Oil leak from level sensor? - ZR-1 Net Registry Forums

conesare2seconds · 04-30-2022

Edit: updating this because the leak ended up being the crankshaft position sensor. The oil pressure switch was a good suggestion. Thanks again to Jerry for suggesting it could be the cause.

I was able to locate a pressure switch locally and tried David Hetrick?s suggested technique of accessing the switch by coming across the top of the engine from the driver?s side. It?s a very good solution if there is no EGR.

On a 94 with EGR, the tube occupies a lot of the space that could be used to access the switch. It may be possible, but I wasn?t able to get a socket onto the switch. Could be a lack of mechanical talent on my part.

So the route to take will be pulling the filter adapter for access to the switch. Not terrible to do but there is no time to get a new gasket and do the job before it?s time to leave for the Gathering Weds morning. Still attending, but I?m a scratch for the touring laps.

Original post:
Has anyone ever seen a leak from the oil level sensor in the pan?

Oil is leaking from somewhere and blowing back onto the exhaust. After a drive there is oil smoke rising from the back of the engine at the passenger side.

I cleaned off the pan and drove it a few miles today. When I got back under the car, I saw oil had run down from the front passenger side of the pan and you can see the new oil on the pan in the pic below.

I assumed it had run down from the oil pressure regulator or maybe the filter adapter since both areas are pretty oily, but I noticed the oil level sensor is also covered in oil and wondered if it could be leaking through the sensor and wicking out the wires. The weather pack seal (not sure, it could just be an o-ring) is pretty loose, the connector pops out super easy.

I?m not comfortable bringing the car to the Gathering with such a large leak but I?ll fix it if possible.

24C62720-37A4-44E0-9EE0-A2B97C52E592.jpeg
39F60013-2811-49DD-9AFB-12CF763BAB98.jpeg

A26B · 05-01-2022

Right(passenger)-Front oil leak is most commonly the Oil Pump Access Cover(loose bolts/gasket), or the Oil Pressure Switch. The oil pressure switch leaks through the switch and can be detected by removing the harness connector from the switch. If there is oil inside the connector, the switch is leaking. Replace the switch.

Another right/passenger side leak on 90~92 models is the exhaust manifold stud located in the center of the manifold flange. Remove, clean & seal with high temp rtv. Apply moderately to stud threads only. Do not apply to end of stud or inside the tapped hole in the cylinder head.

conesare2seconds · 05-01-2022

Thanks, Jerry. The oil pressure regulator cover is snug - the gasket may be leaking but I don?t think it?s the primary source of my leak. The oil pressure switch is a likely culprit and I?m tackling it this afternoon using David H?s suggested technique in the solutions threads.

secondchance · 05-02-2022

I was able to access the oil pressure switch from the front with a small swivel head ratchet and a sensor socket. Wasn't easy. I did this while the motor was still hot (not enough patience) and burned the skin off of my right hand knuckle. Got it done though...

WARP TEN · 05-08-2022

Quote:

Originally Posted by secondchance

I was able to access the oil pressure switch from the front with a small swivel head ratchet and a sensor socket. Wasn't easy. I did this while the motor was still hot (not enough patience) and burned the skin off of my right hand knuckle. Got it done though...

Ahhh, the wounds we endure for the love of ZR-1s.....Bob

Andy · 05-08-2022

Doesn't Marc H discuss how to perform this repair on his site?

If I recall, remove the mount nut so the engine can be jacked up on that side to offer a bit more clearance. Just don?t jack so much that the bolt comes out of the mount as there?s not much room to attempt prying the bolt back into the hole. Pretty easy then with the sensor socket.

Or maybe I?m confusing sensors?.

conesare2seconds · 05-09-2022

You?re right, that is the method suggested by Marc. I may pull the oil filter adapter because I don?t want to replace the switch, then find the adapter gasket is leaking. I?ll give the situation another look this weekend.

conesare2seconds · 11-29-2023

To wrap this thread up, the leak was found to be the crankshaft position sensor. Marc has taken care of it for me, which is for the best because I never was able to solve for the EGR tube blocking access to the oil pressure sensor.

rufcar · 11-29-2023

Just today I replaced the O ring in my camshaft position sensor. I had the same leak. Easy to do took me 1/2 hr. There was no O ring on my sensor. It now has stopped leaking. I got the O ring from Jerrys.

