Hey hoping one of you guys will know the answer to this.

My jaguar series 2 4.2 carby has a rebuilt engine but since it was rebuilt it had sat in a garage for many years not being driven and now i use it as a daily driver it goes through oil a 3 hour drive will use 1/2 - 3/4 of the dipstick but it doesn't leak any oil engine and engine bay is spotless clean and it doesn't smoke when driving.

I did read somewhere that if a car that sits for ages it will get brittle seals and I'm guessing maybe this is what has happened and why my oil keeps disappearing but unsure of and answer or how to fix.

Anyone know what mostly it would be?

Thanks

 

Brittle seals is real, as is the LEAKAGE from that, which you say you dont have.

No smoke is a worry. get a mate to follow you and really confirm the "no smoke". The oil has to be burnt if it aint leaking.

The sitting after a rebuild is a NO NO for any engine, unless proper storage procedures are followed, which is a rare situation.

The piston rings are possibly not sealing as they should, and you may be getting "bore wash", which is fuel and combustion gases going down past the rings/pistons, and into teh sump. This dilutes the oil, which gets burned off. Very complex things these internal combustion engines.

The "softly, softly" driving coz its a new engine is also a NO NO. Drive it soilidly, rev it, DO NOT FLOG IT TO DEATH, make it work, the XK engine is a racing engine, so drive it a little like that. Vary the revs as much as possible.

Valve stem seals may have dried out a tad, but the new generation oils we have these days will soften them sufficiently in most cases, and anyway, smoke on "overrun" will be evident if they are the culprit.

Check under the car for pesky leaks, they may be there, but I would expect oil drops on the ground if that is so.

 

I drive it like it should occasionally giving it some, haven't seen a drop of oil on the ground yet and have had a mate follow and hasn't seen any smoke.

Unless the smoke is getting filtered/trapped by the factory exhaust and the mufflers/baffles it may have? it isn't to much of a problem as I just keep topping it up and it still seems to run good no ticking knocks or weird noises was just hoping there would be a solution.

Will triple check under the car for leaks but haven't had any on the ground yet but it does only seem to use oil when driving and it seems to use more oil the faster I go so it may be just getting burnt.

If it is just getting burnt does that matter to much and will it still be fine to drive fast sometimes if i just keep topping the oil up.

 

Mmmmmmm.

The Xk engine was an oil user of about 1/2ltr per 1000miles. This improved as models improved. In the S2 there were only valve stem seals on the Inlet valves. Engine rebuilders generally fitted seals to both sides, which reduced consumption significantly without any obvious ill effects.

The S3, being the last of the XK engine, had seals on both sides, and EFI, and lots of other goodies that made it a very good engine.

Pollution requirements for various markets, even back in the '60's and '70's, did have an affect on what was allowed as far as oil consumption.

Being an engine builder from the very old school, I question some of the rebuilds I have seen, and not only Jaguar engines.

A classic issue with oil consumption is the incorrect spacings of the ring gaps on the pistons, thus giving a somewhat clear passage for oil to get to the combustion chamber. This I found on "her" S2 Daimler 4.2, when I stripped it due to a dropped exhaust valve. It had NEVER been apart previously (been in my family since new). The ring gaps on #2 piston were all perfectly lined up from the factory. This, then explained the oil consumption on interstate trips.

I would keep an eye on it, let it get quite a few miles on the engine, see if it settles down. Sometimes these engines can take up to 10k miles to really "run in", depending on what the rebuild actually included.

My suggestion would to also stay off Synthetic oils for now, as they sometimes can hinder older design engines "run in" time. A good quality 20W/50 Mineral oil is just fine here.

 

Grant has it pretty well down and explains it well. Not much if any to add. An old time mechanic had a shop next to the full service station that I worked at during a paert of my college years. when he would overhaul or rebuild and engine, he would put a hose ion the radiator, adjust the idle way up and let it run for s time outside his shop. His engines always performed well. But, he used to dip in the crankcase drain barrel for oil for his 39 Chevrolet. It was a tad scruffy, but was dependable and ran well!!

I've use a version of that. Drive on the freeway or open road immediately on start up.
Hilly is even better. Run up the revs and then back off. The back off is to induce some oil ingestion to cool the cylinder walls and assure they get some lube. Running it up wears the walls and rings a tad to get a seat. never idle for any length after over haul till the run up is done.

Yeah, that guy at Brownslane thought he was meticulous and lined up the ring gaps!!!
A no.no, stagger is the way.

And on overhaul or rebuild the bore finnish is the key to a sound engine or an oiler. Even if the bores are not rebored, they must be vigourously honed to bust the glaze.

Oil and filter after 500.

I've used dino for all my critters and see no likelihood of going to synthetics.

Carl

 

Assuming it is Ok otherwise, give it an Italian tune-up: take it out on thehighway and run heck out of it, several hard accelerations and some high-speed driving, and see if this seats the rings.
The sitting is really worrisome. Sometimes you get away with it; sometimes the rings are broken (it only takes one), the cylinder wall is pitted, or there is other similar damage.
If one or any spark plugs are oil fouling, there you have it. Try the tune-up first, though. You might be lucky and the rings just aren't seated yet.

