Strange engine heating problem (new)

[Bolt]

Originally Posted by ab

Anytime you put a SC on any car it can cause it to run hotter because it's putting a load on the engine. Kind of like running your AC on all the time. More power will generate more heat.

This is true but this was not happening last year and it did not start getting hotter till I put my first tank of fuel with ethanol in year.

Reality check:
Engine temprature after 10 minutes of running. 220 degrees
top radiator hose 195 degrees
lower radiator hose 165 degrees


I'm tearing the watter pump out tonight. Even if I don't find anything wrong I'm going to try to go to a smaller watter pump pully. Of course change the Serpentine belt too. Anyone out there know where I can get a smaller watter pump pully or what application would fit? I want to reduce the diameter by 1/2 inch.

[Tom, F&L GoR]

Originally Posted by Bolt

I am now running gas with ethanol in it. Last year there was no ethanol in my fuel. Could this be the problem?

Should not. The O2 sensors adjust mixture ratio and the ethanol has a higher latent heat, so it should actually run cooler.

[Tom, F&L GoR]

Originally Posted by Bolt

Reality check:
Engine temprature after 10 minutes of running. 220 degrees
top radiator hose 195 degrees
lower radiator hose 165 degrees

Please clarify this - one hose should be hotter than engine, the other cooler than engine (assuming the engine temp is measured by a guage? )

[Bolt]

Originally Posted by Tom, F&L GoR

Should not. The O2 sensors adjust mixture ratio and the ethanol has a higher latent heat, so it should actually run cooler.

I don't know much about this but could the O2 sensors be reading the information incorrectly and either making the car run rich or lean and creading the motor to run differently? Is this why we all see the gas milage decrease with the gas which has ethanol in it? Do we need to have our computers reprogramed to compensate for this as more ethanol is added?

[Bolt]

Originally Posted by Tom, F&L GoR

Please clarify this - one hose should be hotter than engine, the other cooler than engine (assuming the engine temp is measured by a guage? )

The 220 came from the guage (Engine temp)
the other two temps came from my hand held laser thermometer at the upper hose and lower hose on the radiator.

[dave6666]

Reset PCM time, for new fuel?

[Bolt]

Originally Posted by dave6666

Reset PCM time, for new fuel?

Than that is something simple to try. Thank you.

[GR8_ASP]

Originally Posted by Bolt

This is true but this was not happening last year and it did not start getting hotter till I put my first tank of fuel with ethanol in year.

Reality check:
Engine temprature after 10 minutes of running. 220 degrees
top radiator hose 195 degrees
lower radiator hose 165 degrees

The delta T across the engine seems high (should be more like 15 F). When are you measuring the hose temps? At idle, while driving or immediately following driving? Is the fan on when you are checking it?

A high delta T across the engine can be caused by low coolant flow rates. So either a pump issue, a restriction (like a stuck thermostat or kinked hose) or something of that nature may be occuring. It can also be caused by excessive heat rejection to the coolant. If your engine is running ok I am doubtful as to that. However, compression leakage to the coolant is a low probability cause (head gasket, erosion of head water jacket, etc).

My guess is on the flow side if the heater performance is poor. Have you checked the aftermarket thermostat operation? That would be my first guess.

[Bolt]

Originally Posted by GR8_ASP

The delta T across the engine seems high (should be more like 15 F). When are you measuring the hose temps? At idle, while driving or immediately following driving? Is the fan on when you are checking it?

A high delta T across the engine can be caused by low coolant flow rates. So either a pump issue, a restriction (like a stuck thermostat or kinked hose) or something of that nature may be occuring. It can also be caused by excessive heat rejection to the coolant. If your engine is running ok I am doubtful as to that. However, compression leakage to the coolant is a low probability cause (head gasket, erosion of head water jacket, etc).

My guess is on the flow side if the heater performance is poor. Have you checked the aftermarket thermostat operation? That would be my first guess.

More good information. Fan is working fine. Runs at both low and high speeds. I'll remove the t-stat and test it in boiling watter. I'll also look for obstructions. Maybe run watter from a garden hose thru the engine. I'll also do a compression test to all cylinders. I don't see any unusual compression or vacume in the coolent system. I am running a new radiator cap. 17PSI I still have the ole 195 degree t-stat. Should I put that back in for testing?

[dave6666]

Originally Posted by Bolt

More good information. Fan is working fine. Runs at both low and high speeds. I'll remove the t-stat and test it in boiling watter. I'll also look for obstructions. Maybe run watter from a garden hose thru the engine. I'll also do a compression test to all cylinders. I don't see any unusual compression or vacume in the coolent system. I am running a new radiator cap. 17PSI I still have the ole 195 degree t-stat. Should I put that back in for testing?

You can run w/o a thermostat. I just wouldn't do it for very long. The PCM won't like it.

[Bob Woodhouse]

You mentioned it heats at idle, the radiator is clean, coolant is good etc.

This is not an ethanol issue, otherwise the entire nation would be overheating since most 91 octane is around 10% which is what I assume you mean by ethanol. The blend yes?

Air in the system is a high possibility and you said you have burped but I would re-do that, the system has been completely apart and you may have trapped air that did not rise the first try.

Remove the water pump if nothing else makes sense, impellers can come loose, altho not common. Yes there was a small rash of them a few years ago.

Air flow, you have no changes in air passing over the radiator, like, the fan is coming on in your garage, you have not opened up an areas around the radiator to allow air to flow around it etc.
Hope you get it fixed, Bob Woodhouse.

[dansauto]

turn your heater on and see if that lowers the temp any. If so then you are just no getting enough airflow thru the rad.

[Tom, F&L GoR]

Originally Posted by Bolt

All air is out. I did this with the vent on the t-stat housing.


I am now running gas with ethanol in it. Last year there was no ethanol in my fuel. Could this be the problem?

You Gen 2 guys have modern conveniences, so I didn't know there is a vent on the thermostat housing. Even so, in a Gen 1 the heater core elbow hoses are the high spots and loosening them to bleed air or even filling from there is the "secret' to getting air out. I still vote for burping.

The only other idea is a collapsed hose - the inner lining has separated from the stringy core and is flopped into the coolant path.

[Bolt]

Good suggestions keep flowing in. Water pump is 1/2 way out. Working around all the SC stuff is a PITA. But I love what the SC does for me. I'll keep checking things out and report back.

Side note: I heard all gas over 91 octain contains the full 10 percent ethanol. I don't know if this is true but I'll be running high octain in my other cars to test his out for awhile.

[Bolt]

Water pump looks like it's in great shape.

Now I'm looking for a water pump gasket on a Friday evening. No luck so far.