95 GT Running very hot

[Bullitt95]

JesusOnIceSkate, that's very useful information that you've provided in your chart and I think I've got my finger on your problems:

1. The big temp. difference between the ECT and upper radiator hose tells me that your thermostat isn't opening properly so I suggest you change it.

2. The rise in gauge readings when you add an electrical load is a sure sign of poor grounding. I had the same problem and cured it by adding one ground cable from the upper intake to the firewall, and a second ground wire from the battery to the chassis. A very simple, cheap, and effective cure.

Do both of the things I've listed above and I'm sure you'll have your problems licked.

 

[JesusOnIceSkate]

Yes!!!!

Hissin50 and Bullitt95...you guys nailed it on the head. I ran the car without the thermostat:

1. At parked / idle the results were more or less the same as in the chart above, except that lower hose temperature was much higher and about the same as upper...since the car wasn't moving and circulation through radiator was much higher. I think with the thermostat the amount of coolant going to rad. was inimal...so it had more time to cool off.

2. While driving the temperatures were MUCH lower that at idle...after continuous driving on the freeways at 65-70 MPH for half hour the reading was mostly on N of normal. I pulled over once to double check if this was right and take temperature reading of hoses and ECT and pump...and yes they were right, the car was runing very cool:

I think before taking out the thermostat the overheating was occuring due to relatively high restriction on coolant circulation and slightly higher opening temperature (I dont know what stock temp is but I'm sure it's not 180*). This effect was also made to appear worse than actual by the fact that power drain of both headlights and fan running on high was showing much higher reding on the gauge (about 3 letters / +25*F more).

Hissin50 I'm with you 100% on an alternative temperature meter. The stock one is not very accurate...you can get the gist but not exact temperature.

Bullitt95..you're right on with the thermostat change... I'll find a lower temperature one which will also perhaps offer better flow...I know Mr.Gasket is a great brand but I think in my case I need something that offers least hindrance when open. This is the 180*F balanced mr.gasket thermostat that I removed: it's for ford...but the water inlets seem a bit small no? Can you guys recommend another?

Thanks again for all your help guys!

I'm glad to have this problem solved ...can finally move on to tweaking timing etc.

 

[HISSIN50]

Nice work with all the diagnostics. Your dedication is impressive.

As for the stat, as far as balanced versions go, I actually have only used the Mr Gaskets. For whatever reason, they've done well for me.

And while I don't have experience with them, if I needed an alternative, I would try a Stewart balanced stat. IIRC, they have a few bypass holes drilled in them to help ancillary flow. I honestly don't know how one would compare design-wise to the Mr Gasket however. I always thought most of the balanced stats were very similar in design and orifice size, etc.

Maybe others will have some suggestions.

And if you can, perhaps you can compare what you get to the Mr G you have now. That'd be interesting.

Again, nice work with all the diagnostics.

 

[Chythar]

I bought the Stewart balanced t-stat for my V6 (same t-stat for V6 and GT), and it ran too cool for my tastes. I bought a Mr. Gasket, and the two t-stats looked identical. Stewart had just drilled some holes in the t-stat to allow for some coolant flow before the t-stat opened.

Sadly, I don't have the Stewart thermostat anymore or I'd send it to you, JesusOnIceSkate.

 

[Bullitt95]

Hissin50 and Bullitt95...you guys nailed it on the head.

Thanks again for all your help guys!

I'm glad to have this problem solved ...can finally move on to tweaking timing etc.

You still need to add the extra grounds that I suggested to fix the gauge readings. They really do make a big difference and you won't need an aftermarket water temp. gauge.

 

[JesusOnIceSkate]

Bullitt95: No question about it....I'll definetly do it. Thanks again!

 

[onestripevert]

this may not help you but my fan doesnt even work at all, and my temp guage never goes above halfway. all stock sepfor cobra 1.72's

 

[HISSIN50]

this may not help you but my fan doesnt even work at all, and my temp guage never goes above halfway. all stock sepfor cobra 1.72's

Either you don't stay stationary or at low speeds for very long or your gauge is seriously lacking accuracy.

I dont say this to be a pud but only bring it up in case it is the gauge. It sucks to be running hotter than you think you are.

 

[onestripevert]

at speed it stays between n & r. sitin still it goes to halfway, but thats it. I hope its alright

 

[HISSIN50]

at speed it stays between n & r. sitin still it goes to halfway, but thats it. I hope its alright

If there's no ambient airflow (your car is stationary and the fan isnt coming on), at some point it will overheat. The radiator simply needs to see airflow to be effective. I'd keep an eye on it or use a mech gauge to be sure you're ok.

 

[onestripevert]

i'll probly just get another fan assembly, relay and a mech. guage.
preciate it