 

haven't checked the plugs will try that and i have taken for 1 fast drive just to see what it could do, thanks for the help

 

One small additional check: If that year had the crank rope seal the oil would end up at tbe bottom of the bell housing, but there should bea a few drops hanging in the mesh at the bell housing bottom as I think you may have the BW model 65 or 12 auto transmission? That rope seal will be well and truly dried out but only leaking with the engine running.

 

The guy did say it had the rope seal but he said it didnt effect the oil levels at all so didnt think it was that, would that use a lot of oil if it was stuffed?

 

If the rope seal, or any other seal is leaking to the quantity of oil you are describing there would be oil on the driveway, and/or all over the underside of the car, the exhaust system, front edge of the rear cradle, and the rear brakes.

I stick by my first guess, as to it burning it.

The exhaust system is huge, and 2 mufflers each side make it what it is, a Jaguar. The smoke will come out the tailpipes, eventually, and no amount of baffling, or whatever, will stop that.

The car I mentioned before, the Daimler, used about 5 litres, Adelaide to Melbourne, about 800kms. NO smoke, NOTHING visible at all. We lived with it. The spark plugs never fouled, never sooty. NO leaks of any kind.

The findings I mentioned when stripped, confirmed my suspicions and once rebuilt by me, and balanced, never used oil again.

I would give it about 5000kms, and keep a close eye on oil levels. If it does not settle by then, you have some very serious decisions to make. It would not be the first XK engine with glazed bores after a rebuild, mainly due to the wrong oil used for run in.

Last resort, if it were mine, would be the Bon Ami treatment. Worked on a few over the years just fine.

 

Thanks, what is the Bon Ami treatment? I can't afford to take it down if it is glazed bores. I would rather just put up with it if it wont do to much harm as long as i keep checking the oil level

 

OK. This helps if you have a good understanding of internal combustion engines. Not saying you dont, but I always err on the side of caution.

You know what Bon Ami is?. That powder cleanser from the "old days" used to clean bath tubs etc. Quite abrasive.

I use a SMALL "T Spoon" amount, about enough to lightly cover a 10cent piece, and with the air cleaner removed, and the engine running at about 1500RPM, I "DUST" the powder into the 1st carby. VERY SLOWLY, basically almost letting the engine "suck" it in. Then do the same with the other carby. LEAVE it running at that rev for about 10 minutes, then return it to normal, refit the air cleaner, go for a drive.

Basically this abravise powder deglazes the bores just enough to give the rings something to "bite" into and bed down. Too much will do the same as dusting an engine by driving without an aircleaner element, hence my caution once again.

I first saw this in about 1965, with a Chrysler V8 driven by a 90 year old, and it simply would not run in, he "pottered" the thing. No idea why he had a V8 in the first place. the service manager removed the aircleaner lid, dusted the Bon Ami, went for drive. The owner obviously never knew, but was happy the engine had settles dawn, and he could stop adding oil.

It was also used frequently here by the Datsun dealers in the mid '70's, for the 200B cars, that had a bad habit of glazed bores. Once done, problem solved.

I have used a few times over the years, and had no ill effects.

AGAIN, too much can damage the rings and cylinder bores, SOOOOOOO, common sense prevails here.

 

I guess I could've just gone for a ride in March in El Paso Texas, where I was born and let the dust in the sir bust any glaze!! Filters, if any in cars of the time were not that great. Oiled steel wool or oil bath. Mebbe that is why a 100,000 mile engine was a wonder. usual more like 50 or 60!!

Beware of an Italian tune up on a coked engine. Detonation can kill them.

I heard of the Bon Ami method. And, an off the auto shelf product tht is liwquid, but possibly contains an abrasive as well.

If it were mine, I'd be inclined to merely drive it and keep tabs on the oil level. I added a quart to my high mileage jeep yesterday. I think it's rocker gasket is leaking again! Plastic, of all things. I tightened the screws once and it seemed to help. I am leary of doing it again. The rear 2/3 is under the cowl and getting the screws out mush less back in looks daunting. I just barely got a socket on them the last time.

Can't mess it up as the jaguar is on the dead line. Sprung driver door. Dumb me did it!

Carl

 

I use a SMALL "T Spoon" amount, about enough to lightly cover a 10cent piece, and with the air cleaner removed, and the engine running at about 1500RPM, I "DUST" the powder into the 1st carby. VERY SLOWLY, basically almost letting the engine "suck" it in. Then do the same with the other carby. LEAVE it running at that rev for about 10 minutes, then return it to normal, refit the air cleaner, go for a drive.

Basically this abravise powder deglazes the bores just enough to give the rings something to "bite" into and bed down. Too much will do the same as dusting an engine by driving without an aircleaner element, hence my caution once again.

AGAIN, too much can damage the rings and cylinder bores, SOOOOOOO, common sense prevails here.[/QUOTE]

Bon Ami is an old school and effective approach. Bon Ami is a polish and not to be confused with Ajax or comet (so it's a lighter abrasive) and if done right, no regrets, just don't go out and grab any old abrasive cleanser. It takes a touch to sprinkle directly into the carb and as an alternative you can also add an inch or so to a soda bottle and fill the rest with gasoline and pour it down the carb while running.

Rislone works well. GM makes an effective top engine cleaner. If you're only suspecting sticky rings, you can pull the plugs and add a bit of Marvel Mystery Oil, or kerosene, let sit overnight but be prepared for a major blue cloud when your fire it up the next day. Take it for a long drive.
This won't free stuck rings overnight but should over time.