Oil burning issues?????

This is all on a 1998 3.8 GP.

Ok, I have what we call a pain in the AZZ motor. It has issues that are unresolvable.

Now this is not a stock motor by any means, far from it. Now two years ago I had it rebuilt, right away it smoked every now and then, and I mean every now and then, not all the time, then it stopped, unless I was in traffic and stopped and very hot it would let out a puff, nothing big.

Then two weeks ago I am driving home, and am giving her a little bosst and after I let off the gas it backfires through the exhaust, fine, running rich as I know already.

So I go about the next week fixing things and some oil leaks etc and making things look good under the hood for show etc, just general clean up. Well I fire it back up, and what do I get, an Oil burner, now it burnt oil on and off again, but at a much faster pace this time, like 50/50 of the time, idle as always was either clean or smokey. Did not matter if it was cold or not, still smoked.


So I got fed up as rulling out the turbo as the cause as I have had the seals go on a turbo before, I figured, I must have toasted the rings or valve seals bad, well I pull the entire motor apart, replace everything, all new, plasma moly rings, extra heavy duty valve seals, new head gaskets, etc. Well fire it up and its running like crap, discovered it was a 2-3 bad wires, now it runs fine again. Now I take it out yesterday for a 5 km drive, everything is fine, no smoke???? then I just get to my destination and what does it do once in park, billow out the smoke. Liek wtf???? Ok so now I sit there for awhile and then go on my merry way home, some times its ok, then its not. Smoked for a bit, then stopped, then smoked again. Now I can see if the rings were not seated yet, which i was hoping for, so I decided to take her out on the HWy today and put on some k's, I fire it up, back it out of the garage, BTW no smoke on initial fire up, clear as day. then drive about a block to the stop sign, take off and what do I get smoke, but it clears up, then I go get some gas, and head out, get about 4 more blocks and have to hit on the brakes a little fast for the old lady that did not know how to drive, and sat there, and what happens again? Well it starts to billow out smoke, give it gas clears right up. Next light no smoke. So take her out in the country and give her some go, no major runs or anything but tried to vary things and stay out of the cuty stop and go shyt. Well its fine on the HWy unless I hammer on it, but this is a mix of richness and oil, so who knows, anyway back into the city, and get to the first red lights, again what does it do, starts to billow smoke, so the next 8 lights i throw it into neutral at each light and no smoke?????????? Now I am getting puzzled here, so I get home and open my door as I have open exhaust and look under, no smoke while its running, then 1 minute into it, poof, out comes the smoke, then it stops, the poof it comes out again, so I rev it up to a steady 3000 plus rpm in my drive, no smoke at all, clear as day, like not even a hint of smoke, I take my foot off the gas and WOW all I got was this huge billowing of smoke, revved it up again and it went away, tillk I let off the gas.

Now I cannot explain this and I hope soem engine \builder here can, I'll post the mod list on it for you to go over in a minute once I grab it. But I am after 7 engines totally confused with this one.

Hope you can direct me in the right direction as I am tired of spending money on it and getting the same results. SMOKE. :banghead:

I also just went outside and ran it again and NO SMOKE, even when revving it. And it is still hot as I have only been home an hour.:shakehead




These are the mods done to the car in case anyone wants to take a stab at it.

Mods done:

Ported and Polished Heads and 3 angle valve job done
Ported and Polished lower intake
Comp cams Turbo Cam
Comp cams 90 pound springs and Victor Reinze valve seals
Comp cams lifters
Intense Oil restricted pushrods
Heavy duty Alt
Turbonetics EVO external wastegate ( externally wastegated to the atmosphere )
Garret Ball Bearing T70 Turbo ( restricted to 20psi of oil pressure )
Spearco modified Air to Water After Cooler
Spearco Heat Exchanger
Flo Jet IC Pump
Lucas 42.5 pound Injectors
L67 Rods
L67 Flex Plate
L67 Block and Crank
L36 Heads
L36 upper and lower intake
ZZP HVII plate
ZZP Stage 2 TB
Intense LSD ( Gen 1 )
HD Tranny Rebuild
L36 convertor
Diamond Forged 8.5-1 Pistons ( ceramic coated ) ( Plasma Moly Rings )
Custom headers
Custom 3 inch charge pipes
Custom 3 inch exhaust
Summit Racing Dump Tube ( open all the time )
DHP custom tuned PCM ( By Charles Beyer )
Mini AFC V2
Strut Brace
KYB Shocks
Eibach Lowering springs
Solid Motor mounts
Custom tranny Dipstick
Twin High Speed Fans ( aftermarket )
Removed Stat
Custom Water hose ( chrome )
TurboXS boost control ( going to go electronic soon )
Moroso Cool Can for IC
Autolite 103 Plugs
Taylor 10.5mm Race Wire
Modified Upper plenum
ZZP Rad
Hayden Tranny coller
Hayden Oil Cooler


