I’ve recently been fortunate enough to inherit my grandpa’s '84 XJS as the 2nd owner. It’s in great shape, except for a couple things I want to tackle over the years. I admittedly don’t know much about cars, and certainly one like this, but I’m proud to have it and intend to keep it running and in good shape.
Hoping someone can help with one of the issues: There is some slight smoke coming from underneath the engine. In the attached image #2441, it appears to be coming from the area of silver piece right in the center (technical term) that bends down to the right. It appears there’s oil on the piece right above. Not sure if it’s related, but there is also some oil that appears to be dripping off of that black aerodynamic in the front under the engine, at the lip and where the fasteners are, second image.
Excuse my lack of knowledge, but I’d like to have some education when I take this to the shop. Can anyone help identify what’s happening? Thanks.
What you are looking at is two items the small cylindrical item pointing to the left with the wire is the O2 sensor, this feeds the fuel trim back to the computer, the larger item pointing to the right is the catalytic convertor… Should’nt be smoke coming from either of those units, are you sure that it is smoke?
Thanks, @Robin_O_Connor. Yes, most certainly smoke. Very light, but after a drive or even an idle for a few mins, I can sometimes see it coming up from driver’s-side hood. It seems to be centered around where the O2 sensor, as you’ve pointed out, and that curved plate, are.
Sounds like a little oil, steering fluid, or transmission fluid is dripping on the catalytic converter and burning off. I assume this smoke only occurs when the car is warmed up?
Thanks @John6. Any idea where those particular fluids might be leaking from / what the specific failure might be? Yes, when warm - it starts smoking after a minute or two. Never gets heavier, always that same light smoke. Any issue driving in this condition, if what you suspect is true?
Hard to tell from photo. Are the power steering pipes from the valve block on the rack nearby? The valve block sticks out upwards from the rack and has a wobbly joint at the end of a shaft.
A check of the power steering fluid level might give you s clue?
Sorry if I sound patronising but trying to help you identify the parts if, as you say you have no mechanical knowledge.
I had a similar problem with my 85 XJS v12 with 68000 miles…there were in fact two areas of oil leaks. The first was the power steering rack tower seal. It would leak oil which was blown back onto the exhaust and then smoke. My solution was to replace the steering rack. Although while there i replaced the rack, pump and hoses…if you get any dirt in the system you can damage seals…so i replaced all new…maybe a bit overkill. The second area of leak was from the cam cover half moon rubber plugs. I throughly cleaned the area and used some gasket sealant and smeared around the half moons…not the ideal fix but definately stopped the leak for now.
Check your power steering fluid level… Should be left side front of engine down pretty low… Black cap, twist to remove and monitor fluid level…if it is low…top up and check again after some days of driving. If level drops…definately steering fluid leak.
My first choice would be the half moons or the cam feed banjo fittings.
Squeeze a hand in at the very back of the cam cover and l would suspect your hand will come out covered in oil and grime.
I think the replies you are receiving are on target. I thought I might add a bit of the big picture replay.
Your 1984 XJ-S is now about 33 years old. I am sure that your grandfather took excellent care of his XJ-S, otherwise it wouldn’t be in this condition when you inherited it. After 33 years a lot of the expendable components on a car are about at the end of their useful life particularly the belts, hoses, seals, gaskets and other similar rubber or plastic items found in the engine bay. By design they were never intended to last forever. The smoke you are seeing is quite possibly due to routine fluid leaks coming from seals, gaskets and hoses that leak when they are pressurized and then drain down to the bottom of the engine when hot where the very hot exhaust pipes exit the engine bay and head rearward to the mufflers and tail pipes. I recently completed an engine bay cleanup of my wife’s 1990 XJ-S convertible (5.3L V12 w Marelli ignition) and as I removed and cleaned and painted many of the metal components for reuse, I found that many of the hoses were oozing fluids and some of the mating metal surfaces with gaskets were leaking fluids. I am a serious Do-It-Yourself hobbyist and found some of this work to be challenging. It is detailed work, time consuming, and some of the parts can get expensive. The good news is that the parts are readily available and the work can be performed by knowledgeable mechanics or DIY guys to keep things affordable.
