TD4 Thermostat Mod - 83° or 89°. Pros and Cons?

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Fair enough. Thanks @Nodge68
My last oil change was not so long ago. I have 5w30 fully synth in atm. Might be worth me waiting for a few miles before doing it then, and combine it with my next oil change..
5w30 is to light for a high mileage TD4. 5w40 full synthetic or 10w40 semi synthetic is better for the bearings.
 
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Well the thermostat arrived. I measured the hose its 42mm external dia, even allowing for a thin 2mm wall thats 38mm internal at the most.

Measured the thermostat, the main body is 40mm with a lip of 0.5mm which will have to go into the hose if it is to be reattached to the spigot. That makes around 41mm dia.

Talk about squeezing a quart into a pint pot!
 
Well the thermostat arrived. I measured the hose its 42mm external dia, even allowing for a thin 2mm wall thats 38mm internal at the most.

Measured the thermostat, the main body is 40mm with a lip of 0.5mm which will have to go into the hose if it is to be reattached to the spigot. That makes around 41mm dia.

Talk about squeezing a quart into a pint pot!

It makes the hose bulge but does fit in. It's very obvious from my picture as too where the thermostat is located.
 
Oh I’m not about to give up just yet I just need to get a couple of hose clips to have ready to refit the hose.

Watch this space!
 
I asked about this in another post but never got an answer either:(:D any one tried one of these?

A couple of members on here have fitted them. I'd have concerns that it's too far from the top hose outlet. This could potentially cause delayed opening and thermocycling.
 
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Been on two runs today and the best temp my td4 got was 69 deg c do you think I need to fit the thermostat mod ?

Yes. Mine runs at 85°C with the stat in the top hose. The engine runs so hot that I can leave my FBH on continuously (on a separate override) in winter. This heats the engine up quicker, resulting in a faster heater warm up time. :)
 
Some quick questions again on this if anyone can help...
1) Is ebay a suitable place to get the Gates stat from? I'm a bit wary of the possibility of copied/cheap parts when using ebay.
2) I'm doing a coolant flush at the same time, so is it worth partially filling the system before fitting the stat in the hose?
3) Can the system be drained and flushed without removing the under tray? I suspect not, but you never know...
 
1. Your local auto parts shop will have the stat but it would probably be OK from ebay.
2. Don't know.
3. Possible but probably easier to take the under tray off if you want to drain the system completely from the read bottom hose. When I did it I sucked the coolant out of the expansion tank with a turkey baster so very little coolant spilt.
 
While we are at it in the great scheme of things with my engine running at aprox 68c apart from it not being as warm what will another 20c make to the engine fuel ect ? .I have looked at the big thermostat and that is rated at 80c were the the actual thermostat should be 88C . Plus will leaving the original one in situ be ok does it just stay stuck open ? one last thing with mine still working all be not fully is it still ok to fit this mod?
 
While we are at it in the great scheme of things with my engine running at aprox 68c apart from it not being as warm what will another 20c make to the engine fuel ect ? .I have looked at the big thermostat and that is rated at 80c were the the actual thermostat should be 88C . Plus will leaving the original one in situ be ok does it just stay stuck open ? one last thing with mine still working all be not fully is it still ok to fit this mod?

You can leave the old stat in, even if it's only partially failed. Having the engine run at 80° + will increase MPG by a few % ;)
 
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@Nodge68 do you happen to know the inside diameter of the top hose on a facelift td4 auto?

I’m thinking of buying a short length of silicon or rubber (any preference) hose to install my new thermostat on the bench beforehand.
 
@Nodge68 do you happen to know the inside diameter of the top hose on a facelift td4 auto?

I’m thinking of buying a short length of silicon or rubber (any preference) hose to install my new thermostat on the bench beforehand.

Not from memory, maybe 30mm ID?
It's quite a bit smaller than the same hose on the manual though. It takes a good shove and lubrication to get the stat into the hose, which then bulges visibly when done.
 
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