Smoke from Engine - Help me diagnose please!

[castle]

Originally Posted By: madRiver
You validated the coolant in turbo is is not getting into compressed air side? Smoke is a sign of failed turbo.


It's definitely an oil leak above the turbo. the exhaust manifold is wet and oily ahead of the turbo

 

[castle]

Did a dry and wet compression test comparison just now. the engine is cold (and partially disassembled so a warm engine isn't an option

#- Dry Wet
1- 132 142
2- 115 120
3- 130 135
4- 120 135
5- 115 125
6- 115 122

Cylinder 4 is the leaker and has the biggest difference from dry to wet. This also seems to point to the rings

 

[Oil_Flunky]

Try a piston soak with whatever carbon eating chemicals you have on hand?

 

[Silk]

Originally Posted By: Linctex


Those "piston ring marks" are NOT normal.

Water got into that cylinder at one time to make those.


The used engine has been sitting, probably with manifolds off...maybe not a lot of water, but just condensation, and those rings have stuck to the bore. You are going to need to re ring it.

 

[Oro_O]

Originally Posted By: Oil_Flunky
Try a piston soak with whatever carbon eating chemicals you have on hand?


I would certainly try this before I tore it down again.

I did that last month with Marvel Mystery Oil and got good results - as have many, many people over the years.

Fill the cylinders and let it sit over night.
Rotate the engine by hand some, and repeat.
Blow out the cylinders (that can get pretty messy).
install the plugs and watch the smoke show for a while.

I did this in the unlikely hope to clear some blocked oil passages and stuck oil control rings on a car with that known problem. What I found afterwards was much easier starting, smoother running, more power, and lower AT temps. I can only guess I also had a/an stuck compression ring(s) I was unaware of. Have not driven it far enough yet to gauge impact on oil consumption though.

It won't address your valve issue, but it might fix the ring issue.

 

[castle]

Too late!

 

[Oro_O]

Originally Posted By: castle
Too late!


D&%mn, you work fast!

Hope this works out well; those are cool cars. Look forward to seeing what you find and the progress.

I just noticed you have some cool 90s Audi iron; I do, too. Or one, in my opinion, - a '91 V8 5speed (factory model). Going to re-furb it back to minty this winter after years of idleness.

 

[Linctex]

Are sleeves easily replaceable?

I'm curious to see what you find when you take it apart

 

[castle]

Pulled it all apart today and as expected, stuck ring on #4.

the oil ring is totally stuck inside the groove on one side of the gap and about half way around the piston:



Stuck so bad I can't actually get it out of there. I'm not sure any additive or soak would have freed it.

Now I wait for parts!



Thanks for all the feedback!

 

[castle]

Originally Posted By: Or
I just noticed you have some cool 90s Audi iron; I do, too. Or one, in my opinion, - a '91 V8 5speed (factory model). Going to re-furb it back to minty this winter after years of idleness.


AWESOME. I have had a bunch of old auds. I had a '93 V8 for a short time until the heater core blew and I retired it. I pulled that engine and put it in a 90 coupe quattro.
http://theprojectpad.com/viewtopic.php?f=11&t=1219

The factory 5 speed V8's are super rare. Nice find!

 

[Oro_O]

I had a bad heater core in one once; that was an annoying repair. I did not know a V8 would shoe-horn into a Coupe Quattro; that would be a mean ride.

I couldn't follow the whole build thread as my iPad and internet are not playing well together right now for some reason. I'll finish it tonight. I'm curious if you got rid of the distributors on the V8, looks like from what I saw on page 1 you were trying to. I'm interested in that and COP ignition if I could mine for that. I've had this V8 since about '99/99, I had another one (also 5 speed) before that which was lost to a deer on a dark Vermont night...

What happened to the 90/V8; I see you don't have it any more?

 

[Omahaug]

Did you get the stuck oil ring out? Not sure I can tell whether you did or not from this:
Quote:
Stuck so bad I can't actually get it out of there. I'm not sure any additive or soak would have freed it.


