Overheating Help

[Synned]

Hey guys
I just had a very sucky drive home from the shore...car kept overheating on the highway.
The temp gauge would go all the way up to past M and if I put the A/C on it would shoot over to A.
I'm thinking one of two things...
The high speed fan isn't coming on (The fan is on but I can't tell if its the high setting or not)

When I filled the radiator right after the intake swap, I didn't use any water. Just straight coolant mix. I'm thinking this could be a big contributor. I also didn't 'burp' the system or try to get any air pockets out.
Thanks for any advice guys
Joe

 

[HISSIN50]

Joe, as you surmised, water rejects heat ~2.6 times better than E/G coolant. This could be a big issue for you right now. Get it to atleast 50/50 or even 60/40 (water/coolant, respectively).

The fan shouldnt have made any difference on the highway - ambient air flow is taking care of things.

Good luck bud.

 

[Stanger007]

I've found that our cars are very tough to bleed - the air pockets in the system make the temp gauge skyrocket.

I've found it helpful to jack the front of the car up so that the radiator neck is the highest point in the system and then get the car up to temp so that the thermostat opens (the host will get HOT when it does). Carefully take a shop town and squeeze the upper hose down, you'll feel air rushing to the radiator - keep the towel out of the fan.

Like HISSIN said, less coolant means lower temps. A popular swap is a 180 degree thermostat if you haven't already done that. I run a 30/70 mix of coolant/water here in Louisiana during the summer. It great crazy hot and I do a lot of sitting in traffic.

Wes

 

[Blackened302]

+1 for the burping. i will never put in a cheap thermostat in my car again, nor will i put one in without drilling at least one hole (situated at 12 o'clock) so the air will pass over the water during filling up the cooling system.

i'd do a new, good thermostat (brass, i've read, are best--i got a Mr. Gasket hi-po from the performance part of the parts store) and drill 1-3 holes (the Mr. Gasket thermo had 3 pre-marked holes for drilling) for the air to pass while you burp it w/ the cap off, re-filling w/ a good mix of anti-freeze/water. that won't cost you much to do and it's pretty easy, too.

 

[Synned]

Alright well I just replaced the coolant with 50/50 water/antifreeze adn that didn't change anything much. I just took it for a spin and it went up to A on the gauge.
Would you guys be worried when it gets that hot? Is that super hot? I wish I could actually measure the coolant at that temp and see what it really is at.
'A' isn't overheating, is it?

 

[The Green GT]

thats about 250* according to my aftermarket gauge.

Its too hot, but mine has gotten there a few times and i never had any trouble (yet).

I would definately burp it. Park it in a ditch or something with the engine up higher than the car and let it run with the cap off, but watch the gauge. As the water goes down, add water to it. When i changed my pump and hoses, it took me like 30 min of running it like that to get all the air out.

Now its getting hot again so Im getting a new rad.

 

[Stanger007]

When I first got my car, "A" was where it always was at. Kinda scared me a bit. If I remember correctly, the high speed fan doesn't cut on till around 220-ish. The stock temp gauge varies a good deal between cars.

Now that I have my twEECer, I see that on *MY* gauge, A is about 218-220.

I replaced my waterpump with a stewart "stage 1" pump, went to a 180 degree thermostat, 40/60 coolant/water mix, replaced front air dam and lowered my fan cut-on temps - runs on the "o" now - or 180-183. The hottest it will get is about low 190s when hotlapping at the track.

EDIT:
Here we go - I opened up the stock automatic EEC tunes (U4P0 W4H0) and the T5 tune (T4M0)...

Highspeed fan cuton/off is at 228/220
Lowspeed fan cuton/off is at 208/204

On the Cobra J4J1...
Highspeed fan cuton/off is at 228/220
Lowspeed fan cuton/off is at 216/212

Wes

 

[The Green GT]

When I first got my car, "A" was where it always was at. Kinda scared me a bit. If I remember correctly, the high speed fan doesn't cut on till around 210-ish. The stock temp gauge varies a good deal between cars.

Now that I have my twEECer, I see that on *MY* gauge, A is about 208-210.

I replaced my waterpump with a stewart "stage 1" pump, went to a 180 degree thermostat, 40/60 coolant/water mix, replaced front air dam and lowered my fan cut-on temps - runs on the "o" now - or 180-183. The hottest it will get is about low 190s when hotlapping at the track.

Mine is usually between the O and R, and i run at 210* according to my gauge, so I guess that shows you how different they can be.



EDIT: After seeing those fan temps, you wanna help me wire my fan to manual? lol

 

[Synned]

thats about 250* according to my aftermarket gauge.

Its too hot, but mine has gotten there a few times and i never had any trouble (yet).

I would definately burp it. Park it in a ditch or something with the engine up higher than the car and let it run with the cap off, but watch the gauge. As the water goes down, add water to it. When i changed my pump and hoses, it took me like 30 min of running it like that to get all the air out.

Now its getting hot again so Im getting a new rad.

When I first start to burp it, is it supposed to be empty?
If theres already coolant in there, can I just run it like that?

 

[The Green GT]

When I first start to burp it, is it supposed to be empty?
If theres already coolant in there, can I just run it like that?

I didnt drain mine completely when I burped it. But i had alot of air in it. It does not take much air to **** it up either, if an air bubble gets in the pump, it could lose its prime.

 

[Stanger007]

I've had great luck filling up the system, jacking up the car on the front driver's side so that the radiator neck is the highest point in the system.

Start the car with the radiator cap off. As it gets up to temp, the thermostat will open and you'll notice that the upper radiator hose gets hot to the touch - this is good - coolant is flowing through it now.

With a shop rag, carefully squeeze on the upper radiator hose and push it down to force the air to the highest point in the system (the radiator neck now that the car is jacked up). As the system starts flowing, don't be surprised if the level in the radiator rises and some coolant comes out of the neck as you are squeezing. You will notice big gushes of air bubbling out. Keep squeezing on the hose until the vast majority of these big bubbles are gone. Also be careful of the fan while you are messing with the hose.

I've done this countless times with great success.

Wes

 

[HISSIN50]

Joe, you're going to have to get a real gauge (even if it's a 10 dollar parts store mech gauge that you run for a couple days and remove). Who knows what's going on otherwise.

The only other thing that can help decide temps is: If you use Wes's and Eric's method (I do it too), get a 99 cent candy thermometer at Wallymart. Put it in the radiator filler so you can kinda see where you are temp wise.

Just to stress it, be REALLY careful if you burp the system as proposed. It's entirely possible to have boiling hot coolant splash/shoot out of the open radiator neck and into your face, arms, skin-in-general. Be CAREFUL.

Good luck.

 

[The Green GT]

Yea, when the water is almost full, it can splash when a big bubble comes out, so watch out when it gets hot.