Engine not reaching temperature reliably - Chevy and GMC Duramax Diesel Forum
01-04.5 LB7 Duramax Powertrain Discussion of components that are directly involved in the power production and all that is needed to get and keep the truck moving . Engine , Transmission, Etc.

 
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post #1 of 4 (permalink) Old 10-22-2019, 09:38 AM Thread Starter
 
Join Date: Jun 2019
Location: Damascus, MD
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Question Engine not reaching temperature reliably

Occasionally makes it to 210, but takes a while or runs a bit cold. Any chance this is a bad fan clutch? The thermostats are fairly new. Guess I can do the old cardboard blocking the radiator bit...

2003 Silverado 3500 Crew cab 4WD LB7 Duramax LT - 185k since new - stock
Leer cap - Reflex liner - tailgate just replaced with MBI Auto prepainted
recent: fuel filter head rebuild, CAT filter mod, hydroboost seals, SAC00 injectors
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post #2 of 4 (permalink) Old 10-22-2019, 11:17 AM
J83
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Quote:
Originally Posted by Tyler Stewart View Post
Occasionally makes it to 210, but takes a while or runs a bit cold. Any chance this is a bad fan clutch? The thermostats are fairly new. Guess I can do the old cardboard blocking the radiator bit...
i mean maybe... buy a bad thermostat is much more likely.

2015 Chevy Silverado 2500 HD 6.6L LML
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post #3 of 4 (permalink) Old 10-22-2019, 11:22 AM
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Location: Maurice, LA
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Quote:
Originally Posted by Tyler Stewart View Post
Occasionally makes it to 210
First it seems you are using your dash gauge which is notoriously inaccurate. Your thermostats are 180 and 188 front to rear respectively. Get a good gauge reader to see what your engine temps really are. My dash gauge reads around 210 when my Edge Insight shows it at 188.

Second, thermostats usually fail open, so that could be an issue if the temp readings from a reliable reader show them to be low.

Third, the fan clutch usually does not lock until the coolant gets up to 235 or so. The exception is in the mornings in cold weather you will hear it locked because the fluid in it is so viscus at cold temps.

Fourth, you only have 3 posts, Im assuming you are very new to these trucks. This thread may be of interest to you:

https://www.duramaxforum.com/forum/m...ew-owners.html

2008 Silverado 2500HD CCSB LTZ Diesel
FASS 95 Lift Pump (with Baldwin filters), Edge Insight CTS Monitor on a Windshield Mount, Nicktane Fuel Filter Adapter w/ CAT 306-9199 UHE tertiary fuel filter, Bilstein 5100 Stock Height, Bushwacker Bed Rail Caps, AMP Research Bedstep, Fumoto oil drain valve, Dorman PS Oil cooler, Pioneer AVIC 7200NEX GPS/Stereo, Air Lift LoadLifter 5000 Air Bags.

Last edited by 407driver; 10-22-2019 at 11:31 AM.
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post #4 of 4 (permalink) Old 10-22-2019, 11:50 AM
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If your fan clutch was bad and it's running cool, it's likely stuck on. You would hear the fan operating the whole time which is very loud if that is the case. We are getting to the time of year where the outside ambient temps are dropping which takes awhile to warm these trucks up. If all else is fine, a winter grille cover would be your best bet.

2004 LB7
S&S SAC00 Injectors
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