F!!!! Oil Leak...

[Daniel_Mc]

Ok, I just got the ZR-1 home yesterday and unloaded and went to fuel it up and take a short spin since I didn?t get to do much driving at Bowling Green this past weekend. I went from my home, about a mile, to the fuel station and from there about 3 miles until I stopped. During the last mile I thought I smelled something however everything was reading normal and sounded normal (I was not beating on the car it wasn?t even up to temp yet). I pulled into another station just to check (I am paranoid a lot of times over things). Well when I did I noticed an oil trail behind the car. I had been under the car at The Gathering and it was clean with no leaks and the trailer is dry and the spot where I parked the ZR-1 in the shop is also dry as well. After it sat for about 3 to 5 minutes I rolled it forward to get a good idea of how much was leaking, below is some pictures of what I had. I have been searching the forums and found where a oil low pressure sensor could cause a leak but I do not know if it would be to this magnitude. Would this be an oil cooler line possibly? The Oil filter is dry along with the pan the only oil on the pan is what was blown there. The leak appears to be coming from the front right side of the motor. Could this be what I am looking for?
GM Part # is: 12555492
Oil temp sensor - 90-91 10096136
Oil pressure ECM ? 25036935

http://img821.imageshack.us/img821/5125/picture005qm.jpg
http://img593.imageshack.us/img593/610/picture006ap.jpg

This is the best picture I could find (Thanks Jeffvette) would this be the sensor barely visiable at the bottom?
http://img691.imageshack.us/img691/4575/jeffvettfrontlt5.jpg

Thanks,

[GOLDCYLON]

Check your oil cooler lines as well as they are in the same area as the "oil low" sensor just a little more forward. Also check the oil pan bolts as they tend to loosen.

[tccrab]

Check your oil cooler lines as well as they are in the same area as the "oil low" sensor just a little more forward. Also check the oil pan bolts as they tend to loosen.

I agree with our Cycloptic Moderator, these are the "Usual Suspects".
If the bottom radiator hose is oily, it's the oil cooler hoses.
If it's dripping from the back of the oil pan, it's the pan bolts.
If it's coming from the weep tube at the bellhousing, it's coming from under the plenum.
Rule these items out before you go messing around with the oil pressure/temp sensors.

TomC
'Crabs

[mike100]

The oil cooler lines, if leaking at the front crimp, can run down the side of the cooler and into the bottom shroud area. You can collect a whole qt down there, it takes days to stop leaking even after you repair the lines.

[Daniel_Mc]

GOLDCYLON,
I will check them all tonight if they are the culprit would it be ok to just go with SS instead of the stockers? I do not think it is the pan bolts Marc H. just checked those last spring.

tccrab,
I am fairly sure the bottom radiator hose was oily the motor is dry along with the bellhousing. Everything is in the front of the motor and lower fan shroud.

mike100,
I was planning to pull the radiator any how to clean out whatever is trapped in there so I will just tackle it at the same time as well. I have had those GM crimped lines fail on my track car numerous times I finally just started making my own hoses and solved that problem all together.

Thank you all for the guidance!!

Daniel

[A26B]

Nice to have met you in BG!!

If not the oil cooler lines:

In this photo, you can see the sensor that typically fails, causing an oil leak in that area. It is under the oil filter, above where the arrow is pointing, and angles downward. Pretty hard to get to, but can be done with the right tool configuration. This sensor is for the low oil pressure light.

http://i190.photobucket.com/albums/z224/A26B/OilPumpAcessCover.jpg

[Daniel_Mc]

Thanks Jerry!
It looks like it would be right in line with the frame maybe the right socket and a swivel could get the job done if no possibly undo a motor mount and rock it to one side?

Daniel

BTW great talking with you this past weekend that 415 is SWEET!!!

[GOLDCYLON]

GOLDCYLON,
I will check them all tonight if they are the culprit would it be ok to just go with SS instead of the stockers? I do not think it is the pan bolts Marc H. just checked those last spring.

tccrab,
I am fairly sure the bottom radiator hose was oily the motor is dry along with the bellhousing. Everything is in the front of the motor and lower fan shroud.

mike100,
I was planning to pull the radiator any how to clean out whatever is trapped in there so I will just tackle it at the same time as well. I have had those GM crimped lines fail on my track car numerous times I finally just started making my own hoses and solved that problem all together.

Thank you all for the guidance!!

