I have a 1994 6.5 turbo S in the vin. this morning it got hot on me so I thought the thermostat was stuck closed. then it cooled down. I did notice that I am not getting heat from the heater at idle but I will when I move. No bubbles in the reservoir or coolant splashing out of it when I rev it up.


where should I start?

t-stat maybe going bad

Just replaced it this afternoon same issues

Either low coolent or flow problem will cause this.

should bleed the cooling system at the t-stat housing

I spent two hours trying to bleed the cooling system today I noticed that I would get heat out of the heater when I would raise the rmp I also would get water out of the bleeder valve. the water in the reservoir is not getting warm I am wondering if the water pump is bad or going bad. It is not leaking but I imagine that they can go bad with out leaking as well. Any one have any advise for me

What's your coolant strength? Sounds like its weak and gelling.

I put 2 gallons of coolant in it when I replaced the themostat

straight coolant? Have you had it tested?

it is not straight coolant it is about 50/50 mix in the engine it self I have not had it tested. I open the reservoir tank first thing this morning and it was all good no gel or freezing it is down to about 11 degrees here in the mornings. I have read a couple of articles on antifreeze gelling I dont think that is the problem, but is there a way to check for it? Should I just drain all the coolant out and put just water in it to see if that is the problem then replace antifreeze. The anti freeze I put in was new.

I noticed that if I rev up the motor I will get coolant out of the bleeding screw. I will also get it to come out if I squeeze the upper rad hose. I noticed that the upper hose was not very hot warm at best. I also noticed the coolant/water in the reservoir was not warm either. I am getting very little heat in the cab at idle I rev it up I get heat if I turn off th heater and leave it closed for a couple of minutes it get heat then it goes away. I am also noticing that the temp gauge is a notch higher that it usually runs at. New rad cap and t-stat. I am wondering if the water pump is going bad.