overheating

[caddyguy]

hello all,,

well im having an overheating problem in 93 eldorado North* i'v already changed the radiator ,water pump and the thermostate and it went up 120 C wich 248 F then i stoped the car,, i really dont know what is the problem,

Regards,,

[Cadillac Jim]

I would recommend two things: First, get the OBD I codes, and second, have a radiator shop check your coolant for combustion products.

If the coolant has combustion products, you almost certainly have a head bolt pulled out and a head gasket leaking. This requires that you replace your head gaskets and use timeserts for all head bolts

If the coolant doesn't have combustion products, then the codes will help locate the problem. Here's how to get the codes:

http://www.caddyinfo.com/readingcodes.html

You can check a few things now. Is your coolant 50% antifreeze? Do you have to add coolant? Look at the hose between the surge tank and the thermostat housing by pulling it off at the thermostat and seeing if coolant flows freely out of it.

[caddyguy]

dont I have to check the fans and how would i do that???and wut about if let to both fans always working

[MAC]

You should be able to see both fans working once the temp reaches 225 degrees. The problem with the fans working continuously is that they were not designed that way. You need to find out why it's overheating in the first place. If you have a defective head gasket which is allowing hot combustion to heat the coolant then I doubt that keeping the fans running at all times will solve the problem.

[Ranger]

The flow in the purge line is from the water pump to the surge tank. Pull it at the surge tank to check for flow. If there is none, locate and clear the obstruction. Also check the water pump drive belt tensioner as well as the surge tank cap.

[caddyguy]

i took the car now to the workshop and the guy said that he check the headgasket without removing all the engine out of the car and he will press the heads an tie it something like that i dont know he said it will finish tomorrow morning ,,,but the thing is that when it reaches to 225 the other fan works but the temp still goes up nothing happens,,,

[Ranger]

guy said that he check the headgasket without removing all the engine out of the car and he will press the heads an tie it

Huh?

[KHE]

i took the car now to the workshop and the guy said that he check the headgasket without removing all the engine out of the car and he will press the heads an tie it something like that i dont know he said it will finish tomorrow morning ,,,but the thing is that when it reaches to 225 the other fan works but the temp still goes up nothing happens,,,

????? What is he going to press and tie????

Was the waterpump belt tensioner and flow from the purge line checked as mentioned previously?

[caddyguy]

yes i have checket the water pump belt and its ok ,,,,,tie n press the pistones n the cylenders scruess and he will check the pipess in and out the engine

[Cadillac Jim]

It is a mistake to mess with the head bolts. Don't do it. If you do, you will mess up the factory torqueing accuracy. An attempt to tighten head bolts on an old aluminum engine will very likely strip out several head bolts. If you do have head gasket leakage, the problem is almost certainly one of the head bolts pulled out already, and it can't be tightened without installing an insert (the insert of choice for most aluminum engines, including the Northstar, is a Timesert kit). In any case, tightening head bolts on an old engine with head gasket leakage won't fix it. I suggest that you troubleshoot the problem yourself with help from this board, or get another mechanic that isn't so anxious to force a very expensive repair that may not be necessary.

Any good radiator shop can test the coolant for cumbustion products in a few minutes. All it takes is to get a couple of ounces of coolant out of the surge tank with an antifreeze tester and put it in a small glass. Then, you add a test strip or a couple of drops of test solution and watch for a color change.

You can check the fans by turning on the air conditioner. They will both run at low speed if the air conditioner is turned on. If only one of them turns on, then you need to check the wiring and relays as well as the fans themselves.

As MAC says, running the fans won't solve an overheating problem. The system, working properly, does an amazing job of keeping the engine temperature very uniform over a wide range of operating conditions.