2G Blowing smoke after boosting and going into vacuum.

[jakk220]

So a while back I had my brand new holset HX40 take a crap on me (it was just dumping oil in my exhaust) and sent it out to @JusMX141 to be rebuilt. It was unclear of the cause of failure but he said it was possibly high EGT's. (I used to tune it at 12.5 AFR on E85, but eventually Kenny tuned it and richened it up to 11.5. But maybe the damage was already done) So I put the new turbo on it and park it for winter.

Flash forward to now.

After boosting and letting off the gas or shifting into a lower gear, this thing DUMPS blue smoke out the back. Once it burns off it goes away. At first I thought it was residual oil from when I blew the turbo. But its not going away.

l don't get a single puff while boosting, idle, or crusing. Only as soon as I let off after boosting. I have no idea what's causing it, but I wanted to see if maybe a defective turbo seal was a possibility. Because the car never had ANY smoke until right after it blew and was replaced. Not even a puff.

Cold compression test: 205....165.....170.....185
--- I will be doing a hot test soon and a leakdown
--- New PCV valve
--- Oil drain is not kinked. 12AN.
--- Head was serviced about 2k miles ago with supertech seals.
--- Im working on getting a catch can set up but never thought I needed it as I didn't have much blow by. I doubt this is the cause because it went from no smoke to a ton.

Just wanted to see if anyone had any ideas for me to check before I go out on a limb and send the turbo to Justin to have him check it over. Thanks.

 

[Vegas Smith]

I remember a member here having this problem a while back ago on an FP turbo and FP blamed it on the lack of catchcan/vacuum source for the bypass gasses. They said after a while it can cause your seals to go bad or cause the oil to not drain fast enough. Don't quote me on that but that's what I remember.

 

[jakk220]

I remember a member here having this problem a while back ago on an FP turbo and FP blamed it on the lack of catchcan/vacuum source for the bypass gasses. They said after a while it can cause your seals to go bad or cause the oil to not drain fast enough. Don't quote me on that but that's what I remember.

After a while I'm sure they are right. Which is why I'm working on getting one. But if it were the turbo, then I doubt it's due to crank case pressure since it's a fresh turbo.

I'm not ruling out other possibilities such as ring lands, valve guide, etc. But it's odd that it doesn't do it under boost, only under vacuum after boost. Not to mention the compression was good.

 

[ThunderChild]

Have you checked your valve seals?

What about oil pressure at the feed?

I know it seems silly, but I think it all sounds like valve seals, maybe the high egt's fried them?

 

[jakk220]

Have you checked your valve seals?

What about oil pressure at the feed?

I know it seems silly, but I think it all sounds like valve seals, maybe the high egt's fried them?

I have not. I planned on pulling the manifold off to see if it is wet on any of the valves. I figured if the new valve seals were going bad that would have been a progressional thing. I would also think if they were bad enough to be blowing as much smoke as I am after boost, then I would be burning oil at idle too.

 

[ThunderChild]

What's your CCV system look like? catch cans, breathers, pcv.. etc? How about the drain and feed for the turbo? What boost level?

Could be just the exhaust guide seals that got smoked?

 

[Crackerman]

I have had a car that had valve seals go out. Was running just fine when parked, sat for a month or 2, then on the next drive, would smoke just like yours. Nothing under boost, but as soon as manifold vacuum increased again, it would pour out.

The stem seals were hard, and some cracked.

 

[jakk220]

What's your CCV system look like? catch cans, breathers, pcv.. etc? How about the drain and feed for the turbo? What boost level?

Could be just the exhaust guide seals that got smoked?

Well currently I just have the nipple on the side of the valve cover vented to atmosphere. I never have oil coming out of it, and would rarely blow my dip stick, so I just assumed I wasn't getting much blow by. The drain is a 12AN and it's fed from the OFH unrestricted which has never been an issue in the past.

The only two things I changed was I moved from rotella T 10w30 to the synthetic 5w-40 and the new Turbo.

Here's a good question: is it possible that the turbo could cause smoke only under vacuum after boosting? If so, I'll pull the turbo, send it out for inspection to Justin, and check the valve seals in the meantime.

 

[jakk220]

I have had a car that had valve seals go out. Was running just fine when parked, sat for a month or 2, then on the next drive, would smoke just like yours. Nothing under boost, but as soon as manifold vacuum increased again, it would pour out.

The stem seals were hard, and some cracked.

I know new does not mean working, but the seals are brand spanking new. I'm going to pull the manifold and inspect them just to be sure.

 

[Crackerman]

After seeing what mild diesel engines put holsets through, I imagine you don't have any issues with your turbo unless Chinese parts are in it. Especially after it has been built.

Is the drain functioning properly?

 

[jakk220]

After seeing what mild diesel engines put holsets through, I imagine you don't have any issues with your turbo unless Chinese parts are in it. Especially after it has been built.

Is the drain functioning properly?

Well considering I blew up a brand spanking new Holset so bad that the cause of failure was unclear.... it is possible.

The drain is not clogged or kinked. That was my first thought... but I have already taken it apart, inspected it, and replaced the piece of rubber push-loc hose I have on the drain.

 

[1990TSIAWDTALON]

After blowing my share of turbo's and snapped shafts, if the exhaust is coated, its gonna smoke for a while. If it has had time and heat to completely burn out then we can rule that out.

 

[jakk220]

After blowing my share of turbo's and snapped shafts, if the exhaust is coated, its gonna smoke for a while. If it has had time and heat to completely burn out then we can rule that out.

