These cold, wet days, I notice when I turn my car on that the left (port) exhaust pumps out a lot more steam than the right (starboard) one. I can't detect any notable difference in pulses when I put my hand near the pipes, but all other things being equal, shouldn't both exhausts emit the same amount? Could this just be something to do with enrichment focusing on one bank (as counter-intuitive as that sounds)?

Left is far more than right. Is this right? Or is there something sinister going on?

Sorry for such a (probably) trivial question. I can't find an answer online as all the stuff I can find deals with either twin outlets from a single pipe, or at least two connected systems. None like our Jags which are completely isolated. The engine sounds fine and behaves fine. So I guess I'm just curious at this point. Curious, but slightly cautious.

 

I wouldn't be that worried. It depends on a lot of things like temperatures, how the car is parked how much humidity is in the air, ...

Watch your coolant level and you'll be fine.

 

Wow, that was a quick response. Thanks!
Coolant levels were oddly low, actually--I managed to get quite a bit more in there. She hasn't been running remotely hot or anything, however. I don't think she's leaking coolant into the engine, though. The oil's fine.
The temperature (low) and humidity (fairly high) are standard, but I'm just curious about why they're not even. They're just as unbalanced up at the university parking lot.

 

I've come to the conclusion that it's "normal". I assume it's something to do with the AAV and balance pipe and the rest of the plumbing that causes it. I don't worry about it any more..maybe I'm living dangerously

 

You are not. It is quite normal. Cylinder condensation, cat warm up times, slight mixture differences owing to injectors, residual water condensing in the exhaust system, etc etc.

 

Normal/common but fixable. I found that my o2 sensors had never been changed in all 250,000km so renewing those and re-tightening and adjusting throttle linkage fixed the exact issue pictured above.

It could be the slightest difference between the sides making a large visual effect with no real problem.

 

Thanks for all your responses, everyone. In my case, both O2 sensors are new, but there could be a tiny difference between throttle linkages, like a mm or so. I think "Living With a Classic" has a bit on measuring the rod lengths to the mm to check.

 

I had a similar problem. Try replacing your gas line filter. I wasn't getting sufficient gas through to the right cylinder bank and thus less exhaust. Hope this helps!

 

There is only one fuel filter, so if it was a plugged filter it would affect both banks equally.

The throttle plate gap in the bore when the throttle is closed is supposed to be 0.002" - half the thickness of a standard sheet of paper. As you can imagine, it is very difficult to set a clearance that small, and a slight variance will allow more air on one side than the other. Off idle it has no effect, but it can result in one bank ingesting slightly more air than the other and thus producing a greater volume of exhaust.

Probably more effort than it's worth to chase unless you feel like adjusting the throttle stops on one bank a tiny amount.

 

Indeed, and my fuel filter is new, so it's not that.

"0.002" " while presumably the Jaguar manual stated measurement, seems to me to about the point when changing to metric makes more sense. Not that 0.05 mm is much more practical, but perhaps it is. Half the thickness of paper is a good measurement. At 50 microns, it's also about about half the thickness of a human hair (90 microns). So yeah, a very tiny, tiny gap indeed. I suppose you'd have to adjust the throttle stops by equally tiny steps. And if you can slip a hair in the gap, it's too big....

 

The throttle stop adjustment is a small bolt with a locking nut to hold it in place once adjusted, so a sleeplessly variable adjustment. Yes, 0.002" is from a Jaguar manual. At these small measurements I don't think it makes any difference if inches or mm are used, they are both decimal measurements.

The usual way to set the clearance is to put a feeler gauge in the bore and close the throttle plate against it. They are steel and have the thickness etched on them to be easily readable. The thin ones are more like foil, so are flexible to conform to the shape of the bore. Or if you have the throttle housing off the engine, it's just about when you get a sliver of light past the edge of the throttle disk. Your eye can discern surprisingly small differences in the gap by the amount of light that gets past.