Overheating.... Well kind of...

[kidneybrah]

So I'll start this with the list of my recently changed/upgraded items, and I'll go from there:

-Upper and lower radiator hoses (the lower one is a bitch to change!!!!)
-New expansion tank cap
-New 14" Mishimoto Performance fan (set to come on at 140* with SCT Tuner)
-New factory replacement thermostat and gasket.

Now to my saga, and my plan (unless I'm told different). With all this the car still likes to cruise up to between the M and the L during traffic. I know mustangs typically run a little hot, but damn I feel this is too much. The car will never surpass the normal range. Nor will it billow out smoke from the engine, but thats too hot for my personal comfort.

There is a few little things that I've noticed, and maybe you can diagnose my problem. If I'm not mistaken, my upper radiator hose, should be hard when I run the car to normal temp, should it not? Mine never gets hard, but it is hot as all hell to the touch. Also, sporadically the car will leavea puddle of coolant underneath it. Now, it doesn't happen often at all. Just every couple of weeks or so, and it seems to be coming from the bottom high pressure connection on the radiator. I know this is something I need to fix, but I'm sure it isn't the cause of my problem.

My plan of action, is buying a Mishimoto Aluminum Radiator, a Moroso coolant expansion tank, new Mishimoto silicon hoses, an Electric water pump, and a Mishimoto racing thermostat.

Hopefully with this, it will fix it. Unless you guys tell me something I can do to fix it with out all that.

Thank you in advance.
__________________
96 Mustang GT Auto
-K&N Cold Air
-O/R X Pipe
-Flowmaster Cat-Back
-3.73's
-17x9/10.5 Athracite Bullits
-Mishimoto 14 in. Electric Fan
-SCT SF3 Tuner- With Bama Custom Tuning

 

[patman0911]

I'd do some testing before I dropped any more money on it replacing stuff that may not need replacing.

You need to put a scanner on it and see what temp the PCM is seeing when the needle is up where you think it's too warm. The gauge is not exactly a scientific calibrated device, but it's not a dummy gauge like the oil pressure gauge is and small changes in temperature can cause a noticeable change in where the needle is pointing. You may still be within the safe, normal operating range of the motor.

You should pressure test the system and see where that leak is coming from. That puddle of coolant is being replaced by air which will cause problems if too much gets in there or a bubble lodges itself in the right place.

The factory thermostat opens at 195 degrees and the stock tune doesn't turn the low speed fan on until over well 200 degrees and doesn't go to high speed until much higher. Modern motors run hotter by design for better efficiency and more power and they can get away with it with aluminum heads and efficient combustion chambers - Modulars are known for pretty much never blowing head gaskets so Ford seems to know what it's doing in that regard.

 

[GDawg]

I'd do some testing before I dropped any more money on it replacing stuff that may not need replacing.

You should pressure test the system and see where that leak is coming from. That puddle of coolant is being replaced by air which will cause problems if too much gets in there or a bubble lodges itself in the right place.

My guess is you have air in the system.

 

[trinity_gt]

My guess is you have air in the system.

^ 2

BTW, having the fan come on at 140o with the OE thermostat is counterproductive. The two systems -- the fan and the thermostat -- will be "fighting" each other and the end result will likely be unnecessary wear and tear on the cooling fan.

Either go to a cooler thermostat (e.g. I have a 160o thermostat in my KB GT to assist in preventing detonation) or set the fan points to stock values.

 

[kidneybrah]

How do I check for air in the system, and/or bleed it?

the SCT tells me that the engine coolant temp is 220* when it gets to the levels where I feel unfortable. The problem is that it never comes down. Well, more like 215-218.

I never drive the car longer than it getting to that temp. On one occasion it got up to about 225* during traffic. And again, never came down.

 

[kidneybrah]

I'd do some testing before I dropped any more money on it replacing stuff that may not need replacing.

You need to put a scanner on it and see what temp the PCM is seeing when the needle is up where you think it's too warm. The gauge is not exactly a scientific calibrated device, but it's not a dummy gauge like the oil pressure gauge is and small changes in temperature can cause a noticeable change in where the needle is pointing. You may still be within the safe, normal operating range of the motor.

You should pressure test the system and see where that leak is coming from. That puddle of coolant is being replaced by air which will cause problems if too much gets in there or a bubble lodges itself in the right place.

