I seem to be having this exact problem. http://www.youtube.com/watch?v=4mMckr_sA3M

Water pump was replaced about a month ago, and directly after I noticed my car running a bit warmer than usual.. and the other day I realized that if I let it sit and idle that after about 5 minutes the temperature gauge will climb up and boarder the red.. But when I rev the engine (stationary or moving) the temperature will lower.. This guy says it was a bad water pump he had put in causing it not to engage at lower rpms.. I really really don't want to have another water pump put in.. Is there anything other than the water pump itsself that could be causing this?

Low on coolant. Get the air out.


- Your not-so-local, untrained, uncertified, backyard mechanic. But my @!#$ runs

Can you explain how air in the system would cause this?

Check your cooling fan, it should kick on a bit after the midlle on the temp gauge and go off at the middle or a litle lower, if it is not working as it should that could be it... When you rev.the engine up the pump pushes more water thru the cooling system thus the temp goes down.

Fan is definitely coming on. new thermostat. Somebody recommended that i take it and have the coolant flushed.

... wrote:Can you explain how air in the system would cause this?

Ender_Wiggin wrote:When i changed my cams i had to drain the coolant, was told to leave the cap off while running, tends to help with bubbles, same with squeezing the hose, definitly agree though, think i've added 8 qts total since the drain, and had a low coolant light the other day (small top off fixed the deal), i'd say just keep an eye on it. If the temperature gets high in the city, then you have an air pocket, (what happened to me).

- Your not-so-local, untrained, uncertified, backyard mechanic. But my @!#$ runs