tnb587

have a 2004 Silverado 4X4 5.3L V-8

Problem:
Engine over heats during slow speeds and idling. (at least that is what the gauge says)

I checked the water level........OK
At highway speeds during the day in Fla.heat, it is ok. But when I get on secondary roads and have to slow or stop at lights, it really warms up.
The other day I was in a parking lot waiting on someone, it got real hot. So, I brought the RPMs up to about 1500 and I could watch the temp drop.
I am very baffled by this. I'm only concerned that it could get worse. Plus, I don't like my engine operating at such high temps.
Any thoughts ????? good or bad !!!
Thanks in advance, Ted

kevinkpk

How fast is the clutch fan turning?

Allan In NE

Replace the clutch hub....and no aftermarket stuff here; chevrolet only!

Allan

tnb587

I think you guys might be right. Although, I was watching the fan @ idle and it seemed to be spinning pretty fast. I then shut down the engine and spun it by hand. It did seem to have a little back pressure on it (like it should), but maybe not enough. I have seen them worse than mine.

But.........if no one else has any other ideas, a new clutch it is. I just wasn't positive the clutch is bad. I hate being a parts replacer 'til you fix it guy...........LOL

PS.....I assume genuine Chevy is still AC DELCO ?? (it's been awhile since I had my shop...like 25 years)

tnb587

Ok.......I looked at how to replace clutch. Never saw one that mounts quite like this one. The instructions say to use special tool.

Do I really need to purchase a tool that I will use once in my lifetime ?????

OR.........can I get it out with a big hammer????? LOL

Just watched video how-to on you-tube..............piece of cake

BW56

Our local chain auto parts stores all have loaner tools for this job. Pre over pay deposit with full refund upon return. Good program.

tnb587

Well, I replaced the fan clutch today............SAME PROBLEM !!!!!

I didn't feel that it was bad. Although, I had it out so I put the new one in. Drove it about 2 miles and the temp is up to 230-240.

If I let it idle, the temp keeps rising. If I bring the idle up to around 1500rpm, it will come back to 210 which is normal.

I didn't take it out on the highway (70-80mph) but if I do I'm sure it would read normal (210)
Radiator is not clogged with bugs, nor is the condenser.

WTF is going on ??? Anybody ??

kevinkpk

Water pump?

tnb587

Do you agree, that if the impeller was bad, that it would not operate at normal temp at highway speed ??? Just asking !

kevinkpk

I don't know if it is the water pump or really believe that. Only time I've ever had a bad water pump was due to a seal leaking, or bearing.
What you've posted tells me you have a restriction.
1) Replaced fan clutch
2) Thermostat? Has this been replaced? You can't just leave it out as you need a restriction for radiator cooling.
3) Is the radiator itself any cooling coils bent, reworked?
4) Is there any white smoke out of the tail pipe?
5) Is the coolent level ok, I know you checked it, also is there any external/internal coolent leaks? Look at the oil dipstick for anything other than oil.
6) Is there a shroud around the radiator?