The factory thermostat opens at 195 degrees and the stock tune doesn't turn the low speed fan on until over well 200 degrees and doesn't go to high speed until much higher. Modern motors run hotter by design for better efficiency and more power and they can get away with it with aluminum heads and efficient combustion chambers - Modulars are known for pretty much never blowing head gaskets so Ford seems to know what it's doing in that regard.

I've been meaning to buy the 140* Mishimoto racing thermostat, but someone told me it would be too cool of a temp. That the coolant would never have time to drop down. The reason I have the fan set at 140* is because it will keep the car cool for a bit longer, than if I have it set at 200*

 

[kidneybrah]

UPDATE!!!!!!

**Update: Well through trying to bleed out the system, I noticed that it doesn't SEEM like my thermostat is opening up. It got up to about 205*, according to the SCT, and I saw no movement what-so-ever in the coolant expansion tank. The hose remained flexible up top also.

Sound like a proper diagnosis?**

 

[patman0911]

It should be able to keep it down below that, especially with the fan blowing non-stop - it should be able to cool it back down and it should sit right around 195 degrees unless it's blazing hot and you're sitting stopped on the freeway in rushhour traffic maybe.

If your cooling system was working and you did put a 140 t-stat, yeah, that would be too cold. The computer would never get out of warm-up mode.

Just saw your update:

That would certainly explain why it can't cool off despite your fan running essentially all the time.

 

[kidneybrah]

It should be able to keep it down below that, especially with the fan blowing non-stop - it should be able to cool it back down and it should sit right around 195 degrees unless it's blazing hot and you're sitting stopped on the freeway in rushhour traffic maybe.

If your cooling system was working and you did put a 140 t-stat, yeah, that would be too cold. The computer would never get out of warm-up mode.

Just saw your update:

That would certainly explain why it can't cool off despite your fan running essentially all the time.

Did you get a chance to read my last update? You seem knowledgeable in cooling systems. If this is the fix, I'm hauling ass to buy a t-stat now.

 

[patman0911]

You could try running without the t-stat and see if that helps. It's not entirely unheard of for t-stats to be bad right out of the box. I had one that opened too early and the car perpetually ran a little cold.

I'm not sure how much movement you'll see in the coolant tank when the t-stat opens though so I'm not sure if that's a reliable indicator. You can also usually see the temp drop a few degrees on the gauge or scanner when it opens up, hopefully right around when it starts to reach around 195 degrees.

 

[kidneybrah]

No that's the problem no change but I know this new t-stat is working. I did the heat test before replacing it. I also went out and bought a 170* thermostat and still nothing. I don't know what the he'll else it could be. I'm gonna pull the upper and lower radiator hoses tomorrow and do the water hose test to check if the radiator is clogged. If it is then I know where to go from there, and I'm just going to replace rather than try and fix it.

Would the water pump be grinding or shooting out water if it were bad? I haven't seen any wear on the belt or eardrum any grinding? Does that debunk that theory or could it still be an issue?

 

[kidneybrah]

I'm on my phone so I can't edit.

But I've also noticed a quick plume of white smoke, sometimes thick, sometimes not while the car has sat idling and it's in that uncomfortable range temp. Very very very rarely have I noticed white smoke after a quick street run.

But I've never noticed coolant in the oil or vice versa. Any other ways to check the head gasket?

 

[patman0911]

No that's the problem no change but I know this new t-stat is working. I did the heat test before replacing it. I also went out and bought a 170* thermostat and still nothing. I don't know what the he'll else it could be. I'm gonna pull the upper and lower radiator hoses tomorrow and do the water hose test to check if the radiator is clogged. If it is then I know where to go from there, and I'm just going to replace rather than try and fix it.

Would the water pump be grinding or shooting out water if it were bad? I haven't seen any wear on the belt or eardrum any grinding? Does that debunk that theory or could it still be an issue?

Start the car with the t-stat housing removed and coolant should come shooting out of the opening like a fire hydrant if the pump is working.

 

[40oz]

I don't know about anyone else, but I find it amusing when someone describes an "overheating problem" referencing letters in the word "N O R M A L."

 

[trinity_gt]

I don't know about anyone else, but I find it amusing when someone describes an "overheating problem" referencing letters in the word "N O R M A L."