jamienoel

I very much apologize for this being so long, but I want to try and describe the problem as much as I can.


I try to follow as much of all your solutions as possible, and with your help, I have accomplished a great deal.

I had to change the engine this past winter, but am still using the same heads from the original engine. This is the second 350 engine using the original 305 heads, which is the same setup I've used since 2002.

When we were taking the engine out, we had trouble with the engine lift and it fell back in, which busted the hell out of the temp sender, so I replaced it with a new one from Advance Auto.

It's been reading as overheating under certain conditions and I'm not sure what to do about it.

I changed the old thermostat, (180) with a higher quality (180) stat that even has 3 tiny bleed holes or whatever they are called, so there was no need to drill holes as some suggested when my old stat was rising way up to the notch before red and then back down. It rises steady now. My old $3.99 stat was all screwed up and simply didn’t work correctly. The new one is working so much better and the heater even gets warm quicker than before for some reason. Wish it would have done that this winter because it took forever to warm up.

Under normal driving conditions on flat road, the gauge shows just touching the 220 mark, but if I go up a hill, the temp will go all the way up in the red and it takes a long time to get it back down to 220 after I'm on flat again. It doesn't matter if I'm on the side road going 30-40mph or on the freeway going 65, the same thing happens going up a hill. It has always raised going up hills, but with the old engine, (and temp sender) it wouldn’t go too far past 220.

I had this problem last week when the outside temp reached about 80 and it scared the kaka out of me because I frequently have to go up a 2-3 mile hill, and this part of Ohio being in Appalachia, there are a lot of them! I stopped and raised the hood to see how bad it was, but nothing was boiling over or gurgling, the hose was pressurized and everything appeared normal, but you can imagine my terror. I was afraid to drive it after that. This is the only car I have and if it dies, I'm screwed.

It has a new radiator, fan motor, radiator cap, water pump and now a new thermostat. Coolant seems to be flowing well in the radiator and after changing the stat, I put some coolant in, let it idle until the new stat opened up and then poured more coolant in. That seemed to be working well and it's staying full and has the correct amount in the overflow tank. I’m thinking those tiny bleed holes in the new thermostat helped out a little, but I don’t know for sure.

The air dam is fine and I have a switch hooked up to the (single) radiator fan and had it running the whole time.


Since it appears to be a generic sender for use on a variety of vehicles, could the gauge be reading 30-35 degrees off? It reads almost 220 as normal and it’s a 180 stat.

Any help will be GREATLY appreciated!

jamienoel

Additional info from driving it today: It's 65 out and it's steady running temp was between 220 and the first notch before the red. This is so worrisome because I didn't go up any hills today. I need to find someone with a laser thermometer or something.

8t2 z-chev

sure sounds like you have the wrong temp sender-220*
is way hot for the conditions you described. For the
overheating pulling a hill,make sure your engine is not
"pinging"-pinging or detonation under load will cause a
rapid rise in coolant temperature,wrong ignition timing
and/or too-lean mixture are common causes of the
pinging. Once you have the correct sender installed,
your gauge reading should be right around thermostat
temp under light load conditions with car in motion-
might climb to 210 or so pulling a hill then quickly cool
back to normal once back to level driving.

jamienoel

Okay, here's what happened the other day when it got up to about 73 outside.

When I left home, it was about 65 and I decided to get on the freeway. To the freeway it was just touching the 220 mark and after I got on the freeway, it stayed about 220. After reaching the top of the 3 mile hill, it went to not quite between 220 and the first notch before the red.

After getting back on flat road, it began lowering to 220. I got off my exit and drove on the side road to my destination. The speed limit was 45 and then 55 and of course lots of little hills.

By the time I reached my destination, the temp was headed for the first notch before red, but no further.

On my return trip, the outside temp was about 72-73. I had to drive through town because of a needed stop (25 mph and traffic lights) and the temp began working it's way to the red. It got to the red and then after I was through town and on a road where I was able to drive fairly free again, the temp began to lower close to the 220 mark again, but not quite to it.

I had the fan running through town and it's working normal. It's a new motor and runs great.

So, I'm going to find someone with a thermal laser gun thingy and check it with the car gauge and see how far it's off. If it's not off, I have no idea what I'm going to do.

It's not pinging.

I don't know if Advance Auto has one they can check it with. The whole dang cooling system was bought there, so I'm hoping they will help.

There is no way I can afford one right now unless I buy one with a check, take it to the car, read the temp and then return it. I couldn't do that though.

I wonder why the gauge is not more detailed on the temperatures instead of 100-220-260 between?

camaronewbie

If it's not literally boiling over, I wouldn't be too concerned. The guages are often off, and yes by that much if not more. Your dealing with a non-accurate guage itself, as well as a generic Autozone sender.

I'd replace the temp sender (driver side head between #1 & #3 plugs, single wire job, green wire), and see what happens with the guage. With new radiator, fan on always, and air dam in tact, I can't see how in the world the car could overheat (short of a bad head gasket or lack of oil or timing really off).

Do you have a Harbor Freight close by? $40 will buy you a laser temp gun if you do. Or can order online: http://www.harborfreight.com/non-con...ter-96451.html

But any shop should have one, and should shoot it for you free of charge to set your mind at ease.

jamienoel

I'll try a shop. As long as they don't want some crazy diagnostic fee or something. lol

The temp sender was bought at Advance auto, (this past winter) which is probably the same thing as AutoZone carries? The brand is BWD.

Unfortunately right now I don't have the extra $40 to spare, which is a bummer because I could probably use it for other things, and I called Advance since that's where everything came from and they won't check the temp with a gun, so I'll go ahead and try the local shops.

I have a candy thermometer. Wonder if that would work?