ST165 smokes out the exhaust after excessive repairs

M

Mateo

Member
Hey all,
I just did a massive amount of repairs on my celica because it was smoking so bad out the exhaust, such as a new head gasket, valve seals, rebuilt turbo and custom power steering lines because mine were leaking. I have been driving the car for the first time in months and it is still pretty bad in terms of smoke. I'm pretty lost on what will fix it, I have the stock PCV system set up currently (Line from the PCV outlet to the turbo intake with the overflow vacuum line)

Anyone have any ideas?
 
9

93celicaconv

Member
Did you check the head for cracks? Did you check the head for warping and did you get the sealing surface ground?

Did you check the cylinder compression pressures prior to starting any repairs? Are the piston rings sealing properly? Any scouring on the cylinder walls observed after removing the head?

Did you verify the turbo is not leaking oil inside, and pushing that oil through the intercooler and into the intake manifold?
 
Tippo

Tippo

Well-known member
Mateo":3l5q2a7p said:
Hey all,
I just did a massive amount of repairs on my celica because it was smoking so bad out the exhaust, such as a new head gasket, valve seals, rebuilt turbo and custom power steering lines because mine were leaking. I have been driving the car for the first time in months and it is still pretty bad in terms of smoke. I'm pretty lost on what will fix it, I have the stock PCV system set up currently (Line from the PCV outlet to the turbo intake with the overflow vacuum line)

Anyone have any ideas?
Click to expand...


First: what kind of smoke is coming out the exhaust? Blue or white? Sweet smell or oil smell? No smell at all (water vapor)?
 
M

Mateo

Member
93celicaconv":3k4wrbzy said:
Did you check the head for cracks? Did you check the head for warping and did you get the sealing surface ground?

Did you check the cylinder compression pressures prior to starting any repairs? Are the piston rings sealing properly? Any scouring on the cylinder walls observed after removing the head?

Did you verify the turbo is not leaking oil inside, and pushing that oil through the intercooler and into the intake manifold?
Click to expand...


Yes the turbo is rebuilt and is pretty solid without pushing out oil and the block and head is fine.
 
M

Mateo

Member
abeans":2u1zpnp3 said:
You had a thread where your car was smoking before you did these "excessive repairs"
Click to expand...

Which is why I'm making another one because I totally thought it was turbo and I'm pretty annoyed it's still smokey
 
A

abeans

Member
If it was me, i would do a leak down test, and pressure test the coolant system. based on what you are saying.
 
M

Mateo

Member
I just drove around with no oil cap for about 10 minutes and it stopped smoking, and I noticed the valve cover has a very restricted baffle for the PCV outlet. I'm going to try to enlarge the baffle hole and see if that fixes it whenever I get the chance.
 
9

93celicaconv

Member
I'm a bit concerned for you regarding the potential to change your PVC restriction, if not knowing the root cause of the problem. Unless you know of a way to return that restriction in the PCV connection of the valve cover if your test result is not favorable.

It sounds like, to me, that you relieved the crankcase pressure by running the engine with the oil cap off. If the crankcase pressure escapes like your test would have it, there is no crankcase pressure to push crankcase gases through the PCV vent into the intake manifold.

I would think there is a restriction in the PVC vent, as there is no PCV valve on this engine. If you enlarge this restriction due to the crankcase pressure being built up, you risk pushing a higher volumetric rate of crankcase gases through the PCV vent and into the intake, and the oil that ends up being carried with it. This step may make your situation worse.

There were some previous suggestions that you get your cylinder compression pressures measured to see where they are relative to the accepted ranges in the service manual; have you done this? Or do you know of someone having another 3S-GTE engine that is in good running condition, so you can compare the amount of blow-by yours might have in comparison to an engine that doesn't smoke as yours does?
 
M

Mateo

Member
Gert":3lihvd6o said:
Mateo":3lihvd6o said:
Gert":3lihvd6o said:
When does it smoke? Under WOT? Idle? Cruising? Always?
Click to expand...

Mostly under boost.
Click to expand...

For me: could be PCV routing or the pistonrings.
Since your engine was fully open, did you replace the pistonrings?
Click to expand...

They were replaced 100K ago. Recently I did all the gaskets, then the head gasket and turbo rebuild. I've messed with the PCV routing so much and it hasn't made a difference.
 
G

Gert

Active member
The smoke must come from somewhere.
If it smokes after WOT and closed throttle, mostly valve seals. But seals are new and no smoke.
If it smokes under idle, mostly pcv or turboseals.
It it smokes under wot, turboseal (massive smoke) or piston rings.

I cannot figure out where otherwise oil smoke is coming from.

But you say 100k ago? I suppose miles? I put my money on the piston rings. Sorry.
 
M

Mateo

Member
Gert":k4q9qgn8 said:
The smoke must come from somewhere.
If it smokes after WOT and closed throttle, mostly valve seals. But seals are new and no smoke.
If it smokes under idle, mostly pcv or turboseals.
It it smokes under wot, turboseal (massive smoke) or piston rings.

I cannot figure out where otherwise oil smoke is coming from.

But you say 100k ago? I suppose miles? I put my money on the piston rings. Sorry.
Click to expand...

I highly doubt it's rings. My current assumption is the valve cover baffle below the PCV being too restrictive, so I'll try to modify that first.
 
M

Mateo

Member
Update:
I found out there were 2 baffles inside the gen 1 valve cover before the PCV port, I removed the one closest to the port and kept the one that you can see and that has fixed my smokey exhaust. My gen 1 engine is so modified it wouldn't surprise me it needed a better venting system.
 
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