Chevy and GMC Duramax Diesel Forum banner
  • Hey Everyone! Vote for the Site Favourite ROTM winner for the year of 2021 HERE!
1 - 20 of 38 Posts

·
Registered
Joined
·
52 Posts
Discussion Starter · #1 ·
Let truck warm up for 5 minutes then drove around town unloaded for about 20 minutes with ppe standard hooked up and engine temp did not go higher than 165f. Got on the free way and romped on it till I reached 75mph and cruised at 2200 rpm for about 3 miles and temp did not get higher than 170f. Cruised back home into town and truck was sitting at 168f before it shut her off. It's 55 degrees Fahrenheit here today. I've owned the truck for about 6 months and it's never reached the 180-195 operating range. Will new t-stats fix this?
 

·
Registered
Joined
·
227 Posts
I would try t stats. My lly runs 180ish in the winter with a grill cover.
 

·
Premium Member
Joined
·
2,284 Posts
Temps seem pretty normal, most of our trucks around here run same temp right now. Grille cover will for sure make it go up a bit
 

·
Registered
Joined
·
3,039 Posts
Mine runs 170-180 cruising empty in the winter with the grille cover on, that with air temps between 30 and -20.
 

·
Registered
Joined
·
52 Posts
Discussion Starter · #6 ·
Ok glad to hear everyone else is around the same temps maybe a little higher. Once weather gets in the 70-80s what engine temps are usually seen on these trucks just driving around town. I just want a tip top running truck. And do you guys think t stats will get me in the 180 range or am I jus not working the truck hard enough
 

·
Registered
Joined
·
7,911 Posts
With a grille cover on I run at 186°, takes a long time to get that warm~20 miles that's in temps warmer then around -15. As soon as I pull off at a gas station or stoplight it will drop to about 170 in a couple minutes. Anything colder then -15 it doesn't get to operating temp without a load.
 

·
Registered
Joined
·
52 Posts
Discussion Starter · #9 ·
Ok Thanks timmay.and 830king mine fluctuates like that too. Wasn't sure if it was just my coolant temp gauge on cluster or engine was actually cooling by 10 degrees +/- reason I hooked up the PPE to see what the ecm was actually reading again.
 

·
Registered
Joined
·
7,911 Posts
I read mine off at cts, the factory gauge bounces inbetween 175 to 200 when cts is showing a steady 186.
 

·
Registered
Joined
·
2,572 Posts
With new Thermostats my truck will now get to 185 emtpy cruising no cover. Still will drop off idling but temp comes right back up
 

·
Registered
Joined
·
58 Posts
Mine runs closer to 170 easy driving. it runs a little over 180 running faster. this is stock gauge.
 

·
Registered
Joined
·
52 Posts
Discussion Starter · #13 ·
@830king that's still warmer than mine. I've never seen my gauge go over 160 on gauge cluster. It might be bad stepper motors idk.

@rd05lly I might try new thermostats after it warms up here a bit if it doesn't reach that 180f. Right now I'm considering it as normal as timmay has mentioned.
 

·
Registered
Joined
·
2,572 Posts
I will say you need them that is what my truck was doing before. 185 on insight is half between 210 and 160 mark heater will now run you out of truck again. I have one more LLY to change T stats on it is doing same thing.
 

·
Registered
Joined
·
52 Posts
Discussion Starter · #15 ·
Ok another question. Maybe this is why I'm not reaching operating temp. After I drive the truck the upper radiator hose is just as soft as it is sitting all night maybe just a tad bit stiffer. Little pressure gets released after opening the resouvoir cap. Shouldn't the upper hose be hard
 

·
Registered
Joined
·
2,429 Posts
With new Thermostats my truck will now get to 185 emtpy cruising no cover. Still will drop off idling but temp comes right back up
Same experience here. Used to be mid to low 170s with the cover on, with old stats.
Changed stats and ran mid to low 180s this winter, never put the cover on once. Like many other places, it was a cold New England winter this year.
 

·
Registered
Joined
·
52 Posts
Discussion Starter · #17 ·
Same experience here. Used to be mid to low 170s with the cover on, with old stats.
Changed stats and ran mid to low 180s this winter, never put the cover on once. Like many other places, it was a cold New England winter this year.
Got the stats on order from Amazon. AC delco. Let's see if it fixes my issue. Will post back with results! Oh and just rebuilt my instrument cluster last night in hopes stepper motor was bad since it wouldn't match what ecm was reading but it's doing the same as before.
 

·
Registered
Joined
·
52 Posts
Discussion Starter · #18 ·
Update! Replaced t-stats it took longer than I would have liked with minimum tools. But on the good note engine temp reaches 185f now and tranny temp is higher for some reason it's always ran cooler on the cluster. Anyways fixed my issue and truck feels like it running better! Thanks for the suggestions.
 

·
Registered
Joined
·
52 Posts
Discussion Starter · #19 ·
Oh and it looked like the stats wernt stock open . The o rings were in really bad shape though.
 
1 - 20 of 38 Posts
Top