BMW V8 M62TUB Coolant Temperature Reduction using a lower temp thermostat

holidaychicken said:

Any thoughts or suggestions much appreciated as always

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Hi mate, never read this thread through before but it looks like some folk go to a lot of trouble trying to cure the high temp cooling systems that bring along with them extremely high operating pressures, so just a question, has anybody with these RR's thought of using waterless coolant?
I see one of the biggest issues with Land Rover vehicles of any type seems to be marginal cooling systems, particularly in this part of the world, where I live ambients very rarely get below 20 deg C, (normal year round 20-35degC). My 300Tdi D1 whilst being happy to run along in traffic at built up area speeds, (40-80Kl/h), the operating temperature of the engine will stay happily within normal operating range,(93-100 degC), even with the A/C on, actually never drive without it on. Getting onto the open road is a much different thing, maintaining 110Kl/h on the flat significantly raises the temperature and any prolonged hills can take the temp in my Disco 300 Tdi up to about 115-120 deg C, and I believe that is getting close to boiling with the system under 15 Psi. I would grant that when new the Tdi or any vehicle for that matter would cope adequately with the temperatures but as the vehicles age the cooling ability falls away. One of my mates has already converted to waterless coolant in his D1, I will be following his move, as it has proven a really big success on our most recent 4WD trip up Cape York, and as it's his daily driver it covers the daily trip to work,160Klm round trip, no problems.
This post refers to BMW powered RR's and how the higher engine operation temps were developed to increase the efficiency and emission control compliance of that engine. Given that the Waterless coolant does not boil until the 180 deg C mark, the vehicle would be capable of operating in its optimum range with plenty of "head room" in the coolant, thereby also reducing cooling system pressure to just about zero at normal operation temp.
Waterless coolant is expensive, about $250.00 to fill a Tdi system, but after reading all the dramas and costs associated with converting thermostats etc, I think it would be far easier to simply drain and thoroughly dry the cooling system of your Rangie, do the refill with waterless coolant and carry on knowing your car is operating at its optimum temp and design emission levels with very low to zero cooling system pressure that will preserve hoses and gaskets. If your worried at all about engine oil temp increase, oil change to the best suitable fully synthetic engine oil, comes at a cost but I think saves a lot of labour and guesswork.

normal running temp using an 80deg stat ranges from 80 to 95 on mine. I have been monitoring this since fitting the stat a couple of months back. I have the advantage of having engine temp displayed on the nav screen using the intravee, so I can keep a close eye on it. I can also confirm my old x5 was identical when I modded that.
I wonder if you may have fitted the stat with the bleed valve not at the top ? Very easy to do with this mod.

Hi guys, happy Christmas and thanks for the replies. I think a few have discussed the waterless coolant but it is probably the cost to fill what i think is 18 litres from dry that puts people off and the want for reducing the actual engine temperature that encourages people to carry out the mod based on the original design of the engine running at the lower temp also, the 80 degree mod is also cheap. i could certainly see the benefits of the waterless coolant benefits in a hot climate though and also the kinder it is to the internal components such as the water pump. I like to run my coolant at quite a high concentration, the upper end of the recomended, as well so whether that is a good idea i don't know.

Regarding the bleed valve i am fairly certain I had it at the uppermost position, I remember reading that i had to so the next step is to take the stat out and make sure i haven't done anything daft like putting it in the wrong way around ..
I will also check my idle speed to make sure that isn't low for some reason and then it is on to try and diagnose the low pressure.
When i started it yesterday i did have quite a pronounced and prolonged tapping from the engine which i have never had since rebuilding the timing chain guides and so i am wondering if one of the seals has failed in either the vanos unit or cam chain tensioners. The tapping stopped and i drove it yesterday a bit while bleeding and also left it on idle for a while and the engine sounded really sweet with no oil light while bleeding but this may be a thread I should start separately...

Onwards and downwards !!

Merry Christmas one and all and as far as the RR goes i quote the famous Christmas song, "Merry Christmas you arse I pray God it's our last"

i run my l322 m62 engine with no stat for the past 3-4 years not noticed any issues at all , just runs slightly cooler , where as before with the stat in if you open the bonnet you cant touch anything because its so hot even the slam panel would burn you [ may not help being a black car ] but i do feel they run to hot and there is no leeway

Well time for an update .
I was getting high temperature even with the 80 degree mod, it was rising to 108 ish even after quite a short drive and i was still getting the flickering oil light at low idle so i was suspecting oil pump, oil pressure leak and all sorts of other bad things so I decided to have another go at bleeding the cooling system and had a read of the meeknet site and he mentioned to raise the front of the vehicle so i did that and got loads more air out by almost brimming the coolant and squeezing top and bottom hoses. I think the electric coolant pump next to the heater valve on mine is not working which makes it harder to bleed also and i think i will give the heater valve a look at some point as the seals in there can go bad and cause more issues. here's a bit of a link that may be of interest. http://www.bmwlogicseven.com/?p=3829
After the bleed, no more oil light at idle so i must have been cooking the oil a bit also.

I was concerned about the oil as i had used flushing oil before i did the timing chains and as i had been cooking the oil a bit i thought i would do an oil change.
When i changed the oil, that was only a few months old and very few miles i noticed it was dark brown with light brown swirls running through it which later on i thought PANIC head gaskets and then went into a series of doing sniff tests at the coolant header, compression tests that didn't work due to cheap chinese compression tester and all sorts of other worries.

Anyway, where i am is i changed the oil back to my usual shell helix ultra, new oil filter and with a bled cooling system i thought i would just drive the thing for a bit and see what gives as the oil could have been contaminated with flush or condensation due to my very short infrequent journeys or build up from inside the engine could have been flushed into the oil and i will monitor the coolant level, temp and oil colour.
After a few good drives including motorway, lanes and a bit lively 'sport mode' the coolant temp settles at 93 when driving, i did see it creep up to 99 very briefly but is generally around 90-95 but mostly 93, the oil still looks golden and not cloudy and it is pulling like a train as i have fitted a new MAF and happily no oil pressure light flickering.