It doesn’t sound like any of your issues are major problems, but the cautious thing to do is bring you XJ-S into a knowledgeable shop and have them take a good look and prepare a list of recommended work for you to consider getting done. Oil leaks that drip onto the steering rack heat shield are probably not something that you need to worry about now. However you need to have someone take a close look at your fuel injector hoses and coolant hoses and belts to be sure that they are in good serviceable condition and that they have been replaced in the past 10-15 years or so. Hopefully your grandfather had records of servicing and repair work done on this car. If you don’t have conclusive evidence of coolant hose and fuel injection hose replacement in say the past 15 years, start there along with fresh coolant (Prestone antifreeze is fine) and an oil change with a new oil filter. Other areas of concern should be the condition of the brake pads, brake rotors and a recent brake fluid change. Once these critical items are addressed then you should drive the car, get a feel for other systems and if needed get them serviced or repaired as time and money allow. Many an XJ-S has been destroyed by engine fires caused by fuel injection hoses that have outlived their useful life, cracked while the car was being driven and sprayed pressurized fuel inside the hot engine bay. Others have been destroyed by overheating caused by clogged radiators, burst coolant hoses, or a variety of cooling system issues that were not attended to properly.
If you have not already done so log onto Jag-Lovers and download Kirby Palm’s “Experience in a Book”, which is free. Read it cover to cover to get an idea of the kinds of issues to be aware of with your XJ-S and post back with any questions. Many of the things you will read about are not unique to the XJ-S but are just the normal systems in a car and the kinds of things that can go wrong.
Good luck with your XJ-S. There aren’t that many of still on the road, and you should be proud to own and drive one. Particularly one with a family history.
As a note, I purchased a low mile V12 in the last few years to install in my 1983 XJS. It became apparent quickly that oil was leaking from almost every seal. Every time I started the car and it heated up I would get a cloud of steady smoke as the oil burned off the catalytic converters. I had initially sealed up the bottom end, pan gaskets etc., before putting the motor in the car and was surprised to find oil literally flowing from the tappet blocks down the sides of the engine onto the exhaust manifolds. I had to pull the heads recently due to another issue and after resealing everything on the top end, I finally have a relatively leak free engine.
Chasing down leaks could become a very expensive proposition if you do not plan on doing the work yourself. I don’t know how many miles are on your car, but at 67k, I found my engine needed some serious attention in the valve/head department after pulling the heads off. This engine was also supposedly well maintained with extensive documentation and relatively low miles.
I would suggest as Paul did, to get the book and start learning a bit about your vehicle. I would also say to identify the worst/easiest to fix leaks first and tackle those. The valve covers are most likely leaking as well as the oil feed lines with banjo bolts on the back of the heads. If you tappet blocks are leaking, that is a more extensive job requiring a more significant tear down of the engine. If you take the valve covers off, you should check your valve clearance.
One final note, whoever works on your engine should account for every single nut and washer and cover the intake ports when the intake is off. I dropped a washer down the intake and ended up having to tear my heads off because the washer became embedded in one of the pistons. It made a heck of a racket.
A long, long time ago, when I bought my 1986 V12 XJS, I had to drive from Oxford to London. The car was OK, but the really fun part came when I stopped at the first London red light after the highway…
Upon stopping, two large clouds of some emerged from the front wheel wells, making me terrified and all people around me quite scared.
I arrived home, to discover my half moon seals were leaking like a sieve!
Thanks a lot to everyone for their input. Consensus seems to be to initially check power steering fluid, so I’ll start there. Special thanks to @Paul_M_Novak for the very detail notes - very helpful in setting priorities and establishing some expectations. I appreciate it, everyone. Stay tuned as I make progress.
