My XJS just hit 100,000 miles today.

The bad news is that on Thursday I realized that the piston rings are bad. The car suddenly started going through oil very quickly. This is no oil leak (amazing) but a lot of shoot in the rear and no blue smoke out of the tail pipe due to the catalytic convertor.

The car however drives perfectly. It is such a blast to drive this car! I drive it about 6,000 miles a year so the worst case scenario is that I have to add 6 quarts per year.

My question is whether I should keep the car or maybe even repair it? Please let me know your opinions. Also, how long the engine can last for?

Thanks.

 

I doubt the piston rings are dead. Even with catalytic converters it will puff out blue smoke... The smoke from oil burning doesn't stop in a cat.

Are you sure you aren't losing oil? May it even be a tiny little bit!? How did you determine the oil loss? Did you go by the dipstick? How long ago was your last oil change? It can well be, that you are using oil, which is too "thin" (not the right viscosity). If the oil is too thin, it will simply burn away.

I used factory spec 0w30 oil for my XJ8. I noticed it was burning that stuff really quickly and being full synthetic oil, it cost a few bob a liter. Sometime ago, Jaguar issued a TSB saying to use/recommend 10W40 oil on a part-synthetic base. I use that and have no oil useage now. So I would be looking into that.

These engines do rarely fail on their piston rings. I know the 2.7l V6 diesels in the S-Type and X350 have sometimes these problems, but I have yet to hear about the AJ16 doing the same...

 

jomo,

Rings on an AJ16 is very unusual. I've not heard of any AJ16 that's had that problem before, let alone at only 100,000 miles.

As mentioned, what makes you think it's the rings? If you've got no blue smoke out the tailpipes my guess would be it's not the engine that's burning oil.

This might sound naive but how have you determined that oil is being lost? Is it just from checking the disptick? Are you doing the check at exactly the same time ie at stone cold or at warm? The AJ16 engines definitely vary a bit as to their measurement depending if a hot or cold check.

Paul

 

Thanks for the positive feedback. I check the oil at different times but will now only check it when it is cold. I was down 2 quarts and only drove about 2000 miles. That oil pressure gauge never dipped even a little. I use Mobil 1 10W-30 extended performance oil. In my opinion it is the best oil available. I check the oil by the dip stick and that oil was put in 9500 miles (I change the oil at 10,000 miles) and it is 2 years old (is that the problem??)

Why do I think it is the pistons? No way at all did 2 quarts leak out onto my garage floor without my noticing it. I can't imagine where it went! I understand that these engines are bullet proof. I am not an expert on cars but the fact that there was some soot by the tail pipe scared me.

OK, you nice folks calmed me down. Thank you. So where do I go from here? I mentioned which oil I'm using so I guess I will wait for your response.

 

Maybe try a oil change with a different oil viscosity. I tried 10w30 in my V12 and switched to 20w50. I definitely like the way 20w50 performs. The thicker viscosity may help with consumption.

 

Jomo,

As always, you'll get loads of views on oil grade and many members will not recognise that you have an AJ16 engine not a V12.

As with many UK members, I run 10w40 semi-synthetic. I expect you're fine with 10w30 though.

Cheers

Paul

 

Or you'll have members that recognize an AJ16 and a V12 use similar oil weights and genuinely want to help. As far as condescending remarks??? I'll keep those to myself.

 

small miles and long oil change intervals ... you may have gummed
up oil scraper rings or ring lands.

for that you could try something like Rislone or running a few tanks of
gas through with a 1:500 mix of TC-W3 marine synthetic two stroke oil
in your gas. it must specifically say TC-W3.

if you want to do it slow, then try Shell Rotella 0W40 or 15W40
heavy duty engine oil.

 

I'd try 40 weight oil and see why happens.

Try Mobil1 0w40? I use it and it's fine. Not sure why your insisting on 30 weight oil. Doesn't seem that Jaguar likes it. They approve it, but with a bunch of notes.

https://www.jaguarforums.com/forum/a...ure-ranges.pdf

 

Which Rislone product will be best for me to use. It seems hard to find TC-W3 in synthetic

Another problem is that I need to store my car for the winter very soon!

