OK, now it's the white hatch... WTF

[markmdz89hatch]

Anyway, the past few days I've been noticing that where my car USE TO run a little on the warm side (the temp. guage was just a smidgin' over level) now, the sum'bitch runs COLD. I'm on the highway doin about 80 and the damn temp guage is reading COLD. Like not just a little below level, I'm talking all the way south. Any ideas?

[Neuspeed87lx]

bad thermastat? hey did you ever get pics of the 17's on your car?

[markmdz89hatch]

nope, long story, I had to take 'em back off for now. After I put in the new hubs&bearings I'll put 'em back on.

[87accordlx]

yeah i would guess it's your thermastat is stuck open, if that's not it it might be a bad sensor?

[markmdz89hatch]

are those easy/cheap to replace?

[jteuton]

Even with the thermostat stuck open....you don't have a clutch fan its electric and won't come on till over 180 degrees so eventually even if the thermo is stuck open your entire coolant will get so hot your fan will have to come on to cool it down. If you had a fan that ran and cooled the coolant all the time then I could understand running cold all the time but you don't. Its probably the little one wire plug on the housing that sends the signal back came unplugged. If the wire is still hooked up bets are its the actually temperature sending unit screwed into the housing. Don't confuse this one with the one that the computer uses to make fuel/air calculations with.....its a different sensor.

[markmdz89hatch]

do i even have that second sensor you mentioned? Remember, my car's carbed. DX all the way.

....so maybe I should let the cat out of the bag completely. Ever since last year (just after I got the car repainted) the car's temp. has been acting funny. I know all this is gonna sound real bad, so unless you've got a strong stomach, don't read on. Before it was painted, it could just sit there for hours idling, and the temp would NEVER change even in the slightest. Since the paintjob (not neccessarily blaming that for the problem), after the car would sit for even as little as 5 min. idling, the temp guage would creep its way to HOT (i'm talking all the way), then the fan would kick on (but not before), and the temp guage would quickly fall back to normal. If i'm flying like a retard down the highway, it stays level, but as soon as I'm sitting or just creeping in rush hour traffic, there it would go to HOT. That's been going on for about a year now. Don't worry, I didn't drive it much the past year. I had been making sure that the radiator was full all that time too. (It usually didn't need even a drop.) But...(I know I'm retarded)...I never even thought to check the reserve tank. I just did that a few weeks ago. It was bone dry, so i filled her up, and now she won't even get up to normal temp.

So, in light of that last little bit of pertinent info., anyone have any more opinions?

[jteuton]

Sounds like the sending unit is a piece of shit and need to be replaced. If your thermo is stuck shut then your car would overheat big time. If its all the way up on hot then you would probably seem steam and smoke coming up from under the hood. Since your gauge does nothing but basically lie all the time....look under the hood and check and see how hot it is. Grab the radiator hose and see if its warming up. Attach a mechanical gauge and get a real measurement.

[HostileJava]

It could still be the thermostat, It could have been stuck shut and your coolant wasn't flowing and now it finally opened up and your coolant is constantly cooling the engine down. It's relatively easy to replace, you'll just need to fill the radiator fluid back up after you take the housing off of the thermostat. You'll need a new thermostat and ring. Just becarefull you don't break the bolts off in the housing, I did that and ended up having to get a new housing(cheaper than buying the tools or having them drilled out at the garage).

