440 Highway temps

[zombezoo]

A bit of an odd situation:
73 satellite 440 swap
Recored factory radiator
180 degree tstat
New fan clutch and 7 blade fan
Factory ac condenser installed but not charged
Fins are clear

Idle and around town the thing runs on the gauge line, approximately 200 degrees on the coolant temp sensor installed for the EFI system in the water pump housing

Highway temps over 70mph spins the motor 2500rpm+
Temps will climb into the 230s on the CTS, just under half way on the gauge

I pulled over with the ir temp gun:
Upper radiator hose 180
Lower radiator hose 135
Radiator core 125-130
Water pump housing 220

Seems to say pump is not moving coolant, I had it apart and the impeller looked great, tight on the shaft, not leaking.
Engine is an RV unit, using all the rv pulleys
I choose not to change the water pump because the unit in the engine had an impeller that was larger than the replacement unit I purchased and I was concerned I had the wrong pump.

Any insights here? I know there are different pumps, pulleys and housings but I would have thought keeping all the RV stuff together would be ok.

Again, around town and sustained speeds up to 50 mph, it's fine. It's extended higher rpm runs that seem to be a problem

 

[#41]

The first two things I would check for higher speed run hot issues considering you have a fresh radiator.

1. Lower rad suction hose collapsing. Make sure it is either very rigid or has a spring in it.
2. A vacuum leak at the carb/intake/hose can be tuned out and unnoticeable at low speed but cause a lean/hot run at high speed.

 

[Sixpactogo]

Are you running the factory pulleys or a serpentine set-up?

 

[davek]

check lower hose for spring.

 

[j-c-c-62]

It would really informative here IMO if we could see the IR gun temps above at 70mph, but the cops might frown on you standing on your front bumper riding down the highway at speed.

 

[zombezoo]

Answers:

There is no spring in the lower hose, didn't think about a collapse. Will add one.

Fuel injection includes wideband and learning function that keeps the afr in the mid to high 13s at cruise

Factory v pulley with factory sized pulleys

 

[zombezoo]

Would holding the throttle to get to 3k rpm in Park collapse the hose the same way as on the highway? In other words, if the hose doesn't collapse in that test is that potential cause ruled out?

 

[Tony 69]

I took the hi flow super dopper water pump off mine and replaced it with stock. Fixed mine. Maybe the coolant flowed through the radiator slower(?).

 

[Aron Gleason]

Would holding the throttle to get to 3k rpm in Park collapse the hose the same way as on the highway? In other words, if the hose doesn't collapse in that test is that potential cause ruled out?

No load in park, so the hose won't collapse. With a load at 3k just cruising it won't collapse not until you actually get on it hard then it'll collapse.

 

[#41]

Fuel injection includes wideband and learning function that keeps the afr in the mid to high 13s at cruise

So if the vacuum leak is at the intake manifold and effects just 1 or 2 cylinders, your system is going to understand and correct for that, or just up the overall fuel delivery leaving those cylinder still leaner that overall afr?

 

[dadsbee]

pulled over with the ir temp gun:
Upper radiator hose 180
Lower radiator hose 135
Radiator core 125-130

Well, I see 180F coolant coming out and 135 going back into the engine. Drive it like ya stole it...

 

[j-c-c-62]

No load in park, so the hose won't collapse. With a load at 3k just cruising it won't collapse not until you actually get on it hard then it'll collapse.

Sorry, rpms effect water flow directly, engine load has little effect on water flow, meaning the lower hose collapsing is directly related to rpm and indirectly related to water temp and thermostat opening, which can be promoted by partially blocking air flow thru the radiator, all achievable while parked sitting still in your driveway.

 

[j-c-c-62]

Well, I see 180F coolant coming out and 135 going back into the engine. Drive it like ya stole it...

Those temps are while parked, at idle, no throttle.

 

[dadsbee]

Those temps are while parked, at idle, no throttle.

No, he immediately pulled over and took Infrared Temps... or I can't f'n read!

 

[zombezoo]

No, he immediately pulled over and took Infrared Temps... or I can't f'n read!

This is correct. Car could idle for hours without issue. You have to be going 70+ for more than 10 min to drive the temps to 220+. Once it's that warm, it takes awhile to cool down at slower speeds or idle. It's not like it drops immediately back into range once I stop. I took those temps 10 seconds after stopping.

 

[zombezoo]

Well, I see 180F coolant coming out and 135 going back into the engine. Drive it like ya stole it...

I should add, the air temps are about 70 today. What should I see through the radiator core?
It's a bit tough to measure since the condenser blocks readings on one side and the shroud on the other.

 

[dadsbee]

Thanks... I'm here all week! Lol

 

[j-c-c-62]

No, he immediately pulled over and took Infrared Temps... or I can't f'n read!

That is not disputed, I and others all read the same comment, but fact remains he was parked ,engine was at idle, and under no load and all recorded temps were normal.
So what magic happens to make a 'hot" engine read normal?

 

[zombezoo]

That is not disputed, I and others all read the same comment, but fact remains he was parked ,engine was at idle, and under no load and all recorded temps were normal.
So what magic happens to make a 'hot" engine read normal?

220 degrees at the pump housing is normal?

 

[Dennis H]

Nobody reads anything. Done.