So I plan on getting a Autocom or something similar soon, but until then I paid $5 for the Android Torque App and ran it on a old (5 year old) Android device I had laying around. I combined that with a OBDLink I also had.

I am getting readings from the truck, trying to use it to troubleshoot a mystery no start issue I am having.

I noticed my temps are staying around low to high 190s. If I stop for idle, the temp goes quickly up to low 200s.

Considering I am using the 180 thermostat, a new Cannibal v8, and a obviously recently flushed cooling system, I would thought my temps would have been lower.

Then I noticed that as soon as I shut off the engine, the temps actually climbed up to 208.

I restarted the engine and the temps went back down within seconds to 203/204. I know the fan spinning would probably explain it going down some, BUT THAT QUICKLY? Also, what would explain it going up after the engine was shut off?

I was thinking that I should have lower temps while driving than what I am reading, but with the temp going up after engine shutoff, I am really starting to not trust my readings.

Is this all normal? And if so, why?

Is there that much heat built up within the engine trying to escape that it would actually drive the coolant temp up that much after the fan stops cooling it down? After the engine stops running, there shouldn't be any coolant circulating past the sensor, so I wouldn't think it would go up

 

Yep heat soak is normal in these. The only way to combat it is with an auxiliary fan or electric fan but only sets off a temperature not with ignition and same can be done with the water pump if it's electric.
In the heat of summer here in Texas I can see 10 to 12° Rise. I now have electric Waterpump and fans
Factory auxiliary kicks in at 212

 

Are you using the genuine LR T stat(Grey one)? Also is your fan clutch new? It might be spinning, but not to max efficiency.

I have 2 04's with the grey T stat and they run at 190 or lower, but will occasionally get to 194.

 

What your saying about your temp going up once you stop the truck makes sense. The coolant has no circulation and therefore the temp of the coolant is warming up to the temp of the engine block.


As for the rest, I cant comment. Mine seems to run around 188-190 on the hwy and 190-194 city with he grey 180 deg thermostat.

 

didn't rebuild/replace the fan clutch, so that might be a consideration to do.

Yep, its the grey 180.

Its good to know that the "heat soak". Makes me more comfortable with the readings. Let me switch out the fan clutch and see if I can get this down more.

 

Its normal

 

x1, it's quite normal. The engine acts as a heat sink or heat soak and the temp rises around ~10% in normal ambient temps.

 

AND YES! I am obsessed with the temp numbers.

After loosing a engine and spending money on the new one due to overheating, I am not taking chances. If I could find a refrigeration system to hook up, I would!

 

Been there, done that, a Pajero 2.8TDi is infamous for cooling system problems and overheating usually with the end result of a cracked cylinder head.

PARANOID , who said I'm paranoid doesn't everyone have 10 temperature gauges all along their dash then