Hey guys, I have a 1999 Ram 2500 HD 4x4 and I can't seem to pinpoint out the problem in order to properly diagnose it....I have noticed that on startup, I can smell a sweet smell (thinking it may be anti-freeze) coming from the air ducts when the heat is on. Once the truck is warmed up this problem seems to disappear. Then, when accelerating or anytime the tach reaches or goes over 2200 RPM the heats seems to cut out completely....I'm a little stumped on this one. Do I have a bad heater core or a vacuum problem or both???? Any help would be much appreciated.

 

by cut out completely, do you mean that it just stops coming out of the vents or does it switch to the defrost vents? if it switches to the defrost vents then you have a bad check valve or a vac leak.

the sweet smell (and a mold smell) are from coolant in the fins of the heater core. if it isn't making the windows fog up when you cut on the heat then you should still have some time before you absolutely have to change it. and changing a heater core is just loads of fun. i changed mine last winter and i was working alone so it took me a while. when mine went it made the windows fog up if i didn't have the climate **** on cold, with the air on or off.

 

Ripley....thats my last name haha

and the trucks are know for water pumps and timing covers leaking. ( but the problems your having wouldnt be caused by these) have you been able to pinpoint any leak?

 

I didnt specify before about the "cutting out"...sorry. Yeah what I meant by that was exactly as you had described. The vents change to the defroster vents...and yes when the heat is on, the windows do fog up no matter how much i make sure the inside of the windows are clean.

And to answer your question 95RAM360, i have already had the pleasure of replacing the water pump already, as well as the thermostat and new hoses. After some investigation, i have found no leaks coming from any of the above. But i have noticed that my coolant level has been going down slowly. I can visualy see a coolant drip here and there right were the gasket for the oil pan is (which makes no sense at all to me because last i checked oil and coolant shoudlnt be together!) But anyway to play on the careful side of things, I check my oil and smell of the exhaust for coolant which would lead to a major gasket problem...Also as you had mentioned, I am in the process of replacing my valve-cover gaskets which is causing a slight oil burning scent which can visualy been seen on the exhaust manifolds...

 

The timing cover has 2 water ports, when you removed the WP from the TC, you most likely damaged the TC gasket. You can try tightening up all the bolts. But the gasket is most likely ruined. You might be smelling coolant because of that leak. And check out this thread about the vent issue.

 

zman17, I remember when I changed the WP but I don't recall seeing any other gasket other than the one I replaced for the water pump itself (inbetween the WP and the engine) I may not be fully inderstanding what you mean by the TC...

 

The timing chain cover is in between the water pump and block.

And here is that link I was suppose to give you in my last post https://dodgeforum.com/forum/2nd-gen...ild-vents.html

 

Thanks alot! I am going to follow that forum hopefully it helps me out with what I gotta do now. Have you ever had to replace your heater core too? My a/c is shot too so would it make sense to also replace the condensor while the dash is dropped?

 

Exacally the water pump bolts to the timing cover. and i had the same leak you were describing, changed te timing cover when i did the wp, and i have absolutly no leaks

 

Yes I have replaced both the evap and heater cores. It's not as bad a job as it seems, just take your time. Here is a thread on how to do it. The only thing I didn't see in the thread was you need to remove the small cable for the shift indicator form one end before you drop the steering column.https://dodgeforum.com/forum/2nd-gen...placement.html