XSeries-forum

Hi All,

Since having various coolant and oil leak and a heater valve failure, these are all related to rubber seals perishing on my V8 engine. I was wondering what the cause for all of this was as I've never had so many issues on other cars before (90's petrol and obviously diesel as they run cooler anyway).

I found that these engines run at scorchingly high temperatures for efficiency purposes. These high temperatures can turn rubber into plastic or to jelly, depending on where it is in the engine bay. I've noticed that if I open the bonnet, that it feels like a fire breathing beast. If I bring up the temperature on the OBD hidden menu, it ranges from 100 to almost 110 which apparently is normal for these cars.

I've been looking online and found another forum (I think US based) that has discussed this, and it appears that there is a lot of interest over there to run their engines at a slightly cooler temperature. https://www.bimmerfest.com/threads/bmw- ... es.716648/

I've been looking for suppliers that deliver to the UK and came across this one. http://electrorefit.com/product/cold-th ... ngine-bmw/

I was thinking of fitting one of these to my engine as preventive maintenance. What would be efficient for me is a fall in MPG of 1% in favour of engine longevity! The engine would run at 90 to 95 degrees which is more sensible.

Has anyone here done this, and if you have any thoughts it would be appreciated!

Regards,

Interesting, if I had this problem I'd go for one without hesitation.....

I lowered the temperature on my M62 about 4 or 5 years ago as I suffered persistent coolant leaks/weeps. I was suffering oil leaks, small but annoying as a small leak spreads a long way. I fitted a kit from Latvia (I think) with an 85c thermostat. Fixed the leaks. The engine is still dry as a bone and I haven’t added coolant for 2 years (last change) The horrendous heat and rock solid pipes have changed to what I would call more normal. To be honest I didn’t notice any difference in fuel consumption on my daily commute. I notice a far bigger difference now l’m retired and have a different use of the vehicle. It runs around 90/93c but I don’t know how much of this is effected by changing the fan to electric. Which only ever seems to run after the engine is switched off. It will do a couple of cycles after switching off. If of interest it’s just turned 159k. It also has the bonus effect of lowering the gearbox temperature

Hi All,

Thanks for your replies. From your experience, and also the thread I posted, being from a US site where the V8s are more common, it seems that it is a no-brainer to go ahead and perform the mod. I think I'll order from that site as I can't find it elsewhere locally. The site seems to explains things in enough detail to give me the confidence that it's good to go for.

Cheers!

I should have mentioned that apart from the thermostat I changed the header tank cap to the 1.4 bar one.

Thanks for your advice!

Can I ask what mileage you changed the thermostat at, at 4 or 5 years ago? Mine's at just above 80k and want it to last as long as possible given the investment I have made in it fixing various issues over the last couple of years! Glad to hear that you're still enjoying it without it leaking! I did order the bimmerfix coolant pipe stent kit from the states, and OEM water pump. I might fit it at the same time as the thermostat while I am there, as a further preventative measure.

I did see some others also change the expansion tank cap to the 1.4 bar one. There was some discussion as to if the cap reduces the system pressure, or if the cap is a pressure relief valve if things did get too hot. In any case, thanks for the reminder as it would be good to change with the lower operating temperature.

I think I have found one here https://www.ebay.co.uk/itm/OEM-BMW-RADI ... SwsDZb~dt~ which should fit. Although designed for older engines, it looks the same as mine.

Regards,
Rehan.

Are you sure it will fit ? looks similar to mine (M62), but listed as NOT suitable for E53.

Lez

Can’t remember exactly the mileage but around 40k ago I done the thermostat, so around 120k, since then I’ve done the chain guides at 147k after finding bits of the guides in the sump. I had no odd noises I had just become paranoid and decided to look.
I bought the diesel cap which is 1.4bar