 

Just FYI, but the oil pressure gauge on the later XJS is really a fancy idiot light. The senders were changed to more of binary type. It's either "on" or "off" with nothing in-between. So the gauge won't show any subtle drops in pressure.

 

all TC-W3 is synthetic because the standard says it must be synthetic.

as for Rislone, I've only ever seen the one type. if you've seen more
than one, then it's time to read the fine print.

 

Well the 2 qts I don't know about. But I'd guess it's some blow by. Did you pull plugs and see what they look like. That would be first thing I'd do. How did you determine bad rings besides the 2qts low in 9500 miles issue? I like Mobil 1 but prefer Amsoil. For flat tapet cams (anything besides roller lifters). Use a oil additive with ZDDP. That's zinc. And your cam needs it. I like Valvoline VR-1 20w50 (racing oil). Only says racing because it's the old oil spec that doesn't meet current EPA standards. It's actually basically the old oil formula before they removed the zinc in all the other oil. I also use a oil additive like Lucas Engine Break In oil at every oil change. It's cheap insurance. There are several brands of ZDDP oil additives and I suspect all ok. If the engine is a roller lifter type you can skip that...I don't know just general old car engine info. (The v-12 uses cam followers that are not roller. Metal on metal....flat follower on cam lobes. Very important to use a oil with zinc)

You more than likely have some blow by and maybe it's just gunned up rings. I'd try some upper engine lube like marvel Mystery oil etc etc. you can run it in gas AND oil. See label for amounts. I use it in my 1940s Ranger aircraft engine and have always been told by the old timers it is a great upper line for Rangers and radials.

 

If your worried about low oil pressure mount a mechanical gauge under the hood. That will give you true pressure.
You can get them quite inexpensive these days.

 

Ah, yes, the oil "discussions". My "ancient" Jeep has one of those "stabilized" oil pressure gauges. All that reading means, is that OP is present!!! Wiggling would scare folks!!!


But, my lumped XJ wuzza six uses the gauges that provide real time real numbers, for the most part, the voltage running a bit late.


My solution has been 20-50 for all critters. The clime is mild here, so cold crank is not n issue. Oil and filter at 5k or one year whichever comes first. So far works fine.


In the instant case, I'd be a bit querulous as to adding any oil to the fuel. Not good for catalyctic converters!!! And, they do cost more than a few $'s. Don't ask...


I would suggest a "break in" trip of some length. Rev it up along a proper road. Shut down the throttle. That creates a high vacuum.
Suck more oil, hot oil up into the bores. Extra lube for the cylinders from below as opposed to upper cylinder lube.


And, definitely, cold to hot measure is likely to result in inconsistent measures.


Bottom line: Is a quart per thousand acceptable or not?
I'd have little or no issue with it. But, my two seldom show any consumption.


Joker. Zero consumption is a myth or a sign of limited lube to the bores!!! Not good.


Carl

 

Update: I am now using 10w40 and added some TC-W3. The good new is that there is hardly any oil consumption.

I must really love my XJS because I never get nervous, but this situation got to me. After all, this is my last car! What would I do if I lost it? Oh yeah, I'd buy another XJS, but this car would be truly missed.

Thanks to all posters who calmed me down by saying that all is well. I respect this forum and your words really calmed me done. Instead of worrying about my engine being bad I instead thought about my options to stop the oil consumption.

Thanks!

 

Great ! Scalpel wins over broad axe !!!


Drive It, enjoy it.


Carl

 

Nobody seems to have mentioned the inlet valve guide seals, so I will !

As the miles build up these seals get harder and gradually fail to prevent oil from being drawn down the inlet guides into the engine. I had this with a Mazda Xedos, and now my daughter would seem to have it with her Fiat 500 that is now heavy enough on oil to need topping-up quite a lot between services.

In fact the old XK engine was really heavy on oil until Jaguar put inlet valve seals onto the inlet guides.

I'm not saying oil might not be getting past the piston rings, but with high miles engines one needs to consider all the paths from oil to combustion chamber !

 

Guides or rings = blue smoke, he's stated there is no smoke.

 

I was surprised that nobody suggested a compression test!