04-30-2022	#1
conesare2seconds Join Date: Jul 2016 Location: Greater St. Louis Posts: 490	Leak - oil pressure switch Edit: updating this because the leak ended up being the crankshaft position sensor. The oil pressure switch was a good suggestion. Thanks again to Jerry for suggesting it could be the cause. I was able to locate a pressure switch locally and tried David Hetrick?s suggested technique of accessing the switch by coming across the top of the engine from the driver?s side. It?s a very good solution if there is no EGR. On a 94 with EGR, the tube occupies a lot of the space that could be used to access the switch. It may be possible, but I wasn?t able to get a socket onto the switch. Could be a lack of mechanical talent on my part. So the route to take will be pulling the filter adapter for access to the switch. Not terrible to do but there is no time to get a new gasket and do the job before it?s time to leave for the Gathering Weds morning. Still attending, but I?m a scratch for the touring laps. Original post: Has anyone ever seen a leak from the oil level sensor in the pan? Oil is leaking from somewhere and blowing back onto the exhaust. After a drive there is oil smoke rising from the back of the engine at the passenger side. I cleaned off the pan and drove it a few miles today. When I got back under the car, I saw oil had run down from the front passenger side of the pan and you can see the new oil on the pan in the pic below. I assumed it had run down from the oil pressure regulator or maybe the filter adapter since both areas are pretty oily, but I noticed the oil level sensor is also covered in oil and wondered if it could be leaking through the sensor and wicking out the wires. The weather pack seal (not sure, it could just be an o-ring) is pretty loose, the connector pops out super easy. I?m not comfortable bringing the car to the Gathering with such a large leak but I?ll fix it if possible. 24C62720-37A4-44E0-9EE0-A2B97C52E592.jpeg 39F60013-2811-49DD-9AFB-12CF763BAB98.jpeg Last edited by conesare2seconds; 11-30-2023 at 11:23 PM. Reason: Leak identified

05-01-2022	#2
A26B Join Date: Dec 2003 Location: Arcadia,OK Posts: 3,393	Re: Oil leak from level sensor? Right(passenger)-Front oil leak is most commonly the Oil Pump Access Cover(loose bolts/gasket), or the Oil Pressure Switch. The oil pressure switch leaks through the switch and can be detected by removing the harness connector from the switch. If there is oil inside the connector, the switch is leaking. Replace the switch. Another right/passenger side leak on 90~92 models is the exhaust manifold stud located in the center of the manifold flange. Remove, clean & seal with high temp rtv. Apply moderately to stud threads only. Do not apply to end of stud or inside the tapped hole in the cylinder head. __________________ 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.

05-01-2022	#3
conesare2seconds Join Date: Jul 2016 Location: Greater St. Louis Posts: 490	Re: Oil leak from level sensor? Thanks, Jerry. The oil pressure regulator cover is snug - the gasket may be leaking but I don?t think it?s the primary source of my leak. The oil pressure switch is a likely culprit and I?m tackling it this afternoon using David H?s suggested technique in the solutions threads.

05-02-2022	#4
secondchance Join Date: Aug 2006 Location: McLean, VA Posts: 3,722	Re: Oil leak from level sensor? I was able to access the oil pressure switch from the front with a small swivel head ratchet and a sensor socket. Wasn't easy. I did this while the motor was still hot (not enough patience) and burned the skin off of my right hand knuckle. Got it done though...

05-08-2022	#6
Andy Join Date: Aug 2014 Location: Chantilly, VA Posts: 37	Re: Oil leak from level sensor? Doesn't Marc H discuss how to perform this repair on his site? If I recall, remove the mount nut so the engine can be jacked up on that side to offer a bit more clearance. Just don?t jack so much that the bolt comes out of the mount as there?s not much room to attempt prying the bolt back into the hole. Pretty easy then with the sensor socket. Or maybe I?m confusing sensors?. __________________ 1990 black on black #1042 - sadly - sold 1993 Ruby #140 - stock 1991 QB #1608 - heads and top end ported, Watson headers, B&B 3"exhaust, Haibeck chip, 4.10 gears

05-09-2022	#7
conesare2seconds Join Date: Jul 2016 Location: Greater St. Louis Posts: 490	Re: Oil leak from level sensor? You?re right, that is the method suggested by Marc. I may pull the oil filter adapter because I don?t want to replace the switch, then find the adapter gasket is leaking. I?ll give the situation another look this weekend.

11-29-2023	#8
conesare2seconds Join Date: Jul 2016 Location: Greater St. Louis Posts: 490	Re: Oil leak from level sensor? To wrap this thread up, the leak was found to be the crankshaft position sensor. Marc has taken care of it for me, which is for the best because I never was able to solve for the EGR tube blocking access to the oil pressure sensor.

11-29-2023	#9
rufcar Join Date: Mar 2023 Location: PA Posts: 70	Re: Oil leak from level sensor? Just today I replaced the O ring in my camshaft position sensor. I had the same leak. Easy to do took me 1/2 hr. There was no O ring on my sensor. It now has stopped leaking. I got the O ring from Jerrys.