Please help: car overheating

[House]

Hi guys

We have a 1997 opel kadet 160is.

The past year the car's engine kept heating up and cooling down, especially when it idled, came to a stop, etc.

I took it to a garage - and found it blew a headgasket.

It was skimmed, two cracked valves replaced, radiator replaced, thermostat replaced, etc.

We got the car back, but now again, with everything fixed, the engine would heat up two-thirds, radiator fan kicks in it cools down again, and then heats up again....

The heating and cooling still continues everytime we slow down to stop or idles the car. While the car moves the temp wont rise.

Is this normal?

 

[ponder]

With a name like House you should have this taped

 

[Masataka]

The car shouldn't really heat up much while driving as air is moving through the engine. On idle, if the car is heating up and then cooling via the fan, you might have a problem, but the fact that the fan is sufficient to cool it makes it sound like the issue is minor (if there is even one). Could also be that the new parts are just configured to be more active, or the thermostat is overly sensitive.

Also, in summer it's more likely with the heat, but strange to have that happen in cool winter conditions - although some days it can get a bit hot out on the road.

 

[isie]

remove the thermostat (temporarily) basically it will send water into the engine at start up, thinking that could still be faulty as its only kicking open when temp gauge is 2 thirds as opposed to little before the half mark.
of course if your car is parked outside good luck with cold starts

 

[Sinbad]

remove the thermostat (temporarily) basically it will send water into the engine at start up, thinking that could still be faulty as its only kicking open when temp gauge is 2 thirds as opposed to little before the half mark.
of course if your car is parked outside good luck with cold starts

Worst advice ever.

 

[isie]

Worst advice ever.

only for testing i did say temporarily.
the thermostat should only open up when the engine temp is about 95 but his seems to be going up higher, if the temp still goes up past the 1/2 with the thermostat out, its something else, if it doesn't his thermostat is buggered,

 

[Sinbad]

The fact it stays cool while the car is moving, and when the fan kicks in, tells me it isn't thermostat. Broken thermostats normally fail in such a way that the car takes too long to warm up, and doesn't run at proper operating temperature.

It may be the fan's thermoswitch activating at too high a temperature, or more likely a busted relay or motor somewhere. The fan probably has 2 speeds, one when the water hits 90 and a higher speed when it hits 100 or so. The lower speed appears to be not working...

 

[isie]

The fact it stays cool while the car is moving, and when the fan kicks in, tells me it isn't thermostat. Broken thermostats normally fail in such a way that the car takes too long to warm up, and doesn't run at proper operating temperature.

It may be the fan's thermoswitch activating at too high a temperature, or more likely a busted relay or motor somewhere. The fan probably has 2 speeds, one when the water hits 90 and a higher speed when it hits 100 or so. The lower speed appears to be not working...

Or the actual fan isnt turning on, OP didn't say if fan is on while idling, it could be turning due to the air rushing past it while moving

 

[House]

Or the actual fan isnt turning on, OP didn't say if fan is on while idling, it could be turning due to the air rushing past it while moving

Hi isie

The fan is indeed kicking in when the guage hits 2/3s. It cools down, the fan stops and then a few minutes later it rises again to 2/3s. The fan kicks in again, and this is how it goes all the time when I drive in traffic, stop at robots or stop streets, etc.

While driving the temperature stays below half and the fan does not kick in at all.

 

[Sinbad]

The car does have a 2 speed fan setup. From what I can see its quite a complex wiring arrangement. At low speed, both fans are run in series, thus dropping the speed. To kick in high speed a switch closes and grounds one of the circuits resulting in both fans getting full voltage.

Based on this I'd suspect that either one of the motors is blown, or there is a loose connection somewhere.

 

[isie]

Hi isie

The fan is indeed kicking in when the guage hits 2/3s. It cools down, the fan stops and then a few minutes later it rises again to 2/3s. The fan kicks in again, and this is how it goes all the time when I drive in traffic, stop at robots or stop streets, etc.

While driving the temperature stays below half and the fan does not kick in at all.

Then I think SInbad's advise could be right, drive a few mintues to warm it up then idle the car and see when the fan kiks in, then once the temp stabilise see how long the fan stays on, also see how long after turning the car of also how long the fan stays on.
It should stay on for a little while even though the temp is at 90

 

[Leimie]

I agree with Sinbad. If the temp rises while the car is idling and drops while the car moves then it tells me the fan is faulty.