Engine/Transmission (1998.5 - 2002) t-stat -- confirm suspicions

[TboneMan]

Ok, for the past few weeks (now that the weather is a bit warmer) I've notice my engine temps seem to fluctuate more than "normal".



Based on my guess of the OEM temp guages, I suspect I'm cycling from a high of 202-205 deg. down to 180 when the t-stat opens.



The t-stat is a 190 (from Cummins) with about 114,000 miles on it (212,000 on the truck).



My suspicion is I need to replace the t-stat soon before it fails. Is that a fair assessment?



While I'm at it, I'm thinking about doing the water pump (original) and hoses (also original). Now where's that check book.

 

[Midnite]

Speaking as someone who had his water pump go out at about 200,000 miles and blow all the coolant about 80 miles NW of Las Vegas in the middle of nowhere, I would absolutely replace all of it. Hoses and t-stat are dirt cheap, and a water pump isn't what I'd call expensive. The old parts you can keep as spares.

Mike

 

[DIESELWRKS]

besides my local cummins anyone know of anyone selling cummins 190 T-stat's for a good price.

 

[Bob Cochran]

I only know of Cummin's that sells their t-stat.

 

[Mikey-KE7LBB]

https://www.turbodieselregister.com/forums/truck-911-archive/49515-overheating.html

Mr. Gasket 4366 Mr. Gasket Hi-Flow Thermostats

 

[Ram4Sam]

I don't know if it is still true, but I bought one from a Dodge dealer a few years ago. It was a Cummins part/box with a Dodge part number sticker on it. It was actually a number of dollars less than Cummins West wanted for the same part.



Sam

 

[rotohead]

Here's a thread I started awhile back. Might be good to look at the t-stat for this failure.
https://www.turbodieselregister.com...80302-defective-t-stat-thought-i-d-share.html

 

[DIESELWRKS]

I will check with the dealer but I forgot about Home Page

they have a cummins 190 for 72$.

 

[BLNRAY]

advance auto parts stat brand-20bucks

 

[AH64ID]

I got mine for about 20-30 from Cummins. I replaced mine with my coolant with 53K miles on it. It still fluctuates a little, but I no longer see above 200 before the T-stat opens... As they age I think they are slower to react.

 

[DIESELWRKS]

I got mine for about 20-30 from Cummins. I replaced mine with my coolant with 53K miles on it. It still fluctuates a little, but I no longer see above 200 before the T-stat opens... As they age I think they are slower to react.

my local cummins wanted 89$ every other brand I have used besides a cummins lasted 1/2 to 3/4 of the year. so I will just use a cummins.

 

[THoltz]

Try schieddiesel.com. They sell Cummins t-stat for $45.

 

[DIESELWRKS]

will do thanks

 

[DIESELWRKS]

saw schieds that is the price for the 180 deg, 88$ for the 190 deg, I have always used the 190. if I dont tow much would going to a 180 be that big of a deal? it about half the price between?

 

[THoltz]

I use a 180 in Arizona, I changed from a 190. My fan rarely cycles on now, before it would come on in the summer at 65 mph running on I-10 which is pretty flat around Phoenix.

 

[TboneMan]

Well I towed the camper over the weekend in 88 deg F heat. The temp guage stayed rock steady at 195. It did not oscillate back and forth. Basically, it just stayed wide open. The odd thing is, the fan clutch never kicked in.



I'm thinking it might be worth replacing that too.

 

[Crazy Horse]

if I dont tow much would going to a 180 be that big of a deal?

I run a 180 all year around and and have since 2005. There's no fluctuation, it opens just below the midway on the gauge, drops a little after opening and stays there under all driving conditions loaded or empty. Recently had 4000 of crushed rock in the bed and driving at hywy speeds it didn't go over the 1/2 way point. It was in the upper 80's. I just like the comfort of the needle never going over midway on the gauge. There is still plenty of heat in in the truck down here in the winter.

 

[Joe Mc]

How's the radiator between the inter-cooler? dirty or clean? I bought the 190* stat from cummins for like $17 about 4 years ago and then a few months back "WHAMO" $80 - had to go for it - too many stories of failed Stant and others . . .

 

[DIESELWRKS]

its okay my temps are not bad right now just time to get a new one I see it move up past 200 on the gauge 3 times driving empty on flat I-5 800 elevation. but soon I will be doing a cam and going to look at dropping a new radiator in at the same time of install due to having 175 on this radiator might as well through what ever I can at the truck when it is going to be apart. I just wanted to know if 180 was going to be that big of deal when I have always used the 190.

 

[Joe Mc]

I'd stick with the 190, diesel like's it hot.