Hello, all. A longtime car collector but new to Jaguars, I've come across a decent '91 XJS for sale with about 65k but I'd sure appreciate your help. I really want a twelve and don't mind spending time and money to fix things, but would like to avoid a nightmare. Can I invite your input on a couple points, please? My concerns appear in the photo.



- While it ran just a hair above the N cruising around, letting it idle saw the temp creeping up slowly over the course of maybe 15 minutes on a 70F day with the AC off. At this point I shut it down. Air in the system? Crud? The belt is tight, the water pump looks newish, and the clutch fan was moving lots of air. The electric fan never came on. Insight? The dealer offered to fill / bleed and recheck but they don't have any particular Jag knowledge.

- The oil pressure was above 50 at cold start but decreased to where you see it here. Even holding it at 2000 RPM, it only reached the (25psi?) line once hot. Note the tach is misleading; the idle speed sounded normal but the tach seems to hang up around 1000 as shown here. The level is ok and the oil looks reasonably clean as does the inside of the oil fill / cam cover. No unhappy sounds from the engine; no exhaust smoke at any time. The oil pressure lamp does light when the engine is off; never flickered while running.

- The car isn't charging the battery, as shown. No warning lamp, though. It's odd because while it's running the lights, blower, etc. work strongly, but when you shut it off the battery is flat. As an aside, the starter sounds really awesome...

- When you first step on the brake while driving, the brake warning lamp illuminates for just an instant then goes off. Fluid level is ok.

The car spent much of its life in the Southwest so it's free of rust problems, but unfortunately it received a poor-quality repaint. I can deal with that because the car's really straight and the trim is nice but wanted to solicit your opinions on these other issues.

Sincere thanks for taking time to reply; all input is appreciated.

Regards,
Jeff

 

Volumes have been written about keeping V12s cool....and about inaccurate XJS gauges :-)

The radiator is probably clogged.

Low oil pressure at idle is normal....even if you're lucky enough to have an accurate gauge.

It's the poor quality repaint that would make me most nervous. A Jaguar quality job is $5000. Most mechanical issues can be fixed for a fraction of that.

Did you read the buyers guide at the top of this section?

Cheers
DD

 

- oil pressure is fine
- temperature needs to be sorted
- alternator / charging needs to be sorted

If the cosmetics are mint, pay less than $4k, fix the outstanding issues, and enjoy a wonderful automobile.

 

Thanks, guys. Yes, I've read Doug's buyer's guide and am working through 'the book' - an amazing effort.

It sounds like none of these problems is awful, but the dealer wants $7k which sounds like way too much given the sad repaint (worse, it looks like single-stage) and other issues.

There's a beautiful XJ12C close to me that suffered a very minor engine fire twenty years ago; it can be had for little money but the long dormancy suggests the engine may be frozen, among other heartbreaks (I opened the master cylinder reservoir and found, well, what looked like sugar crystals instead of liquid...).

There's also a decent '87 XJ6 nearby, but that's only half the pistons...

 

Oil pressure is way too low. I always follow the same rule of thumb, when oil pressure is showing low, or oil light is blinking, never blame the sensors, just run!
My '82 has about 18-20psi pressure at lowest idle of 500rpm, however when RPM is brought up to 1000+ it will go up to 30+, even when hot.
Low(ish) oil pressure is a sure sign of previous overheat, so this is no surprise in my opinion.

 

@Jeff

Close, but not quite. Keep looking...... the way I see it, any car should have one set of things "going for it" ie mechanically it's great, or bodywork and paint it's great. If it's got neither, then it's probably best to look elsewhere.

The XJ12C sounds like a ground up resto almost, and XJ6s are common and not very inspiring. If you want a V12, hold out for one. There are good cars out there that have been cared for by crazy Jaguar nuts which would be a great place to start your Jaguar experience on

 

A cheap pain job can hide a multitude of sins.
Oil pressure may be good, check with a proper gauge.
Temp is ominous.

Too many ifs and but here: Run!

BTW, the XJ12C is a fantastic car but it should be priced for a total rebuild of engine, box and brakes. AC too. Further the side window winding mechanisms probably needs cleaning and greasing. Selling one of mine it is the C that stays.