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Cadillac Repair/Cadillac Seville 1991 (4.9)-Head Gasket failure?


Hello Rob,
A few days ago I drove my cadillac less than 2 miles (from a cold start) and noticed small amount of steam coming from under the bonnet so pulled over immediately. Called out AA breakdown and it seems the top radiator hose was loose and the water/coolant was spraying over the top part of radiator. He topped up the water and let it run for about 15 minutes and said drive it home but get a garage to check out why the hose had come loose or blown off.
The car has not been overheated and never has-after reading all your warnings on here I always keep a close eye on the temperature gauge. At the time of this happening the temperature was below 200 and after being topped up with water was no more than 208.
Have just taken to local garage who after gently revving engine up said the top and bottom hose to radiator were hard and this signals head gasket failure?? I have not been losing any coolant, the oil looks ok with no creamy deposits there and to me it drives perfectly ok.
Is the garage right or is there any other possible cause of this problem?
Have owned the car 10 years now in the UK so would hate to scrap it. Any advise would be very helpful.


Thank you so much for being one of my loyal followers. It is so cool to be known on the international stage.
The first thing I would say, is go to another garage. I ave never heard where if both hoses are hard that it indicates a head gasket problem.
If one was to test such and only depending on where the head gasket was an issue leaking into one of the cylinders, a cooling system pressure tester would display an erratic reading. It sounds like the people at the garage are taking you for a ride. The only reason for head gasket failure that I know of is over heating.
Please remember, the temperatures I give are for a perfect world and a 50/50 mix of coolant. Adding only water will bring the boiling point down, however 208 is not the boiling point of water which is 212.
From your description, it does not sound if there is any concern of head gasket failure.

Besides, its easy enough to  diagnose properly. The cooling system pressure tester is attached where the radiator cap would be. It is pumped up to 15 pounds. If it holds pressure, you have ni problem with leakage in the cooling system, head gasket or otherwise. If pressure does go down, one must look for the leak and it would be obvious, even if it is a trail running down the outside of the engine block from the head gaskets. One cannot just feel some hoses and make that diagnoses. With the tester out, the cap should be checked as well. It should hold 15 pounds.
I guess that is why we never had unhappy customers, because we never guessed and always used the proper diagnostic tools before we made a wild diagnoses, causing the customer lots of cash for nothing.

There is a right way and a wrong way to diagnose problems. Now, maybe this guy knows more than me, but without putting a cooling system pressure tester on the cooling system to even confirm the diagnoses is beyond me.

Thanks for following.

ood luck!

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Rob Painter


Alarm system questions cannot be answered on this forum. These systems are not what I can answer. Without being physically at the vehicle and not knowing what kind of electrical service has been done on the vehicle, there is no possible way to give an accurate answer over the internet. My expertise is in Ignition/key based anti-theft systems. These issues include GM VATS (resistor chip in key blade) PASSLOCK (MRD)-ignition lock rotation based, no special ignition key and the PKIII Transponder (computer chip in key) systems. These systems are not alarm based and are integral with the starting of the engine. This is why I cannot diagnose alarm problems without physically looking at the vehicle: Alarm systems are a completely different annimal than ignition key/lock based anti-theft system. Many alarm questions come from vehicles 10 years old, and since older, many hands that had been involved over the years.I am an expert in all GM factory (ignition/key based)systems. Alarm system questions pose to many situations beyond my knowledge as to what has been done to the vehicle over the years. Some guy may have actually wired the stereo into the alarm system. Who knows? Over my past 30 years in vehicle wiring repair, I have seen unbelievable wiring disaters done by guys that consider themselves "mechanics." I have seen stereos and alarms intalled using surgical tape. I have seen modules burn up, un-fused circuits, wiring jambed between the doors and even lamp cord used for a starter kill. To answer alarm questions over the internet without examining the vehicle is like asking; What does it take to remove a dent?


Education/Credentials-ASE certified. 11 years with a GM dealer and 17 years with a repair facility dealing with only the repair of theft recovered vehicles.

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