What's wrong with my cooling system???

[shelldrake]

Ok, so the temperature decided to skyrocket upon startup on the way back from the autoshop, (as in within 5 mins). I replaced the thermostat - same deal.The water level would drop if I blipped the throttle a bit. the radiator felt warm at the top, cold at the bottom. I assumed(as did others around me that the radiator may be blocked). Got a known good radiator and replaced the following day. Problem appeared solved....Then once again the mystery rising temperature. All I did was take the cap off, pump the throttle a few times and then after a couple of attempts with the temp still rising, left for a few mins. Started up again and the correct operating range was seen on the temp guage. Any thoughts would be much appreciated. From here I will be replacing the guage and sensor, but other opinions are welcomed.

[twentyEight]

Has this engine been re-built?

[airfireman1]

Have you checked the water pump. How cold at the bottom and how hot at the top?. Poor water circulation can be a cause. You should be able to see the water circulating with the cap off and thermostat open.
Another thing is you could have a air pocket so make sure the system has all the air out.

[kme023]

Without knowing to much about the engine, i have to agree with the above.
To much air in the cooling system will cause the water to remain stationary in the block and by revving the engine with the radiator cap off would b enough to clear it.
Has the problem re occurred after clearing it as you mentioned?

[shelldrake]

When I replaced radiator, I ran motor for a few minutes and let warm up. Radiator was full, when warmed up level had dropped. I topped up then put cap on.When I revved the motor the water level drops. I couldn't really see the water circulating...New water pump. yes.

[Vios-GT_07]

BHG?
1. Temperature fluctuations to revs
2. water doesn't seem to be going around properly
3. turning off and turning back on seems to make a difference..

is engine oil cappucino and u got froth at the oil cap?

[allencr]

I havn't read anything to suggest that this isn't just a gauge problem.