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97 Northstar coolant leak


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Ok I have a 97 SLS with the 4.6 Northstar with 110K miles and I've owned it for about a year and a half. Antifreeze has been disappearing for a while. The radiator was leaking around the tanks so I replaced it. The water pump bearings were also leaking so I replaced it (the coolant has been changed twice at this point in the last couple weeks.) For about six months the low coolant message would appear on my dash, recurring ever more frequently. Recently it had been once a week. When starting my car in the morning, there was a huge cloud of water vapor that would evaporate quickly; much more than standard water vapor in the exhaust system (not to mention it smells like ethylene glycol). I checked my oil and it was remaining consistent (except for the half block leak that appears to be common) and did not have water in it. So I pulled the plugs and in cylinder 1, on top of the piston, was a pool of antifreeze. My hope is that it is only a leaky head gasket and not a cylinder wall (also since there was no water in the oil). Is that your assessment as well? With that in mind, I've gone so far as to remove the top engine components (intake and that jazz) and came to the conclusion that I need to remove the engine to actually accomplish the task. I read in another post about time-cert? What is it and how do I do it? Thanks.

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Sounds like headgasket. You have to remove the engine and timesert (kind of helicoil) the aluminum block. A lot of work, but if you do it properly the engine will be like new. Several members of this board have done it successfully and they are a great resource shoul dyou decide to do the repair yourself. Get Factory Service Manual for your car on eBay.

The saddest thing in life is wasted talent

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the novice mechanic may assume the heads can be pulled on most cars. till they run into a FWD northstar beast. look forward to a lot of work or have it towed to a garage that has experience with northstars. or tackle it yourself with some assistance from our group of caddy nuts.

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Yeah and it's too bad because I really love the car.

It's not the end of the world. If you have a decent set of tools, you can definitely do the job yourself. I bought a '97 STS 3-1/2 years ago with bad head gaskets and fixed it myself - I've put 46,000 miles on it since the repair.

'93 Fleetwood Brougham
'05 Deville
'04 Deville
2013 Silverado Z71

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i dream of getting a large shop and car lift. once the motor is dropped out the bottom the teardown and redo is easier but still a lot of work. a first timer might take a few days to get it done. can you leave your car on the lift for a week or more? most friends with shops want the hulk moved in a short time. or if your lift is private, i want to meet your friend.

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You should be able to put something under the body to move the car with the carriage out, ie floor jacks etc, then put it up on jack stands to get it out of the way

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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