Chevy 5.3 Clutch Fans?

dej(Jed) · Jul 23, 2014

Yep it is me again. Last night I changed out the thermostat in my 2003 silverado with the 5.3. Okay so now I have replaced the clutch fan, flushed the radiator and changed the thermostat. No off gases or water in the radiator. Loaded the A on the trailer and headed north to mow. Well after the first hill the gauge went up to 230 F. Got to the top and it cooled back to 210. Ran along at 210F on the level and heated up on the hills. Stoped and checked the fan when the gauge was at 230 degrees F and there was no resistance whatsoever. Aren't these things supposed to lock up and then spin counterclockwise? Appreciate any and all advise or comments. Also I won't post anymore about this problem. Thanks.

jimg.allentown · Jul 23, 2014

230 is NOT overheating. It is a normal operating temperature under a load. That is why you use a 50/50 mix of antifreeze and water and run under 13 to 15psi pressure in the coolant system. This raises the boiling point of your coolant to over 260! The clutch fan operates based on the temperature of the air coming out of the radiator. That is what the bi-metallic spring on the front of it is for. Once you stop, open the hood, and check the fan, the temp AT THE FAN has most likely dropped enough to allow it to disengage.
Also keep in mind that dash gauges are NOT precision instruments. They are only there as basic indicators. IMHO, you are looking for trouble where there is none.

Your post is the exact reason that they stopped putting gauges into dashboards back in the 1950s. Every time a needle moved, customers went running to the dealer to get the "problem" fixed. To this day, most regular cars have little or no instrumentation besides the speedometer and gas gauge, and sometimes a tachometer.

dej(Jed) · Jul 23, 2014

(quoted from post at 05:38:04 07/23/14) 230 is NOT overheating. It is a normal operating temperature under a load. That is why you use a 50/50 mix of antifreeze and water and run under 13 to 15psi pressure in the coolant system. This raises the boiling point of your coolant to over 260! The clutch fan operates based on the temperature of the air coming out of the radiator. That is what the bi-metallic spring on the front of it is for. Once you stop, open the hood, and check the fan, the temp AT THE FAN has most likely dropped enough to allow it to disengage.
Also keep in mind that dash gauges are NOT precision instruments. They are only there as basic indicators. IMHO, you are looking for trouble where there is none.

Your post is the exact reason that they stopped putting gauges into dashboards back in the 1950s. Every time a needle moved, customers went running to the dealer to get the "problem" fixed. To this day, most regular cars have little or no instrumentation besides the speedometer and gas gauge, and sometimes a tachometer.

Okay Thanks-I can never hear the clutch fan engaging. On my 04 GMC when I changed it, you could hear it kick in.

Allan in NE · Jul 23, 2014

Why won't you post any more about your issue? Heck, let's get 'er figured out.

At 230-240 degress, the fan should lock in and you should hear it "roar". If it doesn't, either the air coming across the clutch isn't really that hot or the clutch hub is defective.

I can tell you this much, if you didn't buy that clutch directly from Chevy, you're gonna have trouble. Aftermarket clutch hubs NEVER, EVER work right.

Are ya sure the truck is actually getting that hot? I'd put a heat gun on 'er to verify.

Allan

Sprint 6 · Jul 23, 2014

Those clutches are also speed sensitive, so it could be disengaged due to speed. You can get a Hayden clutch from Napa, same thing as in the GM box, but less money. Make sure the clutch has a spring on the front. Did you check the hose coming off the throttle body to the radiator for flow? No flow there WILL cause heating up, maybe not full boil over, but it will run warmer than usual. Your truck should run just a tick under 210 on the gauge.

Hobo,NC · Jul 23, 2014

A generic test at operating temp is to shut the engine off and see how many times the fan turns on its own. If it turns more than one to two revolutions as soon as the engine shuts down the fan is suspect... Most won't do more than one....

If you are having a heating issue cursing down the road over 35MPH the fan clutch is not your issue... Pulling a load may be a different story but that would be my generic answer...

High Octane · Jul 23, 2014

is the transmission cooler still routed thru the radiators on these like the older trucks? had a 90 gmc ext cab 2wd 2500 with 350. was getting a little warm, then progressively got worse. i replaced everything, didnt help. transmission went out a month later. replaced transmission n couldnt get it over 200 degrees! just a thought... maybe your sending unit is going south?

danofarming · Jul 23, 2014

I had an issue like that several years ago with a 5.7. I put in a high
flow thermostat and solved the problem. Apparently not enough hot
coolant was getting to the radiator to heat it up enough to cause
the fan to kick on.

4play · Jul 23, 2014

I used to have an 03 1500 5.3. I towed up 7k up and down highways on 100 degree days, never heard the fan and temps only went a little over the 210 mark or about one thickness of the needle. I also had the SS cluster with the trans temp guage and the trans temps were always under engine temps. The only time I ever heard the fan was in stop and go traffic on approx 90+ temp days using the a/c. The noise of the fan should be obvious when the clutch is engaged.

Check for debris in front of the a/c condenser and grill. Also remove the plastic panel over the top of the core support and check for debris between the condenser and radiator.

Chevy 5.3 Clutch Fans?

dej(Jed)

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jimg.allentown

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dej(Jed)

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Allan in NE

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Sprint 6

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Hobo,NC

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High Octane

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danofarming

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4play

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