Hi,
So I'm new to this forum I already introduced myself.

This post is going to be long becasue I want to tell you what happened exactly so you guys can figure what caused my car to have a rough idle where the car was shaking when I started it, and had a very slow sluggish accleration.

What Happened
I was coming home from a graduation party the night before this issue started and throughout the night it was raining pretty hard. When I went to start my car in the morning the car started to shake very oddly, and when i put it into drive it got even more shaky. The engine light came on and a message on the gauage clauster read "Restricted Performance" when i started to drive it the accleration became very sluggish (it was sluggish before this issue occured and I just had to replace the fuel filter). The car kept shaking when I driving it and the engine light kept blinking on and off and so I went back home and parked the car didnt want to damage it.

What I have done so far

So I talked with my Father and our personal mechanic about the issue I had, he said to add soem seafoam to the gas tank. I went to the local autozone and picked up a can of seafoam added to the gas tank and filled the car up with prenium gas as always I do. My mechanic also resseted the codes to see if the issue might be glitch or not. The car started to smell like rotten eggs after adding the seafoam and when I drove it, the lights came back on the engine light and the same message before. I drove to back to autozone and decided to add another can of seafoam and get the codes read. After the secound can the accleration got much better but the rougle idle still continued and when I acclerate it quickly the car starts to jerks and hesitate it didnt do that before the seafoam.

The Codes that came up
P0300- Random Misfire
P0301- Cyclinder 1 Misfire
P0305- Cyclinder 5 Misfire
P1313- Misfire Rate Catalyst Damage Fault
P1316- Misfire Rate Exceeds Emission
P1000- ODB System Rediness Test Not Complete

In the meantime Im try to kill all the gas in my car to completely clean the engine. I still have the rough idle and the hesitation. Im just shicked that overnight my car started to act this way. Even the night before i didnt hit a pothole even.

Can you guys help me on how to solve this problem, or understand it better.

Thanks

 

Welcome! Thanks for all the great details.

Since the problem started right after a heavy rain, check for water in the spark plug wells, specifically cylinders 1 and 5. Rainwater can collect there and short out the coils.

Sounds like you already knew, but if the Check Engine Light is flashing, that means youve got misfire severe enough to damage the catalytic converters. Reduce speed and then stop as soon as possible.

I'm not a big fan of Seafoam cleaner. Somebody mentioned once it's great for cleaning out an old 2-cycle outboard motor, but not for a modern computer controlled engine.

 

Thanks for the tip! But I'm still like astonished how rainwater was able to get the spark plugs even when there is a good on the car and the plastic engine cover . So how do I check the spark plugs and confirm that they aren't acting correctly and if they aren't I should change them.

 

If there's water it will be the coil(s) that are the problem.

Stop using seafoam.

Read threads about fuel trims as you may well have an air leak.

Also, check battery very carefully (load test etc) as a flattish/old one can cause misfires (or weird codes).

Something quite bad happened to cause the P1000 as your car should have had P1111. Or you cleared the codes (why???) or have a power fault.

 

Prepare to be astonished more. Open hood/bonnet. Have garden hose running and handy, let a flow of water run from top of windshield down. You will see water pouring on to back of engine!

Many threads and ideas how to correct the problem here. The windshield wiper cowl is not sealing against the windscreen any longer.

 

Thanks, Can you send me a link to that thread. It couldn't be the battery because I replaced it with a new one. We resetted the codes to see if it was the computer or something wrong .

 

Oh wow! Jaguar really did mess up there! I'm sorry I'm new to this forum can you send the link.

 

It can be the battery because even when they are brand new they are no longer fully charged. For these cars you need 12.6 volts between the poles.
Another problem is that the charging system was not designed for maintenance free batteries. They need 14 plus volts which our cars produce for a few minutes then it drops to 13 plus volts. This means that the battery is only charged to around 80%. Most of us use a battery tender.

check your fuel trims using an elm 327
https://m.youtube.com/watch?v=5WnM_NsOtd8 and part 2.
This is one of the first tests for a misfire after charging the battery.

 

Also is the MIL light flashing. If so don't drive or you will have to replace the catalysts.
have downloaded a copy of the JTIS or the workshop manual?.
go to the stickies or jagrepair.com

 

When I drove it on the road it would flash for a bit and stay steady and then when I would accelerate it, it would flash again. Thanks for the sites!

 

Wow, I bought this battery from Autozone and also changed the fuses when I bought it. Thank you for the video I'll check it out and let you know. What if it's not the fuel trim, what else can be the problem then?

 

You use the fuel trims to see if you have an air leak this is all explained in the videos. You can also go to YouTube and search for scannerdanner. He is very good in my opinion and gives examples of fault finding.

 

Any updates? Did you find water in the spark plug wells? No guarantee that was the problem, but the odds are likely based on when it happened.

 

I ended up solving my rough idle and misfires on the 4.0 engine by changing the spark plugs. One surprise was finding oil in the plug wells. If the 3.0's have the same overheating problems that the 4.0 engines have then take a look at the seals. mine looked like they had melted/warped and oil was seeping in.

Replaced the seals, cleaned up the mess and changed the plugs. It solved that problem.

 

Change the IMT O rings on the back of the cast ally inlet manifold it is a known weak spot and check the hoses under the IMT are intact especially the elbow.