Long story try to make it short. I have had my 1998 XJ8 for a little over a year and up til 72 hours ago I was happy. 98,000 miles and while trying to start the car it wouldn't. Acted like a fuel pump so I bought one and towed the car to the local garage I use. Yesterday he says the mechanical cam sensor failed and took the top end of the engine with it. SHOCK and DISBELIEF!! So I went down there and sure enough low compression in all holes. Its cheaper to put in a used engine rather than repair the old one. My question is how many years are compatible with 1998 chassis? The people at Auto Zone tell me the Ford engine has a fail safe mechanism to prevent this from happening. Is this true? What year did Ford start and can I get one into my chassis? Please help!!

 

Mechanical cam sensor took out every single cylinder? Not likely.

It kind of sounds like classic cylinder wash- ask the mechanic what the compression numbers were for each cylinder and get back to us with those figures before moving on.

Quick question- on the day that your engine "failed" did you start the car, then without fully warming it up turn it off, then try and start it again? (like moving it around in the driveway, then turning it off, then jumping back in to go to the store)?

 

I should add: Commonly, the secondary tensioners fail- but this will create a 0 compression on a *few* cylinders since the valves bend and do not fully close.

 

I tried to get the mechanic on the phone but they are closed. No cylinder was at 0. They ranged from 35 to I think 75. The day I tried to start it the engine fired but felt like it was starved for fuel. Like the old days when you could pump it and it would come alive. Instinctively I pumped and it shut off. It would try to start but only one or two cylinders would fire then nothing. I tried for about 6 or seven tries. I came back later and tried again with no luck. The day before I pulled it out in the driveway and shut it off to unload some things. I then started it put it back in the garage. Fired fine both times. Didn't drive it the next day then the day after is when the problem occurred. He has the valve covers off and showed me the cam sensors. The oil pump is working and there is no evidence of broken parts. Not like my 57 chevy for sure :O) Ill get the compression for you hopefully tomorrow. When you say cylinder wash what does that mean? Im not familiar with the term.

 

Here you go-

https://www.jaguarforums.com/forum/x...t-start-87631/

1998-199 XJ8 is notorious for this if you fail to warm it up at every start. You have compression on every cylinder, but it's low- I am going to call this one- cylinder wash.

He can pull the plugs, put a little oil down the cylinders and I'll bet compression comes up. Then he can put the plugs back in, hold the accelerator to the floor (this shuts off fuel flow during start) and I'll be you a British ale it starts.

 

i agree...worth a try...i never trust mechanics..trust the forum lol

 

I cannot even imagine what might be referred to as a "mechanical cam sensor" on an X-308. Either you seriously misunderstood him, or he is full of crap. I agree that it might very well be cylinder wash, and worse, it could be a Nikasil failure.

Was he showing you the secondary chain tensioners? In the front between the chain path connecting the intake and exhaust cams? (they ain't sensors!) If they are plastic, they need to be changed, but with non zero low compression, it is extremely unlikely you have had a timing jump- and not on 8 cylinders at once.

 

I vote for cylinder wash. "Starting it up, moving out of the garage, shutting it off, starting it up and driving it back in the garage", is a classic cylinder wash scenario.

I don't know much, but I know one thing,......I would NEVER take the car to ANY dealer, or Indy before consulting this forum, and exhausting all options. I understand that most peple don't have another car they can use while the forum discusses the one with the problem.

There is NO mechanic in this world that has the knowledge about these cars equivalent to the cumulative knowledge the enthusiasts have on this forum.

 

I think I would avoid that particular shop in the future.

 

+1 and consult this place whilst the car is up your driveway.

 

Ok Guys. I was mistaken the mechanic says the part I referred to was the cam adjusters not sensors. My bad. He believes it was an oiling issue that caused the adjuster on the drivers side to fail but wont discount the cylinder wash. He will try to take your advise but asked if you have any more advice now that you know it was the cam adjusters. Cylinder pressure is as follows: 1=24 2=30 3=30 4=45 5=60 6=35 7=60 8=30 Thanks for your help

 

Does he mean VVT? I can't believe that will keep the engine from running, but I'm no expert. I would fix the cylinder wash, then find a Jag mechanic.

 

I don't think the VVT will cause a no start/compression issue.

To give you an idea, I had 65-90 in mine and it would not start.
Putting oil in the cylinders will bring the compression up I can almost guarantee.

