I bought a cheap non running 1998 XJR with no history. Car is in great condition with 150k miles

To try and get it running I have done the following

1) Fuel pumps – both ok 45psi at fuel rail

2) Spark – yes

Turns over but no sign of ignition

3) Suspected bore washing, added a few squirts of oil to each cylinder. Turned over with accelerator floored for 2 x 20 seconds then attempted to start with accelerator at 50%. Few coughs but will not run

4) Checked compressions – here is where it gets ugly

Front 150 90 110 80

30 40 120 140

5) Boroscoped a few of the bad cylinders. Looks like there may be water droplets on the piston. No signs of water in oil or oil in coolant.

I am suspecting blown head gaskets on both banks. As to why both sides would blow, maybe it was overheated resulting in warped heads etc.

Reading online overheating can lead to nikasil coating damage so maybe that explains some of the low compressions as well. Evidently valve seats may drop.



Looking for recommendations on what to do next:

I am thinking of removing the heads to (1) see if they are warped and (2) examine the state of the bores

If the heads are warped is it ok to use the existing heads after re-surfacing or should source some good used heads. Concern here is that warping may lead to binding shafts.

Is there a way of determining of the nikasil coating is OK or should I plan steel sleaves

Should I replace piston rings? Not sure if they are available

Probably worth checking big end and crankshaft bearings as well



Or should I just look for a replacement engine
Thanks for any help

 

May be easier an more cost-effective to locate and install a used engine.

 

I’d highly suggest that you continue on with the bore wash program. You need a very healthy battery plus another running vehicle (hold at 1500 rpm’s) with jumper cables attached to it to get maximum voltage and amperage to the battery. The faster you can get that starter to turn over, the more heat you can introduce into the cylinders to seat the rings to create more compression the sooner it should be starting up. Patience and persistence is key. Clear out the fuel as it cools the cylinders first, you want heat!

Foot to floor, crank 15 seconds, back off the key and let the starter rest 15 seconds. Do this procedure at least 6 times.

Foot off the gas pedal and crank the engine over. It may pop and fart a few times but continue to crank it. If it sounds like it’s getting ready to start, keep cranking. Until it really sounds like it wants to start.

If/when you do get it running, throttle it hard to get some of that raw fuel out of the cats and clear out the cylinders. Run the engine at least 10 minutes if not more so the engine gets up to operating temperature. Do not turn off the engine in 30 seconds and call it fixed.

 

Thanks for the input, I am away for the weekend and will try the "enhanced bore wash mitigation" you suggest.

 

In worst cases head gasket it easy to do it not that difficult

 

There is the possibility that it did overheated. If it got hot enough the valve seats will drop and cause your low compression.
My suggestion would be to add a little oil to your low compression cylinders and redo your compression test. If it is still low I don't think it would be bore wash.
If and when you take the heads off to check the head gasket you will be able to determine if it is the valve seats. You can have the heads repaired but you would be gambling on if the is any bottom end damage from the overheating. You would need to decide to find a replacement engine or repair this one.
I know about the dropped valve seats. I have 2 XJR engines that have the dropped valve seats from overheating. I haven't repaired them yet. Hopefully sometime in the future.

Best of Luck

 

Tried the suggestions of addicted to boost. Got the car to cough a few times then it dies. Battery was fully charged with a 100. Amp battery support unit connected, engine spun quickly on the starter.

Maybe the rings are stuck so will soak for a few
days in kerosene plus auto transmission fluid. If that does not work then off with the heads!

 

After much encouragement by addictedtoboost (many thanks) I finally got the car started! Took a battery support unit, my wifes car with jumper cables. Ran the starter for a minute plus and finaly got it running on a few cylinders, careful feathering of the throttle allows it to run, clear out the oil and run on all 8. Still a little rough, will check the compressions and see where we are at.

few issues
1) will not run above 3,000 rpm

2) serious transmission leak - dumped a few pints of black fluid on the garage floor! Need a transmission service.

3) Noise from belts - probably idler/tensioner bearing

 

It will not rev above 3000 in neutral/park.

A few pints of fluid? Sounds like more than the usual cable seal.

 

Awesome! Just monitor the coolant temp with a scanner and clear all the codes out. Assuming there wasn’t any previous engine damage (fingers crossed), just let it idle with the heater turned on max heat for awhile. After you get the transmission fluid leak situated and at the correct fluid level, put it in sport mode and blow all the oil and gas out the exhaust hard! It’s probably running rough from all the excessive gas and oil blends you shoved down its throat. The 02 sensors and cats are definitely not happy right now.

 

Making progress here

Compressions are (warm)
Front 125 130 135 135
120 130 120 130

So much improved. Some are still a littlre low, from what I read online they should be ~ 135

Will fix the transmission leak (just got a new gasketm filter and fluid), as Addictedtoboost suggests drive it for ~ 100 miles, recheck compressions and pull any codes and fix whatever shows up

 

The compression numbers look fine. As long as it's 15% (or was it 20%?) within each cylinder, it’s good. I’m sure if you did a proper (hard) drive on it with some fresh 93 octane, it might even improve a little bit. Just monitor the coolant temps and always carry extra coolant just in case.

 

The engine will NOT rev beyond 3,000 RPM in Park/Neutral.(designed that way)

 

Knock sensor

 

Transmission fluid should not be black. If it is leaking from the "window" at the bottom of the bell housing where it joins the engine block, it is more likely to be engine oil. Either from the rear crankshaft seal, or from the block plug above it, or from both.

 

It should be possible to distinguish engine oil from ATF (Automatic transmission fluid) by smelling it.
After fixing pretty much everything on my X-Type, I still got oil dripping (from between engine and transmission). As there is not penetrant smell on that oil, it is engine oil, i.e. as M. suggest above for your issue: rear crankshaft seal is my issue for sure... - maybe yours, too.

 

Yup, I had that exact issue when I had my 02 xj sport. Glad you got it running!

 

Definately transmission fluid - I had just chnaged the engine oil. I have just drained (and torque converter) and refilled the transmission. Some metal chips in the pan - not aq good sign.

Back to the engine
1) Scaning indicates problem with cylinder 1 injector. Resistance open circuit and should be ~15 Ohms. Used injector on order

2) am seeing milky deposits in oil filler cap and the breather tubes on RH bank. Points to a head gasket leak

I ran a block test - blue fluid should turn yellow if there is a head gasket leak. After five mine of testing still blue.

To me this indicates coolant is getting into the oil but combustion gasses are not. Gasket may be leaking beween water and oil ways? Leak may be on cylinder 1 which is not firing at the moment.

I have not driven the car yet - just running in the garage

Any advice on best way to proceed,

 

If coolant is getting into the oil you should see milky oil on the dipstick. Oil pressure is a lot higher than coolant pressure. Deposits on top end may just be condensation from running engine for short periods.

 

Yes, let's see what happens after the number one cylinder is sorted. Then we can make
more comprehensive suggestions based on the way it behaves then. I would not be too
worried about the oil cap condensation just yet. If the dipstick is not showing milky, you
may not have such a terrible problem requiring head gaskets.