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97 STS N* Leaking Oil


zchiefn3

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My 97 STS N* with 162,000 miles is leaking oil. Is there anything that I can do short of paying nearly $3,000 to have the lower girdle regasketed and resealed? Are there any oil additives that may slow the flow? My driveway will thank you.

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For now, put the idea of sealing additives aside.

There are a number of things besides the case-half seal that can cause Northstar oil leaks. Have you checked to be sure that the oil is indeed coming from there? If not, do some searches on this site for "oil leak". You'll find descriptions of the usual things to check. Also, if you haven't spent any time under the car, try to get it up on some jackstands and look around under the engine. You may well find a few easily fixed things that are adding up to some serious dripping.

Report back. There are a number of folks here who can help you through the diagnosis.

Good luck.

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My 97 STS N* with 162,000 miles is leaking oil.  Is there anything that I can do short of paying nearly $3,000 to have the lower girdle regasketed and resealed?  Are there any oil additives that may slow the flow?  My driveway will thank you.

Try to determine where its coming from. If you want to get adventurous, locate the leak with fluorescent dye.

See this site where the following came from

http://www.aicautosite.com/garage/encyclop/ency21a.asp

Use an ultraviolet or "black" light detection.

Pour a one-ounce bottle of the proper fluorescent tracer dye (about five bucks a shot -- it won't hurt anything, and dissipates in 300 miles or so) into the crankcase, let the engine run, or, if the seepage is minimal, take it for a drive. Although cleaning the engine isn't really necessary, it's worthwhile if the grime is thick. Then, look around under the light. Use a shop mirror to take those ultraviolet rays where the light unit can't fit or be aimed. The offending area will jump out at you in bright yellow. It's the same principle as you might remember from the psychedelic sixties when a black light really made the colors of that Jefferson Airplane poster pop.

(I was into Jimi Hendrix) Mike

Early on sailors navigated by the stars at night and the North star became the symbol for finding ones way home. Once you know where the Northstar is you can point your ship in the right direction to get home. So the star became a symbol for finding ones way home or more symbolically even finding ones path in life.

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.

It's the same principle as you might remember from the psychedelic sixties

(I was into Jimi Hendrix)  Mike

I was at the Filmore East on New Years eve, 1970 when they recorded the Jimi Hendrix 'Band of Gypses' album live.

Good times... ;)

'93 STS.. opened, dropped, wide...fast.

user posted image

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zchiefn3,

As odd as it might appear, check your valve cover gaskets / bolts. I had a leak on my '97 that was driving me crazy (could swear it was the block). Tightened the valve covers a bit and ....presto! The leak pretty much disappeared!

Good luck!

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Thanks everyone. I had my local Caddy dealer service folks look at it who gave me the $3,000 quote and a long list of what needs to be done. I'll do some checking of my own before I spend the big money.

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If oil is leaking onto the top one of the exhaust manifolds, then I would say rocker cover gasket. If it is leaking onto the crossover, then it could be either rocker cover or out of the block girdle or oil pan.

Have someone give you a second opinion. You may have a combination of a major leak at the rockercover and a minor leak at the girdle/oil pan seams. If that is the case, I would change the offending rocker cover gasket & see if I could live with the other leak. For $3000.00 I could live with a small leak for quite a while.

Goof Luck.

Britt

Britt
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Sounds like it could be the oil pan gasket. If it’s similar to my pan leak, your leak is at the left (driver) side from the front around the left side. There is sufficient amount of leakage to saturate the pipe heat shield to the point that it has no place to go except onto the exhaust pipe. You will also see that the oil pan itself is coated with oil. I put my car on a lift and could see fresh oil at the oil pan gasket seal. I also have the smell caused by oil on the exhaust pipe. The other day I punched it while in second and aggravated the situation to the point that smoke was visible. As bbobynski said, the half-case seal rarely leaks enough to be noticeable since the oil level is below the seal and there is no pressure forcing the oil out. Check the oil pan gasket. Don't necessarily believe Cadillac service technicians or any mechanic for that matter. Before you spend nearly $3,000 you should confirm where the oil is leaking. You should put dye in the oil if necessary as it may reveal that you don’t have to spend three grand to solve the problem.

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Here's some info I put in another post recently. Thought it might be helpful:

As far as the oil leak, the biggest culprit I've been able to find on my 93 is the oil pan bolts. I've been all over under the engine, with dye in the oil and a black light.

The case half seal is not leaking, except for a slight leak in one spot. The pan bolts are another story. I've read about case porosity on the early lower case halfs. On mine, if you remove an oil pan bolt, it is sopping wet with oil. The bolts are outside of the pan seal, so in theory, they should be dry. The oil seems to be seeping into the bolt holes, where it runs down the bolt to the pan lip, then spreads out and finally runs down the side of the pan in a sheet.

And once it comes down the side of the pan, it spreads all across the bottom because of the casting ridge on center of the pan - including going over to drip on the exahust pipe that runs under the engine. Its actually quite interesting to watch with the engine running and dyed oil in it.

I've removed, cleaned with brake cleaner, coated with thread sealant, and replaced every bolt I can get to. It stops the leaks. Unfortunately, there are a handful of bolts I can't get to with the transmission in. But I have reduced the leaks by about 60 - 70% overall.

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My 97 STS N* with 162,000 miles is leaking oil.  Is there anything that I can do short of paying nearly $3,000 to have the lower girdle regasketed and resealed?  Are there any oil additives that may slow the flow?  My driveway will thank you.

Try to determine where its coming from. If you want to get adventurous, locate the leak with fluorescent dye.

See this site where the following came from

http://www.aicautosite.com/garage/encyclop/ency21a.asp

Use an ultraviolet or "black" light detection.

Pour a one-ounce bottle of the proper fluorescent tracer dye (about five bucks a shot -- it won't hurt anything, and dissipates in 300 miles or so) into the crankcase, let the engine run, or, if the seepage is minimal, take it for a drive. Although cleaning the engine isn't really necessary, it's worthwhile if the grime is thick. Then, look around under the light. Use a shop mirror to take those ultraviolet rays where the light unit can't fit or be aimed. The offending area will jump out at you in bright yellow. It's the same principle as you might remember from the psychedelic sixties when a black light really made the colors of that Jefferson Airplane poster pop.

(I was into Jimi Hendrix) Mike

scotty, that is the COOLEST thing!!! I didn't know they made such a thing for oil leaks! Learn something new everyday..... :D

-dave B)

Crystal Red Tintcoat Exterior | Shale/Brownstone Interior | 32k

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.

It's the same principle as you might remember from the psychedelic sixties

(I was into Jimi Hendrix)  Mike

I was at the Filmore East on New Years eve, 1970 when they recorded the Jimi Hendrix 'Band of Gypses' album live.

Good times... ;)

No way Bob, that is terrific, see we have more in common everyday! :lol:

And so castles made of sand fall in the sea, eventually

Early on sailors navigated by the stars at night and the North star became the symbol for finding ones way home. Once you know where the Northstar is you can point your ship in the right direction to get home. So the star became a symbol for finding ones way home or more symbolically even finding ones path in life.

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scotty, that is the COOLEST thing!!! I didn't know they made such a thing for oil leaks! Learn something new everyday..... :D

-dave B)

Cool Dave, I am glad I could help. The shop that used to work on my 91 before I purchased it used to use this method. Mike

Early on sailors navigated by the stars at night and the North star became the symbol for finding ones way home. Once you know where the Northstar is you can point your ship in the right direction to get home. So the star became a symbol for finding ones way home or more symbolically even finding ones path in life.

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