start. Are you seing any smoke?

my guess too, check CPS sensors, and PCV valve too. also the turbo.

 

[mattsplat72]

Ok so far I have.

cam and crank sensors
valve stem seals
Turbo
Pcv
Oil lines, supply and return
Front and rear mains
Pan gasket
Filter and housing
Valve cover gaskets
Piston rings

Any other places? I am just making a list and systematically eliminating everything until I get to the root of the problem.

It has been sitting for a bit so if I start it and the valve seals are bad it will smoke because of seepage correct?

 

[Jayhall]

From what I'm reading that a typical symptom, there's just nothing typical about my car so that worries me. Other then smoke on cold start how do we check the valve seals?

 

[mkiiichip]

You could take off both manifolds and look at the valve stems. If they're leaking there will be some evidence. I'd rather just take the cams out and replace them though.

 

[mattsplat72]

I started it today ZERO smoke. It ran clean

 

[seoul4korea]

I started it today ZERO smoke. It ran clean

Hmmm, maybe it smoked from sitting for so long.

 

[seoul4korea]

I started it today ZERO smoke. It ran clean

Hmmm, maybe it smoked from sitting for so long.

 

[mattsplat72]

That statement is contradictory. It sat for over a week and did not smoke on start up. So I am unsure of your meaning.

 

[f00g00]

Half moon seals in the back of the head can leak down the back. That's lot of oil loss though.
Its easier to spot smoke coming from the tailpipe at night. When you floor it you can see the smoke in other cars headlights or streetlights.
I would also check the under tray for any oil buildup and the oil pan or anything wet underneath.

 

[seoul4korea]

That statement is contradictory. It sat for over a week and did not smoke on start up. So I am unsure of your meaning.

I must have mis read I though I saw something that said your car had been sitting for a long time. I would at least have a look at aome of those items listed if you think the problem has gone away.


Wait I'm not sure what I've been thinking this whole time. Ok so you started it up and you got zero smoke (which means valve stem seals must be good), but you are still having the missing oil issue. So you can cross that off the list. Did you check the other options as well? For example the sensors and maybe the front and tear main seal?

 

[Jayhall]

Underneath the rear cam positioning sensor is for sure wetter than it should be. Hopefully ill be able to take it for a drive next Sunday, get some more info on what's going on.

 

[JPsToyota]

Those cam sensors leak all the time, normal and won't cause that much oil loss, also the oil would be all over the engine and on to the ground.

I would fill the oil up to a certain point exactly on a completely cold car, let him drive it for awhile (weeks) checking periodically just to make sure the oil isn't dropping to a dangerous level, and then check again to make sure this is an actual problem and not a mistake or imagined problem. If the oil isn't hitting the ground and isn't smoking, I don't know how it could be losing that much unless it's making it's way into your coolant, but that would be a noticeable problem by now. It's gotta go somewhere if it isn't in the intake tract.

My valve stem seals usually started smoking at idle when the car is warm at stoplights and such.

 

[Jayhall]

Well the plan right now is to get it driving. I still suspect valve seals, as that's when I noticed the oil smell was when I would come to a stop and stop lights. We can look all around all day but we might not find anything. I topped the oil up 3/4 of a liter and then later the shop thy did the compression test said they added another 3/4 of a liter. So I didn't add that oil the second time, and it is possible that there was a miscommunication somewhere along the lines. So for now, I have to get a solid idea on how much oil it's burning and go from there