Oil Smoke - Input - Page 2 - ZR-1 Net Registry Forums

Ccmano · 02-21-2018

Dom, all I have to do with mine is let it sit and warm up. Once hot and you rev the engine it will put a good amount of blue smoke out the right side exhaust.
Prior to this oil consumption was negligible. So something changed.
H

XfireZ51 · 02-21-2018

Quote:

Originally Posted by Ccmano

Dom, all I have to do with mine is let it sit and warm up. Once hot and you rev the engine it will put a good amount of blue smoke out the right side exhaust.
Prior to this oil consumption was negligible. So something changed.
H

Hans,

My post was not intended to address your particular situation. It really was directed more to gt. You and I have discussed the similar symptoms my motor was exhibiting last year just prior to and during the MR5. And ultimately what Dr. Greekenstein diagnosed.

Paul Workman · 02-21-2018

Just following along here...

Assuming (for now) the "given(s)" are correct, the only thing exclusive to the one bank are the pistons/rings and the head (including valve/guides)

IIRC, when I did the compression check on Dom's car, compression average differed bank to bank, BUT there wasn't really anything that jumped out, far as static compression test goes.

And again, IIRC, Dom's oil consumption was similar to what you are describing.

I don't remember if Pete did a leak-down test, but I do recall Dom had a cylinder that did have fouling in excess of the others. (Dom remembers if that plug was in the cylinder with the broken ring.)

So, I don't think a leak-down test is out of line: hate to assume b/c static compression was good that a ring is eliminated. Has happened B4!

In the end, the motor was pulled and broken down and the broken ring was discovered upon disassembly. I know I was a little surprised at the broken ring. There wasn't any of the catastrophic "stuff" that usually goes along with a broken ring, far as I know.

Then too, it could be something off the wall - like...IDK...a valve seal breaking or the (off-the-wall) like? I'd want to eliminate everything I could to avoid pulling the motor - that being the last resort, but the best way to explore every nook and cranny. (Would be a good time to refresh the bearings and rings, etc., anyway, huh?)

Going back to my

now...

Ccmano · 02-21-2018

Paul,

I have found only two instances of this documented previously. One was Doms with the broken ring. The other was back in 2014 on a 368. That turned out to be a collapsed oil ring. If I’m not mistaken Pete diagnosed and repaired both. So it’s trending in that direction. I’m keeping my fingers crossed it’s stuck oil ring that can be loosened.

I may run a leak down in a few days when the temps here climb over 40 again and my back, which I put out this morning, gets better.

Btw, no valve seals, it’s a 90’.
H

Ccmano · 02-21-2018

For those following this thread. Lee (Lgaff) and I have been talking off line. He has 2 sets of low mileage stock liners. All show the same vertical scuffing mine seem to show. Appears unlikely that this is related to the current condition discussed here.
H

A26B · 02-22-2018

Do you still have the original exhaust manifolds/cats installed?

Ccmano · 02-22-2018

Quote:

Originally Posted by A26B

Do you still have the original exhaust manifolds/cats installed?

No it has headers and exhaust. This started after I installed them. One of the reasons I did that was because of my concern at the cats breaking up.
H

DRM500RUBYZR-1 · 02-22-2018

Quote:

Originally Posted by Ccmano

No it has headers and exhaust. This started after I installed them. One of the reasons I did that was because of my concern at the cats breaking up.
H

Interesting.
Could oil somehow be getting introduced into either the combustion chamber or into the exhaust stream somehow?
Seems awfully coincidental and odd that the problem appears simultaneously to the installation of the headers.
There is an answer there somewhere.
Hmmm...........................
Marty

Ccmano · 02-22-2018

The only remotely possible area of oil introduction that I am aware of is at the header stud. No way to get into the combustion chamber from there. Generally just causes a leak or oil burning off the header. I my situation oil is getting into the combustion chamber and causing smoke out the exhaust.
H

Sent from my iPhone using ZR-1 Net Registry

XfireZ51 · 02-22-2018

Maybe the correlation is that after 28 years, something is going to give when u push it a bit. My motor had about 70k on it when this happened. And I recall seeing puffs of blackish-gray smoke upon harder acceleration right at the beginning of the season last year. I thought it was just the motor blowing out some carbon.

02-21-2018	#11
Ccmano Join Date: Jun 2006 Location: Sparks, NV Posts: 2,852	Re: Oil Smoke - Input Dom, all I have to do with mine is let it sit and warm up. Once hot and you rev the engine it will put a good amount of blue smoke out the right side exhaust. Prior to this oil consumption was negligible. So something changed. H __________________ 90'ZR-1 #1461 Red/Black Ported Intake, Degreed Cams, OBX Headers & Exhaust, Fidanza FW, Secondary Delete, Custom tune, C6 GS Wheels. Sold 08 C6 Z51 Crystal Red Metallic Sold Vararam Intake, Tune, Sold 05 C6 Z51 Red/Black Sold 90'ZR-1 #1723 Black/Gray Sold but not forgotten 91' Z51 L98 White Vert. My First, you always remember your first. Sold.

