Gearbox getting hot...

These coolers can actually corrode internally the throw coolant through your oil, best idea would be to change it out instead of cleaning it if you're unsure as to if i has been changed previously, then its done and you'll sleep easier. Mine required replacement at around 120k

Get one of these tools, use it to disconnect the cooler oil lines. You don't lose too much oil doing this, just make sure you're checking the oil level correctly afterwards (car running at 40deg oil temp)
BMW Power Steering & Transmission Oil Cooler Line Disconnect Tool T&E Tools 4353 | eBay

Do the LTB000080 test on the radiator, as the pickup is from the lower part of the radiator that can become blocked as well as the oil cooler.

I purchased a new cooler thermostat as well, both from FCP Euro cause lifetime replacement guarantee. If i ever want to replace it, i just send it back and they send me a new one for free.

PFD000020 - Cooler
PEL000060 - Thermostat

If it has been heating up over 100deg then the oil is likely degraded, check the colour of the oil see if smells burnt or not. You may decide to drop the oil pan to check if there's lots of metal on the magnets. If there is, probably need to decide whether you want to grenade your gearbox or get it early and not have to replace everything :D

Re the oil, dropping the pan and replacing the oil w/ some Dr Tranny can't hurt (or can it!?). Maybe not a full powerflush :)

Thanks everyone!

I was wondering if these coolers corrode through, many cars do!

I'll watch it next time I drive and organise parts. At least the transmission cooler is fairly easy to get to, I'll do a flow test first and might pull the cooler off with the system full and see how much coolant falls out... Will let me know if it's flowing in radiator and if the cooler is blocked.

I know I'm eventually going to need tools like that, so I'll order that anyway!

I've already got shudder fix in the gearbox... Makes a difference while it's cool, but not when hot... contributing factor is probably that the gearbox appears to be getting too hot... So I'll fix that first.

I spoke to a tranny expert about it and as it isn't slipping and engages well, he said leave it and just wait until it's shift pattern starts to change then bring it in for a full rebuild and new TC...

Little bits at a time :)

How much fluid do I need to order for the cooler? I'm assuming about 1L should be enough?

More than enough. I'd say the cooler would hold 100ml if that. Depends how much you spill when you change it [bigsmile]

So...

Pulled cooler off this morning... It wasn't blocked entirely, but definitely flows still...

Quite slowly but. I did flush it out and it's definitely flowing more. The radiator itself seems ok, I left it full and pulled the cooler off and a huge flood of water ensued...

So I think it flows ok. I checked the drain tap too and it definitely flows, it didn't seem overly restricted (20s to drain about 250ml).

I've refilled the system with water for now, will need to get some actual coolant!

After flushing it I'll keep an eye on it and see how it goes, if I was to guess I'd say actual flow through the transmission cooler was probably 20%... So not great.

This is what came out:
Attachment 164925

Nice work, might be an idea to check the oil level in the box too, just to make sure its got enough to properly cool it. :)

Sounds like you caught it in time.

PS when checking the oil, make sure you have the car running and at the proper temp, i forgot the first time and got covered in oil haha

Thanks!

I suspect that the temp sensor is about +15 or so... So that's driving the odd values...

On the other hand, I checked the "transfer case" gearbox temp... It's -40deg after being left overnight. So... something very wrong with that haha.

I'll keep an eye on it and retest the temp again after a longer run and see if it's actually hot or not. The cooler is definitely flowing water, so it isn't that. I'll be ordering a new one anyway, it appears to be a pretty low flow circuit and it's original!

At least there's no rush.

Oddly, when I first pulled it out, clear water was flowing out... And the coolant is definitely red, so maybe there is some partial blockage somewhere, I'll reinvestigate after I can check temps again... But radiator is from 08 and cooler from 02, both would do with a refresh.

Quote:

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Originally Posted by FisherX

Hi NUTTER,

I had the exact same issue on my 03 M62. It was a blocked tranny cooler.

Easy to check. Drain your coolant and pop out the cooler from the plastic mount on the bottom of the radiator by sliding back the retaining clip and pulling it out. the oil lines can stay connected. Get your garden hose and stick it in each side of the cooler and see if you have a blockage. I'll bet you do.

On mine I had a full blockage so a coolant system flush wasn't going to help. I used a bit of coolant system acid cleaner in a squirty bottle to clean out mine until the new one arrived.

I also checked my Tranny thermostat and housing when I was checking for the issue with mine but it was fine and pretty clean inside.

When you get your new cooler I'll bet the oil line release tabs will brittle and you won't be able to get the oil lines off. A real PITA. To get mine off I used one of fuel line release plastic tool kits you get from supercheap but the tab that goes into the fitting is too short so you just grind down the outer part by about 5mm and it works a treat.

I also had the radiator out when I was doing my timing chains and although it was changed in 2016 there was quite a bit of brown flaky crap that came out of it when I flushed it. So I would recommend a good coolant system flush when you are putting it all back together.



Brand New Transmission Oil Cooler For Range Rover 4.4L W/ O-Rings Pfd000020 | eBay

https://www.ebay.com.au/i/1329892982...RoC8MwQAvD_BwE

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To check in now I've got a cooler, etc on order, can you still reuse the hoses with broken release clips, or do you need whole new lines? (Or cut then off and use clamps??)

You don't need to worry about getting new lines.

If you do get the oil lines off by removing the old release taps and using another tool, all you have to do is push the oil lines back in. (after you make sure they're clean) The tabs are only there for you too be able to remove them. The seal and locking tabs are still there. Just push them back on till they click.

But always check they don't leak when you start the car of course.

Edit: No don't cut the line and use hose clamps. They are not designed for that!

Defs get the tool, takes a second with the tool and you dont break stuff. It takes a fair bit of force to push them back squarely. If you break the connectors, i'm pretty sure you'd be up for new lines.

Im not even sure where the Transfer Case temp sensor is coming from to be honest, all i know is that it always tracks 15 deg out from the gearbox temp. I cant see anything relating to the transfer having a temp sensor.

Whatever the case, I validated the transfer case was the correct temp as per the pan temperature, which is where the temp sensor for the gearbox is. My thought was, if it is always 15 deg offset, then i can use that. One thing i didnt do is check the line temp before and after cooler, which is a good idea.