another overheating question

[secretz]

98 cobra, stock engine (diablo chipped, but with the timing retarted, since it had an issue of pinging at odd-but-seldom times), no codes being thrown, replaced stock t-stat with a 180 deg. System was burped (yes, at the crossbar). 80% of the time it runs perfectly at the R in Normal. Other 20% overheats, usually when I'm in lower gears @ 4-5k rpms, during the day (either when it's hot out or a decent 75 deg day).

First time, I had it overheat on a track not going faster than 30mph, which is odd because I also had the car charging up a hill at 90mph and had no problems.
Two laps around a quarter mile track and by the time I was off the track it was on the L of normal.

Second time, I was cruisin the side streets keeping up with my bf's 06 GT. Noticed that the gage started creeping past it's normal spot. Radiator hose was hot, coolant sizzling a little, but no leaks.

Do I need to reburp the system, again? Or is there something else that I need to do to get this resolved? :shrug:

Thanks in advance ...if anyone can help throw some ideas my way. :bowdown:

 

[CrazyPerson]

i had overheating issues not matter what i did. i replaced the stock radiator with a better one and havent had a problem since

 

[Dano]

Before I invested too much money in replacing components, I's go to a garage that has one of those laser temperature sensors, and verify that the cooling system is actually hot. The laser gun can be pointed to any spot on the engine, and it'll read the temp.

First thing I'd then do is to burp the cooling system again (I know you said you burped it already, but a lot of times it takes more than one burping - it's a difficult cooling system to say the least, and burping the trapped air out of the system will many times solve the problem), consider changing the coolant, do a light flush of the engine (keep in mind that using chemicals will possibly break-up grit & gunk, causing more problems), get a good aftermarket temperature gage - the OEM is not reliable, and the gradients of the gage cannot be accurately read.

Just because your hose is hot doesn't really mean anything. If it's proven that you are overheating, you can check the hoses for collapsing, have the radiator boiled & cored, replace the rad. cap, look at the water pump, etc.

I assume your cooling fan is going on & off at correct temperatures ...


You have one of the most common problems on the SN-95. Start with the cheapest cure, and work towards the most expensive. JMO

 

[COBRASVT]

I've had two problems on mine forever.

Replaced the overflow with an aluminum one and that solved the main overheating problem. They seem to warp once the engine gets hot.

Second is the connector for the fan. I've even replaced it w/a factory rebuild and it's still crap. Finally just hot wired the fan from the connector to the input on the fan. No problems since.

 

[SNAKEYE]

I've had two problems on mine forever.

Replaced the overflow with an aluminum one and that solved the main overheating problem. They seem to warp once the engine gets hot.

Second is the connector for the fan. I've even replaced it w/a factory rebuild and it's still crap. Finally just hot wired the fan from the connector to the input on the fan. No problems since.

The plug connector on my fan fried, which caused the fan to be intermittent.
It looked just fine until I tried to unplug it. It wouldn't come out of the socket because it was so badly fried within.
I had to cut the wire harness and pull the whole fan/shroud out to see the damage.
Then I had to replace the fan/shroud assembly and splice on a replacement connector available from the stealership.
No more intermittent high temps!

 

[Gallows]

What Dano said and this method for burping. http://www.svtperformance.com/forums/showthread.php?t=232150&highlight=Coolant+burp

 

[venom1997]

try re burping the system again and change your thermostat just to be on the safe side. also if you have a diablo chip like me get your tuner to change your fan settings to come on sooner. my car stays between the NO on the gauge with a 180 thermostat. hope it helps you like i said try reburping it just to make sure:rolling:

 

[venom1997]

sorry i forgot you had a 180 thermostat so you dont need to by one but you need to get your fan settings retuned if you havent already because of the cooler thermostat once it is done you should run in the same range as my car 180-185* range between the NO:banana:

 

[COBRASVT]

Then I had to replace the fan/shroud assembly and splice on a replacement connector available from the stealership.

Same thing I used. Now it's being a pos as well. Ridiculous really.

