I installed an OE 180 degree thermostat 8 years ago. I'm pretty sure I've traced my current cooling woes to that component. (Made a repair on the wife's heep, same symptoms, good fix with new stat.) Any experiences with longevity of genuine thermostats? Any thoughts about quality of reputable aftermarket parts?

 

Absolute garbage. 20% chance they are good and 100% chance they fail eventually. I have been running inline mod for 6 years now and it is the first thing I do, have owned/sold/driven 13 of these. Others have different opinions (Best4x4), but I would never risk my hg to a factory style thermostat.

 

OEM LR Grey if you want to keep it stock or inline mod. Inline mod that Extinct puts together = top notch. It makes for a clean install and it works.

 

I tried a few different OEM style 180 degree stats and I could never get idle temps much lower than 204-206, and hitting that temp at most stoplights. I tried bleeding and bleeding and could never get it down.

With the inline mod, my temps at idle are much lower, 180-188. I was just cruising on flat ground in 103f ambient temps and coolant temps were 188-193. Pretty happy with that.

I was having some trouble getting temps down in 100+ degree heat going over mountain passes but I think that is resolved now too with a upgraded fan clutch / water water and removing the grill.

 

Wow, 103 ambient. I remember those days out west when I lived in Bakersfield, those days test any cooling system. I completely fried the transmission fluid in one of my Chevy pickups going over to Pismo one summer day. 90 degree temp differential is pretty good for stock Disco radiator, mine normally runs about a 100-105 differential from ambient in flat to hilly terrain.

 

I bought the black stamped 78 Celsius from bearmach it failed within 6 months.
Thank god for my ultraguage

 

I upgraded to a 180 thermostat several years ago and it's been great. Here in the tropics we rarely get below 75 for a low. Highs are around 85 all year, with summer temps upper 80s and maybe a few days in the 90's. Most all driving is at around 35mph so lots of slow speed traffic. My ultragage usually runs around 185-189. Sometimes with AC on I'll get into the 193-6 range but never see 200 since the day I installed it. The 180 thermostat was probably the best upgrade to my LRD2 and I think it will contribute to a longer life.

 

Yeah its mega hot here in the CA Bay Area right now. But it is good for testing the system. I can make tweaks and drive up the Santa Cruz mountains to test the temps. 188-193 is with no grill, water water, and the 2291 severe duty clutch, so that is all the tricks I know of to get it there. I will add the grill back today and see if it makes much of a difference. If it does, I will make a mesh Saudi grill.

Do you have an upgraded radiator?

 

Inline t-stat mod, Hayden HD clutch with '02 fan, straight distilled water, newer radiator and pump. This weekend in 103+ temps, drove from Reno to Incline Village up over the Mt. Rose Highway (long twisty uphill road) at anywhere from 50-60 MPH, temp held steady around 194. Fan sounded like a jet engine most of the way. Been running the inline t-stat for about 5 years now - would never go back to the OEM setup.

 

Not yet, working on fitting a big block Chevy radiator in there, kit forthcoming. I have engine coming out of a truck this week and the radiator fitment work will be done then.