I did many searches and didn't find anything specific enough...

so here goes....

My engine temperature will sparadically rise to about 200 and then drop... and then even more spradically, it will rise to 220 and the LOW COOLANT LIGHT will come on and STAY on, even though the temperature comes down to 180 fairly quickly...

when the tempterature is down and i shut the car off and restart it, no more light.

all of this happens at both idle and while driving....

I went to the track the other night and i was getting ready for my 3rd run, and I saw the temp at about 230... freaked out and parked it (yeah it snuck up on me that quickly and i didn't even know it) but the car is RUNNING fine.... there IS coolant....

bad thermo? bad sensor? need to be bled? flushed? bad heater core?

this is almost as frustrating as an electrical problem! =)

thanks for your help guys.

 

Most likely bad/corroded/dirty sensor. Happens pretty often. I just disconnected mine and voila! no more light.

 

i'd start with the simple flush/bleed/clean sensor and see if that helps.

also check to make sure you are not losing coolant due to a faulty rad cap....if it's not holding 18psi than it could cause problems.

 

now that I have had more drive time under my belt wtih this particular car, I am finding that this problem only happens when i am parked and idling. it's completely fine while driving it.
Any thoughts?

 

Can anybody help me out?

 

I'd bet that it only happens when you're parked b/c you have low coolant flow rates and low air flow over the radiator, so then reduced coolant volume cools less effectivly, thus you see a rise in temperature. This is just an indication that you have a problem that needs to be fixed, so I'd get on that. I had the same problem and ended up with a premature rebuild because I didn't catch it soon enough, so it's best to catch it while there's still time.

 

basically, I should send the radiator to get cleaned... buy new hoses, new coolant sensor, new thermostat, check waterpump, all that crap? should I just go through it all?

So you mean when it's idling, the coolant isn't pumping through the block the way it should.... but when i'm driving, it's being forced through a little more?

 

I was having the same problem. Only later on down the line when I was driving, the temperature would rise up. Is your resivior cap mysterously popping off of its seat? It could be as simple as air in your lines or as complex as a blown head gasket (which mine was).

 

YES.. I did notice that the resevoir cap is NOT secure... I had to play with the damn thing for 20 minutes before it would stay on and even then it was a weak fit.

damn I hope it's not a blown headgasket.... the two owners before me were pretty conservative adults... I doubt it's been beaten enough to blow it.

So I guess before I start taking thing apart, get a new cap.... drain and refill coolant... clean coolant sensor. Sound like a plan for starters?

 

The water pump in these cars operates based on engine speed. That means that when you're driving at 3000 RPM there's more coolant flowing than when you're idling around 800 or so. If your coolant level is low for any reason, the rise in temperature will be more noticeable when the car is idling than not. Also, less airflow over the radiator (a la not moving) will cause increases in temperature when you're operating near the threshold of yoru cooling system's ability to disperse heat (low coolant).

I'd start by tracking down any possible coolant leaks by replacing that cap (cheap) and going from there. There's no way to know for sure without trying things, so I like to start cheap and work my way up. Good luck.

 

Thanks a lot guys.... I am going to dig into it first thing tomorrow morning. I'll start cheap like you said. buy a new cap, backflush the radiator, clean sensor, and new coolant... (my coolant is very mucky too... it's almost more like a slime)....
take it light!

 

as it turns out, my primary fans aren't coming on. that explains a lot... the secondary comes on at the right temp, but it should never get that High if the primary was working correctly.

All of my relays are fine....

any suggestions? links?

I HATE electrical problems... GRRRR!!!