View Full Version : Hepl!!!!! Overheating

08-20-2003, 04:09 PM
Hi all and thanks for your time!!!

I am currently having a problem with my car and its really weird!!!

To say "The olny time it DOESN'T overheat" is when i have the A/C or Defrost on.....and it has to be on "HOT AIR"----very important!!!!

I am confident that I'm not loosing any coolant anywhere at all throughout my system....because I never have to add any to it!!

I know that my fan doesn't turn on unless i manually turn it on via the A/C or Defrost!!!! I am suspicous of my 160 tstat.....any thoughts????

Know, what is really weird is when i have my A/C or Defrost on with Cold Air......she overheats?????

And to make it even weirder....with Hot Air on and pedal to the floor for a few Rip & Tears....the Hot Air will quickly turn to Cold Air and the heat guage climbs as well and is very slow to come back down......if I work it????

I have all New Gaskets all around, new timing chain etc.. and rebuilt heads and SC, and am sure the cam sync and crank sensor and Balancer are proper......did it all myself and am very confident!!!!!

Please Help Me If You Can..... and Once again... Thank You

MIKE 38sc
08-20-2003, 04:29 PM
First off 160 thermostat=BAD idea!
Cooling system needs a GOOD flushing! Have the rad rodded out by rad shop.
Put STOCK thermostat back in and all should be fine.

08-20-2003, 05:08 PM
You probably have air trapped in the system. With air in there, the ECT sensor willl tell the computer that the car is nice and cold at all times.

You also could have a plugged up radiator and are using the heater core to cool the engine.

Like Mike said, ditch the 160 and get closer to stock, then purge the cooling system of all air. While your in there flush it out real well.


08-20-2003, 07:41 PM
Hi Mike and Aaron, and Thank You for your reply's...

I will toss the 160 t-stat asap and go to 180.....

As far as the rad, It's one yr old, but is stock!!!! And the coolant is 3 months old, but if air is in the system, could i get rid of it by running the engine w/the Rad Cap off, and undo the bolt on the t-stat housing....

Again and Again....Thank You!!!!!!

MIKE 38sc
08-20-2003, 08:03 PM
Well a 1 year old rad is good. However you may live in an area that has hard water and you should use distilled water instead of faucet water. Hard water will stop up a rad pretty quick, But I dont know what kind of water you have. I'm just making a suggestion.
To get air out of the system remove the vent plug with the engine cool and with the rad cap removed. Just fill the system until coolant and no air bubbles come out. Once you have gooten all the air out that you can reinstall the vent plug. Now fill the rad as full as you can get it. Reinstall the rad cap then fill the overflow bottle.
Keep an eye on the overflow bottle for a couple of days as the engine warms up and cools down any remaining air should get worked out and the overflow level will drop. So keep adding water to the overflow bottle and eventualy it should stabalize and you wont have to add anymore water to the overlow bottle.

Dont let the bottle go dry or you will pull more air into the system.

08-20-2003, 08:04 PM
How old is your water pump?? Usually when the heater blows cold air, it means the water pump isn't circulatiing the water.

MIKE 38sc
08-20-2003, 08:09 PM
Or the water level is low or has air trapped in it.;)

08-20-2003, 08:15 PM
Ahh yes, but he says the coolant is 3 months old, which means he's had it in the car for three months. Now I'm assuming since he is just now posting, and says the car is currently doing it, I am lead to beleive that is just started recently. If he had air trapped in his sytem from the last time he did anything with the coolant, then it woudl have been doing it all along, and not just recently pop up unless he blew a head gasket and is blowing pressure from the cylinder into his coolant system.

MIKE 38sc
08-20-2003, 08:42 PM
Yes thats true but if he accadentaly allowed the overflow bootle to run dry the system would suck air into it. You would be suprised how many times that happens. Alot of people think its just a container for overflow bit it does more than that.;)

08-20-2003, 10:22 PM
But he said he has never had to add any coolant.

08-21-2003, 04:11 PM
Hello again Guys.....Once again thanks for your time!

Sorry, i guess i could have been alittle more descriptive, but didn't want to ramble...

Anyways, to answer the questions.....

1.I did use tap water and will change to distilled next spring(goin in garage soon)

2.In the past spring when i changed all my gaskets(head, timing cover, etc..) I also rebiult everything and torqued to spec's...and when it came time to do the coolant I topped it off w/vent plug hole as much as I could and then to the Rad....And then ran engine to warm up a little with both cap and plug out to bleed out the air.....But since then I've had to take the upper rad hose off, so maybe then I got some air in??

3. My water pump is 3 yrs old!

4. It's basically been doing this since it's been on the road this spring!

My conclusions from all of your info is that it must be air in the system!!!

Could I ask another question? When vehicle's as fine as ours are stored for the winter in the garage...and there isn't any heat available, temperatures probably -20 celcius...what is the best thing to do as far as keeping any fluids in or out of the engine?

I hope this info i posted help's you help me...(lol) but I do believe I must have improperly bleeded out the air!!!!

Thanks again for the Information, it's a great Help, and will be awaiting a reply!

Mike........An Easterner Tearin Up The West!!!!!!!!

MIKE 38sc
08-21-2003, 04:35 PM
The only potentail problem I see is storing it with hardwater in the cooling system. I have no way of nowing if you have hardwater but many parts of the country do and I live in one of those areas.
If stored with hardwater the minerals will attach themselfs(mostly Limestone=White deposites) to the metal parts of the cooling system internals. When that happens in the rad the tube ends will become clogged completely or have there flow seriously reduced. The problem with that is you cant remove the rad cap and see the damage because the SC rad has a baffle plate inside the rad covering the tube ends and blocking them from your view.
That makes the rad look good when looking into the filler neck but you have no idea.
I removed the end tanks from my old rad to get a look at the tubes. They were coverd with white limestone deposites and looked like someone had poured concrete inside the rad!

For storage just get a gallon of cheap antifreeze and fill it up with distilled water its not expensive and you can have piece of mind.:)