Hello all!

I am normally over in the XK8 playground but have recently had the opportunity to join the XJR family. Hoping that you all might be able to help with a cranks / no start situation. Details and ask are below:

1999 XJR 149,000 miles stock as far as can be determined. Complete engine bay and electronics but obvious signs that the car has been overheated (coolant spatter everywhere, replaced upper plastic return line, water jugs in the trunk).

In an effort to diagnose the no start, I have done the following:

• New properly gapped plugs and replaced coils with known good ones from my stash
• purged water / oil from middle cylinders by cranking while plugs were out.
• treated each cylinder with Marvel to try and free rings
• replaced fuel pump relays with known good ones
  • I don't have a fuel pressure rig but am getting spurting fuel from the schrader valve on the fuel rail
• oil change to make sure that water is out of the sump (there definitely was at least a quart..)
• swapped battery with known good and left on charger / tender to make sure voltage is correct
• swapped broken shifter mechanism to confirm that neutral safety switch isn't an issue.
• Did a cold compression test with a new out of box gauge.
  • right bank: 1: 126 2: 145 3: 35 4: 0
  • Left bank: 5: 110 6: 80 7: 30 8: 0
• Locked and unlocked with the key to make sure there isn't a security system issue (getting all doors to lock, unlock and chirps)

She will self check correctly, indicate open door or hood etc, cranks cleanly but will not start or even chug. There does seem to be some raw fuel smell from the bay when it is cranked.

My fear is blown head gaskets, wrapped heads or overheated to the point it's lost timing. I have in the past been able to start a vehicle with damaged gaskets, which will then allow further diagnosis.

Is there something I am missing? I would love to at least get her to run enough to do a warm compression test and see how badly broken it is.

Any help is greatly appreciated!!!

 

0 compression on the last two cylinders doesn’t sound amazing

if you’ve tried the usual bore wash tricks it might be time to pull the valve cover, check for a broken secondary cam chain, misaligned cam flats or anything obvious

 

Two cylinders back to back with no compression makes me think what I am going through now on a vehicle that had overheated the valve seats dropped out of the head and were captured by the valve itself. I knew something was wrong when I stuck a camera down the spark plug hole you could see strike marks on the top of the Pistons if you pull the valve covers off they might stay in a compressed position?

 

Hello everyone:

I recently had an oil change by my friend for 1999 xj8. It gets started and we noticed an oil leak. He didnt install the oil filter properly. He fixed it, top up engine oil, and ignite it but it keep on cranking but not starting.
The obd detects the knock sensor failed on bank 1. Next morning we gave a try and it started. Drove around and turned it off but never started after. Keeps on cranking but not starting up.
now he already erased that code for failed knock sensor, its showing p1000 , i guess thats for not completing the system check.

what should we do now. If i get the knock sensor and still it dosent works. That will cost me 300$ and will not solve the issue.
any inputs or advices are highly appreciated.
thanks

 

Thanks for the replies and the suggestions. After doing the other tasks noted, I did try the bore wash fixes. There was no change in behavior or improvement> I am going to try and do another round of compression testing after I drop a camera down each bore. It could very well be dropped valve seats or other internal damage.

If there is that kind of wreckage she will be probably won't recoverable given the other work she needs.

I will keep you all informed and again, thanks for the assist.

 

 

Extheaterkid,

If you had a least a quart of water in the oil, you don’t need to go any further. At bare minimum you’ll need to send the heads off to a machine shop for inspection to see if they’re still salvageable in terms of warpage of the sealing surface. The valves could be damaged like in the pictures shown above. I believe you’ll be looking at upwards of $1500 for the head work if they can be saved. However, you’ll still need to put a straight edge on the block after you clean up the surfaces to see if it’s within spec and not warped. If you get the heads done and your block checks out ok, it’ll still have a risk of a bad engine due to the water in the oil. You could have a knock after all that work.

Tell me this... do you have an AJ26 or AJ27 engine in that car? I know at some point in 99’ they switched it to a AJ27.

 

all model year 99s are AJ26. OP, the easy way to tell it’s an AJ26 is the throttle body

 

Addicted, the car has an AJ26.

Thanks for the heads up on the oil + water issue. I had suspected that would be a concern and more than likely it was driven that way after it overheated (I don't have any history), therefore wrecking the bottom end.

I did go ahead and pull the plugs again and drop a camera. There was what looked to be a least one bore with a dropped valve seat and water has continued to pool in the cylinders, leading me to strongly suspect blown heads.

I suspect that we have reached what the kids call "a lost cause".

Thanks everyone for the assist.

 

Bottom end will probably be OK. I have a complete pair of 99 XJR heads that just need cleaning, PM if you are interested. Or alternatively I could buy the car from you........