Hello,

I'm a bit stumped on my truck not getting up to temp, the needle rests just over the 130 mark, at about 140-150. It actually sat a little higher before messing with it, but I decided it must be the thermostat so I went ahead and changed that plus the coolant. I'm thinking the new coolant is whats making it read even lower that before? Not sure though

This is a 2000 1500 5.2L with almost 130k miles.

Here is what I know:

1. The system is not building pressure i.e. the rad cap does not get hot/release pressure when opened after running/driving - I changed the rad cap thinking this might be the issue

2. The thermostat was not installed upside down - spring side is facing down into the engine. It is a Murray part no. 3358 and is set to open at 180. I also found out the old thermo was NOT stuck open, and opens with a torch held to it.

3. The waterpump looks recently installed, although I was not the one who installed it/have it installed. This truck was purchased 4 months ago, prev owner only had it for 6 months before that and I know he didn't install it either.

4. The heat in the cab works pretty well. It does get hotter when on the throttle.

5. There are no coolant leaks and all the hose clamps hold strong. The upper hose does feel a bit soft/flimsy, but no collapsing or tears. It gets warm, but not hot when running the truck for a while.

6. I am somewhere where its somewhat cold (34F right now), but the truck was not getting up to temp in 55 degree weather either.

7. There is no CEL or codes when plugging in my cheap-o scanner

I think I burped the system correctly...I've squeezed the hose a bunch and can see coolant to the top of the rad, and it filled to the appropriate level in the overflow tank on its own.

I read if I have a bad fan clutch that it could be blowing too much air into the rad. It seems like its blowing pretty powerfully, but it stops spinning when the engine is shut off and the belt stops (I read that if it keeps free spinning that it could be bad)

Really not sure where to go from here. I thoroughly read this thread https://dodgeforum.com/forum/2nd-gen...to-temp-2.html, but it doesn't seem to be the same issue...or it was never really resolved. Any help is much appreciated.

 

Just as an FYI, the stock thermostat should be 195 degrees in lieu of the optional 180 degree unit. Since you're in a cold area, I'd certainly opt for a 195 degree unit. I don't tend to purchase budget thermostats, so I have extremely good fortune using these, as they are very good and highly accurate -
Since you have a scanner, you can check to see what the PCM thinks your temperature is reading. You can also purchase one of the touchless laser thermometers and point it at the thermostat housing to see what the coolant temp is reading as well. The factory gauge is not always the most accurate.

 

How many miles on the engine? I've had engines doing that many times over the years. I just picked up a Furd that is doing that. While I was trouble shooting it, the engine jerked and ran worse than before. The timing chain had jumped a tooth and gotten out of time. Both my engine in it and your engine are both non-interference engines. I'll bet you just need a timing chain and the previous owner didn't want to fool with it. It's a medium difficulty repair. If you have over 120,000 miles on the engine, I would bet a new timing set will heat the engine up, cook you with the heater and even improce your fuel mileage.

 

Everything Atomic Dog said. 195 not 180.

It sounds like OP didn't actually pressure test the system? I'd do that for sure, and while you've got it test the new rad cap for grins.

I wouldn't trust dash gauge, verify w scanner or IR temp gun as stated.

Get one of the cool funnel bleeders and burp system thoroughly.

I just did a 2000 where the t-stat was stuck wide open. The gauge barely registered engine temp AND the heat from the vents sucked. The bummer was that the only Murray O'Reilly had in stock turned out to be identical to the failed one I pulled - Murray appears to be Autorad

Never heard of timing affecting engine temp significantly, but maybe....still, I'd start with cheapest and easiest first and move down the list.

 

I use this funnel kit. Worth having in your box for the $$

https://smile.amazon.com/gp/product/...?ie=UTF8&psc=1

 

These funnel kits are really nice to use to eliminate air in the cooling system.

 

Agreed. I got myself a funnel kit from HarborFreight before starting this

 

The engine is just under 130k miles. I did read someone else saying thats about time to change it. Only thing is that the engine runs really smooth, and the water pump is obviously newer by looking at it. So I'm thinking it's already been done? I could be wrong...is there a good way to tell without taking the timing cover off (probably not, i know lol). Im not too scared of that job, ive done a timing belt on a 4 cyl before on an interference engine, just a lot of making sure youre following all the steps.

 

thanks for the reply. I will get a 195 thermostat. My scanner says the engine temp is around 115F. Right now I am flushing the system, which i didnt really do before. So this temp reading is with water, not coolant.

 

I service two '98s, a '99 and a '00 with 5.9 gassers and all range 170k to 225k, never seen a timing set put in a one of 'em.

I'd verify timing with a light before taking a single step further down that road. I suppose anything is possible ("I'm not saying it was aliens, but it's aliens.....") but I'd triple check every aspect of the actual cooling system before looking at a timing set for a coolant temp problem, esp if the vehicle otherwise runs and drives well