The most common but most unrecognized oil leak - Page 2 - ZR-1 Net Registry Forums

Dynomite · 10-30-2016

I went to The OPRV cover plate from under car after removing motor mount strut that takes no load from motor. Yes......take photos and describe your methods here

Oh......I got 6mm x 16mm flange bolts with 10mm heads to replace the 6mm bolts with 8mm heads (lots easier to tighten).

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5ABI VT · 10-30-2016

Quote:

Originally Posted by Dynomite

I went to The OPRV cover plate from under car after removing motor mount strut that takes no load from motor. Yes......take photos and describe your methods here

Sent from my iPhone using ZR-1 Net Registry

I couldn't help but want to try

egr is disabled in the time so I would imagine unplugging it shouldn't light up any codes ?!

5ABI VT · 10-30-2016

Well, managed to get to it from above. I also removed the EGR VALVE, as well as the bracket. All together maybe 7-8 lbs of savings

the egr bracket is iron and heavy. I'll toss it on a scale later.

After pulling everything .. I looked from a different angle and realized i may not have even needed to remove the egr bracket from the block.. but regardless it opened up room to get a wrachet and my hand in there to easily pull the 2 8mm bolts out turn by turn and thread lock them and tighten them back up.

I did have a slight drip and under my pan I did see what was described in the original post of oil on the pan and in a wavy pattern. I'm not sure if it was coming from here.. the bolts weren't loose but I'll clean up the pan etc and check again tomorrow.

Pic showing the egr valve. Taken from passenger side near the corner of the radiator shroud looking down under the passenger side valve cover.

Egr valve out

Egr bracket out.

5ABI VT · 10-30-2016

Quote:

Originally Posted by Dynomite

The Oil Pressure Relief Valve Cover you are pointing to is actually the Passenger Side Chain Tensioner.

lol I looked back at the first page photos and realized my error

no wonder after I removed the egr I wondered why it was so easy !! Tried deleting the photo as not to confuse others! Will take another look from above shortly

5ABI VT · 10-31-2016

Pretty sure this is it . Short video showing its location

https://youtu.be/uQkQAuBtylo

That the one dynomite? Looks like 8mm bolts

Saved 4.5lbs too

Pretty sure that was the right cover.. the lower bolt was not even tight and hand loosened . The top was just barely snug. Cleaned the bolts and red loc-tite on both and retightened them. All done from above

Dynomite · 10-31-2016

Quote:

Originally Posted by 5ABI VT

Pretty sure this is it . Short video showing its location

https://youtu.be/uQkQAuBtylo

That the one dynomite? Looks like 8mm bolts

Saved 4.5lbs too

Difficult to tell....but seems very hard to get to from the top

This is the Oil Pressure Regulating Valve Cover near bottom front passenger side of Engine.

5ABI VT · 10-31-2016

Quote:

Originally Posted by Dynomite

Difficult to tell....but seems very hard to get to from the top

This is the Oil Pressure Regulating Valve Cover near bottom front passenger side of Engine.

That's definitely it then. Was raining yesterday when I started or I may have gone the under car route as I didn't want to pull the car outside. I will admit .. I am slim.. and it was fairly tight to get my arm all the way down there. Anyone that isn't skinny .. I would reccomend just doing it from below. Tomorrow I'll fire it up clean the pan etc and go for a spirited drive

dcarroll95 · 12-11-2018

On my 1990, took the inner fender liner out to be able to see it. Then I used vice grips to extend my 1/4 inch socket with an 8mm socket on it. See the pic below.

Tightened these two plus the the drain pan bolts (removed the frame supports and heat shields) and will see overnight if this was enough. I'm getting teaspoons of oil each night on the garage floor.

Dynomite · 12-12-2018

Quote:

Originally Posted by dcarroll95

On my 1990, took the inner fender liner out to be able to see it. Then I used vice grips to extend my 1/4 inch socket with an 8mm socket on it. See the pic below.

Tightened these two plus the the drain pan bolts (removed the frame supports and heat shields) and will see overnight if this was enough. I'm getting teaspoons of oil each night on the garage floor.

Welcome to the Registry

What you tightened is the passenger side chain tensioner bolts (not the Oil Pressure regulating valve cover bolts). If you still have a leak...….check the Oil Pressure Regulating Valve Cover.

