AJ16 engine servicing

[stuart1927]

Hope to get some input from you guys!

I'm quite familiar with the V12 engine, having two XJS's , one with a 5.3L and the other with a 6L lump.

However, I also have a 1996 celebration 4L convertible and haven't really worked on it at all.

Its due a service and want to do it myself. Is there anything i need to be wary of? I've ordered an air/oil filter and some 10w40w oil, the oil change should be easy enough.The coolant was replaced about 18 months ago and the car has been largely stored since. It looks fine so I won't be replacing.

I plan to do some underseal and wax injection as it's a US car that I brought to the UK.

I have spare coil packs, but don't plan to install this time as the car is running well.

Any other advice would be much appreciated.

Stuart

[ptjs1]

Stuart,

Engine oil , filter and air filter are easy enough. Depending on mileage and previous history, you might also consider gearbox fluid and filter change and diff oil change. There are plenty of posts here on gearbox fluid change so have a search through the forum and read up.

I'd also be looking at a brake fluid change and a service of the front brakes. As you know, the front pads can be prone to corrosion on the bottom mounting ledge of the calipers and also sticking calipers if not regularly used. I would strip out the pads, exercise the pistons and clean the lower pad edge mount in the calipers then coppergrease and reinstall.

Also, have a look at the drive belts and change any showing cracks or glazing. The crank sensors are prone to failure but you'll see that through difficult starting and running. I keep a spare sensor in the boot for just such an eventuality.

Good luck

Paul

[davidr]

Nothing too much to get worried about. These are tough and reliable engines that are relatively easy to maintain. Certainly much easier than a V12.
A basic oil and filter change is easy enough. Spark plugs are easy to get to.
I'd also check the hoses, especially the one under the intake manifold that connects to the back of the water pump as it can fail without much warning

[stuart1927]

Thanks for the replies guys!

I am checking all the hoses and belts. With the air filter cannister out of the way, it makes checking things a bit easier.

I was getting a P502 code from the obdII after a check engine warning light. I believe this is related to the wheel speed sensors. However as I understand it, there is one sensor for each wheel and they cost £250plus each, so wondered how to check each one?

I think the front brakes will need looking at as they haven't been done since I've had the car.

The only other thing I noticed was the oil cooler hoses looked to be seeping a bit....will need to investigate further. Car only has 60k miles.

I'm now seeing why folks love this engine....it's so simple in comparison to the V12. The valve cover gasket could be changed so easily v's the V12!

Thanks again!

Sbb

[davidr]

I'm a bit surprise that you have an oil cooler as they weren't standard in 1996. If it is giving you trouble then I would take it out and fit the bypass kit. Its not necessary for ordinary UK motoring

[ptjs1]

Sbb,

Is it the oil cooler pipes (uses a separate small radiator in front of the main radiator) or the gearbox oil cooler pipes (uses part of the main radiator matrix) that are leaking?

If it's the joint of the engine oil cooler pipes to the cooler rad, then sadly, you may have a bigger problem than just a pipe. The steel pipe fitting corrodes with the alloy cooler pipe boss and seizes. I have very rarely seen anyone manage to remove the pipe from the cooler without destroying the cooler. If so, it's a new cooler or fit the bypass kit as David suggested.

As regards the P0502, this is when the ecu sees a difference between the vehicle speed and the speed sensor readings from the ABS sensors. I would start by checking the ABS reluctor rings on the hubs for damage or debris blockage. Then I would check the integrity and resistance readings of the ABS sensors and wiring plugs.

Good luck

Paul

[davidr]

The OBDII on a 1996 car will allow you to trace the ABS fault to a particular sensor. I have done it on mine using my iCarSoft 930 code reader but I had to kid the reader that the car was an X300 but as so much of the late XJS is in common with the X300 that will mostly work.

[stuart1927]

I may replace the cam cover gasket as it's weeping a bit. Should I also replace the shoulder bolts or can these be re-used? They seem to be hard to get now.

Looks as though it is the oil cooler hoses that are weeping a bit, not the actual connection to the cooler itself. I may leave them for now as it's minor.


sbb

[ptjs1]

Sbb,

Cam cover bolts are ok to reuse.

If you have an oil cooler hose weeping, it's either coming from the joint or else from a split in the rubber. If it's coming from a split, you really want to change it straight away. But then you might end up with the problem I described anyway! I would really try and get to the bottom of where it's leaking.

Good luck

Paul

[stuart1927]

Hey Guys...I finished servicing the XJS and on start up, the engine revd up to 3000 rpm or so and stayed there. Didn't want to do this on a stone cold engine so switched off. I wonder if I've disturbed something?

I did have air cleaner and associated air intake gubbins off. As far as I know all the electrical connectors are back on ok. I did replace the cam cover gasket etc.

Any suggestions?

sbb

[stuart1927]

Strangest thing! Went back out to the gaage after dinner, fired her up and she's purring like a kitten.....750 rpm and smooth as!

These cars are weird, even the straight sixes!

sbb