I know some of the stuff has nothing to do with anything, but I just copied it all as I was too lazy to type out engine only stuff.

Oil consumption on an engine with this many internal mods is varied and complex. Excess piston clearance, lined up ring gaps, poor ring seating, low tension expander in the oil ring set up, misfitted or bad valve seals, worn valve guides.. Start with looking at the valve seals, make sure the correct pcv is in place. If all this goes good, the engine has to come apart for analysis. If possible this should be discussed with your engine builder, if there is one.

In the rebuild, did you bronze the valve guides and install teflon seals? Many of your episodes sound like typical valve guide leakage on closed-throttle decel. The occasional billow on startup can also be valve guide/seal leakage.

I agree with Blue that it sounds like a valve seal/guide issue. In the realm of keeping it simple, do you still have a PCV valve in it, are if so, is it clean, are both o-rings there (the black one on the pcv valve itself and the orange one at the top of the housing), and with all your mods, is it getting enough vacuum. If your crankcase is building up pressure, you could be forcing oil past the valve seals and that's why the oil burning/smoke comes and goes so randomly.

The question I have is on the valve guide seals installed. Are the Victor Reinz valve guide seals Viton? Due to his setup and cam normally Viton seals are used for the specific application he has. They have more clearance than regular valve guide seals. But it looks like he had the problem before the new seals were installed.

In addition to the PCV system how are you venting the crankcase?

Did you do the mods or use an engine builder?

I agree with Blue that it sounds like a valve seal/guide issue. In the realm of keeping it simple, do you still have a PCV valve in it, are if so, is it clean, are both o-rings there (the black one on the pcv valve itself and the orange one at the top of the housing), and with all your mods, is it getting enough vacuum. If your crankcase is building up pressure, you could be forcing oil past the valve seals and that's why the oil burning/smoke comes and goes so randomly.

I get 20HG of vacume at idle, the correct PCV is installed it is brand new, with it or without it, it still smokes. I also have both valve covers vented, so the crankcase is very well vented. But like I said I had this problem out of nowhere before this recent engine rebuild. Now if it were the old rings, old valve seals you would think there would be an improvment when everthing is replaced, but no there was not, it is again on and off burning oil, last ight it was on and off untill I got to about 100K on the motor after its rebuild, had to stop and then the car just started billowing smoke like crazy, it was unreal, I've blow motors before, many of them in fact but have never seen a motor burn oil like this. It was as if a person started an oil fire under the car, allthough it was coming out the exhaust, but once again once I started to give it gas, the smoke dwindled away, but then next stop light same thing, and it was like this for the next 508 stop lights, buring oil excessivly at idle, and burning very little during cruising speeds.

The Victor Reinze valve gaskets are of the same material as the vitron ones, also in the previous rebuild I went to stock valve seals as the previous one before that which did use the vitron ones kept blowing the valve seals off the stems. I was told by the Grand National guys to actually glue the seals ontot the stems, which my engine builder did, and all was well for 1 year. Then it started to billow smoke, so I took it all apart saw which cylinder was the culprite as the valve itself was caked in carbon, piston clean though, so I guessed this was the one. I then had it all rebuilt again with new rings and new valve seals and every gasket in between, and again same thing, but this time worse as of last night.

Again at hwy or cruising speeds or higher RPMS no smoke. Just at idle.

Also I do not get smoke at start up, clean as ever.


I was also told maybe the PCV was sucking oil into the chamber so I tried blocking it aswell, not luck there either.

Now none of this has happened under boost either.

