Ok, I just replaced my intake manifold gaskets, thermostat, and temperature sensor. Before my car (1997 3.4L Z34) would inhale air and it would say it is overheating. I could hear the coolant/water boiling and it would make a knocking sound as the air went to the top radiator hose. My temperature would go from overheating to normal over and over again. I now have the system almost completely devoid of air and it still says it is getting hot when im driving over 25 mph or so. When I slow down the temperature comes down again. THis is accurate about 90% of the time, sometimes it does get hot when sitting and sometimes it has a find temperature when driving over 25mph for a bit. I had my water pump replaced maybe 10k mile or so but no more then that. Any ideas guys? This car is almost in reliable condition after much repair and I would just like to get it to that spot! Thanks!

 

I mean fine with idling, not find

 

Thats sounds just like what a car once did to me ages ago.Turned out to be the lower radiator hose. Best way to check is to feel if its soft when warmed up. Also, you can see the hose compress when you rev up the engine. Hope this helps.

 

Do you mean that the lower rad hose had a leak in it?

 

NO. Not a leak. It was just old and was soft from old age. I dont know when you changed your hoses the last time, but it is something to look into.

 

I'm thinking it might be my water pump.. This morning I opened the hood and turned her on and heard a squeal coming from the water pump area. I thought that the water pump will grind but the noise sounds like it is comin from that area. After about 10 min of driving the temp came down a bit but would still get hot during anything over 60 or so but the temp would be straight up at what I'm guessing is 180 during anything lower then that. Any ideas? Kind of frustrating because I had the pump replaced less then 12k ago at a reliable and known mechanic shop, but that was 3-4 years ago. Haven't drove her much til this year! Thanks guys!