Almost over heating

[nickels123]

2003 dodge ram 2500 5.7 v8.. I have this truck lifted 2 inches and road armor bumpers. This truck over heats or almost over heats when pulling, i pull a 6700 camper 29 ft. I've had dozens people looks at it and changed it all. I don't even know where to start... I've changed to elec fan. Changed the thermostat maybe a dozen times, new radar and system cleaned, new ecm, new dash custer. New timing cover, New water pumps 3 times, 1 blew up.new radiator caps sereval times. New cooling tubes. Tested block several times by firestone and other professionals. New belts new pulleys new transmission cooler. Ok so I can cruise and everything works not putting extra strain on motor being easy then all of a sudden the truck will say it's almost overheating i dont go over 3 to 4 k so all back off the throttle , as it cools down and then I get by for another 10-15 miles and nothing happens so then I'll keep going and 15 minutes later it'll say it's almost overheating or it is overheatin i pullover I check to see if it's boiling gurgling making any thing to confirm over heating. Nothing get back in truck restart and it's cooled down.. how? It's been 2 mins? I almost think maybe the lines to the radiator are getting pinched shut but is that possible.it's so erratic everytime I tell a mechanic or my mechanics nobody believes me everything checks out everything's fine until you put a load on it and put a load on it it says it's overheating I once was so sick of it I just kept driving I was going up 6% grades in Colorado I drove with it saying overheating for about a half an hour trying to blow the motor I'm just so sick of it I just kept going and going up grates.. over heating and i just keep going taking it easy as can and still says over heating I'm beginning to think that the trucks just lifted and the bully bumpers weight to much so maybe the truck just can't pull it but if that's the case then when it says it's overheating why isn't overheating or boiling.. what to check next? what you guys think? I've tested thermostats after I pull them out and noticed that most of them that I've tried have failed and went bad I've tried every company that makes them for this truck and just keep going bad what's going on?

 

[JohnnyMac]

I didn't see where you replaced the temperature sending unit. Could be as simple as it's never really overheating and your sending unit/sensor is bad. Also, are there any other problems or malfunctions in the dash area. I had a tiny little voltage regulator go bad in my dash once and it affected a couple different gauges. Lastly, I had a van that constantly overheated until I found that the timing was advanced too far. I'm not familiar with the 03 Rams and maybe it's all controlled by the ECU/PCM but if not, a simple check of the timing my help. Good luck and keep us informed on what you find. You could also pull your thermostat out completely as a peace of mind kind of check.

 

[nickels123]

Sending unit sensor replace 2 times.. I've even replace the mass air flow sensor.. new ecm new cluster..

 

[nickels123]

Timing was checked last year. But should check again.. I will check tomorrow.. thank you

 

[nickels123]

I tryed to let dodge figure it out but 2 weeks later and thousand dollers they found nothing.

 

[JohnnyMac]

Timing was checked last year. But should check again.. I will check tomorrow.. thank you

Man, brother. Sounds like you've really done most everything and then a couple more things. I'm interested to see what (if anything) you find. Good Luck.

 

[nickels123]

No other problems on dash i see .. I do my best to fix this truck.. I get alot of compliments for it.. if it breaks I replace it.. I forgot to say it has 20 inch rims and 33 tires maybe it's just to heavy..

 

[nickels123]

I'm take it to get it weighted tomorrow after I check the timing.. I'll let you guys know. I didn't check timing last time guy who replace timing cover did in denver.. certified mechanic but I didn't check it myself. Tomorrow......

 

[JohnnyMac]

No other problems on dash i see .. I do my best to fix this truck.. I get alot of compliments for it.. if it breaks I replace it.. I forgot to say it has 20 inch rims and 33 tires maybe it's just to heavy..

I can't see that setup being too big for the hemi. That's what the new ones come with stock pretty much. Are you running 50/50 mix? 100% coolant won't cool as well.

 

[nickels123]

Yes ... I'm using Universal .Green from O'Reilly's.. i I mean I can have the camper on it and be doing just fine and I could give it gas do 5k max it out just fine no over heating.. cruise for 5 ro6 miles then it over heats.. it over heat going down a hill no gas. Don't make sense makes me sound crazy.. should just junk it.. sell it lose 15k.. wish there was a car genius in iowa. Or someone drive to me and fix it and just say it just was a circuit like wtf..i even read the chitlins for it.. lol

 

[nickels123]

I'll record it some time soon. and post maybe it help someone help me.. after I check timing

 

[JohnnyMac]

Yah it sounds like it's not really overheating and is just giving a false reading. The way I figured it out with my Nissan, was I drove it til it showed overheated then pulled off the radiator cap (carefully - it didn't blow at all) and took the temperature with an infrared temp gauge and it only showed like 170 degrees. That's when I knew it was electrical and not really overheating.

 

[Karlsweg]

Install a mechanical water temp gauge!

 

[Bloody_Knuckles]

Have you considered going to a heavy duty radiator with more cores?

 

[Spoonsize]

There you go, check it with an infrared temp gauge. Right at the radiator.

 

[Marley]

If the coolant isn't bubbling then it's not overheating.
I would simply install auxiliary gauges to confirm.

It's not your wheels and tires as I tow with lifted truck on 35's, no problem.

I stay out of OD and use tow-mode.....temp never goes above 200*.

Keep an eye on your tranny fluid, should be pink.

 

[nickels123]

 

[nickels123]

 

[nickels123]

View attachment 166118

Camper and truck...

 

[Fitz-0518]

Blake I will share with you what I found in my 03 QC 5.7. At about 70k I started getting intermittent over heat condition on a down hill coast. just odd. Went through too many different parts. Finally surrendered and took it too my Dodge tech. 1. My radiator fins were nearly all closed off from dust and bugs. 2. Installed a VDO mechanical gauge. 3. Replaced a relay that he said was dropping out of spec after warm up. Now have 231k miles and have never had another OH condition.
None of this may apply to your 5.7 But I know how frustrating this type of thing can be.
Fitz