cooling issues (still)

RRkev · Jun 16, 2015

ok so this has been going on now a few months with my bmw m62 engine, so going back about 8 weeks ago i fitted a 80degree thermostat kit, emptied the system as much as possible filled with new coolant etc.
i noticed while moving at around 60/70mph temps would rise to around 98degrees, after climbing a hill around 102 to 104, and if sitting in traffic has peaked as high as 110 on a couple of occasions. temps did however come down but not very quickly.

so i asked the question a few weeks back and i had 2 trains of thought towards the problem one was water pump or viscous fan, the other was the addition of a large air cooled transmission cooler strapped to the front of my rad.

anyway on the weekend i fitted a new hella viscous unit, the old one was very oil soaked on the front and i never heard the 'roar' of it working so can only guess it was faulty, the new one works fine cuts in around 93/94 degrees and definately fully locks up with a roar. i also fitted at 140 (1.4 bar) expansion bottle cap.

my problem is however i'm still getting high temps wheils running although not as high as before, i'm still getting 96/97 degrees running at around 60mph this doses drop as low as 93/94 at 40/50mph and a peak of 102degrees sat in traffic although this did come down 3 or 4 degrees as soon as i started to move.

other have said with the 80deg thermostat they never go over 90deg so i may still have an issue, could the trans cooler be causing higher temps as it's strapped to the rad reducing cooling or possibly the water pump not circulating coolant as it should (i currently have a britpart water pump fitted) my other thought is it could be a faulty temp sensor as i've noticed the temp rises quicker when it reaches 99 degrees than it does below, but dash temp gauge stays central. the engine definately dosent feel as warm as it did when i was running the 105 degree stat.

Datatek · Jun 16, 2015

RRkev said:
ok so this has been going on now a few months with my bmw m62 engine, so going back about 8 weeks ago i fitted a 80degree thermostat kit, emptied the system as much as possible filled with new coolant etc.
i noticed while moving at around 60/70mph temps would rise to around 98degrees, after climbing a hill around 102 to 104, and if sitting in traffic has peaked as high as 110 on a couple of occasions. temps did however come down but not very quickly.

so i asked the question a few weeks back and i had 2 trains of thought towards the problem one was water pump or viscous fan, the other was the addition of a large air cooled transmission cooler strapped to the front of my rad.

anyway on the weekend i fitted a new hella viscous unit, the old one was very oil soaked on the front and i never heard the 'roar' of it working so can only guess it was faulty, the new one works fine cuts in around 93/94 degrees and definately fully locks up with a roar. i also fitted at 140 (1.4 bar) expansion bottle cap.

my problem is however i'm still getting high temps wheils running although not as high as before, i'm still getting 96/97 degrees running at around 60mph this doses drop as low as 93/94 at 40/50mph and a peak of 102degrees sat in traffic although this did come down 3 or 4 degrees as soon as i started to move.

other have said with the 80deg thermostat they never go over 90deg so i may still have an issue, could the trans cooler be causing higher temps as it's strapped to the rad reducing cooling or possibly the water pump not circulating coolant as it should (i currently have a britpart water pump fitted) my other thought is it could be a faulty temp sensor as i've noticed the temp rises quicker when it reaches 99 degrees than it does below, but dash temp gauge stays central. the engine definately dosent feel as warm as it did when i was running the 105 degree stat.

I would have thought that about 95C is normal, my P38 seems to run at between 90 & 95.
The stat is pretty irrelevant, once it's open the system will run at a temperature dependant on the heat input and the cooling available. Most LR products have very little cooling over capacity, so if your water pump is poor, or your RAD is silted up it will run hotter.
As for the temperature sensor, they are programmed to sit in the centre of the gauge over a range of temperature and then rise quickly beyond a set point.
Get a cheap DVM with a temperature probe, tape the probe to the top hose and insulate it with some pipe lagging and see what temperatures you get.

Saint.V8 · Jun 16, 2015

Having a bloody great Cooler in front of your main rad which is already behind the AC condenser is not a great idea....

Also for a comparison, I have no stat in mine (naughty boy!!) and she will sit comfortably in the early 80's reaching a peak of about 87-89 if sitting on a hot dayin traffic, AC on full (as I like it really cold in the car), but in normal everyday driving early 80's is the most.

So with a stat set to open at 80 and it causing a flow restriction, I would anticipate temps in the mid to late 90's possibly.....and with your aftermarket gearbox cooler infront of an already partially blocked rad this could be boosting the temps you see.

Gauge on dash will only start to move at temps above 110-112.

The normal operating range of the M62 is early 90's when pushing hard to 108 on a cruise.....higher temps are more efficient hence why the temp is held higher at steady speeds, but if you are towing, accelerating hard or off roading the ECU then holds the stat open further (hence why it has a coil in it) to keep the engine cooler to provide the temp overhead capacity for the harder work the engine is doing.

RRkev · Jun 16, 2015

i thought it could be down to the trans cooler, i agree not the best place for it but a better idea than the standard cooler that can block and cause issues, so a bit of a trade off really, ideally i would like to move the cooler but i need to look at options and space where it can fit

holidaychicken · Jun 16, 2015

Why do you need the non standard transmission cooler?
I have the standard cooler with no overheating issues in my 4.4.
Are you sure it wasn't fitted to combat a blocked radiator which is the common issue rather than just replacing the rad?

rewmer · Jun 16, 2015

I found all pumps are not made equal.

RRkev · Jun 16, 2015

holidaychicken said:
Why do you need the non standard transmission cooler?
I have the standard cooler with no overheating issues in my 4.4.
Are you sure it wasn't fitted to combat a blocked radiator which is the common issue rather than just replacing the rad?

the company who rebuilt the box reccomended the cooler to prevent any issues from the original cooler blocking (i had a new rad fitted at the time)

took a few data reads, just done a 50ish mile round trip on a & b roads, i found cruising at 50mph engine temp would sit at 95degrees, iy peaked at 102 after a long steep hill.

atf temp stayed at a stable 77-80 degrees (reading taken with hawkeye)
coolant temp when i got home was 100 degrees, but rad temp measured at 54 (again read with hawkeye)

Saint.V8 · Jun 16, 2015

Took photos on my journey home....

Both are on the M3 around the M25 junction, one is cruising and the other is sitting in the queue of traffic for 6-7 minutes at junction 2(M3) and Junction 12(M25).

Temp remains at 84degC

RRkev · Jun 16, 2015

Cheers saint I def think the Trans cooler is driving temp up, as it fills most of the space above the condenser, I think I need to look at where I can relocate it too, perhaps in front of the condenser if there is room. My other thought could be running on lpg can drive temp up by a few degrees so may also be adding to the issue.

Other possibility is if my stat isn't 80 degree but I don't fancy pulling it apart to check, but it does start to open around 75ish degrees

Saint.V8 · Jun 16, 2015

I also run LPG.....

Datatek · Jun 17, 2015

Your ****part water pump could be the culprit if the RAD temperature was only 54 degrees with an engine temperature of 100C. The low RAD temperature suggests your extra cooler is not the problem, but lack of coolant flow.
Some water pumps have fewer impeller blades than OEM.

RRkev · Jun 17, 2015

ok cool cheers saint, obviously something not quite right with my cooling system, i think next course of action will be to see if i can relocate the trans cooler and flush the cooling system out before i look at other issues, such as britpart water pump and possible rad blockage etc

cooling issues (still)

RRkev

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Saint.V8

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rewmer

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Saint.V8

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