Odd oil burning problem with HY35 turbo

[supravw]

I recently got my mirage back up and running. It's running good aside from an oil burning problem I'm having. It only happens between shifts were I get into boost and after a pull it will smoke pretty good for 5 seconds and then be done. It doesnt burn at idle, while at wot, while crusing or regular driving.

Everyone's first thought is turbo seals are bad. Here's the kicker, I've had this problem with my 14b and 16g as well, and those turbos are good. It does it whether I feed from the head or ofh with the MHI turbos, I haven't tried switching my feed to the head with the holset yet. Oil pressure is in check, 30psi idle, 50-60 cruising and 80 psi max at WOT fully warmed up. This issue started after I swapped in a different head and 272 cams. I don't see how it could be the valve stem seals as it should smoke at start up and oil but it doesn't.

So we are back to the turbo again, I check it out. It's oily on the exhaust and outlet piping. So its pushing oil out the seals. Why? No idea, I'm feeding it from the ofh with a 4 an line and inline .075 restrictor and the drain is a full 12an return. The seals were fine before I put it on and they were fine the last time I had it on the car and I had a smaller drain then. So my drain and feed is good, my pressure is good but I'm still getting oil pushed past the seals on all my turbos. How?

My only though is the pressure from blowby on one of my cylinders. Compression is down to 126 on number 2. Could the excessive pressure be causing enough pressure to keep oil from draining and building pressure at the turbo??

Anyone have other ideas on what could be causing this, I'd like to see what everyone thinks before I tear the whole motor apart. I will swap the oil feed to the head and post back the results but I want to see what people are thinking.

 

[JusMX141]

Excessive crankcase pressure or the turbine seal was already leaking prior to installing the turbo.

Do you mean the oil pressure was in check before or after the restrictor? Just curious- if those numbers are pre-restrictor you may not need a restrictor at all.

 

[supravw]

Oil pressure numbers are with restrictor in place. It's not the seals cause last time I ran this turbo about a year and a half ago there were no problems. And the mhi turbos were both rebuilt before I put them on. Looks like the motor will ne getting reringed at least and head rebuilt.

 

[turboglenn]

That could easily be valve seasl

 

[supravw]

That's what I figured, I just wanted to bounce it off a couple guys and make sure I was thinking correctly before pulling the motor apart. Thanks for the input guys, I appreciate it. I'll probably take it to the track once, get some new numbers and then pull it apart for a quick rebuild.

 

[supravw]

So I figured I would update this thread sense I've been driving it still and noticing more stuff.

I've tracked it down to cylinder #2, it is an engine problem and not a turbo problem. There was a good amount of oil on my plug when I pulled it to check, all the other cylinders looked good. Compression is low on #2, 127 last time I checked. Now it's between the valve stem seals being bad or the rings being too worn.

What I've noticed while driving it. I've never been able to get it to idle well, once fully warm it sticks around 1300-1400 rpm normally but sometimes higher. I've blocked off all electrical control to the tb and rebuilt it about 2 years ago with oem seals. If I use idle switch sim, it will surge. If I don't it's pretty steady at 1300-1400.

At idle the car won't smoke untill it's at about 160*. It gets really bad, really quick. If I bring the rpm up to 2500-3000, the smoking will stop. Here's the funny part, if I make a couple good 2-3 WOT pulls the smoking completely stops. As long as I'm giving the car a good beating she doesn't smoke, if I take it easy, it makes a spy getaway cloud.

My money is on bad valve seals. But if I'm going to take it apart I'm going to throw some new stock pistons and rings in as well and replace the rod bearings just for good measure and fix the compression issue on #2. I'll keep updating this as I work on it.

 

[pats16valve]

Do a leak down test. My bet is Exhaust guides are worn.

 

[ZenkaiRacerDsM]

I had a similar problem with mine where it would only smoke on engine decel or in between shifts. It was the valve seals.

Looks like your on the right track.

 

[90_GSX_DSM]

So I figured I would update this thread sense I've been driving it still and noticing more stuff.

I've tracked it down to cylinder #2, it is an engine problem and not a turbo problem. There was a good amount of oil on my plug when I pulled it to check, all the other cylinders looked good. Compression is low on #2, 127 last time I checked. Now it's between the valve stem seals being bad or the rings being too worn.

What I've noticed while driving it. I've never been able to get it to idle well, once fully warm it sticks around 1300-1400 rpm normally but sometimes higher. I've blocked off all electrical control to the tb and rebuilt it about 2 years ago with oem seals. If I use idle switch sim, it will surge. If I don't it's pretty steady at 1300-1400.

At idle the car won't smoke untill it's at about 160*. It gets really bad, really quick. If I bring the rpm up to 2500-3000, the smoking will stop. Here's the funny part, if I make a couple good 2-3 WOT pulls the smoking completely stops. As long as I'm giving the car a good beating she doesn't smoke, if I take it easy, it makes a spy getaway cloud.

My money is on bad valve seals. But if I'm going to take it apart I'm going to throw some new stock pistons and rings in as well and replace the rod bearings just for good measure and fix the compression issue on #2. I'll keep updating this as I work on it.

Did you ever figure out what was causing this? I'm having a similar problem.

I had a similar problem with mine where it would only smoke on engine decel or in between shifts. It was the valve seals.

Looks like your on the right track.

This also sounds like my issue. Everyone keeps telling me that if it were valve seals it would only smoke until the car warms up. Did your car do this even with it warmed up?

 

[ZenkaiRacerDsM]

Yes it still did it when warm. Even more so when it was cold.

 

[supravw]

I have sense taking the motor apart and found some good detonation damage in #2 around the rings. Pretty good amount of damage to the block from scuffing. That would explain my smoking problems.