I have a 94 deluxe pu, 3.0 v6, and have changed everything in the cooling system. It still gets hot when going uphill with a/c on. I have changed waterpump, radiator cap, hoses, thermostat, and last week, removed a two row radiator and replaced with a three row, metal tank radiator. Since installing the three row radiaror, it just barely goes above the halfway mark on dash gauge when going uphill ( freeway or mountains at hwy speed, 50_70 ) with ac off, but still wants to go beyond 3/4 with AC on. Not so concerned about having ac as much as figuring out the heating issue. I had reputable mechanic check to see if the head gasket might be an issue but they said no. Any ideas?

Also, oil gauge on dash stopped working. Same mechanic said it is the dash gauge itself. Where can i get that gauge repaired or replaced. First time on forum. Thanks.

 

First off welcome to the forum.

Hows the cooling fan clutch feel? You didn't mention it in your list of things checked. Hill climbs are usually slower speed higher rpm. So that's when the fan should be doing a lot of the work. Get it hot and then turn the fan by hand. A bad clutch will be easy to turn. A good clutch will feel tight and difficult to turn. If it's bad replace it and do your hill test again.

The thermostats in these trucks are notorious for being duds out of the box. I'd try temporarily removing it and then try your hill test again. That should rule out if the stat isnt opening all the way. I recommend getting an OE stat if possible. Otherwise I've had good luck with Murray stats.

Is your temp gauge accurate? I've seen a lot of overheating cars that weren't actually overheating.


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My apologies. I did replace the fan clutch and the shroud as well. Someone mentioned the timing last time i was over at a friends. Is that a possibility? I thought timing was electronic but maybe not. Thanks for sharing! Doug

 

The headgaskets in just about all different engines have coolant openings in them that are much smaller than the corresponding passages in the head and block.

The gaskets are designed with these calibrated passages so as to equalize coolant flow and temps throughout the engine.

If a cooling system has been run rusty and dirty, or fouled by the use of stop-leak products, these smaller coolant passages thru the head gaskets can become further restricted, or plugged up.

When this happens, it is practically impossible to restore proper coolant flow without replacing the head gaskets and hot tanking the block.

This is sometimes found to be why an engine cannot be made to run cool under load, no matter what you do to it.

 

It is electronic, but the 3VZE doesn't have a "hard" cam position sensor. Instead, it uses the distributor to find "base" timing. So base timing has to be set, and the computer takes over from there.

If the base timing is retarded, it can actually make the exhaust manifold glow orange-hot. You'll need a traditional timing light, which will set you back about $25.

 

Thank you for your time and opinion. I dont think ill be pulling the motor for that. Is there any good flush product you might suggest. Thanks again, i appreciate your thoughts.

 

Prestone flush is ok. We use BG at work and it works awesome. You can find it on E-bay and many auto shops.