Among other problems, I still commonly have a repeated no-start condition on my 4.0 w/ 200K miles. After any time that I have problem starting the motor, the only way to again start it is with a healthy squirt of oil in each of the cylinders.

I cannot drive the car anyway because what I believe to be a transmission solenoid causing it to stall when put in gear. I still need to be able to easily start it though, so I can finish diagnosing and repairing other issues and hopefully drive it. I am getting aggravated by the constantly lengthening list of problems it has had and am considering just giving up and selling it, but having it be able to start would be a great selling feature.

I have even had the police called to investigate the smoke cloud from the startup procedure.

I know the rear cylinder on bank #2 is not firing (not sure why). The plug comes back out covered in un-burned "starting oil."

When it doesn't want to start, it will sound like it wants to fire but doesn't on every 4th rotation of the motor. Holding the accelerator to the floor and strategically letting it up slightly on the count to three with hopes that it fires on the forth cranking rotation gives me the best results. However, if it does fail to start, I'm back to the oiling again.

I always shut the motor off warm and even have tried to shut it off by pulling the injector fuse with hopes of not leaving any fuel in the cylinders. I do still always end up with it not starting.

With freshly oiled cylinders and a full battery charge, it will start always.

I am wondering if this is the standard degraded Nikasil bore problem or something else. I am wondering how the engine would have managed to get to 200k with such a problem existing for the last decade or so.

Any input/suggestions?

 

A compression check dry and wet should give you a quick initial clue on your cylinder condition.
Checking on pressure in the crankcase gives an other indication.

 

I do not currently have access to a compression tester, but when I unplug the hose that runs from the intake to the valve cover; air blows out of it. So, the crankcase pressure is very positive.

 

I am sure others will chime in with more practical advice.

I remember doing the oil-cap-off test when buying my 1998 Nikasil car.
Pressure indicates a problem, and can be easily seen by putting a sheet of A4 paper on it while open.
Mine does not show significant blow, if that is a reference.

Low compression / blow-by could be an explanation why you keep getting these problems, maybe ...

 

I've noticed oil where it shouldn't be with Nikasil engines, the intake tube for instance is a good place to check by wiping a paper towel along the inside, if there's an amount of oil it's almost certainly lining failure. Hate to say it but stall outs and long cranking are the other two classic signs. A compression test will confirm this.

 

The fact that you have an XJ with a nicasil engine amazes me. I remember replacing these engines left and right, under warranty at that due to wash down, but that could be due to fuel additives at gas stations in the south. Anyhow, once the nicasil is washed down, you pretty much lose compression. You really need to do a compression test to confirm this is your problem. If that's the case, you're going to need a donor or a rebuild.

 

Why?
I have a XJ8 and a big V-2 VTR1000, both with nicasil engines.
Both going strong.

It was actually a very nice material in itself, and will never wear down during the lifetime of an engine.
It was just that 'little' problem with fuel in some parts of the world which gave it its bad name.

 

I agree with Eric. My 98' XJR has the original 240K mile (971003 date code) engine. When I had the heads off 7K miles ago, the lining looked great. Lucky I guess. However, I've seen low mileage nikasil engines with liners worn away almost entirely. The life of a early nikasil engine depends entirely on the fuel it was fed.

 

Add engine restore to the oil you will need a can and a half for 8qt engine. Worked wonders back when these were a issue when customers didnt want to buy engines from low compression and repeated cylinder wash. Jason is right, we used to replace these all the time but mostly on poor maintenance and overhets. Then they built the 4.2 and never replaced engine again. Until.......

 

Hence why I said probably something to due with fuel additives that are used for Southern states. When I came to NZ, and was able to get back into the dealer environment, I asked about the common problems that I saw while working in Houston, which in most cases were not the same issues, mostly due to environment. Here in Auckland, they have a lot more older Jags still on the road and coming into the dealer, as far back as XJ40's, still have a working WDS, which has saved me in a few situations.


Back to my point, most customers that owned these cars just wanted to get in and drive. They only come in either when their told to, or when something happens. Most people on this forum are much more particular about their vehicles, hence why they are better taken care of. Cant tell you how many cam covers I've pulled off for leaking, and can tell when and how well its been serviced.


Bottom line, recommend doing a compression test before making any assumptions. Then move to your other issues. As for your #8 cylinder not firing, could be a number of things, seen everything from bad coil, ignition amp modules, wiring fault, to ecm fault on that circuit. The fact that its "oily", I'd be a bit more concerned with that first.

 

There was considerable oil in the intake tube when I got the car.

Can anyone tell me what pressure I should see during a compression test, or an example of a compression test on an engine with a known cylinder wash problem?

Thanks!

 

I think the compression for a "good" engine is at least 140 psi with a 15% variation among cylinders. I'd double check with someone more experienced for the exact numbers but that should get you in the ballpark.

 

Did this really work?

 

Yes it works well. just add with every oil change. I always have some in the shop for older higher mileage cars. and I just used a little in the generator in my RV for oil burning on start up and that now stopped