Engine troubles. Need solid advice.
 

So I was pretty stoked when i purchased my used 2000 XJ8 last week until the dreaded engine light came on followed by the RESTRICTED PERFORMANCE message. So of course the first thing I did was take it to the local mechanic and he of course provided me with a laundry list of "urgent" repairs needed before permanent damage is done (Laundry list to follow).

My plea is thus: I'm definitely taking it back to the dealer who I got a 50/50 60 day warrenty from, But I'd like to know:

- Which of these seem like the mechanic just throwing **** in there
- Which of these will cause serious harm if not taken care of
- Which of these can I do myself? (I'm no car guy but i've changed a spark plug or two in my time)

Car info: 2000 XJ8, one owner, full service records (no issues), 84k miles.

Reason for taking it in: Check Engine light came on, then went off followed by RESTRICTED PERFORMANCE message. Also the car is idling rough. Not severe but definitely noticeable when sitting still at a light or when you first turn it on.

Laundry List Given:

- Remove & Replace Oxygen Sensor - Rear, One
- Remove & Replace Serpentine Belt
- Remove & Replace Alternator Drive Belt
- Remove & Replace Engine Mount - Front, Both
- Remove & Replace Ignition Coil - Right, One
- Remove & Replace Fuel Injector - One

Total Estimate Cost: ~ $2500.00

The ones in red are of course the ones that made me cringe. Any thoughts, help would be greatly appreciated.

Thanks all,

hrushkie

Probable, but w/o the codes the mechanic pulled, it may have been the result of another true cause

Good possibility, depending on the age. You can do this yourself - 4 sure

Pretty sure there's only one belt on your 4.0L ^ the serp. That drives all pulleys.

Very probable, these are fluid filled, and leak over time. Mine is an 03, and I had to replace one of the two.

Happens all the time. If there is any oil leaking, or you get any water inside the engine bay, these earlier engines are known for allowing water/oil into the plug wells. When that happens, misfires occur, and the coil fails. This could be related to the 02 sensor being triggered too. Fix the bad coil first, then see if the 02 sensor code is still there.

The codes will reveal EXACTLY what cylinder is misfiring.

Also, very easy to do it yourself, no need to pay someone.

This one is real iffey...i've never heard of injectors failing, but it could be possible. I'd fix all the other code related issues first. Then see if there are any other issues.

Did I mention to find out the codes the car is stored? Any local autoparts store can scan the car, some work, others dont'. Write down the numbers and return for more advice.

Total Estimate Cost: ~ $2500.00

The ones in red are of course the ones that made me cringe. Any thoughts, help would be greatly appreciated.

Thanks all,

hrushkie[/quote]

Also, since you're new, there is a ton of information on the forums regarding restricted performance. Also, we have a vast number of documents either hosted or linked on the forums that deal with identification and repair of your 4.0L engine. The 1997-2002 XK8s, for example, share the exact same engine. And our FAQ sticky (at the top of the XK8/R forum) has a great deal of information for you to familiarize yourself with.

You need to ask him for the codes he pulled and we will tell you what they mean and what you should look for. If you can change plugs you can perform a little maintenance on this car. We can give you several reasons for the Restricted Performance but the codes will help narrow the list down.

Thanks guys. This info was extremely helpful. Im brand new (with the forum and owning a jag) so I'll definitely familiarize myself with all the info i can here.

Also, just chatted with the mechanic and the codes pulled were: P1316 and P0304

Reading similar posts and reading up on the DTCs it sounds like cylinder 4 is a misfiring troublemaker. Which, it sounds like could be caused by a Number of things... most of which are on the list the mechanic gave me. I'm now wondering if they just wanted to use the sledgehammer approach to fix the issue or if they had reason to suspect ALL of the listed problem parts.

My questions now would be:

- Would these codes trigger the car's "safe mode" aka Restricted Performance? Which by the way, both this message and the check engine message have been gone all day

- From all of this info, do you think its safe to drive? Am i risking severe damage or just an annoying idle and sub-par efficiency?

Sounds like a coil failure on # 4 cylinder that is your P0304, The P1316 refers to the plugs http://www.gusglikas.com/images/Auto...J27%201999.pdf and this will explain the misfire http://www.gusglikas.com/images/Auto...to%20P0308.pdf
Thought I would give you a little reading!!

At times you will get a garage that has a few mechanics that are hungry and you end up with a laundry list that will put you in the poor house. Use good judgment in moving forward on the list and ask to see why it needs to be done. If the mechanic is offended by you asking you are in the wrong garage.

Hey, reading works for me Gus. The more i know about something the more comfortable I am.

Thanks again for good info!

You need to know if your engine has the plastic timing chain tensioners. If it does, you are going to have to lay out at least $850 to have the chains and tensioners replaced. If a chain jumps a tooth, your engine will crash the pistons into the valves, and you will be out thousands of dollars. Have someone start the engine cold, after it has set for a full day or two, and you listen near the front of the engine for a rattle. If you hear it, take the car back to where you bought it and tell em it is their's again, or they need to do the upgrade for you. This has nothing to do with the problems you mentioned, but is a very common problem.

Thanks for the note linuxenigma. I've heard of this happening and it does concern me since the car is getting on in miles.

Is there a way I can easily determine if the tensioners are indeed plastic?

If the dealer can't give you a service document confirming it, only way to tell is to open the valve covers and look. Its not that difficult to do, they're right there on top...easy to see.

If it were my car and my money I'd do two things:

1. Buy a good Code Reader. I spent $99.00 on mine. It has all of the software to tell me what the codes are built in.

2. Replace the #4 Coil and Plug. ($92.00 and $5.00)

While I was doing that I'd look for oil down in the sparkplug hole. If the Valve Cover Gasket is leaking, oil can build up in the hole and short the coil out. That's likely the cause of a failed coil. Check all of the other plugs/holes while you are at it. An hour spent doing a cleanup can save big $ until you can get to replacing the VC Gaskets.

Once you have the Coil and Plug replaced, use your new code reader to clear all codes and take it for a ride.

We're on the same page Sinister. I wen't out and got a reader this AM, bought a plug and ordered the coil.

No engine lights or messages since yesterday AM. The reader pulled up the old codes the mechanic was seeing but they haven't been triggered again. Hoping this is sign that the plug and coil will fix the issue and its not something greater. Stay tuned...

Kudos to you! On the road again!

i wouldnt call that a laundry list, nor does it meen a hungry mechanic (imo) 2 reasons
1) my job is to let you know what I see when I am looking at your car, not what just what you complain about. I know alot of tech that think theyre doing a diservice to a customer when they write additional needs. personally I would like to know if a hose/belt is in need of replacement rather than being stuck on the side of the road broke down waiting for a wrecker.
2) other than alt belt(it doesnt have 1 as h2oboy pointed out), nor would I go for a injector, while possible not as common as coil/plug failure. the 02? based on what code/condition. the engine mounts very cmmon and useally the results of the joint they suffer from potholes/curbs. Ive already had customers break the bew ones with a cast aluminum body when they bubble a tire/rim on potholes...
I always appriciate whne customers what to look at their cars so I can show and explain WHY I recommend something. its not my money, its theirs and they can deny all repairs or do it all or we can sit down a detemrmine what should be done as their budget/needs dictate...
and they restricted performance is cause the misfiring cylinder was severe enough to cause permanent damage to the cats if let go....I still dont understand why people let misfires go and then wonder why the get cat codes down the road...misfires should always be priority fixes.
on those other issues you may want to talk to who you bought the car from about fixing those items unless they discounted the price to you based upon those issues