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Transmission fluid in cooling system 2.5 Diesel Auto 1999
Posted: Wed Feb 18, 2015 4:03 pm
by Douglas
Had a big overheating problem. System flushed out now but evidence of reddish oil in the coolant. Garage says there is a transmission fluid radiator as part of the cooling system that could be leaking into the engine coolant. Does that make any sense, and is there a solution please?
Thanks
Re: Transmission fluid in cooling system 2.5 Diesel Auto 199
Posted: Wed Feb 18, 2015 4:33 pm
by Bob
Yes, it does make sense.
The ATF (transmission fluid) is piped through the bottom of the radiator, if that pipe is leaking there's your problem.
Answers would include a new radiator, which will need bleeding, of course, or bypass it and fit one of these:
http://www.rimmerbros.co.uk/Item--i-RX1572
Re: Transmission fluid in cooling system 2.5 Diesel Auto 199
Posted: Wed Feb 18, 2015 5:12 pm
by mikeonb4c
What an interesting one. Has radiator had any impact damage or are we to believe it's an age related defect.
Re: Transmission fluid in cooling system 2.5 Diesel Auto 199
Posted: Wed Feb 18, 2015 6:23 pm
by Gasy
^^^^^^
That's a dear auto oil cooler kit
They can be got for about £70 with a filter aswell
Re: Transmission fluid in cooling system 2.5 Diesel Auto 199
Posted: Wed Feb 18, 2015 7:40 pm
by mikeWalsall
May be a sign that the internal plastic to metal parts are damaged or 'degrading' .. to me I would flush out the cooling system and fit a new rad ..
Re: Transmission fluid in cooling system 2.5 Diesel Auto 199
Posted: Wed Feb 18, 2015 11:10 pm
by Northern Bongolow
if the gearbox oil has got into the coolant via the oil cooler in the bottom of the rad, this is a very thin walled brass tube, then more worrying the coolant could have got into the gearbox,

.
ive been on here for more than a few years and ive never heard of this happening,even after an accident/repair, first time for everything though.
Re: Transmission fluid in cooling system 2.5 Diesel Auto 199
Posted: Thu Feb 19, 2015 1:08 am
by Simon Jones
This is one of the pipes that carries ATF to / from the heat exchanger in the bottom of the radiator (just to give you an idea where it's located):

Re: Transmission fluid in cooling system 2.5 Diesel Auto 199
Posted: Thu Feb 19, 2015 10:54 am
by teenmal
Yes it is advisable to drop the Auto Box Sump and give it a good clean out and Replace the filter.
Best done after the vehicle has been idle for a few hours (Cold).
Re: Transmission fluid in cooling system 2.5 Diesel Auto 199
Posted: Thu Feb 19, 2015 11:34 am
by wonkanoby
you clean the auto box filter not replace
Re: Transmission fluid in cooling system 2.5 Diesel Auto 199
Posted: Thu Feb 19, 2015 1:51 pm
by Simon Jones
Filter can be cleaned with a solvent such as petrol, or replaced for about £40 but unless damaged this wont be necessary. The cooling system will also need a very thorough flushing out.
Re: Transmission fluid in cooling system 2.5 Diesel Auto 199
Posted: Thu Feb 19, 2015 4:44 pm
by teenmal
Its really up to you guys what you do with Your filter, I would recommend changing the filter if no history is known(when last changed).These are old vehicles that we are talking about, and parts can Disintegrate with age (especially if contaminated with water).
It will cost a wee bit more that £40 to recondition the box.
Good Luck.
Re: Transmission fluid in cooling system 2.5 Diesel Auto 199
Posted: Thu Feb 19, 2015 5:15 pm
by mikeWalsall
The filter in my V6 is fine stainless steel mesh ..
I put it in the dishwasher along with the sump ..
Re: Transmission fluid in cooling system 2.5 Diesel Auto 199
Posted: Thu Feb 19, 2015 6:00 pm
by Gasy
Is it defo oil
That rad weld is a rad oil like substance
What's the auto box dip stick look like
The oil in the auto box will be a right mess with water in it
If dip stick is still showing clean red oil might not be that
I don't think it will be ATF as the pressure in the water radiator is going to be more than the ATF at that part and you would quickly fill your auto box with water till it all went out the header tank at least
Re: Transmission fluid in cooling system 2.5 Diesel Auto 199
Posted: Thu Feb 19, 2015 7:07 pm
by rita
Gasy wrote:Is it defo oil
That rad weld is a rad oil like substance
What's the auto box dip stick look like
The oil in the auto box will be a right mess with water in it
If dip stick is still showing clean red oil might not be that
I don't think it will be ATF as the pressure in the water radiator is going to be more than the ATF at that part and you would quickly fill your auto box with water till it all went out the header tank at least
The ATF pressure at that point will be a least Twice as much as the coolant pressure.
And an automatic box pump can produce 300 psi.
Re: Transmission fluid in cooling system 2.5 Diesel Auto 199
Posted: Thu Feb 19, 2015 7:13 pm
by Gasy
Not on mine from the ATF sump to the rad
Pressure don't get above 1 bar at full revs
Don't think that part is at that pressure
Why don't it spray out the dip stick hole then