-98 Transport overheating
vette.se
12-26-2005, 03:32 PM
It seems like overheating is a common problem but I need to get your opinion before I start take things apart.
Car runs fine at normal temp and suddenly the temp climbs up to the redline and the warning light comes on, at the same time the heater starts to blow cold air. With the car still running opening the airvent screw(on the thermostat housing) it's only steem no water coming removing the screw completely still just steem. The coolant system is filled to the correct level so it seems like sometimes something blocks the water flow. Is it the thermostat that do not open or could it be something else ?
If it is the thermo do I need to remove the airduct + the throttelbody to access the thermostat ?
Thanks !
Car runs fine at normal temp and suddenly the temp climbs up to the redline and the warning light comes on, at the same time the heater starts to blow cold air. With the car still running opening the airvent screw(on the thermostat housing) it's only steem no water coming removing the screw completely still just steem. The coolant system is filled to the correct level so it seems like sometimes something blocks the water flow. Is it the thermostat that do not open or could it be something else ?
If it is the thermo do I need to remove the airduct + the throttelbody to access the thermostat ?
Thanks !
LMP
12-27-2005, 05:05 PM
All these symptoms are typical of a blown head gasket, which itself is typical of the 3.1/3.4, a well documented subject o this forum.
What blocks the coolant flow is compressed air and exhaust that invades the coolant circuit, something the pump is incapable of moving around and that is a 500 times less efficient heat transfer medium than water.
Normally however, this is accompanied by a relentless need for adding coolant to refill to proper level. For a while it is possible that air trapped in the system may impair replenishment and leave the impression that the system is full. Check the radiator level by removing the radiator cap(not the reserve/overflow tank) when car is cold and if coolant is needed, open the vent on the thermostat housing to let gases escape.
Since this diagnostic is undesirable, several will attempt to correct the symptoms by replacing radiator, water pump, thermostat, all that ends up as unnessssary added costs to the final operation that needs to be done anyway.
Every time I started to see these symptoms (I speak of decades ago), I would completely remove the thermostat to allow for unrestricted coolant flow...but that would maybe just retard the symptoms but finally the conclusion was always the same...and this has not changed decades later. I wish there could be miracles....
What blocks the coolant flow is compressed air and exhaust that invades the coolant circuit, something the pump is incapable of moving around and that is a 500 times less efficient heat transfer medium than water.
Normally however, this is accompanied by a relentless need for adding coolant to refill to proper level. For a while it is possible that air trapped in the system may impair replenishment and leave the impression that the system is full. Check the radiator level by removing the radiator cap(not the reserve/overflow tank) when car is cold and if coolant is needed, open the vent on the thermostat housing to let gases escape.
Since this diagnostic is undesirable, several will attempt to correct the symptoms by replacing radiator, water pump, thermostat, all that ends up as unnessssary added costs to the final operation that needs to be done anyway.
Every time I started to see these symptoms (I speak of decades ago), I would completely remove the thermostat to allow for unrestricted coolant flow...but that would maybe just retard the symptoms but finally the conclusion was always the same...and this has not changed decades later. I wish there could be miracles....
Automotive Network, Inc., Copyright ©2026