02-21-2018	#13
Paul Workman Join Date: Nov 2007 Location: Squires (near Ava MO in the Mark Twain N'tl Forest) - Missouri Posts: 6,493	Re: Oil Smoke - Input Just following along here... Assuming (for now) the "given(s)" are correct, the only thing exclusive to the one bank are the pistons/rings and the head (including valve/guides) IIRC, when I did the compression check on Dom's car, compression average differed bank to bank, BUT there wasn't really anything that jumped out, far as static compression test goes. And again, IIRC, Dom's oil consumption was similar to what you are describing. I don't remember if Pete did a leak-down test, but I do recall Dom had a cylinder that did have fouling in excess of the others. (Dom remembers if that plug was in the cylinder with the broken ring.) So, I don't think a leak-down test is out of line: hate to assume b/c static compression was good that a ring is eliminated. Has happened B4! In the end, the motor was pulled and broken down and the broken ring was discovered upon disassembly. I know I was a little surprised at the broken ring. There wasn't any of the catastrophic "stuff" that usually goes along with a broken ring, far as I know. Then too, it could be something off the wall - like...IDK...a valve seal breaking or the (off-the-wall) like? I'd want to eliminate everything I could to avoid pulling the motor - that being the last resort, but the best way to explore every nook and cranny. (Would be a good time to refresh the bearings and rings, etc., anyway, huh?) Going back to my now... __________________ Good carz, good food, good friendz = the best of timez! 90 #1202 "FBI" top end ported & relieved Cam timing by "Pete the Greek" Sans secondaries Chip & dyno tuning by Haibeck Automotive SW headers, X-pipe, MF muffs Former Secretary, ZR-1 Net Registry

02-21-2018	#14
Ccmano Join Date: Jun 2006 Location: Sparks, NV Posts: 2,852	Re: Oil Smoke - Input Paul, I have found only two instances of this documented previously. One was Doms with the broken ring. The other was back in 2014 on a 368. That turned out to be a collapsed oil ring. If I’m not mistaken Pete diagnosed and repaired both. So it’s trending in that direction. I’m keeping my fingers crossed it’s stuck oil ring that can be loosened. I may run a leak down in a few days when the temps here climb over 40 again and my back, which I put out this morning, gets better. Btw, no valve seals, it’s a 90’. H __________________ 90'ZR-1 #1461 Red/Black Ported Intake, Degreed Cams, OBX Headers & Exhaust, Fidanza FW, Secondary Delete, Custom tune, C6 GS Wheels. Sold 08 C6 Z51 Crystal Red Metallic Sold Vararam Intake, Tune, Sold 05 C6 Z51 Red/Black Sold 90'ZR-1 #1723 Black/Gray Sold but not forgotten 91' Z51 L98 White Vert. My First, you always remember your first. Sold.

02-21-2018	#15
Ccmano Join Date: Jun 2006 Location: Sparks, NV Posts: 2,852	Re: Oil Smoke - Input For those following this thread. Lee (Lgaff) and I have been talking off line. He has 2 sets of low mileage stock liners. All show the same vertical scuffing mine seem to show. Appears unlikely that this is related to the current condition discussed here. H __________________ 90'ZR-1 #1461 Red/Black Ported Intake, Degreed Cams, OBX Headers & Exhaust, Fidanza FW, Secondary Delete, Custom tune, C6 GS Wheels. Sold 08 C6 Z51 Crystal Red Metallic Sold Vararam Intake, Tune, Sold 05 C6 Z51 Red/Black Sold 90'ZR-1 #1723 Black/Gray Sold but not forgotten 91' Z51 L98 White Vert. My First, you always remember your first. Sold.

02-22-2018	#16
A26B Join Date: Dec 2003 Location: Arcadia,OK Posts: 3,394	Re: Oil Smoke - Input Do you still have the original exhaust manifolds/cats installed? __________________ Jerry Downey JERRYS LT5 GASKETS & PARTS http://www.jerrysgaskets.com 1994 *ZR-1*, Black/Black, Lingenfelter Aerobody, 416cu in, 3.91 gears, coil-over susp, Brembo brakes, etc. 2016 Black-Red, 3LT-Z51 Auto 8-speed.

02-22-2018	#19
Ccmano Join Date: Jun 2006 Location: Sparks, NV Posts: 2,852	Re: Oil Smoke - Input Needed The only remotely possible area of oil introduction that I am aware of is at the header stud. No way to get into the combustion chamber from there. Generally just causes a leak or oil burning off the header. I my situation oil is getting into the combustion chamber and causing smoke out the exhaust. H Sent from my iPhone using ZR-1 Net Registry __________________ 90'ZR-1 #1461 Red/Black Ported Intake, Degreed Cams, OBX Headers & Exhaust, Fidanza FW, Secondary Delete, Custom tune, C6 GS Wheels. Sold 08 C6 Z51 Crystal Red Metallic Sold Vararam Intake, Tune, Sold 05 C6 Z51 Red/Black Sold 90'ZR-1 #1723 Black/Gray Sold but not forgotten 91' Z51 L98 White Vert. My First, you always remember your first. Sold.

02-22-2018	#20
XfireZ51 Join Date: May 2007 Location: Chicagoland, IL Posts: 9,708	Re: Oil Smoke - Input Maybe the correlation is that after 28 years, something is going to give when u push it a bit. My motor had about 70k on it when this happened. And I recall seeing puffs of blackish-gray smoke upon harder acceleration right at the beginning of the season last year. I thought it was just the motor blowing out some carbon. __________________ [SIGPIC][/SIGPIC]Former Membership Chairman Former ZR-1 Registry - BOD 1972 Corvette 4speed base Coupe SOLD long time ago 1984 Corvette Z-51/4+3 SOLD 1992 Corvette ZR-1 Aqua/Gray #474 SOLD 1992 Corvette ZR-1 Black Rose/Cognac #458 2014 Honda VFR Interceptor DX Last edited by XfireZ51; 03-08-2024 at 03:10 PM.