Would this leak be from the plenum gasket? - ZR-1 Net Registry Forums

rush91 · 02-07-2018

I keep finding a line of oil on top of my left side cam cover. I can't figure out where it would be coming from....my guess would be the plenum gasket or injector gasket? There isn't oil splashed around anywhere else, just always in this one spot.....IMG_20180203_142718516.jpg IMG_20170705_163016610.jpg

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-=Jeff=- · 02-07-2018

check the tube above the (PCV tube) I have to wonder if the hose at the back of the plenum is leaking.. I doubt it is from the Plenum to IH gasket

lfalzarano · 02-07-2018

Try putting a small slice of paper towel around each potential source of the leak. Fire her up for a few minutes. One of those towels will be stained. If you you still don’t have a soiled towel, run the engine until the oil gets to normal operating temp. Good Luck!

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Top Toy · 02-07-2018

Sure it isn't antifreeze?

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jss06c6 · 02-07-2018

Might want to check the hose clamps and hose just above where you keep seeing the stain. I too believe this might be coolant, not engine oil.. Nice clean LT-5!!!

rush91 · 02-08-2018

Quote:

Originally Posted by Top Toy

Sure it isn't antifreeze?

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It doesn't seem like anti-freeze.....It has same color as oil and consistency as oil. I flushed my antifreeze last year, and went non dex-cool. It was yellow antifreeze. Could it turn that consistency and color running through the system??

rush91 · 02-08-2018

Quote:

Originally Posted by jss06c6

Might want to check the hose clamps and hose just above where you keep seeing the stain. I too believe this might be coolant, not engine oil.. Nice clean LT-5!!!

I did check the clamps above the leak, they were dry and as normal. I try to keep her as shiny and clean as possible......but this leak is eating away the finish on the valve cover. Would a plenum pull diagnose this better?? Thanks for the reply guys

Paul Workman · 02-08-2018

There is no oil between the plenum and the IHs to leak out.

However, there is the coolant manifold, and I get a line of antifreeze (looks kinda like oil too, btw) along that lip at the top edge of the cam cover, right side of the motor. And, when you said the stuff was attacking the paint on the CC, THAT rang a bell!

Leaking PVC connections and boots at the rear of the motor, and the little right angle grommets attached to the IHs - are sources for oil.

A picture of the leaked line of oil would help too.

RussMcB · 02-09-2018

See if your nearby auto parts store or garage has a coolant system pressure tester. It screws on like a radiator cap and in a minute you'll know if it's a coolant leak.

secondchance · 02-09-2018

Just don't pressurize it more than 18 lbs. we had a WAZOO car with blown heater core. Suspicion was a dealer mechanic who pumped the system to find coolant leak too vigorously.

02-07-2018	#1
rush91 Join Date: Feb 2016 Location: Carterville Illinois Posts: 852	Would this leak be from the plenum gasket? I keep finding a line of oil on top of my left side cam cover. I can't figure out where it would be coming from....my guess would be the plenum gasket or injector gasket? There isn't oil splashed around anywhere else, just always in this one spot.....IMG_20180203_142718516.jpg IMG_20170705_163016610.jpg Sent from my XT1585 using Tapatalk

02-07-2018	#2
-=Jeff=- Join Date: Jul 2007 Location: Bartlett, IL Posts: 7,169	Re: Would this leak be from the plenum gasket? check the tube above the (PCV tube) I have to wonder if the hose at the back of the plenum is leaking.. I doubt it is from the Plenum to IH gasket __________________ 1990 Corvette ZR-1 #1051 Watson Headers (2" Primary) - Flowmaster Cats - Borla Catback Late Model IH - Plenum Coilovers - 4.10s Custom Interior NCM Lifetime Member #978

02-07-2018	#3
lfalzarano Join Date: Feb 2011 Location: Clayton, North Carolina Posts: 1,133	Re: Would this leak be from the plenum gasket? Try putting a small slice of paper towel around each potential source of the leak. Fire her up for a few minutes. One of those towels will be stained. If you you still don’t have a soiled towel, run the engine until the oil gets to normal operating temp. Good Luck! Sent from my iPhone using ZR-1 Net Registry __________________ Lou[COLOR="Red"][B][SIZE="4"][/SIZE][/B][/COLOR]

02-07-2018	#4
Top Toy Join Date: Jul 2012 Location: Allentown, PA Posts: 309	Re: Would this leak be from the plenum gasket? Sure it isn't antifreeze? Sent from my HTC U11 using Tapatalk __________________ '95 ZR-1, aqua/gray, #167 368 LPE/Haibeck, Web cams, Stainless Works headers, B&B Fusion exhaust, 18" Fikse wheels, Alcon brakes, lowered. 491 SAE RWHP.

02-07-2018	#5
jss06c6 Join Date: Aug 2015 Location: Magnolia, Texas Posts: 884	Re: Would this leak be from the plenum gasket? Might want to check the hose clamps and hose just above where you keep seeing the stain. I too believe this might be coolant, not engine oil.. Nice clean LT-5!!!

02-08-2018	#8
Paul Workman Join Date: Nov 2007 Location: Squires (near Ava MO in the Mark Twain N'tl Forest) - Missouri Posts: 6,493	Re: Would this leak be from the plenum gasket? There is no oil between the plenum and the IHs to leak out. However, there is the coolant manifold, and I get a line of antifreeze (looks kinda like oil too, btw) along that lip at the top edge of the cam cover, right side of the motor. And, when you said the stuff was attacking the paint on the CC, THAT rang a bell! Leaking PVC connections and boots at the rear of the motor, and the little right angle grommets attached to the IHs - are sources for oil. A picture of the leaked line of oil would help too. __________________ 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 Last edited by Paul Workman; 02-12-2018 at 09:34 AM.

02-09-2018	#9
RussMcB Join Date: Jan 2015 Location: Marietta, GA USA Posts: 1,160	Re: Would this leak be from the plenum gasket? See if your nearby auto parts store or garage has a coolant system pressure tester. It screws on like a radiator cap and in a minute you'll know if it's a coolant leak.

02-09-2018	#10
secondchance Join Date: Aug 2006 Location: McLean, VA Posts: 3,723	Re: Would this leak be from the plenum gasket? Just don't pressurize it more than 18 lbs. we had a WAZOO car with blown heater core. Suspicion was a dealer mechanic who pumped the system to find coolant leak too vigorously.