over heating after tune

Randy N Connie

Registered User
My car has been over heating since I got a tune at the OK Shootout.
It was tuned with low octain gas 89. This was the highest octane
I could find in Oklahoma.

During tune Dave D. said that he thought it was detonating. I could
not hear it. But I am hard hearing. And could smell anti-freeze.
I had zero loss of coolant(was running straight water). So I thought
maybe the head lifted then resealed while on the dyno. I drove back
home To IL. the car ran warmer after chip tune.

After I got home a I ran the car hard to blow the headgasket out
.But it would never blow completely out, but I think the head lifted
then resealed,because I could smell coolant. But never lost any
coolant.

So I pulled the heads off. Could not see any head gasket damage.
Install a new head gasket. but car ran even warmer .I can't drive
the car over 50 MPH. If I go 60 MPH the temp guage max out.

So I took the heads off again because of the over heating. No
sign of head gasket problems. checked the heads they looked
just fine checked the block, block checks just fine. I think that
I check out ever part ,nothing wrong.

So I pulled the heads of again, inpected every thing that I could think
of, had heads pressure tested, I found no problems. replaced head
gaskets again.

I can,t find one problem. I just got it going again and tried the
car out today again. If i drive 45MPH the temp guage gos
pass the L in normal. If I floor the car for less than one second
the temp guage gos max. and I can smell coolant. but no leaks
no coolant loss.Wet around radiator cap.

I have replaced the radiator cap three times.
I have tried three new thermostats.

I would install my old chip, but it got takin from my car
during the dyno shootout in Oklahoma. So thats not an option.
damm theves are every where.

Anyone have an idea of what to do next. I have tried for two
years now to get the car running right, but no luck yet.
out of ideas.

Thanks Randy

PS Forgot it has always blown black smoke since SCT chip install.
From the beginning up to today.
 
Last edited:
what do you mean as in overheating?.....is it actually boiling over?......you mentioned you were running all water, i hope with the summer heat you have went with a 60/40 water/coolant mix.
 
Well, that's a weird deal. Cooling is dependent on air flow, water recirculation, and internal pressurization. So that means either the water pump is bad, the radiator is clogged up, or something is bleeding off the system's pressure. You said that you have replaced the radiator cap, which is the only part that can bleed off pressure without leaking coolant.

Are you still running 89 octane? Detonation would cause over heating at WOT.

60mph has plenty of air moving through it, which eliminates the fans being a cause.
 
Well, that's a weird deal. Cooling is dependent on air flow, water recirculation, and internal pressurization. So that means either the water pump is bad, the radiator is clogged up, or something is bleeding off the system's pressure. You said that you have replaced the radiator cap, which is the only part that can bleed off pressure without leaking coolant.

Are you still running 89 octane? Detonation would cause over heating at WOT.

60mph has plenty of air moving through it, which eliminates the fans being a cause.

I think the belt driven water pump works just fine.
I installed an electric wter pump,for testing,still runs hot.
Reinstalled belt driven pump.

I tried four radiator caps including the one that was there when my problems started.

The radiator is new, clean, aluminum. that worked great before problems.

I run 93 octane around home ,I have add & tried octane booster ,no help.

Thanks Randy
 
Last edited:
I'm sure you checked to see if you have an air bubble in the system but these cars are notorious for it. If you have an air bubble the coolant will not circulate and it will get hot.

Best fix is to put in a 180 thermostat and drill a 5/32" hole in it so that water and air can bypass the thermostat.

Then drive the car. If it gets hot, first verify that the fan is running. Then verify the temperature of the upper and lower rad hoses. Both hoses should be hot but the upper one should be hotter. If it is getting that hot then the upper hose should be under pressure and it should also be pushing some fluid into the reservoir. When the car is hot the reservoir should be full to the "hot" line.

Verify all of this.

Then let the car cool off completely (overnight). The coolant reservoir should lower down to the "cold" line. If it goes lower than that then you had an air pocket. Fill it back up to the "cold" line and drive the car until warm again. Do this until you can verify that the reservoir is both accepting coolant when the motor is hot and giving fluid back when the motor is cool. If the hose going to the reservoir is blocked or has a leak, however small, then the system won't work and you'll have cooling problems.

