96 ram 1500 318 heat trouble

[kyhillbillymonster]

jamesslcx, The thermostats I used were from a local mom and pop auto store here in town. Plus when I threw my arms up in the air and took it to a mechanic, he used a different supplier. I'm sure the thermostats are fine. I'm also very confident that I purged all the air out. Did it running. Jacked up the passenger side of the truck. Did it on an incline at the beginning of my driveway. All that stuff. The fan clutch. That's what's got me so puzzled. I don't hear it engaging from inside the truck. I'm not familiar enough with them to know what they should sound like. It's thermostatically controlled so I won't hear it like an electric one correct?
Thanks for replying.

[jamesslcx]

Hey kyhillbillymonster, when the fan clutch engages you should be able to hear a roaring type noise from the engine compartment. I would say disable the fan and then drive it for a short distance but this would be a major pain on these trucks, your truck still has the fan shroud doesn't it?

[kyhillbillymonster]

jamesslcx, Yes it still has the shroud. How would I disable it? Unbolt it from the pully? I hadn't considered that.

[jamesslcx]

Bad thing is you need special tools just to to remove or change the fan or clutch. Probably not your problem but have you replaced the radiator cap lately? When your engine is warm have you felt your upper and lower radiator hoses also your heater hoses? Both should be very warm or hot to the touch if not it could be a circulatory problem. Just a guess mind you but worth a check.

[kyhillbillymonster]

Yeah, i forgot to mentino a new cap was put on last year also.
I've checked all the circulation issues. Cleaned the entire system.
I bought a fan clutch this morning. We'll see if that fixes it.

[kyhillbillymonster]

Wasn't the fun clutch. Don't know what to do next. Very frustrating. At least I can use cardboard to stay warm this winter. Anyone else have this problem?

[Chris Stewart]

Turn the temperature knob from cold to hot & back to cold a few times in case the blend door is sticking.

[kyhillbillymonster]

Blend door isn't sticking. Thanks though.

[aleekat]

Everything points towards the thermostadt. After driving how hot is your upper radiator hose? I believe you are dealing with 2 issues. The cold running engine and no heat in the cabin. Heater cores can be partially blocked where they do flush but transferring heat is no good. Do you know the temp rating of the thermo that the mech installed?

[kyhillbillymonster]

Yeah, I know. Everything does point to the thermostat. I'll have to take it out again and inspect it to see if there is something that keeps getting into there and holding it partially open or something. As far as heat goes in the cab of the truck. Once the engine comes up to temp. I get plenty of heat in the cab. It'll run you out it gets so hot. Thanks everyone for all the input.

[jamesslcx]

Kyhillbillymonster, how long has your truck been doing this? Your engine temp should be at least 200 degrees when hot, strange problem. I had an older van with the same overcooling problem, I never could figure out why, I replaced everything cooling related but I never could get it right so I did the old cardboard trick like you did.

[kyhillbillymonster]

It's been going on for at least 3 years now. I am almost convinced that the coolant is somehow bypassing the thermostat and the engine is trying to heat all the coolant in the system. Which will never happen because it's being cooled in the radiator. Would like to take some time this weekend to investigate further. Has anyone ever heard of this happening?

[aleekat]

Originally Posted by kyhillbillymonster

It's been going on for at least 3 years now. I am almost convinced that the coolant is somehow bypassing the thermostat and the engine is trying to heat all the coolant in the system. Which will never happen because it's being cooled in the radiator. Would like to take some time this weekend to investigate further. Has anyone ever heard of this happening?

I've heard of improper gasket or wrong gasket install where the coolant flows around the thermo.

[PeteA216]

Two words: Blend Door. The plastic shaft that enters the blend door actuator distorts over time and gets sloppy, not allowing the blend door to fully shut off the intake for cold air. If you look under the passenger's side dash and watch the actuator turn as you reach up and turn the dial from cold to hot and vice versa. Look carefully and watch the white plastic portion of the actuator and the black plastic of the blend door shaft. If you see significant slop, that's your problem.

[kyhillbillymonster]

Blend door is fine for now. Thanks though. When I put cardboard in front of the radiator, I get heat.