Hi guys,

Kitty is burning a surprising amount of oil (possibly as much as a quart per 1K). The rear bumpers are always sooted and I do get a bit of a cloud occasionally on acceleration.

Damn thing is: she runs BEAUTIFULLY! Starts right up. Idles great. Never misses. I even get great gas mileage. Doesn't leak a drop.

She has 105K miles and a Nameless exhaust system (the only possibly related mod). Haven't pulled the plugs yet though, so I don't have that "minor" tidbit of info for you all (sorry).

Could there be something as simple as a PCV valve causing the problem? (Wouldn't THAT be nice - lol)

Thanks!

BTW: Is there anyone in Southern Maryland (SOMD) who could help me get the JTIS to download & open properly on a Vista OS? (Three tries so far)

 

A quart per 1000 miles is my threshold for a rebuild if it's burning it and not leaking it. If that much is going out the tailpipes, get it reringed and valve seals replaced just to bwe sure. Otherwise you'll add two new converters at about $2K each! Even if the oil is gong from the breather into the intake, the bad rings are still causing it by pressurizing the crankcase too much. Ring problems in this engine at 100K is unusual though, so be sure this is the problem. Get a leakdown test done by an expert at reading them. Take a look at the plugs, is one really bad and the others not bad? If this is so, you could have stuck or broken rings on that cylinder. I have heard of broken rings from the factory on this car, so it is possible, but very rare.

 

Thanks Oldmots.

I'm gonna take a peak at the port side (ex-Navy doncha know ) plugs tonight I hope. We'll see what they have to say.

Rebuild the engine when it runs so sweetly? What's the cost of a rebuild compared to a few extra gallons of oil per year? (She's registered in Florida, so I don't have to worry about the Cats - which I believe are after market free-flows anyway)

I'm hoping for the stuck-rings option. Like all my other over 100K (miles) car purchases I'm running a little Marvel Magic Mystery Oil in the fuel. It has never failed to do amazing things for me. It's possible that this has partially loosened something(s) that were sticking in the engine.

Fingers crossed!

 

Update:

Just swapped out a new set of plugs today. All the right bank plugs showed varying accumulations of "junk"; worsening from front to rear. The 3 & 4 plugs (right bank) also did have a little oily gunk. But to be honest, neither the difference between the right and left banks, nor the amount of gunk on R3 & R4 seemed sufficient significant enough to account for the rate of oil consumption. See pics.

Just in case the oil burning was a transient state because to the MMO use, I'm starting a new record with the dip stick right up to the top line (but not over).

Out of curiosity: Has history identified some things that would cause just one bank of cylinders to burn differently? (and of course the solutions - lol)

Thanks guys

 

My 97 uses about that much oil. It varies between 900 and 1300 miles per quart. I'm on the end of the scale that says if you can get through a tank of gas without adding oil then oil is cheaper than a rebuild. So, I've got a ways to go yet. I believe most of my oil is going by a few valve guides as it has the tell tale pinging that goes along with goosing it. No clouds of smoke killing the neighborhood mosquitoes and none on the ground. I do find oil in the intake under the TB that comes from the engine breather so some is getting pushed in from tired rings. On the other hand I just passed 181k driving to work yesterday, still on the original nikasil engine.

 

What oil are you using and what is the viscosity?

 

Haven't gotten around to an oil change yet (just have her for about 4,000 mi), but I've been topping her off with service station (mostly SUNOCO) 5w-30. The last two quarts were a Valvoline high mileage product. We'll see how it all works out.

Thanks!

 

When you change the oil use a good 10w-30w oil. If you look in your owners manual you will see that it is acceptable. I would do this before you begin digging any further.

 

I ran my '99 XK8 on 5w30 (in Florida) and found that it burnt a little oil.Changed to Mobil 1 10W/40 high mileage and it reduced oil consumption.

 

OK, first: oil burn update. Worse than I thought. Might have actually been as high as a quart per 300 miles() (on straight 5w-30). Been using a high mileage 5w-30 for last 2500mi and it's now either between 500 & 1000 mi per quart or slowly improving (I can dream, can't I?).

Anyway, with the rate at which I was adding new oil, I began to wonder what the actual maximum average age of my oil might be (). It took a while but I finally figured out the necessary math. And here is the result:

Take the number of miles you drive before adding a quart of oil; multiply that by 5 and you have the absolute oldest average age for your oil. So if you're adding a quart every 1,000 miles, the oldest your oil can possibly be is 5,000 miles old, regardless of how often (or rarely) you change it.