The chip cannot make the car run hot. The chip turns on the fan at 180 something degrees. Other than that the chip does not have an affect on engine temp, at least not to the point that it would make a car with no AC overheat.
 
Randy, are you going by this overheating cause of the gauge? whose to say your gauge is working properly? have you replaced the temp sending unit, and the sensor for the comp reading? maybe those have both gone to junk,
 
I'm sure you checked to see if you have an air bubble in the system but these cars are notorious for it. If you have an air bubble the coolant will not circulate and it will get hot.

Best fix is to put in a 180 thermostat and drill a 5/32" hole in it so that water and air can bypass the thermostat.

Then drive the car. If it gets hot, first verify that the fan is running. Then verify the temperature of the upper and lower rad hoses. Both hoses should be hot but the upper one should be hotter. If it is getting that hot then the upper hose should be under pressure and it should also be pushing some fluid into the reservoir. When the car is hot the reservoir should be full to the "hot" line.

Verify all of this.

Then let the car cool off completely (overnight). The coolant reservoir should lower down to the "cold" line. If it goes lower than that then you had an air pocket. Fill it back up to the "cold" line and drive the car until warm again. Do this until you can verify that the reservoir is both accepting coolant when the motor is hot and giving fluid back when the motor is cool. If the hose going to the reservoir is blocked or has a leak, however small, then the system won't work and you'll have cooling problems.

The chip cannot make the car run hot. The chip turns on the fan at 180 something degrees. Other than that the chip does not have an affect on engine temp, at least not to the point that it would make a car with no AC overheat.

I am not saying the chip is the problem, that just the starting point of my problems. I have ask for help on line before,and my post turns to trash
just because I bring up that the starting point of my problems was after
chip swap.

I have install a 197, 195,180 degree thermasstats. all but the 180
had weap hole in top of thermostat.It is not drivable with the 180
thermostat.

I have check the hoses, the reservoir is full, no bubbles.

Car is well over 180 degrees before fan comes on. guess...
I have no hand held temp guage to be sure of exact temp.

I am positive that all air is out of system. I check for this.
I jack cars front up. this helps to get the air out. reservor
And radiator are full.

I am totaly stumped. I even tried different heads.I have reinstall
the first set of heads .

Thanks Randy
 
Last edited:
I am not saying the chip is the problem, that just the starting point of my problems. I have ask for help on line before,and my post turns to trash
just because I bring up that the starting point of my problems was after
chip swap.

I have install a 197, 195,180 degree thermasstats. all but the 180
had weap hole in top of thermostat.

I have check the hoses, the reservoir is full, no bubbles.

Car is well over 180 degrees before fan comes on. guess...
I have no hand held temp guage to be sure of exact temp.

I am positive that all air is out of system. I check for this.
I jack cars front up. this helps to get the air out. reservor
And radiator are full.

I am totaly stumped. I even tried different heads.I have reinstall
the first set of heads .

Thanks Randy

I'm just saying that all the chip does is turn on the fan at whatever temp it's set for. You have the software, it might be a good time to open it up and look at the fan temps. It's under the category "environment". It will be set somewhere between 180-190 deg.

I have verification that the EEC was going closed loop in OKC. I have logs to prove it. The point with that is just that if the car goes closed loop it MUST run 14.7:1 AFR. In other words, it can't be lean - unless - it has a bad sensor telling the EEC lies. Now if it has a bad sensor it MAY send a check engine light. Does the car have a check engine light? If so, what codes does it send?

If you don't have a check engine light but you don't believe that the car is running correctly then the only thing left to do is connect your LM1 and drive the car. It will verify 14.7 AFR under steady throttle cruise. If it makes 14.7 AFR under stead throttle cruise then the problem is NOT related to the tune and MUST be related to a mechanical cooling issue. If you do not get 14.7 AFR under cruise then we have a place to start looking.
 
