XJ6 4.0 1995

Ok, a bit of a weird one this. I was unloading out of the trunk this morning and noticed no exhaust coming out of the left pipe. I put my hand there and it was stone cold. I revved the engine and still nothing, just exhausting from the right pipe.

The car recently went in for a service a week ago with a Jag mechanic where he tested the O2 sensors and replaced one, so I can't imagine there was a fault that he didn't pick up on.

Some background - it is full-on winter here. Loads of snow and cold temps.

Am I missing something, could it be a block? The car seems to be running ok, no CEL.

 

Could be a block in the underfloor catalyst or after in the pipe or muffler. It might not manifest itself as a problem at idle but i would have thought that on the road at higher speeds/loads that there would be a reduction in performance.

I'd get under the car and have a listen with a stethoscope to locate where it might be blocked. Also check to make sure the catalyst is not glowing red!!

 

Yeah, probably a clogged muffler.

The system is mostly single exhaust so the problem must be after the branch-off to dual exhaust.

I had the same thing happen on my old Ser III XJ6. Hardly anything coming out of one side.

I took it on the highway and gave 'er the boot. In my mirror I could see all sorts of brown crap blowing out from one side and just a normal light grey wisp from the other. I repeated this a few times then pulled off the road for the hand-behind-the-tailpipe check. Both sides were equal again.

My conclusion was that the mufflers one one side were (internally) rusting-out more than the mufflers on the other. I dunno why that would happen, but.....there you have it.

Cheers
DD

 

A couple years ago I had the same problem Drove me insane looking for it and as soon as I had driven it for a while it went away. Eventually It went to both pipes clogged. I'd come out after work car at 15 degrees try to start it and nothing… it would sputter for a second then choke off. I drilled a 1/2 inch hole in the exhaust in front of the muffler (upstream) between the cat and the muffler. and magic it started and ran… melted the exhaust and ran fine. Now I have a little hose clamp across both holes on both sides and when it freezes up I just loosen the clamp and start it. After warming up it blows a cloud of steam out and runs fine. Not sure why I'm collecting water in the muffler but I am. I've been doing this for 2 winters now with no issues and I'm not having a rust problem….
Steve

 

Water is a normal byproduct of internal combustion.

Some muffler have drain holes specifically for this reason.

If your driving falls mostly in the "short trip" category then the exhaust system doesn't have enough time to build up the heat required to dry itself out.

Cheers
DD

 

A clog, no doubt.

Take an infrared temperature gun and site it at strategic locations along the exhaust (both sides) from source (manifolds) to where it's "coldest" (no doubt the south side of a CAT or muffler) - obviously the point between where it's hottest and coldest is where the clog is.

 

thanks for the responses. i contacted my jag mechanic and he told me not to worry. life went on and suddenly it was unclogged. I can also hear a lot of gurgling in there, so water it is. I do a lot of short trips.

Thanks all.

 

Hi all, i am revisiting this as I am right now sitting in the waiting room of the exhaust shop. Same problem this winter, the left exhaust stopped working. I came in to have the right muffler replaced, and asked them to look at the left. They said it might be the left cat which made me sweat, but they made a cut and it turns out the muffler and pipe before it were full of ice. So they are replacing the muffler and we should be good to go.

 

Here are some pics of the ice in the muffler and length of ice that fell out of the pipe.

 

Very useful and kinda shocking thanks very much

 

Thanks for the update.
It is a lot of ice! I've never seen / heard something like that before.
I would be interested to know if other members experienced a similar problem. I also wonder why it is only in one side...

 

As always thanks with diagnosis. This is the first day in Boston above freezing since February 6th. I had the same problem on the drivers side. I would guess it is a combination of short trips and backing out and getting snow in the end of the pipe. Today I jacked it up and put the kerosene heater at the height of the pipe and let blow in for an hour and now it's defrosted and working again

 

This is a picture of the exhaust clearing itself, it took about 20 minutes with the accelerator propped at about 1800 rpm

 

Wow, that is interesting.... have never seen an exhaust frozen up.

.

 

I believe this happens to my 1995 XJ6. Starts with tailpipe "gurgling" and when VERY COLD weather comes, car stalls on startup (sometimes making a hissing sound). Warmer weather thaws some of the pipe and then one tailpipe works, car runs very rough at first...after a few minutes other tailpipe works.
I like the idea of having a drain hole at lowest point. And an emergency re-sealeable hole in case of major ice clogage. Thanks!

 

I have had the same problem for two Winters now, the right side exhaust partially plugs up with short drives. I can hear it gurgling on that side. A longer drive on the local bypass takes care of that problem.

Some vehicles I have had in the past had a small drain hole at the underside and end of the muffler. I had thought about drilling a small hole in the end of both mufflers to aid drainage.

Seeing those pics. of the complete ice blockage is just crazy!

 

I haven't had this problem since I took all the CAT's out and am running with the rear resonators only. The water seemed to gather in the underfloor CATs because they didn't get hot enough. They had all rusted out anyway and in Mass. there is no emissions inspection on anything older than 15. I do have a permanent CEL:-) but that's a separate issue I can live with