What I came to realize is that the maximum age of my oil is less than the interval at which I change my oil. Viola! I won't be changing my oil any more - just replacing the filter every few thousand miles. What a concept!

Take a look at the attached chart for some sample curves. What's interesting to consider is that this awareness can significantly reduce the frequency of your oil changes even if your burn rate is much lower than mine. Miles Driven is the X-axis; Oil Age is the Y-axis.

Look at the top chart (1qt per 1,000mi). You can see that the maximum possible oil age is only 5,000 miles. But "you" say that you like throwing money at 3,000 mile oil changes? OK, look closely at the vetical line to the left. At your burn & replenishment rate your oil's age won't reach 3,000 miles until you've actually driven 5,000 miles. That's a 40% savings. Nice!

I can provide these charts for any burn rate any of you might have. I can also send you (or maybe even post) the excel "Laboratory" I made. You can play with it all you want.

Back to Oil Burn Problem. Compression check next. What'll be? Rings? Valve seals? The suspense is killing me (yeh - right. Wait until I find out how much it will COST!!! lol).

By the way. The plenum below my TB is quite clean. Normally I'd consider this to nullify ring blow-by. However, I'm still playing with the dynamics of a supercharged engine, so I'm not sure.

Ciao guys! - Jim M

 

You might want to give "Engine Restore" a try here, that may help to reduce some of the oil consumption. Although I would 1st do a compression and leakdown test as suggested, as you don't want to mask an issue.

 

Hard to see on those plug pics, but it looks like oil is getting into your plug wells on one side also. Valve cover leak perhaps?

 

One flaw- the contaminants that accumulate in the engine may or may not be burning off/leaking out with the oil. I'd still change it at the recommended interval.

 

And again this is a prime candidate for engine restore additive and ide also change to shell rotella t 10-40. Ive had several engines not only reduce oil use, but several that quit

 

Thanks Guys,

I always been afraid of things like restore, but to be honest it was out of ignorance - no research. I'm planning on changing to a higher viscosity oil as soon as I'm done with the oil I've got now. I'll add Restore to the mix.

BTW: There "are" other engine treatments like Restore, but I never hear mention of them here (i.e., Rislone, Ceramizer, Lucas). Is there a report or comparison that has sway opinions toward Restore?

Do you think the Rotella has any advantages over the "High Mileage" oil choices. I do know that Rotella is a pretty good oil though - tough shear strength and additives to handle diesels.

The "No more oil changes" plan does need a little more evaluation. Any contaminants should burn off with the oil - so I'm not worried about that, but heavier deposits that don't make it to the filter could accumulate in the pan. They wouldn't affect much, at least for quite some time, but it could just be "bad form".

Ciao! - Jim

 

I couldn’t think of a better referral than from Brutal, which is also why I mentioned it earlier as he had some successes with it. So you have a choice of going for something that has been reported effective by a professional Jaguar Technician or something else which may or may not work without any referrals here on the forum.

 

Good enough for me. I learned a long time ago to respect the expertise of others. (I still ask a lot of questions though - character flaw, doncha know )

Got a 1500 mile road trip this weekend. Good time to try these things out. Any special recommendations for how to maximize the benefit of the Restore (beyond just reading the label, of course)

Ciao! - Jim

 

Strange happenings: I just completed a 600+ mile drive to Detroit and I may not have lost "any" oil. In fact I accidently overfilled her by about 1/2 a quart before the trip and I swear the mark on the dip-stick hasn't budged.

I've put in a little less than 6 quarts over the last 3,000 miles, and I'm still just using the high mileage 5w-30 stuff (no Restore yet). I had a feeling the oil usage rate might have been dropping, but I can't explain "zero".

Do these types of "hauntings" occur regularly to Jags? - lol

We'll see how she does on the way back.

Thanks all - Jim

 

Completed the 1300 mile round trip, consuming what appears to be about a quart and a half (maybe). So since I started tracking this it's been 4000 miles on about 7 quarts then, but the consumption rate is certainly less now than before.

BTW: Does anyone know the oil quantity represented by the distance between the holes on the dip-stick? (One quart? Two quarts?)

I'll schedule a oil change soon and throw the Restore in as well as upgrading to 10w-30 high mileage oil.

We'll see how the next couple of thousand go.

Ciao - Jim

 

It sounds like you may have administered what we used to call "an Italian Tune up". That's where you just blow the crud out on an all day run.