It has definitely had some time to clear out. And I would think that it would smoke under boost too if it were just residual oil. The amount of smoke coming out of the back of this thing in between shifts is pretty insane. It will smoke out a highway . I am trying to get in contact with Justin with a few questions regarding the turbo, but he has not logged on in a while so that could take some time.

 

[1990TSIAWDTALON]

He will answer you. Its possible you are sucking in oil if the valve seals are hard and not doing their job but more research needs done before you do those unless you just want to.

 

[jakk220]

He will answer you. Its possible you are sucking in oil if the valve seals are hard and not doing their job but more research needs done before you do those unless you just want to.[/QUOTE

I doubt the valve seals are bad since they are brand new. If anything it would probably end up being a valve guide or something. I'm still leaning toward something with the turbo but valve seals / guides is always a possibility. Im going to do a leakdown test at some point to make sure the ring lands are okay.

 

[chrysler kid]

Your compression is messed up on cylinder 1 from oil contamination. Pull the plugs and use one of those tiny cameras to inspect the Pistons to see if they are oily.

Pull the exhaust manifold off, if it's dry you know it's the turbo

My hunch says you have a bad valve stem seal on cylinder 4. It wasn't properly seated and now it's leaking in under high vacuum

 

[jakk220]

Your compression is messed up on cylinder 1 from oil contamination. Pull the plugs and use one of those tiny cameras to inspect the Pistons to see if they are oily.

Pull the exhaust manifold off, if it's dry you know it's the turbo

My hunch says you have a bad valve stem seal on cylinder 4. It wasn't properly seated and now it's leaking in under high vacuum

Good point. This does make sense, however it doesn't blow any smoke when I start the car. I would think that if there was oil sitting in that cylinder, that I would get a nice puff when I start the car. Or maybe its possible that there is enough on the piston to effect the compression results, but not enough to burn blue smoke? Is it even possible for a turbo to smoke only under high vacuum?

Edit: The compression results are backwards. It was cylinder 4 that had the higher compression than the rest.

 

[jakk220]

Another point I am going to address: I cant remember if I re-torqued my new L19 head studs or not after I replaced the head gasket last time. I think I did, but its possible that I forgot because shortly after my transmission took a crap. Could it be lifting the head under boost, and then sucking in oil from the head gasket? I'm going to re check them now anyways but figured I would see if it a possiblity.

 

[ThunderChild]

I doubt you're getting head lift to cause this.
I still think you have a valve seal issue, and you need a better CCV system, something higher flow to deal with the fair amount of pressure the block is seeing.
@chrysler kid has a good point, the higher compression cylinder could be getting oil leaked into it under throttle lift, but you'll need to look at things to be sure.
I really don't think it's the turbo.

 

[chrysler kid]

Good point. This does make sense, however it doesn't blow any smoke when I start the car. I would think that if there was oil sitting in that cylinder, that I would get a nice puff when I start the car. Or maybe its possible that there is enough on the piston to effect the compression results, but not enough to burn blue smoke? Is it even possible for a turbo to smoke only under high vacuum?

Edit: The compression results are backwards. It was cylinder 4 that had the higher compression than the rest.

Yeah #4 is the cylinder on the furthest left. It's also possible you're sucking oil into the intake manifold on the #4 runner where the pcv suction port is

 

[jakk220]

Yeah #4 is the cylinder on the furthest left. It's also possible you're sucking oil into the intake manifold on the #4 runner where the pcv suction port is

Which would be due to excessive crank case pressure?

I have tried changing out the pcv valve to no avail.

 

[jakk220]

I doubt you're getting head lift to cause this.
I still think you have a valve seal issue, and you need a better CCV system, something higher flow to deal with the fair amount of pressure the block is seeing.
@chrysler kid has a good point, the higher compression cylinder could be getting oil leaked into it under throttle lift, but you'll need to look at things to be sure.
I really don't think it's the turbo.

I will pull the exhaust manifold to see if I can see anything out of the normal. I may do that tomorrow or the day after. I'm also going to check the torque on the headstuds just for peace of mind since I'm not sure if I did it last year.

I am not denying the need for a better CCV system. It is literally the first thing on my list. After a battery relocation because I'm putting the catch can where it currently is. I have all the wiring and breakers and what not. I just need to get time to do it.

 

[jakk220]

I checked the torque on the head studs today and they were all tight. So that rules that out. I am going to try to pull the manifold off tomorrow or Thursday to see if there is any signs of oil.

 

[chrysler kid]

I checked the torque on the head studs today and they were all tight. So that rules that out. I am going to try to pull the manifold off tomorrow or Thursday to see if there is any signs of oil.

Tight is not an accurate measurement for torque on arp head studs. Depending on your use of the original supplied grease torque values differ

I used the 30-60-90 then a 92 pass after 500 miles to verify torque. I was re using the studs so I didn't have grease

So did you check the torque on the studs? I don't recall the torque spec using the arp moly grease.

I've blocked the pcv valve port on the intake and run the pcv to the T to the breather, suprisingly the car will idle better. However it can cause oil stagnation over a period of time and moisture build up in the crank case.

 

[jakk220]

Tight is not an accurate measurement for torque on arp head studs. Depending on your use of the original supplied grease torque values differ

I used the 30-60-90 then a 92 pass after 500 miles to verify torque. I was re using the studs so I didn't have grease

So did you check the torque on the studs? I don't recall the torque spec using the arp moly grease.

I've blocked the pcv valve port on the intake and run the pcv to the T to the breather, suprisingly the car will idle better. However it can cause oil stagnation over a period of time and moisture build up in the crank case.

I just meant that they haven't loosened up. I believe I set them to 95 ft/lb when I torqued them. The wrench clicked at 95. It is a different wrench. But its the best I have. I use the ultra torque.