I was wondering what is a good year for Jaguar's V12 for a "budget" project car. I know the earlier "flathead" V12's are the way to go for performance, but are the later model years any good, I've read that they're only good for about 400 hp and was just curious as to which was the best year(s) for the HE engines? Thanks

 

Also I was curious about later model straight sixes as well and good model year(s)?

 

Welcome to the forum wortzman,

I've moved your post to the XJS section, you'll find most of the V12 gurus here.

Please post an intro in the new members section when you can.

 

99% of people just maintain and use their cars. Although it gets mentioned, performance is not really something most owners care about with these cars. It just isn't a worthwhile base and the car is good as it is.

That being said, it depends a little on what you like. Some people prefer the facelift cars and others don't, strictly speaking aesthetics.

Those cars have some more options, but the addition of ABS and other luxuries also adds complexity. While the 90s straight sixes seem to be regarded as good cars, my impression is that this is largely due to that vintage being so lightly used. Of all the XJSs, the youngest ones are kept in garages with low miles far more than any other.

That being said, when you are talking this vintage XJS or XJ6, about 1986,1987, and 1988 are regarded as the "best" years. Jag was under BL for a bit and then came into their own, any quality assurance issues they had were largely during BL and right after they came into their own. They really had the cars squared away in the previously mentioned years.

After that some thing got updated that people don't like, such as new steering wheels, ABS, airbags, marelli ignition, etc. This isn't at all to say any other vintage is necessarily a bad car. Get it squared away (mostly) and they will treat you right. I've been driving my XJS daily for coming on 8 years and I mostly just put gas and oil in it, its a damn good car.

 

For the most part all XJS years can be good cars of you buy a good car. So it really comes down to personal preference. Pre-H.E. black bumper cars are a little rarer, have less chrome, no wood and a few other unique features. H.E. cars are available everywhere in any quality from parts car to show car. Facelift cars have a different look from the rear.

One thing all XJS seem to have in common is that well maintained cars are not cheap and cheap cars are not well maintained. My daily driver was undermaintained, but the price was right. Now that everything is maintained well she just purrs every day.

The extra gas mileage the six cylinder gets only matters if you drive a lot of miles. If it is your fun car, it doesn't matter. The V12 engine definitely provides more smiles per gallon. I love that V12 grin in my face when I go from 0 to 60 in first gear and then to 99 in second. :-)

 

Well the reason I was asking about performance is that Jaguar did well in LeMans in the early 90's with a production based V12 and it was noted for the reliability during the 24hr races, so that is why I'm curious in that regard.

Are there any "dead give aways" that I should look out for when purchasing?

 

Any of the Jag V12 are very durable and robust as far as the engine itself goes. You'll very seldom hear of any problems with the reciprocating assembly, oiling system, block, etc.

The only thing that will hurt one, it seems, is lack of cooling system care which can ultimately cause dropped valve seats.

"Reliability" issues come from the ancillaries: fuel injection, ignition, engine wiring, etc. I'm sure the Jaguar's race cars were much different in these areas

In terms of the engine......

-Lack of cooling system care is a red flag, as is a runaway temp gauge

-Clattering noise which might be dropped valve seats

If interested in power, as suggested in your earlier post, you might wanna look for a later 6.0 car

Cheers
DD