I need help with my truck overheating

[dartnabout]

OK I bought this 97 Dodge Ram 2500 a 360 with 64,000 miles. It runs warm but when I pull a load it overheats. I had the radiator checked cleaned and flushed by a rad. shop and he said it was fine and not plugged. Next step was to replace the pump and Thermostat. Still over heated. I found out that it over heated for the guy before me and he put in a pump and thermostat so it has had two new water pumps and thermostats. Now I take it to a shop and he tells me that exhaust is getting in the water. so off come the heads. they are reconditioned and checked for cracks good to go. I put the best head gaskets available on. Still heats up. I replaced the viscosity fan. Still heats up under a load. What next I am out of ideas? Even though the shop said the radiator was good it is the only thing not replaced...oh I even replaced all the hoses including bypass hose. l am at a loss here any suggestions? :-k

 

[66plyValiant]

did they inspect the exhaust flow? is it lazy under load? the converter could be stuffed up and agravated more when you put a load on it, causing it to heat up quickly (can't get hot gases out)

I'm guessing they checked the flow of coolant and made sure the coolant passage wasen't blocked by something in a previous tear down, seen it happen!

 

[dartnabout]

It does seem lazy as a matter of fact. And no the exhaust flow was not checked. That sounds like a logical idea. But would it cause it to heat up like that?

 

[66plyValiant]

It does seem lazy as a matter of fact. And no the exhaust flow was not checked. That sounds like a logical idea. But would it cause it to heat up like that?

very possible for the exhaust to be clogged at the converter, simple to test, get the truck up to temprature where its giving you the problem and see if much flow is coming out of the the tailpipe

also did they check for the normal things such as cracks in the block?

 

[mullinax95]

Does the truck have a trans cooler? Most do.
If so have the check valve examined. If I remember correctly there was a recall on it for the earlier model trucks. A trans getting hot doesn't help any.

What kind of load are you pulling? Not to much is it? lol
You might need to get yourself a heavy duty diesel truck... just saying.

 

[SirDan]

radiator cap? Pressure raises the boiling point. not enough pressure and it boils over. Worth a shot after changing all the other stuff. I have heard of a few vehicles that had everything replaced, then it turns out being a radiator cap.

 

[dartnabout]

Thanks guys for the help. This is the greatest site! I am going to check on the Exhaust and even change the cap out just for the giggles. This has driven me nuts!

 

[camd64]

I would put it on a scanner and drive it under a good load to recreate the issue. Could be something like the fuel leaning out under load (this can cause the cat to heat up and melt or break apart). Plus the scan would tell you why it's leaning out, bad sensor, etc. It could be a quite a few things really. Spend a little money at a GOOD diagnostic shop and get it fixed without having to change anymore unnecessary parts. Any codes stored?

 

[dartnabout]

I am headed to the shop now to put the scanner on and do some more checking. No codes! Thanks again everyone. Keep the suggestions coming.

 

[mullinax95]

I would put it on a scanner and drive it under a good load to recreate the issue. Could be something like the fuel leaning out under load (this can cause the cat to heat up and melt or break apart). Plus the scan would tell you why it's leaning out, bad sensor, etc. It could be a quite a few things really. Spend a little money at a GOOD diagnostic shop and get it fixed without having to change anymore unnecessary parts. Any codes stored?

True

I was thinking a lean condition as well but thought it had a ECU so it would throw a code. He would saw that.

 

[camd64]

True

I was thinking a lean condition as well but thought it had a ECU so it would throw a code. He would saw that.

Yeah thats the issue because most times it will throw a code but I have seen a number of times where none where stored even after weeks of having a problem. Sometimes the limit for a reading might have such a huge range the sensor might be giving a value for an idle condition when it's actually at WOT. The newer stuff is alot better at this but the early OBDll stuff not so much.

 

[440Ken]

Does it have a clutch type fan? Sounds like a bad clutch problem to me.

 

[dartnabout]

Well...I think we got it! Unbelievable but it was the first thing that came to mind. I was thinking radiator and I even said above took it to a reputable shop and had him check it. A second generation owner. And not a young guy. Very reputable he has done work for me before and I stood and watched him flush it and pressure test it. He handed it to me and said this is NOT your problem. So we started over again from scratch today. We took the theromostat out to check it and was going to put it together without it. I know not the greatest idea but I am telling you my mechanic is one of the best around. And he opened the shop just for me to work on it with his guidence to double check me. When we were flushing everything again! we noticed that the water was not going through the radiator right. So to make this long story short I put a new radiator in and so far so good. I have my Challenger on the trailer and I think I will take a little drive with it. Thanks again to all of you with the help. I keep telling people about this site and the people on here and how great it is. This was just one of those crazy problems and you guys came through for me.

 

[dodge freak]

yep new rad solves many problems

an old man once told me you can not tell how a rad is by looking at it

no t stat is next, u thinking ev erybody used t stat in the 40's, 50's, 60' 70's...its all when the smog control **** hit the news it became a big no no not using a thermostat in the summer heat

 

[66plyValiant]

yep new rad solves many problems

an old man once told me you can not tell how a rad is by looking at it

no t stat is next, u thinking ev erybody used t stat in the 40's, 50's, 60' 70's...its all when the smog control **** hit the news it became a big no no not using a thermostat in the summer heat

it helps with fuel atomization but it works without it also, correct most systems on a vehicle are there just to pass the new car emissions crap