Oil consumption on an engine with this many internal mods is varied and complex. Excess piston clearance, lined up ring gaps, poor ring seating, low tension expander in the oil ring set up, misfitted or bad valve seals, worn valve guides.. Start with looking at the valve seals, make sure the correct pcv is in place. If all this goes good, the engine has to come apart for analysis. If possible this should be discussed with your engine builder, if there is one.

This would not explain why it did it pre rebuild and aft rebuild, you would think some improvment would happen. Ithe PCV is brand new. The car started smoking right after 10km's of travell, and has just got worse as I am now at 100km's of travell.

Also

I get 20HG of vacume at idle, the correct PCV is installed it is brand new, with it or without it, it still smokes. I also have both valve covers vented, so the crankcase is very well vented. But like I said I had this problem out of nowhere before this recent engine rebuild. Now if it were the old rings, old valve seals you would think there would be an improvment when everthing is replaced, but no there was not, it is again on and off burning oil, last ight it was on and off untill I got to about 100K on the motor after its rebuild, had to stop and then the car just started billowing smoke like crazy, it was unreal, I've blow motors before, many of them in fact but have never seen a motor burn oil like this. It was as if a person started an oil fire under the car, allthough it was coming out the exhaust, but once again once I started to give it gas, the smoke dwindled away, but then next stop light same thing, and it was like this for the next 5to8 stop lights, buring oil excessivly at idle, and burning very little during cruising speeds.

The Victor Reinze valve gaskets are of the same material as the viton ones, also in the previous rebuild I went to stock valve seals as the previous one before that which did use the vitron ones kept blowing the valve seals off the stems. I was told by the Grand National guys to actually glue the seals ontot the stems, which my engine builder did, and all was well for 1 year. Then it started to billow smoke, so I took it all apart saw which cylinder was the culprite as the valve itself was caked in carbon, piston clean though, so I guessed this was the one. I then had it all rebuilt again with new rings and new valve seals and every gasket in between, and again same thing, but this time worse as of last night.

Again at hwy or cruising speeds or higher RPMS no smoke. Just at idle.

Also I do not get smoke at start up, clean as ever.


I was also told maybe the PCV was sucking oil into the chamber so I tried blocking it aswell, not luck there either.

Now none of this has happened under boost either.

The 20 in-hg of vacuum is excellent considering you're cammed up. Crankcase ventilation looks good too. Engine rebuild looks good. The moly rings will either seal or not (no break-in) but it would not hurt to run a compression test just to rule any specific cylinder causing the problem.

Although it will be hard to convince yourself I would not rule out the turbocharger. Maybe oil is passing through the seals at low rpms or high engine vacuum but not at high rpms with boost. I had a 300ZX Turbo back in the 80s. Blew the turbocharger out at the strip after putting on an aftermarket wastegate. One smoking SOB when it went.

Other than that another teardown may be in order checking everything including clearances. Good luck!

The 20 in-hg of vacuum is excellent considering you're cammed up. Crankcase ventilation looks good too. Engine rebuild looks good. The moly rings will either seal or not (no break-in) but it would not hurt to run a compression test just to rule any specific cylinder causing the problem.

Although it will be hard to convince yourself I would not rule out the turbocharger. Maybe oil is passing through the seals at low rpms or high engine vacuum but not at high rpms with boost. I had a 300ZX Turbo back in the 80s. Blew the turbocharger out at the strip after putting on an aftermarket wastegate. One smoking SOB when it went.

Other than that another teardown may be in order checking everything including clearances. Good luck!

Allthough loud, I coudl always remove the Turbo, but its a big T70, its not under boost very often, but everytime I take off the DP it is bone dry. I too had a T3 Super 60 , the seals went bad and this is how it smoked, it was unreal.

http://www.automotiveforums.com/vbulletin/images/icons/icon5.gif That Oil Burning Issue ( updates )
Ok, I went and since it was smoking as you may have read in the other post when I parked it, I would be under the asumption that I could narrow it down by checking the plugs and their colour, well I checked everyone, but to my surprise every single one, except #1 was the proper colour of brownish and not sooty or anything, but #1 was BLACK and sooty, now the car runs fine, no hesitation so I am not thinking this one plug is just a dead plug otherwise I'd have a missfire code and I would also be running once again like a 5cyl, and I knwo what that feels like.


