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Hi all, I recently bought a 1985 xj6 4.2 auto and am having some issues with it using tranny fluid. I have done a search but haven't managed to find any info.
When I got the car I put in almost a litre of fluid because the level was low, which I thought was a bit weird but didn't worry about it too much because after topping up the gearbox still seemed fine and was shifting ok. Since then in driving around I have done about 500kms and used 500ml of fluid. There are no leaks so the fluid is definitely going through the engine. The engine also blows some smoke on hard acceleration.
From this, I guessed that the problem would be the vacuum modulator, but in looking around a bit on the internet I read that these cars didn't have a vacuum modulator as they were only on the earlier models? Can anyone confirm this, and if so, where could the fluid be going?
An '85 would have the BW66 transmission and, correct, no vacuum modulator.
How does your engine coolant look? If reddish, the transmission cooler might be leaking...letting trans fluid enter the cooling system.
Also, are you checking the level in a consistent manner? For example, the reading will be a fair bit higher when the fluid is *hot* as opposed to cold or merely warm. Hot in this case would be after 10 miles of driving or so.
I haven't noticed any leakage at all in my driveway and it is concrete so I should have noticed any coolant or fluid (unless the coolant is only coming out the overflow while driving). I have also checked for oilyness under the car in case the leak is only active while driving, but didn't find anything.
Yep, I have been always checking it cold after idling for 5 or so mins as recommended by the manual.
Is it possible that an earlier transmission could have somehow made it into my car and that it could still have a vacuum modulator?
Is it possible that an earlier transmission could have somehow made it into my car and that it could still have a vacuum modulator?
Anything is possible. A swap to a GM trans is more likely than an older BW trans but the easiest way to tell if you have a vacuum modulator....is to get under the (safely elevated) car and take a peek !
I have been meaning to get under it for a while and am in the process of making wooden blocks for my 2t workshop jack and axle stands so that I can lift and support it safely. I also have a knock from the rear suspension and a broken exhaust gasket so once I get all the blocks sorted I will do all the work at once.
The transmission fluid cooler leaking internally is a fairly common problem. The cooler is located in the large coolant tube below the radiator. However leakage soon shows up in the coolant, yet you say coolant looks OK, but where did you look ? You need to look in the top cap at the front of the engine, not the expansion cap tank. It might, however, be worth dipping this tank to see what ends up on the dipstick. A piece of wood or bamboo is good enough. Leakge via the cooler is the only way tranny fluid can escape without any drips being noticeable.
Had another look tonight, pretty sure it is a BW66. It has no vacuum modulator and looks to have similar bolt bosses on the bellhousing to google images of a BW66.
Originally Posted by Fraser Mitchell
The transmission fluid cooler leaking internally is a fairly common problem. The cooler is located in the large coolant tube below the radiator. However leakage soon shows up in the coolant, yet you say coolant looks OK, but where did you look ? You need to look in the top cap at the front of the engine, not the expansion cap tank. It might, however, be worth dipping this tank to see what ends up on the dipstick. A piece of wood or bamboo is good enough. Leakge via the cooler is the only way tranny fluid can escape without any drips being noticeable.
I looked in the expansion tank - no signs of any redness, mayo or oilyness. Poked my finger around and there was no sediment or anything in there and the coolant didn't seem any more slimy than usual.
Where is the top cap at the front of the engine? I couldn't see a radiator cap, but it was hard to tell as there are covers over the top of the radiator. There were no other obvious inspection points that I could see anywhere on the engine? The only thing that I could see that would be easy to remove without major leakage would be to take a sensor out of the water rail?
Where is the top cap at the front of the engine? I couldn't see a radiator cap, but it was hard to tell as there are covers over the top of the radiator.
Here is couple of pics of a series 1, I assume the series 3 is much the same.
After looking at a couple of photos I see what you mean about the two different caps - my car only has one cap on the reservoir and no other caps, like below, so there are no other places to check.
'85 xj6 using tranny fluid
