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AC Not working / Possible Overheating?


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i am a bmw guy.

but a friend of mine came over to my house and asked if i could have a look at the ac that just stopped working.

i checked the fuses . there was pressure in the system , and the ac seems to start up.

but i noticed something fishy and i thought that is odd

the engine paint is pealing off (its a 99 sevile cts with 60k miles) and i thought that might be an overheating sign.

kennyjrengine99cadillacsevillect-2.jpg

april09gkidsspringbreak070.jpg

there is also a weird stain on the hood insulation

april09gkidsspringbreak067.jpg

that made me investigate a bit more.

april09gkidsspringbreak068.jpg

there is something like gasket maker visible in the oilfiller

and it looks like the camshaft has damage

april09gkidsspringbreak069.jpg

i noticed something that looked like oil on the coolant reservoir

april09gkidsspringbreak072.jpg

but worse... something that looked that well known choco-milkshake inside

april09gkidsspringbreak071.jpg

i then noticed there is barely any oil in the car. and my friend had to fill 4 quarts (?!) in 4 weeks in it.

to me that sounded like the car overheated at some point and the cylinders are warped now.

but again i am not a caddy guy ... i have bmw. and so i asked a mechanic friend to look at it.

the only thing that he thought was odd was the oil consumption but nothing else.

what do you guys think of it?

and thank you for helping my friend, the cadillac owner.

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I fixed the title of this thread to be MORE informative

Don't jump to so many conclusions

This is a 99, if the coolant was NOT maintained properly that will cause the problem you are seeing

If the cooling system does not hold pressure, that is a problem, did you pressure test the cooling system.

Cylinders do NOT warp in this engine, it was designed to run WITHOUT coolant for 50 miles

Oil being low does not concern me, it could have a case half leak or a pan leak or it could be consuming it, the cause needs to be determined. If it is consuming it, the rings need exercise via the WOT procedure do a search here.

How has this car been maintained?

You say cam damage, do you hear cam noise? does it misfire, do you have a misfire code, or check engine light?

Is the engine currently overheating when it is driven? Flush the coolant immediately and use the cooling supplement.

Sensors can cause AC problems, do you have a guage set? What are the readings?

If you do not know how to dump the DTC codes click HOW TO at the top of this page, then DTC CODES and follow the directions for a 99, post the codes here, that might tell us something about the AC, overheating etc

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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If there is engine oil in the coolant, the first thing I'd suspect is an oil cooler leaking in the radiator. A simple fix. There are a lot of perfectly running Northstar engines with peeling paint on the cam cover. Don't jump to any conclusions based on that... Why do you think the cam is damaged?

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

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If there is engine oil in the coolant, the first thing I'd suspect is an oil cooler leaking in the radiator. A simple fix. There are a lot of perfectly running Northstar engines with peeling paint on the cam cover. Don't jump to any conclusions based on that... Why do you think the cam is damaged?

it looked a bit discolored at some parts , a little blue-ish.

and yes that was oil in the radiator fuild

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If there is engine oil in the coolant, the first thing I'd suspect is an oil cooler leaking in the radiator. A simple fix. There are a lot of perfectly running Northstar engines with peeling paint on the cam cover. Don't jump to any conclusions based on that... Why do you think the cam is damaged?

it looked a bit discolored at some parts , a little blue-ish.

and yes that was oil in the radiator fuild

On the NS the only way for OIL to get into the coolant is via the oil cooler in the tranny, so if you are seeing oil you probably need to change the radiator as Kevin noted

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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[it looked a bit discolored at some parts , a little blue-ish.

and yes that was oil in the radiator fuild

I would not rip into the engine to change a cam based on that. If the engine was overheating, there are numerous warnings to the driver.

The oil cooloer assembly is replacable without replacing the radiator but you will need a new tank gasket and recrimp the tank. I'd check with a radiator shop. I would get this fixed asap.

When the oil level is 2 quarts low, the CHECK OIL LEVEL message is displayed on the information center. If the sensor fails, the CHECK OIL LEVEL message will display even if the crankcase has the correct amount of oil. The oil level must be checked when the engine is HOT. Topping off to the full mark on the stick when the engine is cold will result i overfilling the crankcase and oil will be burned off via the PCV system. Based on the your description, it sounds like your friend was overfilling the crankcase.

Back to the air conditioning, does the compressor engage? Is there cold air blowing out of the vents?

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

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the ac works again it was a fuse under the back seat apparently.

my friend took the car back to the place they bought it from and there they cnaged a

part under the car , that was suposingly leaking.

i'll get an update this eve and let you all know.

thank you for the help and maybe this could be usefuly to someone else

~michael

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