After Sitting for Years, do ALL 12 Cylinders Have Compression? - - Restoring an Early XJ-S ep.7

[@LivingWithAClassic]

I tried out a new microphone with the big camera for this video. Not 100% happy with the sound but I hope it’s alright.

[@jamieduff1981]

I thought it was alright to be honest.

[@mikedx2706]

A trick I have learned to remove deep set spark plugs is to loosen them with a spark plug wrench, but not completely. Instead use a length of 1/2” or 13mm inside diameter heater hose pressed over the plug . The hose will grip the plug and allow you to screw it out the last few turns and then pull it out of the cylinder head without dropping it down into the underworld.

[@mikedx2706]

The low compression on Bank B is probably due to rings not sealing very well from sitting a long time, as shown by the increase in compression when you retested them when “wet.”. To confirm that you are losing compression past the rings on those 2 cylinders, a leak down test would allow you to pin it down with certainty, as you stated. For years I only did compression tests, then I bought a leak down tester, and swear by it as a much better diagnostic tool for the home mechanic. I love your videos and they are always getting better. Keep up the good work!

[@hanoiboy9839]

I admire your drive and courage in these cold conditions there. Good video ! Thanks for sharing Adam.

[@russellfurzer6911]

I really enjoyed that. I have an xj12 project with a couple of low cyls and was dismayed. Looking forward to how yours turns out

[@streetkaaccord344]

The V12 engine always reminds me of the Borg spaceship in Star Trek Next Generation 😂

[@jaguarrroman]

I enjoyed this video! Good luck to all Jag lovers watching it!

[@springy-2112]

Valve clearances would be prudent anyway . I'm sure the compressions will come up with running . As you've said valves could be not quite seating perfectly and the rings might need a few heat cycles to fully start working . Ok know one thing , it's in very capable hands . Peace and love brother 👍🏻☮♥️

[@stephanusjohanneshough2646]

Good day Adam and thanks oncd again for sharing it with us.May it really be something that just need to work a little to get loose.Hopefully those two low compression readings is only because it was sitting for so long.Best of luck with it and a blessed day for you.

[@LivingWithAClassic]

Thank you! I hope so too

[@jeffharrison5265]

I think it just needs an Italian tune-up.

[@LivingWithAClassic]

I think so too! Will be great fun 😃

[@donnysweekendvanlifetravel7854]

Great video Adam good investigation into the engine 👏 I think it will pick up fine it's sat along time great update look forward to the next vid all the best donny

[@johndavey72]

Hi Adam. It could be a lot worse and l'm sure it will turn out fine . Thanks Adam.

[@Thanos.m]

I wouldn't worry too much over these 2 cylinders I think after you get some heat cycles they will come back to life

[@weofnjieofing]

I think a borescope of the two offending cylinders should reveal something esp, if you your scope is able to look at the cylinder head. Also adjusting valve clearances will help. Could possibly be excessive head corrosion from sitting around. If there is leakage between the cylinders you should be able to pick that up by screwing in the spark plug of the adjoining cylinder (and vice versa) and redoing the compression test. For the first drive i think a 5W30 oil to wash the engine and free up everything before say a 10W40 for everyday use. I think a 20W50 would be too thick for that engine especially the cold climate in Sweden. Hopefully its something more simple and we can get her purring on all 12 with minimal fuss!

[@RickCT2000]

Great investigation. Love the way you chase down leads on what's going on in the pre-HE engine. Sounds like a lot to look into for those two cylinders. What's the worst case scenario cost wise?

[@LivingWithAClassic]

I do think that they will go up in compression after some use. Otherwise it would possibly be off with one cylinder head. A leak down test could help me see if it’s valves of piston rings

[@RickCT2000]

@@LivingWithAClassic 🤞

[@SparkyGage]

My wife likes your glass block windows in the shop. I hope the compression returns. The saddest part of this video for me was "11 to 1 for the European spec engine and sadly 7.5 to 1 for the US spec". :(

[@BKNORWOOD24]

Adam, found this series tonight, and watched them all. Brief background: I have a ‘91 XJS that i bought & drove for a year before it overheated - badly. I have obtained a ‘91 V12 engine that experienced a minor engine fire (just hose & wiring damage - didn’t even bake the hood!!) Q1: I’m wondering if I can do compression testing while the engine is out? I’ve borescoped the cylinders and they look good. Q2: I’m *VERY* interested in the Simply Performance Tremec TKX conversion, but they don’t list it on their website. Are they still planning to put this out? I REALLY enjoy your channel - it is my first “go to” in researching problems & procedures! (I also have the maintenance manual and Kirby Palm’s book). Thanks!!

[@grayfool]

Not too bad really considering how long it's been sitting around. That's a lot of holes to test though.

[@alexandrecouture2462]

Not too bad. Maybe sticky valves?

[@annahopp]

Would a leak down test help?

[@davidsolloway9349]

Will keep my fingers crossed that it is a simply valves sticking or out of adjustment.

[@LivingWithAClassic]

I really hope it’s just some light corrosion on a valve or sticking rings. May soak the rings in those two cylinders for a few weeks