Heads on 1997 Cadillac Seville (sls) pulled loose from engine letting antifreeze enter into the combustion chamber of all eight cylinders. Heads were warped and had to be taken off engine and milled to refit to engine block. This work done at local Cadillac dealer (sam swope Cadillac, service manager dave holland 502 499 5015) cost to repair engine $4,999.47........I have spoken to quite a few Cadillac owners and service personnel and this is a constant problem with the Cadillac northstar engine and all Cadillac dealerships are well versed in repairing this engine defect........I have been told that if General Motors had put steel inserts into the aluminum block for the headbolts to tighten into at the factory that this problem would not repeatedly occur! from what I have been told GM was trying to save weight and improve fuel consumption and that is why they went to an aluminum block and heads.

- Louisville, KY, USA

Engine exhibited extended cranks after sitting for several hours. Dealer replaced fuel pressure regulator($$$). engine continued to exhibit extended cranks only more severe. Dealer replaced fuel pump ($$$$). engine continued to exhibit extended cranks. Dealer replaced fuel filter ($$) and fuel pump again. Crank problem now replaced by stalling after decelerating to near stop then doing a gentle tip in on accelerator as in making a turn or entering a traffic circle.

- Goleta, CA, USA

Vehicle has developed a major leak that is pumping oil onto the exhaust system. Nlm oil leak caused by a faulty rear main seal. Engine was running rough due to faulty 02 sensor, fuel gauge reading erratically due to bad spot on sender. While driving and hitting a bump, there was a rattle under the vehicle, dealer replaced the right strut and mount.

- Wonder Lakes, IL, USA

The engine cracked at 68000 miles. I called Cadillac to replace the engine, but they refused. I had a ost of other problems with this car from the beginning. They should all be recorded by the Cadillac dealer in conroe, Texas and here in lexington ky. I believe that this car was a lemon when I bought it.

- London, KY, USA

I have had extreme oil compsumption since I purchased the car from superior. It was used and still is under warrenty. I have had it back to them three times for this and they ran two different oil comsumpion tests.. one for 4000 miles which took 5 1/2 quarts oil and one 500 mile test that took 1 qrt.. since then they have declined to tell me what the statis of the complaint to GM is..thanks.

- Cross Lanes, WV, USA

Engine backfires at start---engine stops on decelleration both intermittently. Dealers have replaced air intake sensor, fuel sensor, fuel filter and crankshaft position sensors.

- Innsbrook, MO, USA

Engine oil consumption very high, unable to repair/rectify on several repair attempts. Mjs

- Norcross, GA, USA