Now before when I pulled it apart as some of you may have read, it was what I though #3 cylinder that was junk as it was caked with soot, never at that time did I think of checking plugs , which I wish I did now. So from this little bit of looking, seeing as obviously the other 5 cylinder rings and valve selas are obviously ok ( right ? ) since the bunrn on the plugs is right on target, and since # 1 is what I would call either soaked in gas or soaked in oil, I would guess oil since my fingers are slipping off the keyboard, lol. Would you be under the impression that is the root cylinder, and can just on cylinder pump out that much smoke at idle on and off like it does ( for those who have not, read my other thread it explains this scenario very well. )

I can still do a compression test, but if it turns out ok then what? last time, before the most recent rebuild and it smoked on and off then aswell I might ad, just not like this, not where you could make people look at you like you were from Mexico driving a beat up VW with a million miles on it, but it did burn it a bit, and I did a compression test twice and it was 140 or more across the board. I have no idea what it is after this recent rebuild, but I would guess judgeing that the other cylinders have obvioulsy seated, that this one should have aswell as this actually when looking at the block itself was the best looking cylinder of them all. So that leads me back up top to those valves, which I am going to check into now after I pull the cover off, but just wanted to hear your oppinions on my impromto engine diagnoses.


Also everyone talks about valve guides in these heads, I looked at my other 2 sets and I do not see any guides in there, I pull off the valve seal and it is just regular cast material where the valve goes through, everyone talsk about bronze guides and such, am I missing something here?

Thanks
Jeff

Re: That Oil Burning Issue ( updates )

Originally Posted by maxwedge
You cannot check the seating of the oil control rings with a compression test, you can check the top 2 rings with a leak down test looking at leak percentage on the gages, the oil ring requires pulling the piston for inspection. Are the valve seals the type that fit down over the top of the guide if so, make sure an intake seal has not lifted off the guide and is not sealing anymore.


Yes they are the ones that fit over the top, I looked at the valve seal and it looked a little messed up in the inside, not where the valve stem goes through but on the inside, it was still firmly in place though not off the guide. I replaced it anyway with another.


As for the oil ring issue you speak of, what am I suppose to look for as remember these are brand new rings all around and Ihad the same issue, exact same prior to the

On the cylinder heads were they the originals and how many miles were on the car when you decided to mod? When you had the 3 angle valve job and porting done what was done to the valve guides. Was the wear checked? Normally you have the option of knurling (least recommended), bronze billet inserts or oversize valves including chroming if there is wear that brings it out of specs.

If the valve guides are worn it will suck oil down either the intake or exhaust valves no matter how good your valve guide seals are.

Oil consumption can be more of a problem on the intake side because of constant exposure to engine vacuum, oil can also be pulled down the exhaust guides by suction in the exhaust port. The flow of exhaust past the exhaust guide creates a venturi effect that can pull oil down the guide and is complicated due to the turbocharger.

I would tear down to at least the cylinder heads and inspect the valve guides and the condition of the intake and exhaust valves. Look for excessive carbon formation as an indicator.

BTW - I have never had my heads redone without tending to the valve guides.

On the cylinder heads were they the originals and how many miles were on the car when you decided to mod? When you had the 3 angle valve job and porting done what was done to the valve guides. Was the wear checked? Normally you have the option of knurling (least recommended), bronze billet inserts or oversize valves including chroming if there is wear that brings it out of specs.

If the valve guides are worn it will suck oil down either the intake or exhaust valves no matter how good your valve guide seals are.

Oil consumption can be more of a problem on the intake side because of constant exposure to engine vacuum, oil can also be pulled down the exhaust guides by suction in the exhaust port. The flow of exhaust past the exhaust guide creates a venturi effect that can pull oil down the guide and is complicated due to the turbocharger.

I would tear down to at least the cylinder heads and inspect the valve guides and the condition of the intake and exhaust valves. Look for excessive carbon formation as an indicator.

BTW - I have never had my heads redone without tending to the valve guides.

I wish I had you here you are like an encylopedia of knowledge and have been a great asset to this all.

I took your advice, compare the valve wiggle we'll call it in my stock heads that are sitting on the floor to the one that I beleive is the issue due to the cruddy spark plug. Also before I rebuilt it the last time I did have alot of crude build up. Anyway it wiggles alot compared to the stock heads which IMO do not wiggle at all even after oiling them and everything,

Now you ask what was done to the heads.

