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Installed 180f thermostat in place of 192f thermostat

46K views 33 replies 16 participants last post by  flamandj 
#1 ·
Hi all
just for everyones info I have installed the Motorad 439-180 thermostat in my landy in place of the original 192F thermostat. The thermostats are identical in size just the motorad opens 12 F cooler (its 82C instead of 88C which is OEM). Its been in for about a week not and the car seems to run fine - definitely hitting closed loop and the heater works great.
According to my ultragauge the engine is running 5 to 7F cooler which makes me happy.
very much the same as the inline conversion figures but without the problems (hassels for bosbefok)
I have attached a link to the ebay seller I bought mine from but they seem to be freely available
eBay: Motorad 439-180 Engine Coolant Thermostat
and a picture although its identical to OEM just cooler running
 
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#3 ·
I think you are correct with regard to the 4.6L, he has the 4.0L which might vary
 
#4 ·
As far as I have ever heard or read, all D2 t/stats start to open at 180 and are full open at 192.
 
#5 ·
disco Mike has it right (as always :)). The disco 4.0 starts to open at 180 but is only fully open at 192. The Motorad 439-180 starts to open at 174 and is fully open at 180. Makes a few degrees difference.
After reading all of the theories on discovery 2 head problems I think the one outstanding factor is the higher running temp to try and get better fuel efficiency. I was nervous of doing the in line swap so thought I would try the 180 thermostat instead.
the difference is not great but those few degrees may make the difference:D
cheers
barri
 
#6 ·
for general reference you can use the following numbers. All of these are in the same shaped canister. The K4 is a rover car engine series. Almost all of the thermostats for sale in NA are PEM 100990.

PEM100990 - Cream is 88° With hard Spring (Designed for Diesel and V8 applications)

PEM101020 - Black or Cream is 82° With Hard Spring (Designed for a V8 and used as a stopgap with K4 engines)

PEL500110 - Grey is 82° With Light Spring (K4 engines)

The spring referred to is the pressure relief setting. the car K4 engine has a lighter spring because the volume flow is much smaller than the V8 or diesel engines.

the 88C is 192F and the 82C is 180F the listed temperature at full opening.

Multiple euro and North african sites with the land rover numbers listed otherwise have a look at rimmer bros
Thermostat - Hose Mounted - Genuine MG Rover at www.rimmerbros.co.uk
Thermostat at www.rimmerbros.co.uk
lots of discussion on the thermostats in euro countries and africa and australia. I can send links if anyone is interested :lol:
cheers
Barri
 
#7 ·
Really glad you posted this information.
Other then e-bay, is there any online site where you can purchase these t/stats.
 
#8 ·
If you want one of the european ones then rimmer bros is your best bet. I bought the motorad 439-180 because its made locally to the PEM 101020 specs. You can buy them from Amazon etc etc
Amazon.com: Motorad 439-180 Thermostat: Automotive

or just do a google search on Motorad 439-180

Or you can order through Oreileys etc. here is the motorad where to buy page
MotoRad - Where to Buy

I just wanted to run cooler without having to do the inline modification and talking to friends in South Africa and Australia discovered that a lot of them run the cooler thermostat - I believe from new but could be mistaken, I'll find out - so started to search for a NA available version.

cheers
Barri
 
#9 ·
Might also consider running a bottle of Water Wetter, Purple Ice or the new B&G Super Cool in your system for an additional 5 or 6 degrees lower temp as well as the water pump lube and wear to head gaskets from pitting.
 
#10 ·
I am wondering id the light spring version my be even better, I would think it would flow faster and be more responsive at long idles.
 
#11 ·
I just got one of the grey body thermo from Justin at Lucky 8 or you can get direct from LR part No. PEL 500110. From my understanding this is the thermo from the Diesel Freelander. I will be installing later this week along with a new radiator. I am looking forward to cooler temps even if they are only 3-5 degrees lower. That should put me at 190-195 on the highway but more importantly while running in DOwntown philly and stop and go traffic the Idea of staying below 200 is simple bliss. Once all checks out I will be heading up into the central Pa region to help a cartographer friend of mine do some research then I will get to see the running temps while in low range as we go off trail. I will report back as I get the numbers.
 
#12 ·
Please do report back. I also wondered about the lighter spring. evidently one of the main functions of the pressure restrictor is to flow more water through the heater system in the cab in the higher flow motors. A few of the people on the euro sites said that when they used the thermostat with the lighter duty spring their cab heaters ran cooler as there was a lot less flow at idle through the heater core as more water was running through the thermostat to the radiator. At highway speed of course there would be no difference but at idle speeds the heater may run a lot cooler.
cheers
Barri
 
#14 ·
what is your heater temperature like at idle. thats about the only problem I heard being reported using the lighter spring?
 