I've soaked pistons in Berryman you can get at Walmart, works extremely well dissolving carbon. Comes with a dip tray too. Maybe soak the piston until it comes free and soak to get the rest of the carbon and oil off?

https://www.walmart.com/ip/Berryman-Chem-Dip-Carburetor-and-Parts-Cleaner/17491945
https://www.youtube.com/watch?v=bRiZOTTel34

Otherwise standard procedure in any manual is to scrape the carbon out of the passages with an old ring, if you can remove the old ones without damaging the lands. Me, I'd just clean everything spotless.

 

[castle]

Originally Posted By: NoNameJoe
Me, I'd just clean everything spotless.


That's what I did too

 

[castle]

Originally Posted By: Or
I had a bad heater core in one once; that was an annoying repair. I did not know a V8 would shoe-horn into a Coupe Quattro; that would be a mean ride.

I couldn't follow the whole build thread as my iPad and internet are not playing well together right now for some reason. I'll finish it tonight. I'm curious if you got rid of the distributors on the V8, looks like from what I saw on page 1 you were trying to. I'm interested in that and COP ignition if I could mine for that. I've had this V8 since about '99/99, I had another one (also 5 speed) before that which was lost to a deer on a dark Vermont night...

What happened to the 90/V8; I see you don't have it any more?



The V8 just BARELY fit into that coupe. It was a [censored] of a swap. So much torque and quattro at the same time.

I did have to get rid of the distributors when I did the swap. The left distributor wouldn't fit in there so I ended up pulling the valve covers, intake and harness from an ABZ (early 4.2 A8 engine) and made a bit of a hybrid. Then I could plug the distributor holes and switch to coils though I did have to keep part of the passengers side distributor for the hall sensor.

To do a swap on your PT (the 3.6 V8) for the coils you'd need to pull those same parts - but also need to swap ECU's to an A8 ECU. That's where it gets complicated. The ABZ uses a 60-2 trigger where your PT uses a mix of crank sensor, hall sensor and flywheel ring to time the engine. You can do that if you have a 10 bolt flywheel with a 60-2 ring milled in (early S8 from europe is the only thing out there)

I ended up going with standalone ECU for that car. VEMS

I sold it last year so I could build the 5 cylinder turbo audi 90 I am slowly working on. It stayed in Ohio and the new owner is a great dude.

 

[Oro_O]

Dude - you have so much intimate knowledge of those Audi platforms. More than most guys on the V8 quattro mailserve list.

Given what you said, I wont't go to those lengths then to ditch the twin distributors and wires. Too much work for little gain. I am not above pulling a transmission that needs rebuilding, etc. I had thought it was less work based on some things I had casually read in the past. Thanks for setting me straight. Yesterday I pulled the car in out of the weather and into the garage to put on the lift to start the over-winter project. It has not actually been driven in a few years and a few systems have gone to pot. SO I am getting on it now before it gets out of hand.

What is a good forum to go to for platform/model-specific knowledge on this car? I know the 5-speed knowledge is almost non-existant, but most of it is generic V8. I am going to need help on many things I need to do (ps hose, clutch hydraulics, brake bomb (got one already), 1/2 axle rebuild) and I know the knowledge is out there if not on places I know. I know a lot is overlap with the 200 and S4. I have retrofit S4 (G60) brakes on the front, thank god. (had the UFO's on my prior one. - way better brakes, but a maintenance nightmare. Actually, "nightmare" is inadequate. More like "horror show.").

How is your Maserati doing? Because that's what this thread is about, and of course, it's COOL! I totally responded to the thread on that basis alone, then latered noticed the Audi angle. I liked these things back then and was way into a thread on someone keeping one up to speed.

 

[castle]

I agree - the conversion to coils isn't necessary. I had to do it for the swap or I would have happily run distributors. The switch added lots of time and $ to the swap.

Forums for V8's - I'd suggest:

http://forums.quattroworld.com/v8/
http://www.motorgeek.com/
or
http://theprojectpad.com/

All filled with knowledgeable folks who lust after 5 speed v8's

The maserati is still under the knife. It's soccer season for my kids and my weekends have been eaten up! I found a bad cam lobe on one side so I'm going to replace it while I have everything open. also time to re-shim the valves which is a pain in the [censored].

Hope to be driving it again in a couple weeks!