Daniel

Daniel the SS oil cooler lines are NLA im not sure if anybody else is making them. The last set here were sold by Jeffvette im not sure if anybody is maing them at the moment. There is a repro set available on Ebay at the $180 Price point @ http://cgi.ebay.com/ebaymotors/CORVETTE-ZR-1-LT5-OIL-COOLER-LINE-HOSE-SET-PN-12472184-_W0QQcmdZViewItemQQhashZitem2a0dcccbc9QQitemZ18062 0151753QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccesso ries

These are being offered by Jerry a forum member here. I also have a nice original used set that dont leak if thats what you are looking for original as well that I would let go for $120 shipped. Let us know what you find out. GC

[Paul Workman]

I can attest to the fact that if the low (idiot light) pressure sensor (the black sensor just above the yellow arrowhead in Jerry's photo) blows, it can pump a lot of oil out in a short time. (Pull the connector plug and look for oil to pour out of the weather pack connector housing. If wet, you know for sure it has been leaking!)

http://i190.photobucket.com/albums/z224/A26B/OilPumpAcessCover.jpg

I fussed around for quite a while, trying to figure out access to that little beotch. But, in the end, I found that had I removed middle fender pannel and the oil filter housing in the first place, it might have been a 30-45 min job. As it was, it took hours of fussing before figuring out how best to get to it.

Pulling the center fender pannel may not even be necessary, come to think of it!

FWIW,

P.

[Daniel_Mc]

GOLDCYLON,
If it is the Oil cooler lines I may try and make them myself out of some SS line it doesn't look to bad and I have done it with several other parts similar to that IDK if not I will defiantly take you up on that offer! I am not worried about "original" this car is far from it.

Paul,
That sounds easy enough but I am worried that the additional frame bracing on this car will get in the way... It looks to be forward of the sensor but I still may be in for some fun with this LOL

Daniel

http://img844.imageshack.us/img844/2360/1000646.jpg (http://imageshack.us/photo/my-images/844/1000646.jpg/)

[GOLDCYLON]

GOLDCYLON,
If it is the Oil cooler lines I may try and make them myself out of some SS line it doesn't look to bad and I have done it with several other parts similar to that IDK if not I will defiantly take you up on that offer! I am not worried about "original" this car is far from it.

Paul,
That sounds easy enough but I am worried that the additional frame bracing on this car will get in the way... It looks to be forward of the sensor but I still may be in for some fun with this LOL

Daniel

http://img844.imageshack.us/img844/2360/1000646.jpg (http://imageshack.us/photo/my-images/844/1000646.jpg/)


Lol reminds me of mine not a NCRSer. No sweat you will need a 1/1/4 and and 1/1/8 wrench if memory serves me correctly to get em off

[Daniel_Mc]

Well it's not the oil cooler lines they are dry aloof with the lower radiator hose. I am going to try getting at that sensor but at this point I can't even see it!

**got the sensor disconnected and it is full of oil (disconnected not removed that's going to be a bish!) It is still a bunch of oil could it really all just come from this one sensor?*

[A26B]

If it were me, think I would go with removing the oil filter adapter.

[Daniel_Mc]

I think that is what I'll have to do. I attempted to go from the bottom but everything is welded. The bar and bracing up top doesn't get in the way to much I can get my hand to the sensor but that is about it. Thank you Jerry :cheers:

[Daniel_Mc]

Anyone know what size wrench goes on this sensor?

[A26B]

1-1/16" open end. 12pt box end won't go on. Sensor socket is 6pt (rounded corners)

[Daniel_Mc]

Jerry,
Thanks! I'm going to owe you a few beers after this is done :-D

[-=Jeff=-]

I have a slight leak, coming from that area too. i am starting to wonder if mine is the beginning of what you are seeing..

[Daniel_Mc]

Jeff,
I looked over the car and never noticed it and it never leaked a drop before this "blow out". But then again I only had it for 3 days before this happened... None of the engine cradle or aluminum on the block is stained so it doesn't look like it was leaking much if any before. So do these things just go like this? I am still worried it is something worse but after going all over it I can't find anything. The motor starts with no issues and runs just fine with no loss of oil pressure.

[Paul Workman]

Jeff,
I looked over the car and never noticed it and it never leaked a drop before this "blow out". But then again I only had it for 3 days before this happened... None of the engine cradle or aluminum on the block is stained so it doesn't look like it was leaking much if any before. So do these things just go like this? I am still worried it is something worse but after going all over it I can't find anything. The motor starts with no issues and runs just fine with no loss of oil pressure.

Well, mine recently blew. I was wondering why I had some dust "freckles" on my passenger window and the right side of the windshield. Marc said that apparently the car used 1/2 quart of oil during his runups while tuning it. Hmmmmm....sez me. :confused: Never used oil like that before.

Then on my first pass on the drag strip on the infamous day Dominic crashed, the sensor finally blew out big time!!

Far as a trend goes, a single datum does not a trend make, but there now you have ONE!:cheers:

P.

[Daniel_Mc]

Paul,
That makes me feel a little better (I guess LOL). I lost about a quart and a half of oil when the sensor went. I have some of the ?freckles? under the passenger side floor board and rear wheel well.