Post 249 - Oil Pressure Regulating Valve Cover Plate

See Also...……. Potential Oil Leaks and the OPRV Cover Plate

I replace both top and bottom 6mm bolts with 6mm x 16mm Flange Bolts that have a 10mm head for a 10mm Box or ratchet Box wrench. It is a lot easier to tighten a 10mm bolt than an 8mm bolt which sometimes strips in the small 8mm box wrench. I used Red Loctite on the 6mm x 16mm Flange Bolts. No need to remove the Oil Pressure Valve Cover Plate or associated gasket.

Two 6mm x 16mm Flange Bolts installed in Oil Pressure Regulator Valve Cover (10mm Heads)
replacing original 6mm x 16mm (8mm Heads) Bolts.
Top 6mm Bolt shown before tightening with 10mm Box Wrench

dcarroll95 · 12-12-2018

Thank you! Now I see it just in front of the oil pan front bolts. What a nightmare, but I was able to tighten them and they were each about 1/2 turn loose and leaking plenty right there. Lifted the engine as much as it would go and pulled the passenger side engine strut loose as suggested to get to it from the bottom. Didn't drip overnight but would have eventually so you saved me lots of time!

Thank you - great write up and pictures.

10-30-2016	#11
Dynomite Join Date: Aug 2009 Location: South Dakota/California Posts: 3,807	The most common but most unrecognized oil leak I went to The OPRV cover plate from under car after removing motor mount strut that takes no load from motor. Yes......take photos and describe your methods here Oh......I got 6mm x 16mm flange bolts with 10mm heads to replace the 6mm bolts with 8mm heads (lots easier to tighten). Sent from my iPhone using ZR-1 Net Registry __________________ Left Clickable links -Solutions- LT5 Modifications/Rebuild Tricks Low Mileage ZR-1 Restoration 1990 Corvette (L98) Modifications LT5 Eliminated Systems LT5 Added Systems LT5/ZR-1 Fluids 1995 LT5 SPECIFIC TOP END REBUILD TRICKS Last edited by Dynomite; 10-30-2016 at 05:08 PM.

10-30-2016	#13
5ABI VT Join Date: Jun 2013 Location: Toronto Posts: 780	Re: The most common but most unrecognized oil leak Well, managed to get to it from above. I also removed the EGR VALVE, as well as the bracket. All together maybe 7-8 lbs of savings the egr bracket is iron and heavy. I'll toss it on a scale later. After pulling everything .. I looked from a different angle and realized i may not have even needed to remove the egr bracket from the block.. but regardless it opened up room to get a wrachet and my hand in there to easily pull the 2 8mm bolts out turn by turn and thread lock them and tighten them back up. I did have a slight drip and under my pan I did see what was described in the original post of oil on the pan and in a wavy pattern. I'm not sure if it was coming from here.. the bolts weren't loose but I'll clean up the pan etc and check again tomorrow. Pic showing the egr valve. Taken from passenger side near the corner of the radiator shroud looking down under the passenger side valve cover. Egr valve out Egr bracket out.

10-31-2016	#15
5ABI VT Join Date: Jun 2013 Location: Toronto Posts: 780	Re: The most common but most unrecognized oil leak Pretty sure this is it . Short video showing its location https://youtu.be/uQkQAuBtylo That the one dynomite? Looks like 8mm bolts Saved 4.5lbs too Pretty sure that was the right cover.. the lower bolt was not even tight and hand loosened . The top was just barely snug. Cleaned the bolts and red loc-tite on both and retightened them. All done from above Last edited by 5ABI VT; 10-31-2016 at 04:45 PM.

12-12-2018	#20
dcarroll95 Join Date: Dec 2018 Location: ALLEN Posts: 10	Re: The most common but most unrecognized oil leak Thank you! Now I see it just in front of the oil pan front bolts. What a nightmare, but I was able to tighten them and they were each about 1/2 turn loose and leaking plenty right there. Lifted the engine as much as it would go and pulled the passenger side engine strut loose as suggested to get to it from the bottom. Didn't drip overnight but would have eventually so you saved me lots of time! Thank you - great write up and pictures.