z6 overheating

[themeltingpointofwax]

So my car's overheating. It mostly does it after I've been on the highway, and then it wont go away. If I just drive around town, I find that it doesnt really overheat very much. If I turn the heater on full blast it brings the temperature down pretty much to normal (the middle). So far, I've flushed the radiator, and changed the thermostat. I checked, and the fan is turning on up front when the car gets hot. I changed the water pump with the timing belt/tensioner job this past September. I'm thinking possibly the water pump might have gone bad, but I'm not sure. I'd like it if that wasn't it so I don't have to go through the entire timing belt ordeal again. Here's where it gets kinda weird... If it starts overheating, and I put the tranny in neutral and rev the engine to like 5 or 6k, it will drop the temperature guage drastically.



Any suggestions?


One person told me I might have to take it to a radiator shop to have the coolant passages checked to see if they're rotted or something...


:(

-Rick

[H2Bcivic]

do u have to add coolant after it over heats?

[themeltingpointofwax]

I havent had to add coolant yet, but I'll double-check that in the morning. It does have a slow leak coming from the draincock, but I don't think that lack of coolant is the issue.

[H2Bcivic]

thermostat is good? how many miles is on teh car? have u always put distilled water in?

[94z6ex]

i say water pump...........just because you replaced it recently doesnt really mean anything......parts go bad all the time.

start the car, drive it to get up to temp faster and park it and let it run for 10 minutes........take a look under it and see if there is a coolant leak under the location of the pump. youve gotta eliminate all possibilities one by one until you know what it is.......i would almost guarantee water pump if the thermostat is good, and youve flushed the system already.

[vtec_bomber]

I havent had to add coolant yet, but I'll double-check that in the morning. It does have a slow leak coming from the draincock, but I don't think that lack of coolant is the issue.

That is a problem there. Even a little air leak will cause the car to over heat. Tighten it tight so that no coolant is leaking. Check all the radiator hose and look for wear on them.

[transzex]

Rick, hit me up sometime, gonna be warm this week, don't hurt it!

Almost seems like a headgasket, but I've never had the issue your having.

WEIRD!

[H2Bcivic]

ur problem does sound wierd! im thinkin either head gasket or water pump!

[streetforce]

dude i think we may have the same problem....im going to change my coolant temperature sensor tommorow i think the guage or the sensor might be fucked up cause mine can go from normal operating temp to...like almost red in less than 10 seconds...try change the temp sensor its on the tranny side of the head right over the tranny just behind the header

[93reddelsol]

Radiator cap should work, I skimmed through the read, Just buy a new one. If it works, hmm just call me god. :)