Overheating issue... could use some brainstorming.

[Taxman]

I just did some major work to my car (short block, electric water pump, etc...) and I'm having an odd issue now with coolant temps. When I'm driving around town, my car runs normal temps. However when I get up to freeway speeds, no matter what gear, my coolant temps start to rise. When it gets hot, if I slow down to 60 mph, it cools off immediately.

Any thoughts? I'm puzzled.

 

[stkjock]

Did u check the fans?

Was the tune adjusted? Maybe the tune is not commanding the fans to come on.

 

[Mach2burnout]

Could be the water is not spending enough time in the radiator to be properly cooled at the higher rpms. Don't know much about the electric water pumps. What temp thermostat do you have?

Have you tried an additive like water wetter?

 

[Kenaizer]

I had a similar issue with my '90 IROC in high school. Replaced a thermostat and pump, then gave up and took it to a mechanic. Turned out to be a lower air dam.

Did you recently change anything dealing with airflow?

 

[Taxman]

I checked the tune and the fans are set to turn on at the right temps. I have not done anything that would effect airflow. I'm not sure what temp my thermostat is. I do know it's a fail safe, so if it failed, it would fail open. But if it were stuck open, wouldn't the opposite occur, run hot in the city and fine on the freeway?

And Mach2 it has nothing to do with RPM. I'm in 5th gear going 70 at 2300 rpm and it gets hot, but if I'm in the city in 3rd at 2300 rpm, it doesn't get hot. It's totally related to speed.

It's bizarre.

 

[05moneypit]

What are the fan settings for ECT in your tune. Stock setting the low speed fan turns off at 60mph regardless off coolant temp. High speed fan comes on at 228* regardless of speed.

 

[Taxman]

I'll have to ask my tuner. He looked at the settings the other day and said they are set at the right temps.

 

[05moneypit]

If your tuner has the options opened up in your Xcal for the fans you could try commanding the high speed fan on at a lower temp....say like 200* Stock setting it doesn't come on till 228* and see if that makes a difference.

You running an aftermarket temp gauge or just the stock one?

 

[Taxman]

I'll discuss that with him. I'm running the stock gauge.

 

[durr4456]

Maybe a faulty thermostat. Not a failed one, but it isn't working fully.

Sent from my Nexus 4 using Tapatalk 4

 

[CPRsm]

What pump and how many gpm? Only time I have seen a cool down at slower speeds was an electric pump that couldn't keep up. One was rpm based where if I cruised anout "D" rpm it would heat up. Slow the enigne down and it was fine. One turd was so bad it could only move enough water to keep up with idle. Pro comp junk, LOL.

 

[gray1622]

I would think that when at higher speeds your engine is under a higher load on it. Therefore creating more heat. My guess would be a bad pump. I would put the stocker back in and see if it fixes the problem.

 

[V8 Vol]

blockage in the radiator?

 

[Taxman]

I would think that when at higher speeds your engine is under a higher load on it. Therefore creating more heat. My guess would be a bad pump. I would put the stocker back in and see if it fixes the problem.

Yeah cuz that's really easy...

I've got the standard Meziere electric pump. I'm gonna check the cheaper stuff before I go taking off my supercharger to get to the damn water pump. Hoping it's the thermostat or the relay powering the pump.

 

[TexasBlownV8]

Is anything in front of your radiator..like an intercooler?

Otherwise it sounds like either the radiator is not able to keep up or the water pump is not pumping enough.

 

[dre256]

A simple cheap idea is maybe your pressure cap is bad/not holding the correct pressure

 

[skwerl]

My first inclination is to focus on what has changed since the car operated normally. I'm in agreement with the folks who suggested looking at the water pump.

 

[Taxman]

Is anything in front of your radiator..like an intercooler?

Otherwise it sounds like either the radiator is not able to keep up or the water pump is not pumping enough.

My intercooler is. I know it's probably that the pump can't keep up. I guess I'm just hoping it's not that

 

[skwerl]

My intercooler is. I know it's probably that the pump can't keep up. I guess I'm just hoping it's not that

If it's not the water pump, it could be something creating excessive friction in the short block. I think the water pump would be the easier issue to deal with.

 

[BruceH]

what signal turns the pump on and where does the power come from? Is there any chance that the fan power is used to trip a relay?