Oil Cooler problem 1990 V12 XJS
#1
02-11-2013, 06:25 AM
Oil Cooler problem 1990 V12 XJS
Hi The last time I had my Jag on the road, the oil cooler sprouted a leak.
I thought it would be dead easy to fix, except that I was so wrong.
It was an almost impossible job to disconnect the hoses from the old unit as they had almost welded themselves to it.
In fact as I remember it was such a pig of a job, that there was a big temptation to by pass the oil cooler altogether and just use a straight hose instead.
At the end of the day, or a number of days in this case, I struggled on and did the whole job properly, replacing the oil cooler and new hoses.
But what do you think would have happened if I had cut the oil cooler out and by passed it with a straight hose?
Would it have blown the engine? or is the oil cooler just over engineering?
I thought it would be dead easy to fix, except that I was so wrong.
It was an almost impossible job to disconnect the hoses from the old unit as they had almost welded themselves to it.
In fact as I remember it was such a pig of a job, that there was a big temptation to by pass the oil cooler altogether and just use a straight hose instead.
At the end of the day, or a number of days in this case, I struggled on and did the whole job properly, replacing the oil cooler and new hoses.
But what do you think would have happened if I had cut the oil cooler out and by passed it with a straight hose?
Would it have blown the engine? or is the oil cooler just over engineering?
#2
02-11-2013, 06:35 AM
Many. many schools of thought on that one.
If the UK gets the same as us, it is a by-pass cooler, so I believe that the removal of it would make little difference. Then add the advances in oil technology in the last few years, mainly the ability of it to handle heat better, I reckon little would happen.
BUT.
If you have the full flow cooler, then its part of the cooling system is required, and I would not mess with that.
Not sure which one?. Check the large pipes running up to the oil filter housing, 1 pipe is the by-pass type, and 2 pipes is the full flow cooler.
If the UK gets the same as us, it is a by-pass cooler, so I believe that the removal of it would make little difference. Then add the advances in oil technology in the last few years, mainly the ability of it to handle heat better, I reckon little would happen.
BUT.
If you have the full flow cooler, then its part of the cooling system is required, and I would not mess with that.
Not sure which one?. Check the large pipes running up to the oil filter housing, 1 pipe is the by-pass type, and 2 pipes is the full flow cooler.
#3
02-11-2013, 07:25 AM
Hi Grant
The oil cooler is a stand alone unit that sits behind the radiator on top of the power steering oil cooler (if I remember correctly?)
In trying to undo the hose couplings that go into this, there is a massive danger that you can damage the main radiator in the process.
Unless you are 'extremely lucky' those couplings won't come undone being a mix of steel couplings on an aluminum rad, which weld themselves together.
There is one hose going into it and one hose coming out, so what I did was to buy a new oil cooler, then had some hoses made up and bolted the new oil cooler on top of the old one. (so I almost did the job properly)
Needless to say it works a treat without any problems at all but if it ever happened again, I would be very tempted to just go with a single pipe and cut the oil cooler out.
Unless anyone can think of a reason why not?
Just wondering if anyone else has by passed the oil cooler without any problems?
The oil cooler is a stand alone unit that sits behind the radiator on top of the power steering oil cooler (if I remember correctly?)
In trying to undo the hose couplings that go into this, there is a massive danger that you can damage the main radiator in the process.
Unless you are 'extremely lucky' those couplings won't come undone being a mix of steel couplings on an aluminum rad, which weld themselves together.
There is one hose going into it and one hose coming out, so what I did was to buy a new oil cooler, then had some hoses made up and bolted the new oil cooler on top of the old one. (so I almost did the job properly)
Needless to say it works a treat without any problems at all but if it ever happened again, I would be very tempted to just go with a single pipe and cut the oil cooler out.
Unless anyone can think of a reason why not?
Just wondering if anyone else has by passed the oil cooler without any problems?
#5
02-11-2013, 11:32 AM
Veteran Member
Hi Grant
The oil cooler is a stand alone unit that sits behind the radiator on top of the power steering oil cooler (if I remember correctly?)
No, the oil cooler sits below the aircon condenser in front of the water radiator.
then had some hoses made up and bolted the new oil cooler on top of the old one. (so I almost did the job properly)
If I understand this correctly, have you left the old cooler in situ? if so, better to remove it, as quite a bit of airflow will be blocked to the all important water rad. Quite easy to do, loosen/remove the top panel above the rads, unbolt the two fixings holding the oil cooler to the cross member under the rads, pull up the aircon rad about an inch, pull out old cooler, install new cooler.
Needless to say it works a treat without any problems at all but if it ever happened again, I would be very tempted to just go with a single pipe and cut the oil cooler out. Unless anyone can think of a reason why not?
I am with Mish on this, if you drive the V12 as intended, your oil cooler is a must, I believe. A 1990 model will have the full flow oil cooler, by the way.
The oil cooler is a stand alone unit that sits behind the radiator on top of the power steering oil cooler (if I remember correctly?)
No, the oil cooler sits below the aircon condenser in front of the water radiator.
then had some hoses made up and bolted the new oil cooler on top of the old one. (so I almost did the job properly)
If I understand this correctly, have you left the old cooler in situ? if so, better to remove it, as quite a bit of airflow will be blocked to the all important water rad. Quite easy to do, loosen/remove the top panel above the rads, unbolt the two fixings holding the oil cooler to the cross member under the rads, pull up the aircon rad about an inch, pull out old cooler, install new cooler.
Needless to say it works a treat without any problems at all but if it ever happened again, I would be very tempted to just go with a single pipe and cut the oil cooler out. Unless anyone can think of a reason why not?
I am with Mish on this, if you drive the V12 as intended, your oil cooler is a must, I believe. A 1990 model will have the full flow oil cooler, by the way.
#6
02-11-2013, 02:40 PM
Hi Guys
You are probably right on all points, its been too long since I have looked under the bonnet or had the car on the road.
Having just had another look, I did take the old unit out but instead of using OE hose with the metal bends, instead I used a custom made hose that swept around the engine without the metal bends, which was not only a fraction of the OE price but did the job every bit as well.
You are probably right on all points, its been too long since I have looked under the bonnet or had the car on the road.
Having just had another look, I did take the old unit out but instead of using OE hose with the metal bends, instead I used a custom made hose that swept around the engine without the metal bends, which was not only a fraction of the OE price but did the job every bit as well.
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