Join Date: May 2009
Location: Damn near a dam in NV
Thanked 26 Times in 17 Posts
iTrader Score: 0 reviews
Won't warm up even in 100* weather
I have SEARCHED. I have advanced searched. I read and read. I replaced the thermostat with a genuine cummins stat. I pulled that new stat back out and tested it in boiling water. It moved at ~185*. I am STUMPED... Here is the whole story...
Had the head replaced (I cracked it) by Power Driven Diesel. Ran fine for 200-300 miles then the temp gauge just dropped to about 150*. Within another 100 miles it suddenly dropped to 140 (I watched it plummet) and stayed there. This is dead of summer - 115* in the southern Nevada heat. Called PDD and they said probably a bad Tstat. So I went to cummins and got a new one based on my vin (can't get more specific than that). Replaced it and fired it up for a test drive. NOPE... no movement, so I plugged in the block heater, let it work over night and THEN drove it - gauge read ~150*.
Pulled the new tstat and tested it as recommended repeatedly here on CF. Worked fine if the internal piece sliding along is all that is supposed to happen. I have never seen a Tstat function, but it did it repeatedly and consistently.
Got to thinking maybe a bad gauge or sensor. Got an inferred heat thermometer. Temp at the thermostat after a drive is 180. That is good. Gauge in the cab still reads 140. NO HEAT in the cab... OK it is very luke warm.
SO NOW WHAT? If the stat is working WHY OH WHY is the engine not warming? Any and all ideas are welcome.
I have winter coming and do not want to be running this thing cold. I know some do, but everything I read and even PDD said cold is VERY BAD. I don't care if the gauge doesn't work, but I want to know the engine is warm. I have the downloaded shop manual and it says the sensor is at the top of the block, drivers side, way back behind the fuel filter... all I found there is a plug. Am I mistaken where the sensor is? I would buy a ISSPRO gauge if someone will tell me where to put the sensor in the engine.
Thanks for the help everyone. Love this forum and all the gurus here.
UNICORN of HOLY GRAILS - '98 2500 12V QUAD cab 5sp 4x4 SB- PERFORMAX. Torktek overflow, Power Driven Diesel installed 650 hp pack: AFC Live, 5x14, 7mm DVs, 4K kit. Studs, O-ringed, 60lbs springs, Garrett BB turbo, 4" straight, SB DD w input.