Its been raining cats and dogs and city busses here the last 3 days and I haven't driven the Jag since Sunday morning (And it ran great).
So I decided to go grocery shopping a couple hours ago. The Jag fired right up like usual and I let it warm up a minute or 2. While still in park I put the a/c on as its 88 and humid. As soon as the compressor came on the engine started shaking and died. Turned the a/c off and started it again. It ran rough as heck and the check engine light and the orange light came on along with "Engine performance limited" and "Low oil pressure" (because it was idling so badly). It seems to smooth out if I revved it a little but at idle was very rough and sometimes died. I got out and listened to see if I could hear any chain noises and no funny noises. I don't have a code reader yet but I see one in my near future. Then I got brave and drove it for a few minutes at around 40. All the errors except "Check Engine" went away. I disconnected the battery for a few minutes. Now no errors at all and drove it again around 55 for about 30 minutes and now it runs great and idles smooth as silk.
The car has been in the rain for 3 days and I am hoping it was just something got wet and the heat from driving it dried it up. On the other hand I hope this isn't a tensioner laughing at me while its disintegrating. Scary stuff when your broke and its your only car.


Dave

 

Dave - best thing to do is invest in a blue tooth reader and the Torque app for android so you can read the codes. Between the reader and the Torque Pro app - it cost me $20 but between it and the folks on this forum - you will get a lot of peace of mind when the dreaded Restricted performance message flashes




Here is the link to the ELM 327 reader I bought
http://www.ebay.com/itm/Vgate-Mini-E...3D290996643323

 

I'm one of those people that don't own a cell phone or a windows based computer so a Bluetooth reader would be useless as I can't find any apps that work with MacOS X. I'll have to settle for a standard ODB2 reader. I am still hoping that it was just that something didn't like being rained on for 3 days. I also looked (and listened) for vacuum leaks and have found none so far. I am also planning on changing the spark plugs in the next couple of weeks and when I am doing that I'll pull the passenger side cover and see if a crumbling first gen tensioner awaits me.
That of course if it doesn't fail first.

Dave

 

I use both movi and auto doctor on my macbook air - work perfectly.

 

Thanks, I just bookmarked those and will check them out. Now the only problem is I don't have a laptop. I do have a Mac compatible Bluetooth adaptor I can put on a long USB cord to (hopefully) get it in range.
I guess another clue will be if it only does this after heavy rains. This is the heaviest rain we've had here since I got the Jag.


Dave

 

I had forgotten to mention that when I restarted it with the a/c off after it died the first time the idle speed kept revving up and down by itself like the computer was trying to find a spot it was happy with. I just went and tried it again after it sat a couple hours and its still running fine. Weird stuff.
I also found that if I let the tires spin on the wet grass in my back yard the orange light comes on and you get "ASC" error unti you stop then they go away so I guess thats working ok


Dave

 

I had very similar problems with my '99, after driving in the rain and then slowing down in town, it went into reduced performance and then "limp mode". After sitting in a pizza joint parking lot a couple of hours and doing a hard reset at the battery, it came back to life. After I got home I got a can of contact cleaner and and a can of dielectric grease and took apart every connector I could get to in the engine bay, cleaned them and filled them with dielectric grease. I suspect water vapor entered and shorted the MAF connector but just guessing. Never had another problem after that, at least 'til #1 coil pack went south

 

It was acting like a MAF or massive vacuum leak. I'll check the MAF connector in the morning and clean the contacts.


Dave

 

As previously mentioned, these cars despise moisture in the engine bay. The slightest amount that makes its way into the throttle body can play havoc. Our S-Type is the same way. I'll never wash our Jaguar engine bays or even use a wet rag under the hood. Nothing but old rags, a little WD-40, and lots of elbow grease....

When the sun returns to your neck of the woods, open the hood and let the sun work its magic for you. Hopefully that resolves your issue....

 

It did it again when I started it for the first time since yesterday - "Engine Fault - Poor Performance". And like yesterday it cleared up after a few minutes of driving. So this time I went right to AutoZone and had them read the codes as the reader I ordered hasn't got here yet.
351, 353 and 354 which seems to mean the coils on that side must have gotten wet. The way they are hidden under the cover moisture can get back on them again from condensation dripping from the underside of the cover overnight when the temp drops to around 60. So I am going to change the plugs as I have no idea how old these are and I will make sure each coil boot gets a liberal application of dialectic grease so hopefully it won't do it anymore. Otherwise its running great and no other codes.


Dave

 

My engine bay was a bit dirty, so I borrowed a steam-cleaner from my mother-in-law and filled it with distilled water. Since distilled water is non-conductive, I figured it would be a lot better than using regular tap water. Didn't have any issues at all, after a thorough clean.

 

I left the hood open to the partial sunlight today and now its all back to normal. I've got some Bosch Iridiums on order and a tube of Dielectric grease and will do that job next week sometime weather permitting as it looks like rain most days. While I am at it I will take the passenger side cam cover off and see if there is a plastic tensioner under it snickering at me. If so I will order those when I can afford it and hope the old ones lasts long enough. I did take it out for a nice top down drive and it performed flawlessly which likely means something is about to break. (I learned this first hand from all the other Jags I've owned).


Dave

 

I got caught in the rain today and after a few minutes of driving in it the engine died every time it came down to idle. Got the "Engine Fault - Poor Performance" readout and the Amber light. It would start right up and as long as the speed was over about 1000 rpm it ran fine and all the faults will go away. OBDII says same 3 cylinders as before misfiring. I wonder how moisture gets in there so quickly when it rains? Guess I will have to break down and change the plugs and grease the boots. Another though is maybe its not that at all and maybe its the connectors on the coil packs that don't like moisture. That may be why some have had silicon put on them.

As a sort of "funny" aside to this - When you take the wiper arms off to get the fascia for the cabin air intake off to clean it out remember you *REALLY* have to get those damn nuts that hold the arms on tight. They came off easy enough but the arms were stuck to the shafts and took some persuasion to get off. I was afraid of over-tightening them putting them back and the drivers side one came unscrewed while using it in the rain. All fixed now.

Dave

 

Hmmm, I was poking around trying to find an answer to the 3 right side cylinders misfiring when raining or just really humid. The right side is where the dealer replaced the tensioners. I checked the cable harness to the coils where it comes out of the back of the cover and it seemed damp as did the general area close to the windshield end of the hood. Not soaking wet or anything like that but more like condensation. And no, I am not losing any coolant, the level has stayed static the entire time I've owned the car and so far have not had to add a drop. I'm beginning to think that maybe that harness got nicked or pinched when that work was done 40k miles ago and its likely had this problem ever since. Later when I feel more motivated I want to pull the coil cover off again (and of course the MAF tube etc) and unplug all the coils so I can pull the cable partly back out the grommet in back so I can see if it appears damaged there. The fact that its always the same 3 coils that give errors only when humid to me says it may be the cable. Otherwise the 4th coil on that side should be doing the same thing if it was just moisture under the coil cover. or it could be that those 3 coils have cracks in their insulation and that would also make them fail when damp. Will be nice to figure out what is doing this anyways and fix it.


Dave

 

Keep at it Dave & good luck

Hope to hear

 

Yep, hang in there and you'll figure it out. As you know, the early coils always have more issues than the later ones....