[jteuton]

quote' your coolant is constantly cooling the engine down' unquote ......I'm not going to expain this anymore OK.....If thermo is stuck close the engine will overheat. If the thermo is stuck open if will take longer for your car to warm up but the coolant will eventually keep getting warmer warmer (especially sitting still, idling, and not moving) You see the fan is electric and won't come on till over 180. So if your car is sitting still and has no air flow (via fan or incoming from highway driving) it doesn't matter if your thermo is stuck open or not.....the coolant has no way to cool down even if it does have a path to the radiator....the radiator has no fan or air flow over it. If you are running down the highway and it is stuck open your car will definitely run cooler especially on a cold day cause of the path to the radiator but the hand in the dash will still creep up some. Just cause your thermo is stuck open doesn't mean your car will run ice cold.....it will on a clutch fan but not on a car with an electric. Do me a favor and idle it in the driveway for 10-15 minutes and see if the hand moves. By this time the coolant will have time to get hot (even with it going through the radiator) and should see movement in the gauge.....if not then its your sending unit. The fan will come on as you approach past the neighborhood of 180 which is what cools the coolant down especially when you have no wind hitting the radiator. Am i wasting my time?

[jteuton]

quote' your coolant is constantly cooling the engine down' unquote ......I'm not going to expain this anymore OK.....If thermo is stuck close the engine will overheat. If the thermo is stuck open if will take longer for your car to warm up but the coolant will eventually keep getting warmer warmer (especially sitting still, idling, and not moving) You see the fan is electric and won't come on till over 180. So if your car is sitting still and has no air flow (via fan or incoming from highway driving) it doesn't matter if your thermo is stuck open or not.....the coolant has no way to cool down even if it does have a path to the radiator....the radiator has no fan or air flow over it. If you are running down the highway and it is stuck open your car will definitely run cooler especially on a cold day cause of the path to the radiator but the hand in the dash will still creep up some. Just cause your thermo is stuck open doesn't mean your car will run ice cold.....it will on a clutch fan but not on a car with an electric. Do me a favor and idle it in the driveway for 10-15 minutes and see if the hand moves. By this time the coolant will have time to get hot (even with it going through the radiator) and should see movement in the gauge.....if not then its your sending unit. The fan will come on as you approach past the neighborhood of 180 which is what cools the coolant down especially when you have no wind hitting the radiator. Am i wasing my time?

[jteuton]

check that.....i think the fan hits in maybe around 200-210.....need a mechanical gauge with numbers to be sure

[markmdz89hatch]

jteuton --> You're definitly not wasting ur time. I'm trying to follow everything you've suggested. I'll have to read over it another time to make sure I understand everything correctly. What I can say is, as you suggested for a test, to just let the car idle for 10-15. I've done that, when it's just idling, it seems to get up to temp as the engine warms up, then it may go a little over the dead level position, fan kicks on, engine cools back down to position the needle just below dead level. That would seem logical, and OK, but as mentioned before, once I hit the highway, or even just regular around town driving, she goes COLD. (When I'm mentioning cold, warmed up, etc. I'm speaking only of what I'm seeing on the temp guage.)

Now, as mentioned before, she use to sit there dead level all the time. I could Idle her for an hour, and the needle stayed put, never budging up or down. And, my coupe that I just picked up is the same way.

Not to beat a dead horse, but now that I've explained a little more in depth as to the problems, is there any other suggestion, or would that lean you more toward Thermostat, or sending unit? Or do you think it'd be best to start over with a clean slate, and do both?

[anchovies]

Test the gauge by grounding the sending unit. If the gauge goes all the way up, then your sending unit is the culprit. Easy change, but becareful, because it's at an angle.

[jteuton]

That last post makes me lean to the thermostat now. Because if you sit still and idle it gets warm....(thermostat is stuck open and coolant is flowing through the radiator but there is no air flow over the fins so it has to get warm)......when you start driving and with it being so cold out now....the air flow hits the radiator cooling the coolant way down and thus the engine. This is a hard call. Do both at the same time and you'll know you got it whooped. Get a Robert-Shaw Thermostat (absolute best) at Pep boys or Autozone for like 5-10 bucks and a sending unit for another 5-10 bucks and it takes like 15 minutes to change them out. The suckiest part of the whole job is having coolant go ever where when you pop the housing off.

[anchovies]

Just wanted to add that I got the same problem as you described. For me, it was the sending unit. But hey, a new thermostate is good for the car too.