When I drive first thing in the morning, the temp needle rises to near the red after about 5 minutes (though later in the day, it sits at about 9 o'clock or slightly higher during extended drives no problem). However, the engine does not seem overly hot to me when I look under the hood. Hoses are only warm to touch, coolant reserve not boiling. I'm looking to replace the coolant temp sensor/compensation board bypass. But I was wondering if there was an easy way to confirm that the engine was not overheating even though the needle is registering near the red? Thanks.

My car has this same problem. When warming up, every once in a while she continues to climb in temp, sometimes close to red, but it helps if I blast the heat. The strange thing is that it isn't due to working the engine hard, so there should be plenty of cooling power. After she calms back down all is good and there are no other signs of problems.

I think the engine really is getting hot because I have bypassed the temp comp board. I have also replaced the thermostat, the radiater with a heavy duty 3 row from IPD, radiator hoses, heater core hoses that go back to the firewall, and the coolant reservoir cap, and a new engine wire harness. None have had any effect. All of the above needed to be done as all were basic maintanence anyway. I also bypassed the non functioning AC pump by moving the powersteering unit forward about an inch.

The only other symptom my car has is a small stumble at idle which is supposed to be due to a vacuum leak. But I have gone around the entire intake manifold listening with a hose and can't find any leaks. I have cleaned the throttlebody, but I think I missed some of those small hose outlets so I am going to go back and do that again just to be thorough.

I was thinking that it might be a slightly unhappy ECU, or that the mixture might be off and during the initial warm up period the ECU doesn't look at the O2 sensor because it assumes it hasn't warmed up yet. But these are just my wild conjectures. I am starting to think about the fuel pump as well because it makes a bit of noise. If the fuel pressure is down, then we might have a lean condition which might cause a warm start.

If anyone has any suggestions, I would be more than happy to hear them.

My car just started doing this one day. Everything was stock at the time, so it wasn't due to one of my crazy modifications. And everything I have done since then hasn't changed the condition. And I don't loose any significant amount coolant so there doesn't seem to be a leak.

Maybe your thermostat is sticking. After it 'breaks loose for the day' all is well. I would replace this inexpensive component first. Why not flush the cooling system and wash the dirt out of the radiator while you are at it.

By the way, the radiator hoses will remain cool while the engine overheats if the thermostat gets stcuk closed.

Dan

I just replaced the thermostat with one I ordered from IPD. And I did blow the dust out of the radiator as well. Wasn't too dirty. Didn't flush the system yet though...