1988 Jaguar XJ40
Discussion
cdp said:
Jaguar got their V12 in there. But wouldn't it be easier and cheaper just to replace the car?
I suspect this is the right answer. I recall that there was at least a couple (?) of years overlap between the introduction of the AJ6 XJ40s and the discontinuation of the XJ12 Series 3. I suspect the V12 XJ40s are different under the bonnet in more ways than the engine.
I know the yanks have put V8s in XJ40s - you might find reference to that on: www.jag-lovers.org/ - you'll have to register to get at some of the site.
The XJ40 was designed at a time when Jguar were part of British Leyland. As such, BL wanted to put the Rover V8 into the 'new' Jaguar. Understandably Jaguar weren't too keen on this and so designed the engine bay of the XJ40 so it was unable to accept a 'V' engine configuration without major re-designing (and ofcourse investment). It is for this reason that the Series 3s overlapped XJ40 production in order to continue selling V12s.
By the early '90s Jaguar had committed to replacing the XJ40 with the X300 and had decided that the 'new' car would carry over the old cars architecture. At this point they decided it was worthwhile investing in the necessary engine bay re-design as this would be carried over to the new car. Hence V12s were slotted into late XJ40s and early X300s.
In short, no. A V8 will not fit into an '88 XJ40.
>> Edited by groomi on Saturday 18th February 11:57
By the early '90s Jaguar had committed to replacing the XJ40 with the X300 and had decided that the 'new' car would carry over the old cars architecture. At this point they decided it was worthwhile investing in the necessary engine bay re-design as this would be carried over to the new car. Hence V12s were slotted into late XJ40s and early X300s.
In short, no. A V8 will not fit into an '88 XJ40.
>> Edited by groomi on Saturday 18th February 11:57
It would be alot cheaper just to get a later year XJ40 with a v12. Or just to buy a 95/later version, but I tend to fall in love with my cars and this wis my first Jaguar so it has sentimental value. From what i have learned the earlier XJ40s only have had electrical problems and engine problems around every 100k. Im still a novice on British cars so I dont have too much hands on experience with Jags, and since an engine conversion on an XJ40 seems to be a dead end, is the 88 AJ6 a reliable engine??????
charlie_b said:
It would be alot cheaper just to get a later year XJ40 with a v12. Or just to buy a 95/later version, but I tend to fall in love with my cars and this wis my first Jaguar so it has sentimental value. From what i have learned the earlier XJ40s only have had electrical problems and engine problems around every 100k. Im still a novice on British cars so I dont have too much hands on experience with Jags, and since an engine conversion on an XJ40 seems to be a dead end, is the 88 AJ6 a reliable engine??????
XJ40s with 250K on them are fairly common over here. The AJ6 has a fairly good reputation.
charlie_b said:
It would be alot cheaper just to get a later year XJ40 with a v12. Or just to buy a 95/later version, but I tend to fall in love with my cars and this wis my first Jaguar so it has sentimental value. From what i have learned the earlier XJ40s only have had electrical problems and engine problems around every 100k. Im still a novice on British cars so I dont have too much hands on experience with Jags, and since an engine conversion on an XJ40 seems to be a dead end, is the 88 AJ6 a reliable engine??????
The AJ6 engine is a million times more reliable than the later V8. I believe it's fairly tuneable too, if you have some money to throw around.
I wish I'd kept my '90 XJ40.
groomi said:
It would be alot cheaper just to get a later year XJ40 with a v12. Or just to buy a 95/later version, but I tend to fall in love with my cars and this wis my first Jaguar so it has sentimental value. From what i have learned the earlier XJ40s only have had electrical problems and engine problems around every 100k. Im still a novice on British cars so I dont have too much hands on experience with Jags, and since an engine conversion on an XJ40 seems to be a dead end, is the 88 AJ6 a reliable engine??????
The AJ6 engine is a million times more reliable than the later V8. I believe it's fairly tuneable too, if you have some money to throw around.
I wish I'd kept my '90 XJ40.
The two problems with the V8 are cam tensioner wear and the nickasil (I think that's how you spell it) coatings used in the cylinder bores. The tensioners are easily dealt with - a good dealer will notice them before they get too bad; look out for a slight rattle on startup. The coatings are damaged by short runs and cheap fuel. This is (apparently) a problem common to some BMWs and Porsches of the period, they all seem to go well enough on decent fuel and getting the engine properly warmed up. Latter V8s have iron bores so this won't affect them.
cdp said:
It would be alot cheaper just to get a later year XJ40 with a v12. Or just to buy a 95/later version, but I tend to fall in love with my cars and this wis my first Jaguar so it has sentimental value. From what i have learned the earlier XJ40s only have had electrical problems and engine problems around every 100k. Im still a novice on British cars so I dont have too much hands on experience with Jags, and since an engine conversion on an XJ40 seems to be a dead end, is the 88 AJ6 a reliable engine??????
The AJ6 engine is a million times more reliable than the later V8. I believe it's fairly tuneable too, if you have some money to throw around.
I wish I'd kept my '90 XJ40.
The two problems with the V8 are cam tensioner wear and the nickasil (I think that's how you spell it) coatings used in the cylinder bores. The tensioners are easily dealt with - a good dealer will notice them before they get too bad; look out for a slight rattle on startup. The coatings are damaged by short runs and cheap fuel. This is (apparently) a problem common to some BMWs and Porsches of the period, they all seem to go well enough on decent fuel and getting the engine properly warmed up. Latter V8s have iron bores so this won't affect them.
The timing chain tensioner problems are certainly not easily dealt with. A dealer will not spot them because they are a non-serviceable item - you will have to ask them to check, which will involve labour costs and if they have any sense, they'll advise you to get them replaced at a cost of about £1k. Also, you don't get a warning rattle if the engine already has the first revision tensioners.
Nicasil isn't much of a worry now, because most cars have either had the problem by now or never will.
These topics on the V8 have been covered many times and very comprehensively in this forum, if you need to find out more, use the search facility.
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