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Re: 1990cad deville overheating
The first thing to check is to have the engine running. as soon as it reaches operating temp the upper radiator hose should get hot. if it doesn't then it's the thermostat. if it does then i believe your water pump is probably not circulating like it should and it should be replaced. however before replacing the wter pump make sure that the wire to sending unit is tight and not giving you a false reading. if your model has electric fans make sure the fans are running when the engine is hot. if they are not running check the relay in the fuse box for the fans with the engine running switch out the fan relay with the a/c clutch relay. ifthe fans kick on replay the relay with a new one. if they don't click on the it's either a bad wire or the temp sensor probe is bad. hope this answers your question. please rate this solution...thanks.
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ENGINE HOT TURN A/C OFF
Cooling System Description and Operation
ENGINE COOLANT HOT
The instrument panel cluster (IPC) displays ENGINE COOLANT HOT message when the IPC receives a class 2 message from the powertrain control module (PCM) requesting illumination of this driver warning.
The IPC displays ENGINE OVERHEATED message when the IPC receives a class 2 message from the PCM requesting illumination of this driver warning.
DTC P1258: Engine Coolant Over temperature - Protection Mode Active
Have it check
It may be in the computer programming for the engine to shut down when it gets too hot. FInd out why it is overheating. Low coolant ( leak )? Thermostat not working properly? Rad fan not coming on? Head gasket failure? To name a few
Is the thermostat opening at 195 degrees ? Does the radiator fan come on at 220 degrees ? The gurgling noise is usually air or coolant moving around in the system. If the engine is very hot this noise can be normal.
The most common overheating problem with the Northstar engine is a blocked purge line(small hose).The purge line is designed to purge air out of the cooling system. There is a small diameter hose coming from near the top of the coolant tank (not the cap) ,this is the purge line. With the engine idling,pull the purge line from the tank,if there is no coolant flow from this small hose,it is blocked and this will cause overheating. If the hose is clear, check for blockage at the nipple on the tank.Or trace the hose back until you find the blockage. The hose goes in to the engine to a crossover and comes out the other side close to the thermostat housing,the blockage may be there.
CAUTION: Never open, service, or drain the radiator or cooling
system when hot; serious burns can occur from the steam and hot
coolant. In addition, when draining engine coolant, keep in mind that
cats and dogs are attracted to ethylene glycol antifreeze and could
drink any that is left in an uncovered container or in puddles on the
ground. This will prove fatal in sufficient quantities. Always drain
coolant into a sealable container. Coolant should be reused unless it
is contaminated or is several years old.
4.5L and 4.9L Engines
Drain the coolant to a level below the thermostat housing.
It may be necessary to remove the upper air filter assembly on some models.
Remove the 2 bolts securing the upper thermostat housing to the lower housing.
Remove the upper thermostat housing.
Remove the thermostat and O-ring from the lower housing.
Fig. Thermostat installation-4.5L and 4.9L engines
Install the thermostat and a new O-ring to the lower housing.
Install the upper thermostat housing to the lower housing. Tighten the thermostat housing bolts to 20 ft. lbs. (27 Nm).
Refill the cooling system using a 50/50 mixture of water and ethylene glycol antifreeze.
Start the engine and check for coolant leaks. Allow the engine to
come to normal operating temperature. Recheck for coolant leaks.
Hope helps with this (remember rated this) Good luck.
If you have checked all of your coolant levels, and don't see any leaks - then more than likely your thermostat is bad. The part isn't any more than $10 -$15 dollars and can be replaced in less than an hour.
pull codes from on board diagnostics turn key on not running press and hold hot button on temp and off at same time till dash lights up write down codes respond with all computer codes i will help you determine prodlem and try to fix
if you have a northstart motor on it most likelly it is overheating
i went to the junk yard to get one of those engines and was tols all they are overheated, some problems with cadillacs nortsart
the only sujestion i will give you is to drain all the coolant and make sure to bleed the cooling system, and add only 50/50 coolant to it, some dealers are adding 100% solution of coolant or antifreeze, and that will cause the car to over heat
also autozone has a block tester tool with the directions to test for posible bad head gaskets and very easy to use, that's a loan tool service so you odn't have to buy it