Update! Just replaced the intake manifold gasket. So far no leakage anywhere to be found. But still no heat. The heater hose feels hot to the touch and the return hose from the core feels warm. Can't figure it out. Help!?!

Thanks
Marc

 

could be a plugged heater core.. I'd think it should still be pretty hot on the outlet side of the core.

btw, did you flush the cooling system and re-fill it with distilled water with the anti freeze. sometimes using tap water will help to create sludge because of the crap in it.

 

yes I did flush the system. the outlet hose did get hot eventually (maybe air was still in the system) but no heat. is there a valve or something that controls temperature when the **** inside the cabin is turned?

 

Sorry, this is where my help dies out... dont know enough about your van to help much more... I can say that if your control valve is working, you will get flow thru the core and the oulet side will get hot like you experienced. maybe one thing you can try is to warm it up with the valve in the cold position, then have someone change it to full hot and put your hand on the outlet side and see how long it takes for it to warm up. should be pretty quick if things are flowing right. that will also tell you if your control valve is working ok. crude test but it should at least let you know it works.

oh one thing comes to mind... if your air flow is coming out of the defroster there is a couple of check valves on a vacuum line that tend to go bad and cause your airflow to go to the defroster... that is a common problem with the magnum motors.

 

Thanks I will try it. As I was paying close attention to any engine noises and leaks I noticed that at high rpm's especially towards the top of first gear, then after it shifted to second the rpm's dropped and the noise went away until high rpm's there was a knocking sound maybe coming from passenger side of engine. It almost sounded like something get tossed around.

Thanks
Marc

 

sounds like pinging to me...

 

what would be the cause of that. It is pretty loud when it does it.

Thanks
Marc

 

leaky plenum gasket... yank off the TB and look down into the intake with a flashlight & mirror and look for oil pooling on the bottom of the intake. a light film is normal, pooling is not. it is a common problem on the magnum motors. use a felpro gasket to fix it. stock dodge gaskets still fail.

 

I hope that is not that the problem because that is exactly the part I changed this past weekend. (Plenum and upper gaskets)

 

if it's a bad enough leak, you should be able to see it easily. it could also be your fuel pump not putting out enough pressure to keep up with the motor. slap a guage on there and you should measure 49 +/- 5 psi