different overheating issue.

[grant007]

okay. some days after work i go get a bite to eat. not all the time, but sometimes ( when i go through the longass arbys line). i look down and my gauge is screaming red.. shut down .. wait.. then we are back to normal. normal/cooling back down . i can turn the heater on and it will go back down..bad sensor, bad relay, bad thermostat. car has 95k thinking its the thermostat.
fred G

 

[grant007]

never does is while driving

 

[01 Venom]

are you low on coolant?

 

[brkntrxn]

With or without the AC on?

 

[01vert]

Bubble in the system.

Wait till cool and check the coolant crossover cap, (1/4 inch rachet or extension) Be careful as it can be stripped easy. If it does, use a pair of vice grips on the edge of it.
I can bet your tank is full but the crossover will have some air in it.

search for posts on burping the system.

if only when idling, is your fan kicking on? When on AC does the fan kick to high?

 

[CobraDDz]

Might be the water pump if it over heats where your not moving.

 

[01cobravortech]

Something is up. If you do overheat I'm sure you know the basics of checking the t-stat, fan & lines for leaks.

1. Drill (3) 1/8 holes in a new stocker or pm me as I have a brand new one ready to go out with the drilled holes.

2. Replace as many Ford hose clamps as possible.

3. Check for leaks and fan operation.

4. Be patient with the burping procedure. Took me 3 days to burp my 03 and it took my another 3 days to burp my old 01 Cobra.

*If you overheat I strongly recommend that you ALSO replace the radiator overflow tank. Many only think to replace the radiator cap. But the lip on the overflow tank can warp slightly from an overheating episode. Its plastic too! You'll drive yourself nuts going through one new radiator cap after the next until you realize you can't hold pressure because the lip is warped.*

 

[elyrain]

I think one thing that is overlooked when you check your coolant crossover tube is the engine has to be cold. Not just cooled down but cold, like in the morning. Then add fluid to the crossover.

 

[01cobravortech]

I think one thing that is overlooked when you check your coolant crossover tube is the engine has to be cold. Not just cooled down but cold, like in the morning. Then add fluid to the crossover.

That is an excellent point. Whenever I do idling sessions when reburping the system I always make sure to have at the minimum 5-6 hrs of cooldown to insure that the coolant is cold and not in a state of expansion. This insures you have accurate system readings of how much air is left in the system.

 

[RedRocketMike]

What ever it is, watch that temp gauge until you figure out whats wrong. Moving high into the red is setting you up for warped heads, if you didn't warp them already.

Does your antifreeze have any grey tint to it? Sometimes with a head gasket failure you'll get exhaust forced into your antifreeze, this air in the system causes pockets that make you overheat. In the early stages you will overheat at idle only. After a while you're antifreeze will turn grey from the exhaust contamination. You can get your antifreeze tested for hydrocarbons, then you'll know for sure.

 

[grant007]

thanks guys, not when the ac is on.. only when i go through arby's. i say this because it takes almost 10min to go through. sitting at a light, overheat'g never happens doesnt rise. Question on burping the coolent, do you raise car,open x-tube, open res cap. cold start. Then add fluids until a steady stream and car is fully warmed up? tried that today.
so ill keep checking that ,more often. Ill check the color of the coolent too, didnt notice.
i know its never a easy solutions so ill keep looking till i find something broke/failed.
thanks guys
fred G