 

[timpryor]

Before I invested too much money in replacing components, I's go to a garage that has one of those laser temperature sensors, and verify that the cooling system is actually hot. The laser gun can be pointed to any spot on the engine, and it'll read the temp.

First thing I'd then do is to burp the cooling system again (I know you said you burped it already, but a lot of times it takes more than one burping - it's a difficult cooling system to say the least, and burping the trapped air out of the system will many times solve the problem), consider changing the coolant, do a light flush of the engine (keep in mind that using chemicals will possibly break-up grit & gunk, causing more problems), get a good aftermarket temperature gage - the OEM is not reliable, and the gradients of the gage cannot be accurately read.

Just because your hose is hot doesn't really mean anything. If it's proven that you are overheating, you can check the hoses for collapsing, have the radiator boiled & cored, replace the rad. cap, look at the water pump, etc.

I assume your cooling fan is going on & off at correct temperatures ...


You have one of the most common problems on the SN-95. Start with the cheapest cure, and work towards the most expensive. JMO

^Listen to this guy

My stock guage kept reading that I was hitting over the L on normal, replaced it with a new autometer & sender & its just fine never goes past 210 even when sitting in traffic with the A/C on

 

[SNAKEYE]

Same thing I used. Now it's being a pos as well. Ridiculous really.

Did you replace the fan (thusly getting a whole new socket with it), or did you do just a plug replacement?
Did you use the compression connectors that came with the replacement plug? I did not. Instead I soldered the wire splices to avoid any chance of a poor compression connection, and mechanical problems with the splices due to vibration and corrosion.

 

[COBRASVT]

Did you replace the fan (thusly getting a whole new socket with it), or did you do just a plug replacement?
Did you use the compression connectors that came with the replacement plug? I did not. Instead I soldered the wire splices to avoid any chance of a poor compression connection, and mechanical problems with the splices due to vibration and corrosion.

The fan had been replaced last year.

I only replaced the plug this time.

I soldered as well. I'd never use compression on someone that draws that much amperage. You're just asking for trouble.

It's weird. When testing the plug, it would come on when pushing down on the plug...not side to side like you'd think. But I'm happy with the "rigging" job now. It's working.

 

[secretz]

So last night, I reburped the system (didn't see any bubbles), check the fuses (all were good), and noticed that my fans weren't turning on... :dw:
Noticed they never came on and after the car was idling for about 10-20 minutes, the gauge started to creep towards getting hotter, still the fans never came on. My dumbass turned the defroster on full blast - no fans. Turned the air conditioner - no fans.
So, it kinda looks like I need a new fan assembly or atleast just the electrical components.







:burn: muwahahawhwha (sorry, couldn't resist)

 

[COBRASVT]

So last night, I reburped the system (didn't see any bubbles), check the fuses (all were good), and noticed that my fans weren't turning on... :dw:
Noticed they never came on and after the car was idling for about 10-20 minutes, the gauge started to creep towards getting hotter, still the fans never came on. My dumbass turned the defroster on full blast - no fans. Turned the air conditioner - no fans.
So, it kinda looks like I need a new fan assembly or atleast just the electrical components.a

Not necessarily.

Run power to the fan and see if it comes on. The left pin is high...the middle is low...the right pin is ground. If it comes on, then you need to ground the #17 (I think) pin on the CCRM and see if it kicks on. If not, CCRM might be bad. Also, you need to jump the water temp sensor connector once the car is at the temp where it should come on. If it comes on with the connector jumped, the temp sensor is bad.

 

[secretz]

Not necessarily.

Run power to the fan and see if it comes on. The left pin is high...the middle is low...the right pin is ground. If it comes on, then you need to ground the #17 (I think) pin on the CCRM and see if it kicks on. If not, CCRM might be bad. Also, you need to jump the water temp sensor connector once the car is at the temp where it should come on. If it comes on with the connector jumped, the temp sensor is bad.

I changed out the ccrm, no change in the fans (tho the fan itself isn't frozen). They still haven't come on. So, I did some research and found a Mark VIII electric fan, bought one and am waiting for it to arrive soon. Although, now I'm wondering if I have to upgrade my alternator and/or my radiator...?