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pscan.eu
(Trader)
Hi everyone.
Question:-
Can anyone tell me how the coolant hoses to a Jatco transmission cooler are arranged on a 75 1.8 auto?
I suspect that the input side to the transmission cooler would be between the thermostat and the inlet to the engine, so that the transmission cooler gets a regulated temperature of coolant. Am I right? But where does it drain? Does it go back into the engine? or does it bypass the engine and go to the water pump or expansion tank side?
Feel free to skip my long winded explanation below if you don't like reading....
Background:-
A couple of years ago I fitted a Jatco transmission to a 1.8 K series Freelander.
There is a video about it here https://www.youtube.com/watch?v=Yq10MU-ecKM
However I have been having occasional overheating issues under heavy load.
Around town it's fine, even in the heatwaves this summer.
Long motorway drives seem to cause it trouble.
What happens is that it will cruise along fine until there is long hill. After a while climbing the hill, the temperature guage will very suddenly swing up to something like 65 to 70 percent. Backing off will make it very quickly drop back to normal.
The temperature doesn't slowly climb, it's very sudden, and so is the drop.
This happened on Saturday on the M40. The first time it happened I pulled over on the hard shoulder and had a look and the coolant level looked normal.
The second time I pulled over the fans were on high speed and the coolant expansion tank was completely full with steam coming out the cap.
So I shut it off and waited a while. Once it cooled a bit the expansion tank went empty and it took two litres of water to get it back to normal.
I nursed it home (drove slowly with the heater on) and it was fine. Since then it's been in and out of central London twice and hasn't used a drop of coolant.
I suspect that the coolant flow through the transmission isn't high enough, and it's maybe boiling inside the transmission cooler/heat exchanger, which is injecting steam into the engine causing air locks or over pressurisation.
I'm thinking of re-arranging the hoses so that the outlet side goes to the expansion tank rather than back into the cylinder head.
Hence my question.
I know this sounds like a head gasket failure (and it could be) but my head gasket is relatively new, and, if the HG has failed then something has caused it to fail, and I would still need to get to the bottom of it before doing the HG again.
Question:-
Can anyone tell me how the coolant hoses to a Jatco transmission cooler are arranged on a 75 1.8 auto?
I suspect that the input side to the transmission cooler would be between the thermostat and the inlet to the engine, so that the transmission cooler gets a regulated temperature of coolant. Am I right? But where does it drain? Does it go back into the engine? or does it bypass the engine and go to the water pump or expansion tank side?
Feel free to skip my long winded explanation below if you don't like reading....
Background:-
A couple of years ago I fitted a Jatco transmission to a 1.8 K series Freelander.
There is a video about it here https://www.youtube.com/watch?v=Yq10MU-ecKM
However I have been having occasional overheating issues under heavy load.
Around town it's fine, even in the heatwaves this summer.
Long motorway drives seem to cause it trouble.
What happens is that it will cruise along fine until there is long hill. After a while climbing the hill, the temperature guage will very suddenly swing up to something like 65 to 70 percent. Backing off will make it very quickly drop back to normal.
The temperature doesn't slowly climb, it's very sudden, and so is the drop.
This happened on Saturday on the M40. The first time it happened I pulled over on the hard shoulder and had a look and the coolant level looked normal.
The second time I pulled over the fans were on high speed and the coolant expansion tank was completely full with steam coming out the cap.
So I shut it off and waited a while. Once it cooled a bit the expansion tank went empty and it took two litres of water to get it back to normal.
I nursed it home (drove slowly with the heater on) and it was fine. Since then it's been in and out of central London twice and hasn't used a drop of coolant.
I suspect that the coolant flow through the transmission isn't high enough, and it's maybe boiling inside the transmission cooler/heat exchanger, which is injecting steam into the engine causing air locks or over pressurisation.
I'm thinking of re-arranging the hoses so that the outlet side goes to the expansion tank rather than back into the cylinder head.
Hence my question.
I know this sounds like a head gasket failure (and it could be) but my head gasket is relatively new, and, if the HG has failed then something has caused it to fail, and I would still need to get to the bottom of it before doing the HG again.