Daniel

[jrd1990zr1]

I had a problem with a leak and it was caused by one of the bolts (there are only 3) holding the oil filter housing losening up causing a leak.

It might make some sense as Jerry mentioned to remove the oil filter adapter if you have clearance problems. I'd use a new gasket (from Jerry) and torque the three bolts as shown in the FSM. I think you are supposed to use threadlock on them, check the FSM.

Good Luck :cheers:

[Daniel_Mc]

jrd1990zr1,
I did just that. I was worried that I might have to remove the filter adapter so I went ahead and got the gasket. Do you happen to know the torque #'s? I need to get a FSM!

Daniel

[VetteMed]

I think this is the source of my persistent oil leak as well. I was pretty stupid for not replacing it when I last had the filter housing off.

[VetteMed]

Nice to have met you in BG!!

If not the oil cooler lines:

In this photo, you can see the sensor that typically fails, causing an oil leak in that area. It is under the oil filter, above where the arrow is pointing, and angles downward. Pretty hard to get to, but can be done with the right tool configuration. This sensor is for the low oil pressure light.

http://i190.photobucket.com/albums/z224/A26B/OilPumpAcessCover.jpg

In this pic, what is the plate that the arrow is pointing to? And what size are the bolts that secure it?

Thanks
Andrew

[jrd1990zr1]

jrd1990zr1,
I did just that. I was worried that I might have to remove the filter adapter so I went ahead and got the gasket. Do you happen to know the torque #'s? I need to get a FSM!

Daniel


Daniel,

I'll look it up and post later tonight. Sorry for the delay in responding.

John :cheers:

[Daniel_Mc]

John,

Thanks! I honestly haven't had a chance to do anything with the car the past 2 days. Hopefully tonight I will have a couple of hours.

Daniel

[-=Jeff=-]

In this pic, what is the plate that the arrow is pointing to? And what size are the bolts that secure it?

Thanks
Andrew

7mm or 8mm and yes oil can leak from there. if you can get to it.. let me know how, I want to check mine as well

[VetteMed]

7mm or 8mm and yes oil can leak from there. if you can get to it.. let me know how, I want to check mine as well

I've got my oil filter housing removed right now, and am thinking that while my AC system is apart, I may have some extra clearance to reach down in there with a box-end wrench. I will let you know what I am able to come up with.

[jrd1990zr1]

Daniel,

19 ft-lbs

Good luck, John :cheers:

[Daniel_Mc]

Awesome! Thank you. I should be home in and able to start on the car in the next 2 hours. Great way to spend a Friday night huh?

Daniel

[Vikki]

Hi, I'm new to the forum and have a small oil leak. I think it is coming from a pipe plug below the left cylinder head in the block. The oil drips on an O2 sensor on the left exhaust pipe creating a burning smell. Does anyone know what size Allen wrench will fit it?
Thanks in advance for your help.

[LGAFF]

I had same issue with Cam Position Sesnor...new O-Ring and problem solved

[VetteMed]

7mm or 8mm and yes oil can leak from there. if you can get to it.. let me know how, I want to check mine as well

It's 8mm bolts that hold that cover on. Once I removed my oil filter housing, to change out the leaky oil pressure switch, this plate is fairly easy to access. I don't see how you could get to it with the oil filter housing bolted in place, however. My bolts were snug, but not tight - I gave 'em an extra 1/4 turn with a box-end wrench.

Not a bad job:

Remove serpentine belt
Unbolt belt tensioner
Remove oil cooler lines
Unclip 3 electrical connections on filter housing
Remove bolts for oil filter housing (3 down low, one up high).

an $8 gasket from Jerry for the filter housing, and you're good to go.

Andrew

[ittlfly]

I had same issue with Cam Position Sesnor...new O-Ring and problem solved

I'll drink to that....:cheers:

[-=Jeff=-]

It's 8mm bolts that hold that cover on. Once I removed my oil filter housing, to change out the leaky oil pressure switch, this plate is fairly easy to access. I don't see how you could get to it with the oil filter housing bolted in place, however. My bolts were snug, but not tight - I gave 'em an extra 1/4 turn with a box-end wrench.

Not a bad job:

Remove serpentine belt
Unbolt belt tensioner
Remove oil cooler lines
Unclip 3 electrical connections on filter housing
Remove bolts for oil filter housing (3 down low, one up high).

an $8 gasket from Jerry for the filter housing, and you're good to go.

Andrew

Thanks.. my next winter project

[Daniel_Mc]

Well It took all of about 30 minutes with the correct tool and the sensor was changed and I haven't had another issue with the ZR-1 at all. Thanks for the help from everyone and Jerry Thank you for the part and gasket!!!!

Daniel