Randy, are you going by this overheating cause of the gauge? whose to say your gauge is working properly? have you replaced the temp sending unit, and the sensor for the comp reading? maybe those have both gone to junk,

I have installed a new temp sensor. It ran hotter.
I reinstall old temp sensor, still reads hot.

I have not tried a hand held temp guage to check.
cant afford one.

I am not just going by the guage. I know when my car is overheating.
Beleive me it is over heating.

I have tried different type Fle-pro gaskets. regular,MLS coated.
I now have regular fel-pro head gaskets. All the holes in the gaskets
line up and are the proper gaskets to use on my car.

Thanks Rasndy
 
I'm just saying that all the chip does is turn on the fan at whatever temp it's set for. You have the software, it might be a good time to open it up and look at the fan temps. It's under the category "environment". It will be set somewhere between 180-190 deg.

I have verification that the EEC was going closed loop in OKC. I have logs to prove it. The point with that is just that if the car goes closed loop it MUST run 14.7:1 AFR. In other words, it can't be lean - unless - it has a bad sensor telling the EEC lies. Now if it has a bad sensor it MAY send a check engine light. Does the car have a check engine light? If so, what codes does it send?

If you don't have a check engine light but you don't believe that the car is running correctly then the only thing left to do is connect your LM1 and drive the car. It will verify 14.7 AFR under steady throttle cruise. If it makes 14.7 AFR under stead throttle cruise then the problem is NOT related to the tune and MUST be related to a mechanical cooling issue. If you do not get 14.7 AFR under cruise then we have a place to start looking.

I have no idea on how to open up my program in lap top, I have tried to look.
And I do know how to hook up the racer tune package. to change a tune.
T

I have not check the o2 sensors. they are new as far as miles. they have never had anti-freeze on them that I am aware of. I have no codes
or check lights .

I have no idea how to hook up my LM-2
I tried to with my the first LM-1. it burnt up because I did some thing wrong.

Every part in the cooling system is new. and have swap new parts to check on the old new parts.

I have been tring to fix for two years, not much that I have missed.
But it is ovius that I am missing somthing.

Thanks Randy
 
The LM1 doesn't require hookups to work. Just install the sensor, plug it in, and plug the meter into your cigarette lighter. There is nothing else required. There are other optional hookups but they are not required to use the wide band.

Have you fixed your exhaust leak? An exhaust leak will cause the O2 sensors to read lean and that will make the car run rich. It will not set a check engine light.
 
I have no exhaust leak. Your refuring to another post that I said
last year, it sounded like an exhaust leak, For one second When
head lifted. that was the exhaust leak sound. When I tried to blow
the gasket out.the day you left my house.

The head lift head had a sound of an exhaust leak for one second.
It then resealed. this is a normal sound during head lifts.

Thanks randy
 
The LM1 doesn't require hookups to work. Just install the sensor, plug it in, and plug the meter into your cigarette lighter. There is nothing else required. There are other optional hookups but they are not required to use the wide band.

Have you fixed your exhaust leak? An exhaust leak will cause the O2 sensors to read lean and that will make the car run rich. It will not set a check engine light.

I burnt my first LM-1 hooking up aux sensor wires.I guess .5 volt
hook-ups do not like 12. volts :)

The car is over heating in around one mile of drive time.
Less if I add boost.

I am running 15% overdrive now. tune was with 20% OD.
I have also tried 10% OD can't go lower than 10%.

Thanks Randy
 
Last edited:
All I'm saying is that if the 02 sensors are getting a true reading and are not damaged, and you don't have a check engine light, then the car is running closed loop AND therefore can't be very far off on the part throttle tune.

I don't have your current tune file in front of me right now to be able to tell you exactly what is in that file which is why I suggested that you figure out how to open your software and look at it yourself.

If you are so convinced that nothing mechanical is wrong, then hotwire your fan so it runs all the time and see if that helps. This can easily be achieved by cutting the #14 wire on the IRCM. The pins are numbered so you can see which one it is but I think it is tan with a red stripe. If you do a search here you'll see a diagram somewhere. This will cause the fan to run anytime the engine is on.
 
Back
Top