Today I went to the Techno Classica in Essen, Germany. One of Europe’s largest Classic Car shows. Great day.

On the way back home to the Netherlands I noticed something strange.

I was driving on the Autobahn at an unrestricted speed limit stretch. So I put the hammer down, as one does! Buried the throttle and lifted at about 180 km/h. When I lifted you would not believe the amount of smoke coming out of the right exhaust. And I mean it was a lot of smoke! People behind me were popping their headlights on.

I tried it several times. It only happens when I really mesh the throttle and lift at high speed (>170km/h0 and high RPM (>4.5- 5.000 rpm). No smoke when I’m accelerating.

I tried to simulate it at lower speeds, by keeping the gear in 2/3 and just going all the way to 5000 RPM and then lift. Nothing.

Although, difficult to see, I was by myself so I use the rear view mirror, the smoke appears grey, not blue. I checked the oil, but the engine uses hardly any oil, maybe 1l per 4-5000km if that.

Other then the smoke, nothing out of the ordinary. Car pulls up (very) strongly, no unidentified noises, vibrations or anything like that.

Nothing on the dashboard. I’ll put my OBD analyser on it over the weekend, see if there’s anything amiss.

A few months ago also on the Autobahn, I wanted to see how fast it would go. Nailed it and it was still accelerating at well over 250 km/h and that was GPS speed. I lifted as my bottle ran out long before the engine ran out of puff. But no smoke at that time.

Any thoughts/ suggestion were to start looking?

Jeroen

 

If it's consistently out of only the right side, I'd guess the head gasket is on its way out, maybe a hairline crack between a cooling line and cylinder revealing itself under high stress? You could pull spark plugs and see if any of the pistons look unusually clean. That's just a guess though, I've never rebuilt a head before so I'll defer to those with more experience.

 

When you lift at high speed you get a lot of engine vacuum. Operating at high speed you get a lot of oil flow. I'm guessing valve seals. The high engine vacuum could be drawing all that pooled oil in the heads from high speed operation through them when you snap your foot off the throttle. I suppose it could also be pulling oil past the rings.

Before getting too serious, I would make sure the breather system is ok and that things like the part load breather are not clogged.

Steam from a head gasket would be white. I would also think that a head gasket leak at 100% sustained power would cause an overheat.

Does the grey smoke have any tinge of blue? Assuming your car has cats, they can cover burning oil unless they get overwhelmed. Since the introduction of cats you see a lot less cars trailing blue smoke because it gets burned up in the cats.

Then there is that common muffler. V8s typically have a crossover pipe. If that muffler crosses over, then the trouble could be from the left side of the engine.

-Mike

 

Jeroen,

Maybe you follow this one on the Dutch Jaguar Forum, seems to have started with a same kind of problem (although he seem to have more severe problems).
Car is going to the Jaguar specialist, maybe they will come up with some conclusions.

Link: https://www.jaguarforum.nl/forum/top...-door-uitlaat/

 

Thanks everybody for the suggestions. I don’t think (hope?) it’s the head gasket. I would think that would show up differently then only at lifting at very high speeds. Also, I have not seen any coolant disappear. I would expect any problems with the head gasket to show when I’m stepping on the throttle rather then coming of it. But you never know, so I’m not ruling it out yet. But I’m focussing on some other items first.

I’m familiar with the problem of valve seals. I also have an Alfa Romeo Spider and they are notorious for leakage on the valve seats. You lift and there will be a lot of blue smoke. (My spider doesn’t have a catalytic convertor).

I can’t be 100% sure of the color. Doing 170-180 km/h you want to look in front of you and not too much time looking into the rear view mirror. Yes, my Jaguar has cat.

Yes, I’m also a member of the Dutch Jaguar Forum. Very interesting thread. I’m going to follow up on some the things mentioned. (e.g. crank case ventilation etc)

As a matter of fact, this Saturday I will be attending the Auto-box overhaul Workshop at one of the forum’s sponsors (G&G). I want to check the basis stuff myself and then discuss with Raymond, see what he says.

Thanks so far, I’ll keep you all posted

Jeroen

 

Well, this morning I checked the codes. I’m getting a P1111, which is perfectly normal and a P1649 Something to do with a problem in the Flash Memory & FCCP. I resetted it and it seems to stay away. According to the JTIS could be a ground short or to B-Voltage.

Doubt this caused the smoke. I checked the air filter, but no oil at all. also checked the breather pipe on the left bank, fine! Next would be the crank case ventilation, but if memories serves me correct I need to take the valve cover of for that?

Jeroen

 

Check the intake pipe between the air filter and the TB.
If any oil collects, you will find it there.
The crank breather is on the passenger side (Dutch car), the small hose connecting to this intake pipe, just after the airfilter + MAF.

 

sorry my mistake, I checked the crank breather on the right (passenger) side. I.e. the one sitting just the air intake filter. Seems ok.

But I’m pretty sure there is something on the left (bank) side as well, but I need to do some digging around.
Anyway, I’ll ask Raymond tomorrow, see what he says

One thing I did notice as well. The little frame holding the supercharger cooling pump is dangling loosely. I will need to replace the grommets. Just checked a few places, this little rubbers are costing Euro 10 each and I will need four. Oh well, nobody ever claimed owning and maintaining a Jaguar will be a cheap affair.

Jeroen