'96 Cadillac w/smoking exhaust & overheating

Most temp gauges are set up to where the mid-point on the dial is normal operating temp. If you were told there is a bad head gasket, and this hasn't been replaced, then that is likely your issue.

No, that person is correct and hopefully it's just a gasket. Usually a Norstar Engine overheated isn't too healthy and you may need a cylinder head or two. It's nearly a 20 hour job when it's all done (just 4 gaskets). If you like the car perhaps a used engine may be cheaper.

Bad Head Gasket

ity sounds like the electric fan is not turning on, if it is only overheating at idle (sitting still) and is not overheating when driving, but any good shop should have already determined this. open the hood while idling, and watch to see if the fan by the radiator turns on when idling, and the temp is going up. if the fan is indeed working, then it may be the head gasket, or it may be a slow-to-open thermostat.

if it is the head gasket, you should notice one of the following symptoms: smoke out the tailpipe- usually white, green or red (depending on your type) coolant dripping from the tailpipe at start-up, murky or bubbly oil from coolant leaking into the oil, or an oily film on top of the coolant from oil leaking into the coolant. a clear water drip from the tailpipe is normal, form condensation, but if the drip is the color of your coolant, then you definitely have a head gasket issue.

OK, check that the 2 fans are turning on when it gets to operating temperature. If not, replace the 3 or so relays that control the two speed fans on your car.If that doesn't solve the problem, then you may have to buy new fan motors and also have the harness replaced if necessary to make it cool reliably.

I had this problem on a 1997 Cadillac Deville Limousine that overheated over 157 deg. F and went into its limp mode for cooling the engine off by allowing 1/2 of the cylinders to circulate fresh air into the engine in case all antifreeze would leak out or the car would overheat.

Don't run the Northstar engine too long, more than 45 min. at a time in this limp mode.

Good luck on this repair of your Northstar Engine.

These engines are know for leaking head gaskets. A good quick test for this is fill the coolant tank to the top with the cap off. Start the engine. If the the coolant blows out of the tank, you have a head gasket leak.

It could be signs of early head gasket failure. I had a subaroo do the same thing, ran great but would boil out water, then it finally blew. Had to replace the engine. It was cheaper than doing the heads. There was no signs of white smoke, no water in oil, just ran hot, some of the time. I don't know if a compression check would help, but what I would do is get it to a radiator shop, they will tell you more than anybody.

A head gasket leak is usually indicated (among other things) by continous overheating of the motor, and subsequent loss of coolant.
It can also be indicated by the presence of engine combustion gas bubbles in the coolant resevoir.
Ensure the coolant system has no external leaks, such as faulty hose/s, radiator etc.

Ensure motor tune or other motor mechanical condition is not the cause of overheating.
I assume the motor is actually running hot.

Check cooling fans are operating ok (as necessary when car warms up):- if not check
1) fuse,
2) relay operation,
3) heat sensor switch.

Check/replace the thermostat,
Check the coolant pressure cap is serviceable & of correct rating,
Ensure cooling system is correctly filled, bleed off any airlocks as necessary when re-filling,
Ensure radiator hose on suction side of waterpump is not collapsing at engine revs above idle (due softening),
If the motor has been severely overheated, the head gasket could be blown - look for combustion gas bubbles in the coolant resevoir.

did you run a compression check? if so and its good then you have a blockage in the water jacket
if not then you have a head gasket leaking

welocome to fixya

if you have white smoke out the tail pipe this means that the car is burning the coolat and sounds like it could be the head gasket or could be a cracked head