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After sitting in its car tent, under its car cover for a month of rain during which it remained dry, I decided Christmas day was XJ-S day. I started it up, went back in the house to get my wife and came back to find the smell of burning plastic and a small amount of smoke in the car tent. I turned off the ignition, grabbed the fire extinguisher and carefully opened the hood (bonnet) and found a little more smoke but no flames.
The smoke smelled of plastic (not fuel or oil) and seemed to be coming from the back of the Vee or, possibly, under and behind the engine (cats?). I had to shine a light across the engine to see it, so it wasn't clear where it was coming from but there seemed to be a little wafts of smoke coming from the back of the engine. I thought I briefly heard a hissing sound around the A/C, forward of the distributor.
After a few minutes, the smoke subsided. I sat with the car for the better part of the next hour, watching for smoke or fire but the car stoically resisted the urge to turn into an inferno.
There are no fuel or oil smells. It just smelled like burning plastic and now that the car is cold, smells like it always does.
I'll probably have to have the car towed to my local shop next week (always an adventure depending on the driver) but I'd love to hear any theories or suggestions of what I might have them check.
Of course, the car ran beautifully a month ago.
Lucas distributor, not Marelli. Injector hoses are all newish as is the injector wiring harness. I just made a list of everything I've had fixed or replaced and it is amazing to me that a. the car still surprises me like this and b. I'm still married.
Could it be disintegrating foam pad from on top of gearbox falling down and coming to rest on the cats, or maybe foam lagging from around the vacuum feed to efi in the boot. Both are around the bellhousing area. A quick look or feel around the area might be in order.
Correction: I said ''no oil smell'' because we thought it smelled
like plastic but a good look under the car (which I should
have done before posting) revealed that the right side cat
is drenched and dripping a surprising amount of what looks like oil, even
as I type.
There seems to be a bit of oil and gunk toward the rear of
the Vee but nothing like what's on the cat. No trapped trash or fallen foam (that I can see).
Right side catalytic converter is drenched in oil while left side is dry. Any thoughts what might have suddenly started leaking so much? ('88.5 XJ-S)
This problem has a VERY good chance of being caused by a leaking oil pressure sender, either the warning light or the gauge, or both. I had exactly the same problem. The leaks are very hard to spot, and usually only really leak fast when the engine is revving, rather than at tickover.
If you clean everything up round the oil distribution casting behind the capstan, you will very likely find oil there. New senders are not that dear, but support the casting they are screwed into against the torque or it will snap! If you want to check, clean it all up, rig up a bright light, rev the engine while yuo look carefully and you may see droplets of oil escaping. I blew out half the oil on a longish run! I calculated that 1 millilitre per second of drip was enough to blow out the quantity of oil lost.
It was the great XJS prophet Grant Francis who diagnosed mine when I was in full panic mode!
Greg
Last edited by Greg in France; 12-30-2014 at 04:51 AM.
Also on the RH side of the beast is the impossible to see, and near impossible to feel rubber grommet that seals the trans dipstick tube TO the trans casing, kind of forward and above the vac modulator.
Is the oil reddish, as in trans oil, or brown/black as in engine oil???????.
I have done that grommet insitu, but we dont have cats down here, but I still had to remove the vac modulator, exhaust pipe, lower the rear of the trans waaaaaay down, and still only by feel, nothing seen at all, just that I knew it was there, and I kept going until finished. I replaced it again when the engine came out, MONGREL task. The grommet, not the engine R & R, thats easy.
Heaps of JD consumed doing that grommet, trust me.
The other thing to look at, IF THE FLUID IS RED, is the rubber elbow attached to the vac modulator. They die with the heat and old age, and IF that modulator springs a leak, as they do, it will spray on the exhaust, BUT, this is very rare in all my dealings.
More if the fluid is RED, is the trans cooler lines , the steel ones, pass in that area, and they are secured by top quality, HAHA, metal brackest, and they rub on said bracket, and leak at the most inappropriate time.
Have fun. I am sure you will.
Last edited by Grant Francis; 12-30-2014 at 03:56 AM.
Oil is brown/black. The oil pressure sensor seal looks okay. Our mechanic got the car on the lift at his shop for a cursory look and said (if I understood him correctly) that he found oil inside the right side air inlet.
Oil in the Right side air cleaner unit is odd at best. The engine breather system is all connected to the Left air filter, and YES, that can leave an oil mess in the backing plate after a long period of neglect.
I would be asking, carefully, what he really means.
I will keep thinking as the coffee kicks in ever so slowly.
How much oil? Both my aircleaners have oily deposits in them, quite normal I think. (Grant, as you have removed the balance pipe, maybe this affects matters?)
Red oil in the RHS inlet could be the gearbox modulator diaphram having failed, but I would have thought if you were burning oil the exhaust would be steaming like the Queen Mary. You have two pressure sensors, and they fail where the crimp is, not at the threads. Has your guy looked carefully behind the capstan at the base of the V at the rear of the engine? Very hard to do properly, and very hard to see as oil is so transparent these days. If there is any oil there at all, under the oil casting, it is odd on to the the sensors. To see my drip I needed a very bright light, my face about a foot from the sensors and the engine revving!
Trevors HE V12 is "stock as a rock" and his RH is dry, the LH is "messy" but not bad in the whole scheme.
I do remember that Jaguar altered that balance pipe. The early ones (my '85) had a basic 1" pipe with bent ends. The update had a "kick up" in it as well, to raise the section behind the fuel rail up to a higher plain. The story has it that this was to stop/reduce oil entering the ECU vac hose??. Soooooo, maybe there is an oily mess that gets moved to the L from the R.
I do remember long ago, someone reporting finding small pieces of a broken valve seat from the 6B inside the "A" side of the engine, and the only way I know it could have got there was via that balance pipe.
Monday is the day, I will wait.
Last edited by Grant Francis; 01-02-2015 at 03:07 AM.
At the risk of being taken the wrong way, the Right you mention is the "passengers side", as yours is a LHD car??. I have to ask as we are getting very used to people stating "Drivers" and "Passengers", then working out where the driver sits in the posters market, as to the "Handed" terminology we all know a tad better.
If so, pop the filter out, and open the throttle disc (engine OFF for obvious reasons), and note the oily goo that may be coating the inner bore of that housing, OR, the presence of actual oil.
If there is oil, pop the filter out of the L side (drivers), and observe the same muck.
Clean ALL the muck out of both sides, clean the throttle discs thoroughly, install 2 new filters, clean the PCV valve (situated in the front portion of the LH filter backing).
Blocked filter elements can cause the engine to suck oil out the engine, as the engine needs air to run, so it can/will suck air from anywhere it can.
Opinion 2. The trans modulator is leaking, slightly, and the "normal" combustion MUCK in the RH manifold is being washed out with the sucked up ATF. The trans modulator is plumbed into the RH inlet manifold. Once the engine is shut down, the excess drains out thru the throttle disc, and into the filter casing, and since it has picked up that "black muck", is now not Red.
12-28-2014, 02:18 AM
Where there's smoke, there's ...?