#16 ·
Yeah, this thread was going on over at Discoweb awhile ago with the same info. the reason that I went with the motorad was, I can source that stat locally. as opposed to the other options. with that said, a couple of weeks ago, myself and another person did a trail ride in the mountains. it was all up hill and slow moving, with a 55-60* outdoor temp. had a few stops and never shut the vehicle down on the trail. temps by the ultragauge never climbed above 201*, and that was sitting and running. once moving again, she was back town to 195*...

I'll take those temps ALL day long. not going to knock the other t-stat options. but so far.... I'm happy

I will say that, I've been watching the UG as the outdoor temps have been rising, but so far, nothing over 201*.
 
#17 ·
damn Bill you have to post that sort of stuff earlier :rolleyes:
I spent hours on the euro rover web sites looking up the k series and v8 engine stuff. Mind you I also totally missed that the freelander uses the 82C thermostat - so much for my search skills:eek:

do you have a link to the discoweb article?
cheers
Barri
 
#19 ·
thanks Bill
I found the thread that they link to in that article - the MG - Rover one.
looks like they have been running for some time with no problems - good to know. next replacement I will try the lighter spring thermostat.
cheers
Barri
 
#21 ·
PM sent

but in case anyone is searching here is what little I know

I actually used the motorad thermostat but the PEL 500110 was used locally in the 97 -99 freelander and rock auto has them for $65, also they are the same as the gates TH35882. check for 97 feelander on other online sites and if ot I believe Justin has some in stock. I dont know his price though. They are freely available in europe and if you buy from the UK try rimmer bros first as per my link, it may be cheaper than local even with shipping - there are a multitude of UK sites and ebay UK tyhat have them. links are ebay.co.uk
PEL500110 | eBay UK
and
Google
cheers
Barri
 
#23 ·
Hey glad you chimed in. Have been monitoring these threads awhile and just linked the info here a couple times. Thx to the guy who posted all the part # with expl. Justin @ lucky 8 sells these thermos and bputah for localer sourcing.

I should note the differences in temps claimed between the motorad and pel 51... The difference was ten degrees or so between the motorad 82° hard spring. He claimed the motorad direct replaced pel 110... and could be sourced more locally. The pel 5... series because of softer spring rate demo'd here having the lower temps.

Moving on to me buying one. Alot of reason for newer cars running the higher temps are for properly fuctioning catalytic converters. The cats use this increased heat to burn fuel better before reaching them and raise temps enough to satisfy requirements for the cat to burn off the excess hydrocarbons on the wayout. Im concerned the softer spring weight would effect cat operation and increase over all water flow through the system which could effect something in the ports, rad., etc...

I still opt to buy the lower temps soft spring rate. Im willing to chance all the cons to run lower temps. I use really good gas. And hope this damn thing never comes close to overheating again and still run in closed loop.

Thx for the update. Well documented thread to the o.p.
 
#24 ·
Yeah I too felt the potential cons were far outweighed by the immediate pros.

I wasn't running crazy hot but I found that my temps were jumping a lot. Where I live is a lot of large hills, small towns and stop signs on the highways. Every time I went down a hill or stopped at a stop sign my temps would spike up, they would then go down when I started accelerating again. Obviously this was due to the extra hard bypass spring in the oem thermostat (I installed a new one a month ago when I replaced my valley pan gasket and it was the same). I was cycling anywhere from 195 - 215.

Now that I have the soft print pel50110 in there, temps stay nice and consistent at about 185 - 195 in the city, on the highway, idling, whatever. Nice and consistent.

The way I see it, the temp range is about the same, just much tighter.

All that heat cycling couldn't be a good thing.

Hope this helps :)


Sent from my Autoguide iPhone app
 
#25 ·
Also, a little food for thought when worrying about how these t/stats may effect our cats.
The only thing that is changing with the better t/stats is the temp of the coolant, the combustion chamber still fires at it's usual temp as do the cats. If anyone is concerned about the cats, the only thing that will effect their operation is additional oxygen, such as supplied by some of our SAI system, other then that, as long as the engine is well tuned, the cats will not be effected by a 10 degree coolant drop.
 
#26 ·
Thanks for letting us know Discovery4Life - always good to get feedback.

Mine is still running well below temperatures where it was with the standard thermostat. Everything else is working fine and my fuel economy has not changed at all. Its a nice feeling looking at my ultragauge and seeing it 5 to 10 degrees below where it used to sit.
cheers
Barri
 
#27 ·
I went with the Motorad as well, and my temps dropped about 10 degrees across the board. I guess that would be the 180 degree heavy spring option. I bought it for $42 from a parts store in Alabama that sells on ebay. No change in mileage, either. It still totally sucks.
 
#30 ·
Ordered mine yesterday too :drink1: cant wait to get it installed... going to change out the coolant while i am at it.

I am in the process of installing my oil temp and pressure sensor setup so i will report back on what the oil temp is doing before and after the mod.
 
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