A- they were magnafluxed to check for cracks
B- Milled for trueness
C- Milled to accept a higher lift cam
D- Full Port and Polish
E- the stock valves and the heads were treated to a 3 angle valve job.

Nothing was done to the valve guides that I know of.


Now my question is, how can I fix this, or are my heads totally shot, I really do not want to redo another set of heads and getting even a stock set just to accept my cam will take milling. I'd rather save these heads. But what will a machine shop do with them, or is this something an old shadetree mechanic can do aswell.

And thank you for all the help.

Jeff

I wish I had you here you are like an encylopedia of knowledge and have been a great asset to this all.

I took your advice, compare the valve wiggle we'll call it in my stock heads that are sitting on the floor to the one that I beleive is the issue due to the cruddy spark plug. Also before I rebuilt it the last time I did have alot of crude build up. Anyway it wiggles alot compared to the stock heads which IMO do not wiggle at all even after oiling them and everything,

Now you ask what was done to the heads.

A- they were magnafluxed to check for cracks
B- Milled for trueness
C- Milled to accept a higher lift cam
D- Full Port and Polish
E- the stock valves and the heads were treated to a 3 angle valve job.

Nothing was done to the valve guides that I know of.


Now my question is, how can I fix this, or are my heads totally shot, I really do not want to redo another set of heads and getting even a stock set just to accept my cam will take milling. I'd rather save these heads. But what will a machine shop do with them, or is this something an old shadetree mechanic can do aswell.

And thank you for all the help.

Jeff
The only way to truly eliminate the guides as the cause is to pull the heads and check valve to guide clearances, usually .0015 on the intake and .002-0025 on the exhaust is in the ball park. I wouldn't do anything here till the problem is pin -pointed. Another possibility is oil getting sucked in thru the intake manifold gasket seal to the heads, especially after the heads were milled.was the intake side trued to fit the manifold after the head deck surface was machined?

The only way to truly eliminate the guides as the cause is to pull the heads and check valve to guide clearances, usually .0015 on the intake and .002-0025 on the exhaust is in the ball park. I wouldn't do anything here till the problem is pin -pointed. Another possibility is oil getting sucked in thru the intake manifold gasket seal to the heads, especially after the heads were milled.was the intake side trued to fit the manifold after the head deck surface was machined?

The car ran fine for over a year without any oil being sucked in, the heads were done 3 years ago, so 3 years of driving on them already, then like I said if backfired through the exhaust,and then it started to smoke on and off like a son of a b*tch. I then rebuilt what I thought would be the rings and valve seals and no luck, same problem, then today as mentioned by alot of you, was to pull a spring off , I took the spring off the offending plug, the one that was covered in oil as all other 5 were brown and clean. and even with the valve all the way up and seat, you can visably see it go back and forth, it obviously gets worse when you let it down a bit and un seat it, you can here the valve aswell when you shake it back and forth. So either way these Valves guides are shot or at least that one is, and it may only be that one, I'll find out tomorrow when I try more. But gasket wise, very unlikely when it ran for so long with no issues.


Jeff

The car ran fine for over a year without any oil being sucked in, the heads were done 3 years ago, so 3 years of driving on them already, then like I said if backfired through the exhaust,and then it started to smoke on and off like a son of a b*tch. I then rebuilt what I thought would be the rings and valve seals and no luck, same problem, then today as mentioned by alot of you, was to pull a spring off , I took the spring off the offending plug, the one that was covered in oil as all other 5 were brown and clean. and even with the valve all the way up and seat, you can visably see it go back and forth, it obviously gets worse when you let it down a bit and un seat it, you can here the valve aswell when you shake it back and forth. So either way these Valves guides are shot or at least that one is, and it may only be that one, I'll find out tomorrow when I try more. But gasket wise, very unlikely when it ran for so long with no issues.


Jeff
Jeff , good work, you more than likely found the problem , you should just about have no movement in the valve stem as installed in the guide, you did the test is with valve partially open that is when it really shows.. Didn't review the history carefully enough to see the intake was on for that period of time. You will be able to see into the intake ports once the head is off and make sure no other cylinders show signs of oil.

I am glad to see we have all come to a general concensus on this problem. :bigthumb:

Good luck!