a little to hot

[bender4040]

My 1991 Silverado 4x4 extended cab has 250,000 miles! I've had it since '91. I rebuilt the motor at 207,000. I put a new delco tranny (5 speed) in it. Also a new radiator.
This truck sometimes runs hot when I try to run my air conditioner. It is okay out on the open road but not arround town or idling.
Could this be fan clutch? Should fan clutch turn easily when cold? How much does the sroud affect cooling? (Mine is missing the bottom half.)

Are there any aftermarket products to help cooling? I have seen electric fans and three layer radiators. Any experience with them? Thermostat seems okay but I am going to change it. Will probably go ahead and change out fan clutch. (Replaced it once, long ago, with a new thermal fan clutch.)

[V-8Fan]

Bender,

The shroud is designed and installed for a reason! I'd get that puppy put back on before I drove the truck another mile, and I definitely wouldn't spend another nickel on any other "maybe" solution before trying it.

Let us know how it works out.

[aelwero]

the shroud is nowhere near as important as the fan, it's supposed to loosen when it gets going very fast, when you don't usually need the airflow as much. If it's loose when it isn't spinning it's quite broke. Before you hassle with a clutch, price a flex fan, the cheap looking little sheet metal ones, they make more noise, but they look a tad better and they work a tad better, and I have yet to see one break. If you still have the shroud, put it back on, but it's not the end of the world if you don't. My wife's olds (god rest it's soul.. it was killed by a bird...long story ran for 3 years with no shroud at all, and a flex fan bolted straight to the pulley, never had coooling problems at all (until the bird went THROUGH the radiator...)

[Joe_Rocket]

I'd keep the fan shroud. It may not be as important as a fan, but they are designed to work together. THe shroud forces all the air it is pulling to come through the radiator. THis is what you need, especially at idle.

Whether the car runs good with or without the shroud depends on the car. They are all different. So, what works for one, may not work for you.

I'd avoid a flex fan, because many of the ones I've seen have smaller blades and won't pull enough air at idle for a truck. Pulling enough air at idle is always the trick. You don't need ot worry once your up to speed. THe engine RPM's are obviously low at idle. So, you need the big blades of the factory type fan and the shroud to get all the air through the radiator you can.

A good fan clutch, with the proper fan and shroud is probably the best combo. You don't want to rob horsepower by not running a fan clutch.

Joe

[bender4040]

Thought I would update everyone that answered my post on my overheat situation.
I replaced the missing bottom half of my shroud with a new one. While doing this I discovered that the missing shroud had allowed some crud from a power steering leak to build up in the lower part of the radiator. I cleaned the radiator and added the shroud. I also pulled the grill and went over the air conditioner condenser opening up some squashed fins with a little screw driver and a tool made for spreading them.
The crud was probably the main problem, but I will not ever run without a shroud. I think the shroud focusing the air flow across the radiator is important.
The truck runs cool while a/c is on max even when at idle. Yeee-Haaw!!
I just rolled over 250,000 miles this week.