I wouldn't let it get over 200. Even with the factory 180 Tstat and some air included, it shouldn't hit 200f. The engine in mine made ticking noise at temps over 200 so I would avoid that if at all possible. And although LR orig designed the system to run @ 205f or whatever, you see they made a 180 Tstat so obviously warranty claims from overheating made them think better of their initial calculations.

 

The 180 stat was made for the TD5 diesel engine. Never for the V8.

I still stand by the fact that these engines were designed to run way hot for emissions reasons, to burn every single bit of fuel and byproduct.

You are not going to damage the block until you are over 240. Sure once you get it dialed in, no need to be over 200 much except it will happen in hot weather on hills, etc.

Literally these are designed to hot idle at temps up to and above 220. It wasn't a problem until other components failed leading to many of the common cooling system failures. Yes it is running on the hairy edge but that is why we change to the 180 stat. Which by the way is totally against factory protocol. Even my LR indy guy put a stock stat in it when he did my head gaskets. I could not talk him into going against factory spec... So i made that change myself soon after and tossed the factory stat.

My theory is that so many of these made 100k miles with the factory stat running up into the 220's regularly that this might be the reason we have HG issues at around 100k. Running cooler may and should help with the longevity of HG's in the future.

Regardless you still need to find out if you have air in the system or your problem is mechanical in nature.

 

Land Rover has marketed the 180 for the Disco2 since 2012, thereabouts, so you are wrong about that.
Also, there are a number of threads discussing engine "ticking" sounds at temps barely over 200f (not valvetrain but @the block as proven by wetting the block with cold water from a garden hose=ticking stops, pinning the sleeves=ticking stops, lowering coolant temp under 200f=ticking stops) so I'd say that you are completely wrong about the block handling 240-degrees. The liner/sleeve block interface does not maintain the tolerances originally calculated and therefore break loose at temps just over 200f as metals expand.

I urge any D2 owner to keep their coolant temps under 200f and not even run the engine if experiencing temps higher than this. Some of the blocks have just that much more material in the cylinder walls and can survive the 230-240 threshold but those are far&Few between. There is a book titled "building rover V8s" which discusses this in detail.

 

I recently have been through an engine replacement.

I cannot agree more with the comments made here as more and drastic thermocycle the block goes through the sleeves and the block have to endure thermostress. Regardless of the actual quantifiable numbers, less the delta, the better.

I have ran gray thermostat and it has never ran beyond 198 degree F. After coolant flush, I could not get all the bubbles out causing the engine to run hot going above 220 and cool down irradically.

This bugged me enough that I decided to do Thermostat bypass mod. I haven't seen 193 degree F yet even when going up Whistler doing 65mph during past 3 months.

 

bravo!
I had a guy flame me on a different board because of how the inline Tstat mod looks; multiple splice & hose clamps. He claims that his factory 180-deg stat has never let coolant temps go above 180-something. I'm thinking hmmm...either this guy has the sweetest cooling system ever to behold a rover V8 OR (more likely) inhabits a cool, rural environment & never turned the AC on. The LR system by-design, can't hold a cool, steady operating temp; it was never intended to.

 

He is right, The 180 grey t stat is made and sold for the TD5. If you call the Land Rover dealer in the US and ask for one they will tell you they don't have it. If you give them the part number, it will not show up in their system as it's specific to NAS vehicles.

 

well fine, just be that way.
no but really: all of the big box stores that I've shopped at don't even stock models rated over 180-deg so I had to assume the 190 version is obsolete because aftermarket follows OEM.

 

i was surprised when I called the dealer.

 

I bet! so geographical location makes no difference? NA is NA?

 

I have to say Chubbs, I am not trying to be argumentative with you at all. Just to be clear... strictly for testing purposes this guy is not going to harm his engine by going over 200, or over 215 for a very short duration.

I agree keep it under 200 for everyday purposes.

The original poster needs to diagnose whether he has air in his system or a mechanical issue. Virtually every one of these ran up to 220 for most of their lives until guys like us started figuring out cooler is better. One more time for testing is not going to be the end of the world as long as you don't let it get away from you. Got to keep an eagle eye on it for sure.