Thread: Who is running a PEL500110 thermostat in their D2

Agree, not much in it. Could be air or maybe some else is going on

Give a lower temp thermostat a try.

This took a lot of reading. I'm running a PEM100990B 82 degree thermostat. I have a brand new std radiator, water pump and hoses. TD5 in great condition.

I read my temps via Nanocom.

I typically run between 82-87 degrees C outside temp about 25 degrees. Temps are fine for around town and highway.

When I'm trying to climb muddy rutted hills on a track somewhere my temps will climb as expected, low speed high revs traction control working, eg. 3rd gear low range 3K-3500 rpm.

Nanocom over temp is set at 95 degrees, this will go off without fail. Max temp will be approx. 107 degrees, which i feel is too high, although it should be only for a short time. This is not an uncommon occurrence for me as I enjoy my off roading, i'm not a hoon but do occasionally drive challenging tracks.

Would changing my thermostat to one of the other numbers help me? Am i worrying about nothing? Would it be a better option to consider another electric fan on the front?

Originally Posted by Pedro_The_Swift

Bought from Roverlord Sept 2014,,
how time flies
its was stamped 82, actual part number requires more effort

I believe you are running the same as me PEM100990B

I am probably going to a grey 82 stat... Ie soft spring bypass LR. Cheers

showoff!

just googled ebay and theres millions of different countries and pricing

Haha. I will get back to you Pedro thanks mate... Want to get air out and get it cool as a priority. Cheers

I put a grey soft spring 82 stamped thermo in to see how it went. Lower than stock temps but not as good as a hard spring 82. Having had a good look at the Rave diagram I am satisfied that a harder spring is more resistant to coolant coming into the top centre port of the thermostat and back out the side port to the water pump...ie the bypass circuit. Firmer spring means less hot coolant likely to return from the engine Valley to the water pump without first running through the radiator. See attached photo.... If that top spring is stronger it will more easily keep that bypass closed meaning cooler running. The hot coolant would only trickle in through the small holes to land on the thermostat sensing area to control opening and not much more. Cheers

OK old 3 way LR thermostat back in. Put a 1/4 inch restriction in the hose from the valley to the bypass plate in the thermostat (ie the radiator bypass circuit). Still plenty of flow to allow sensing in the thermostat (these trucks get most of their sensing from this circuit and very little from the radiator - cool - side of the thermostat) but with the advantage of forcing more coolant through the radiator. Happy with results. Sitting on 86-89 round town and idling is 90-91. Highway is 89-91 depending on gradient. I found the inline got the engine running much cooler in cooler weather, but hotter than this in summer days. Every motor is different. The 4.6 would also tend to run a little hotter due to the extra displacement and burn within the same size block with same size cooling passages compared to the 4.0. Also relevant to note is that the temp sensors are all likely to be different from each other, so comparing electronic readings taken from the ECTS is a general guide only. What is important is that in stock form when I had the same sensor in my 4.0 the normal temps were mid to high 90's and up to 102-105 on very hot days...so I have achieved a 10 degree reduction in running temps.

Cheers