Have him do that first and then report back what the compression is. He should be pulling the injector fuse when cranking to get the oil around the cylinders so that the cylinders don't get washed again.

What it *sounds* like is that he thinks both sides of the engines' VVT failed and caused interference to bend the valves, yet there is still (albiet little)compression? Nope.

It sounds like he is not familiar with the X308, as cylinder wash is pretty common- I have seen at least 5 in this forum in the last couple months alone. Let's put it this way:

Option a: Put oil in the cylinders- cost of labor (maybe $65?)
Option b: Keep trying everything else, including buying parts/troubleshooting labor... probably 1K-3k, plus an engine if he does not figure it out.
Option c: Buy new engine, probably 3-4K with labor.

Option a looks like a no brainer to me. Some folks like to spend a bunch of money first, though- your call.

 

Are you saying it is just the 1998 and 1999?

Can you give an explaination of what cylinder wash is?

And does depressing the pedal to the floor stop gas flow in all 308's? What else would you need that "no gas" feature for?

Lots of questions - I know!

 

Mostly 98-99.

Owner attempts to start car cold- car automatically enriches the fuel mixture to run rich (in this case TOO rich) and car is shut down shortly thereafter with some unburnt fuel- which finds it's way down the cylinder wall, "washing" the oil down with it. The next time the car is started, it may start fine, or it may be too rich again, washing any remaining oil down the cylinder. Without oil between the cylinder and rings, the compression drops significantly, and the car will not start- usually paired with a faster cranking than normal since the compression is low. When you add the oil, you do not want to introduce fuel again until you are ready to start it, since without spark you would just wash the oil down again.

Once compression is up, the car will start again- but be warned, you should not turn the car off until it is warmed up as a precautionary measure.

Yes, I do believe depressing the pedal to the floor stops the flow of fuel-

I prefer the oil method myself as you can measure compression before trying to start again and make sure that there is enough to start- and add more oil if need be to bring it up. I have not heard of this issue with any other make/model of car- but definitely with the x308.

 

Flooring the pedal on the start up, cuts off fuel to aid in starting the flooded engine. This feature is present on almost all fuel injected cars. Snyder explained the "wash", and why it happens.

So,....remove the plugs, inject the oil in the cylinders, do not reinstall the plugs!!, floor the pedal, and crank for a short time, several times with a little pause (easy on the starter motor). Once the cylinders are recoated with oil, you can measure the compression again if you wish, but to me it's a waste of time. If you put a table spoon of oil in EACH cylinder, coat the walls, reinstall the plugs, and try to start normaly,....and she DOES NOT start, adding more oil will be a waste of time, and it will not help. IF you are faced with the "wash", one table spoon of oil in EACH (some people say just one bank is enough, but I don't like one bank firing, and one running empty, and being washed with fuel AGAIN!) cylinder WILL bring her back to life. Get yourself a syringe, or a dropper, and DO NOT put too much oil in there!

 

tea spoon ,not table spoon of oil. There's a danger of coating the catalysts with oil and wrecking them, remote but possible.

One bank is enough to treat in this way, although just pulling the plugs and leaving it for the gas to evaporate (depends what your ambient is) might work, but while the plugs are out....

 

I stand corrected. "Table" spoon, "tea" spoon,......I didn't use the spoon at all. I injected 15cc from the syringe into each hole. MANY people say "one bank is enough", but I did it all. I had this problem the second day after I bought the car. Too many vehicles, moving them around, to provide space for the VDP. Starting and turning it off. Didn't know anything about the "wash". I sure learned in a hurry, thanks to this forum. It worked like a charm. Some smoke out back, and I let it warm up a little. Took it for a nice long drive, and brought it back fully warmed up. Never had a problem since. Now that I know about this, I drive it a little longer if needed, in order to warm it up completely.

 

OK, so my logic (fuzzy) says that if you floor the pedal, stop the flow of gas and crank the car, the oil pump should allow splatter of the oil along the cylinder walls and re-establish ring seating and the compression goes up. That would avoid the whole adding oil to each cylinder.

Does this not work?????

 

Robert- Correct, that *should* work.

Oil in the Cylinder *does, in fact* work. Every time.

I prefer oil because I can then confirm the compression numbers- and even perform a leakdown test as well if so desired.

Potato potato, to each his own I suppose. There are supporting arguments for both sides. At least with oil you KNOW if the compression has come up- and can eliminate that as a potential issue, then move on to the next troubleshooting step.