Oil leak help...

[bans25]

Oil leak on pass side of the block I think it may be this sensor near oil dipstick? Any idea what this sensor is? Does this typically leak oil or probable it's something else leaking? I have about 40k miles on my 90.

Thanks much!

[LGAFF]

Header stud

[Dynomite]

Oil leak on pass side of the block I think it may be this sensor near oil dipstick? Any idea what this sensor is? Does this typically leak oil or probable it's something else leaking? I have about 40k miles on my 90.

Thanks much!

Oil Pressure Regulating Valve Cover Plate :cheers:

Potential Oil Leaks and the OPRV Cover Plate (http://forums.corvetteforum.com/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp.html#post1581302471)

[GSJoe]

Oil leak on pass side of the block I think it may be this sensor near oil dipstick? Any idea what this sensor is? Does this typically leak oil or probable it's something else leaking? I have about 40k miles on my 90.

Thanks much!
The sensor you're talking about is the switch for the low oil pressure warning light in the dash cluster. I and numerous others have experienced a leak from that little bugger. If you can get your hands on it and remove the connector, you might find that oil is even leaking into its wire loom. That was the case with my '90. It's kind of a pain to get at this switch because of everything around it, and some folks have removed the whole assembly in which it's mounted. Others claim going through the right front wheel well is the way to go. My hands are small, so with the right size socket and extension plus a little diligence and a few swear words I was able to replace the switch without removing anything else. If you search "oil light switch" in this forum you'll probably find what others have done. You might also look at Marc Haibeck's article on oil leaks at http://zr1specialist.com/HAT%20Web/articles/finding%20and%20fixing%20oil%20leaks.htm If I were you, though, I'd first try to remove the connector from that suspect switch to see if there's oil in it and in its wire loom. If so, you've found the source.

[bans25]

thanks all, I will put it back up on the lift and take another look.. its tight up there! I cant tell exactly where it is coming from but looks like its from that switch..

Here are some pictures I snapped when it was on the lift.

Does anyone happen to have the PN for that switch? I am thinking if I get this back up on the lift I might as well replace it.. I assume its an O-ring behind the switch assembly?? I am having problems finding this sensor or info about it online or with forum searches?

[bans25]

When I look online I find this sensor: http://www.ecklerscorvette.com/corvette-engine-oil-sensor-low-level-1990-1995.html

Yet I believe this one is closer (however mine is all plastic): http://www.ebay.com/itm/Engine-Oil-Level-Sensor-Standard-FLS-18-/251953325460?hash=item3aa996a594&vxp=mtr

[garyhugo]

Your looking for "oil pressure switch".

[PhillipsLT5]

Jerrys Gaskets can set you up

[A26B]

This is the Oil Pressure Switch if that is what you need.
http://www.jerrysgaskets.com/switch-low-eng-oil-pres-indicator-new-90-95-9b3/

Post #4 Good Advice:
........If I were you, though, I'd first try to remove the connector from that suspect switch to see if there's oil in it and in its wire loom. If so, you've found the source.

Post #2 is a common leak & good place to investigate if no oil in the oil pressure switch connector, quoted above.

[GSJoe]

When I look online I find this sensor: http://www.ecklerscorvette.com/corvette-engine-oil-sensor-low-level-1990-1995.html

Yet I believe this one is closer (however mine is all plastic): http://www.ebay.com/itm/Engine-Oil-Level-Sensor-Standard-FLS-18-/251953325460?hash=item3aa996a594&vxp=mtr

I wonder if we're talking about the same switch. What you're looking at in these two links is a low oil level sensor located on the pan of your engine. That's not the switch I wrote about in a post above. The switch I'm talking about is located at the bottom of the oil filter housing. It's near the dip stick tube which is what you mentioned in your post. Here's a picture of an oil filter housing removed that shows the low oil pressure switch for the light on the dash. If we're talking about the same item, its GM part number is 25036935 or AC Delco D1846. It's an easy part to buy.
https://us-mg6.mail.yahoo.com/ya/download?mid=2%5f0%5f0%5f3%5f365131%5fAGLsw0MAAMc3 VWNemAI%2bOJpPEL0&m=YaDownload&pid=2&fid=Draft&inline=1&appid=YahooMailNeo Note that it has only a single wire attached to it.

[Dynomite]

http://i287.photobucket.com/albums/ll142/dynomite007/B%20Engine%20LT5/SOilFilterHousingLabel_zps4cacf14a.jpg

Oil leak on pass side of the block I think it may be this sensor near oil dipstick? Any idea what this sensor is? Does this typically leak oil or probable it's something else leaking? I have about 40k miles on my 90.

Thanks much!

A bit more information on exactly where the oil is "dripping" from and how much?
Is the oil dripping from the side of the oil pan and between what two oil pan bolts?

One method to use is to pressure wash the under side of the engine including from top right and left side (under hood) just below cam covers (when engine is NOT hot). Do not get water below the Plenum in the Valley. After the pressure wash it is then much easier to see fresh oil leaks.

[bans25]

I wonder if we're talking about the same switch. What you're looking at in these two links is a low oil level sensor located on the pan of your engine. That's not the switch I wrote about in a post above. The switch I'm talking about is located at the bottom of the oil filter housing. It's near the dip stick tube which is what you mentioned in your post. Here's a picture of an oil filter housing removed that shows the low oil pressure switch for the light on the dash. If we're talking about the same item, its GM part number is 25036935 or AC Delco D1846. It's an easy part to buy.
https://us-mg6.mail.yahoo.com/ya/download?mid=2%5f0%5f0%5f3%5f365131%5fAGLsw0MAAMc3 VWNemAI%2bOJpPEL0&m=YaDownload&pid=2&fid=Draft&inline=1&appid=YahooMailNeo Note that it has only a single wire attached to it.

The sensor/switch I am talking about is not on the oil filter housing, its back right next to where the oil dipstick goes into the block and just behind the motor mount.. the oil filter housing is closer to the front of the car.

This one has me confused so far :)

[bans25]

Sensor is circled in the picture. I cleaned up the oil when the car was on the lift and let it run for about 20 mins, you can see the fresh oil in the area. I think its coming out from the right side of this sensor? it does not seem to be coming from above but its possible I am mistaken. If I can find one of these sensors I plan on just replacing, cleaning it up again and running to see if this is the leak..

[LGAFF]

why not just replace the o-ring?

[bans25]

why not just replace the o-ring?

I have not pulled the sensor out yet but could try replacing the o-ring, I am still confused on what sensor this is (since its not on the oil filter housing), I am assuming its a oil-level switch?

[A26B]

It is the crankshaft position sensor.
1990 does not have an oil level sensor.

[bans25]

It is the crankshaft position sensor.
1990 does not have an oil level sensor.

thank you, I just looked up the crank position sensor and it does look much closer than other sensors I have been looking at.

When I pull this, replace the O-ring and re-install, is there any case learn procedure that needs to be run?

I appreciate all the help! Will be nice to clean up this leak.

[Jitse]

You can take out the sensor without any problem, it can be sticky but play a bit with your fingers and you can pull it out. I am taking of the - pole from the battery when working on electronics / engine.
If taking off the negative cable, computer needs to learn again after connecting battery.