My 91.5 (d250 int cool) has the hottest cab of the 2 trucks (d350 non ic) , it seems like all the heat under the hood comes up in the cab,with the windows down it just seems to help draw the heat,Is it just my truck or do some of ya"ll have the same problem???? Is there a thought out way to direct the under hood heat out under the truck,????

 

On my 89, I punched louvers in the fenders. I did it for cosmetic reasons, but it probably helped heat dissipation...

 

Hey ,MTD., i'm think'n maybe hood lovers angled to push air down & under the truck,input would be helpful, anyone,?

 

Hood lovers usually make big dents on a hood!!

but loovers will not only push air, but also rain, show, ect. in the engine bay.

 

Yea!, True to all the above,my other (d350) truck don't seem to have this heat problem, neither one runs hot by the therm. reading. Love my truck, mostly in the winter tho, maybe park it for the summer,hey!!

 

My 91 does that in the spring until it dries out. It came from Arizona, so it has NO insulation. Cold and noisy in the winter, hot and noisy in the summer. My 92 is an Alaska truck, well insulated. Warm and quiet in the winter, cool and quiet in the summer. I think some good insulating will cure your (and my) problem.

 

In many cases the engine bay is designed to flow air, louvers typically disrupt the flow and if anything raise underhood temps. I would wrap the downpipe and make sure all the heat shields and insulation are in place.

 

Sealing off the little sliding vent by the divers foot helped my summer heat. Some guys use duct tape and seal it off for good. I used weather strip so it still functions. Maybe that is where your heat is coming from? I'm already using ac when ever the truck is running, FREAKING ARIZONA, don't move here unless you have good ac!

 

Louvers in the hood wouldn't be good for directing air into the engine bay, but out they would. With the Coke machine aerodynamics we have, there isn't much air flow over top of the hood, at least I would think not enough to scoop any through the hood.

 

check the firewall above the fuel and brake pedals. You may have and open hole where the wiring etc goes through and allowing engine heat into the cab. I sealed mine in my ram 2500 with insulation foam spray and then duct taped it and trimmed the carpet and mat to go around it so its covered.

 

Ck. the fresh air vents on each side of the cab,, also the heat from the hood area is sucked down in the crowling at the wind shield ,goes down inside the fender ,, that's also where the leaves get into the HAC unit.
My 91.5 has orig. carpet plus a full rubber covering,, thought mine was the only that suffered from the " Heat Exchanger ".

whosdunit.

 

Check the water valve for the heater core.. if it is stuck open then the air forced through the cowl induction grill,(at the base of the windshield) being heated.. turning off the hvac uinit may help by closing the fresh air door on the passenger side. The door is set to only close in max AC and off all other settings are fresh air through the passenger kick panal. The vac pot could have failed hear as well.
how are your brakes ? Lo vac could also cause the doors/valves to not move properly.

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