Jaguar AJ6 3.6 Engine Resurrection

Jaguar XJS 3.6 AJ6 Engine Resurrection

Jaguar AJ6 3.6 Cam shaft after 18months in the dry storage. Look closer on two sections of rust. These are going to trash your engine right after some "skilled" "respected" "experienced" workshop wanker will engage starter motor.
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This guide is especially recommended for each car classified as “barn find”, projects taking a nap longer than 10 years or amputations from breakers. Applicable to all Jaguars with AJ6 3.6 / AJ16 4.0 engine, all other cars and brands as well.

THIS GUIDE SHOWS HOW IT SHOULD BE DONE. Jaguar AJ6 is bulletproof enough to survive the instant cranking after 30 years of sleep, HOWEVER you will probably cut 100.000 miles from the engine lifespan in seconds. The choice is yours.
If you're buing barn XJS from trader "who managed to start it up already after sooo many years!" - ask fro a 50% price discount straight away, your almost-owned XJS is probably utchered already. My XJS purchase was a pure gamble, no risk, no fun* (this rule is applicable to AJ6 3.6 / AJ16 4.0 engines ONLY. What? what about V12 owners? I don't know. You're the 5.3 lover. Maybe build yourself a V12 TV stand or try to enter the missing vowel: W_NKER )

BEFORE YOU START

Order JumpStart spray on Amazon or eBay -big one or three smaller. Order cheapest semi or fully synthetic 10w40 engine oil and filter. Order 5L of coolant concentrate - ONLY G05 grade (ethylene glycol) no other rubbish, no subsititutes no "great products" recommended by George in EuroCarParts. Order Gasket making silicone and kneadable epoxy putty f.eg. "quicksteel". I assume that you have consummables like spark plugs, belts and filters under your bed. DO NOT skip pt. 29 as this is where the true fun starts.

1.Meet Bulletproof AJ6 3.6 Engine from Jaguar. this is best-case scenario, stored 15 years in the barn with 50% of the coolant still in the system. Don't expect it to look like mine. FIRST THINGs - drain the old coolant if any. Drain the fuel if any in the tank, get a reasonable battery under the charger - can be way oversized but working (no smaller than recommended)
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2. Start from removing Air Filter Housing. I can ben that you'll find some vermin's leftovers inside. Housing will make some space and won't be needed until road test.
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2A. Just letting you know if you don't know already. This big cylindrical thing with silver label - that's Jaguar's AJ6 3.6 Air Filter Housing (see pt. 2) If you're finding this photo helpful - you shouldn't be here, seriously.
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3. Throttle Body. Spray with WD40 everywhere. grab the top and try to move it gently. If stuck - see the next point.
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4. If your throttle body is moving freely - skip this point (and return later on when you'll get main shaft seals). If not disassemble, clean and assemble to manifold with layer of RTV silicone regardless of the gasket condition (you will get one leak point excluded for later research)
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5. Water Pump. Easy with this one. Loosen the belt -if present- and take it off. Cut the belt if you have new one – don’t waste time, you will have 3 days to play with it. Use alternator's tension adjuster, remember – you need to loosen MAIN alternator's bolt and all the bolts from adjuster. DON'T TOUCH/SPIN the water pump pulley. Just don't.
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6. Thermostat housing. Spray the bolts and mating surfaces with Liquid Wrench (recommended) What is it? Check the XJS ToolBox section. And don't give me your crap about WD40 being OK. You will have serious problem with one of two bolts here. Play with it, don’t snap it. Remove housing. Remove thermostat. Look inside - You will see white Hedgehog inside, nice isn't it? That's your Cylinder Head Killer – aluminium oxide. Attach a garden hose to the lower hose of radiator's expansion tank. Fire it up with as much pressure as it's possible. Let it drain through the thermostat housing. Close the housing without thermostat, with use of old seal or RTV.
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7. AJ6 Engine's Rocker Cover. When I migrated to UK I was truly believing that everyone is washing their hands after piss or droppings release. Soon I realised that UK's meaning of word "CLEAN" is completely different than European. Returning to the subject - CLEAN whole upper part of the engine, all around the rocker cover, everywhere. NO, not in the way like you wash your hands, not in the way you were cheating your mother - by opening a tap and dipping your fingers. Do it correctly. Any dust, grime, alloy oxide, chipping paint. Everything. Use degreaser, power washer, your sister, anything you want. Miss it - you will hear the grinding noise for the next 20k miles. (assuming that you'll be successful with start-up). Dry the cover and remove the HT leads, blow the spark plug channels with compressed air (sure, you have no compressor... so buy yourself a duster spray for £5 for God's sake). Pour down some WD40 into each bore.
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8. Ignition coil. Unplug HT lead, clean it/spray it with contact cleaner or UK-beloved WD40. Do it for all terminals.
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9. Jaguar AJ6 3.6 Ignition Amplifier. Before you start - these engines ARE state of art. Were way ahead of it's creation time. Cannot be compared with V12 which was exactly opposite. Same as the fans of V12 rumble. Ignition amplifier is placed on the plate called heat sink. This one is made from BERYLLIUM alloy - currently used in high end electronics. Apart from being extremely efficient - it is also extremely deadly when inhaled. Now go to your boyfriend and borrow some nail lacquer and apply it on every damaged/oxidised surface of the heat sink. Now pull out the long flat plug and clean it with something (I know, you've got only WD40 right?). Plug it back.
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10. After making sure that top of the engine is completely clean and dry, free from debris - unbolt the top cover with use of large Phillips screwdriver or Phillips socket (bolts on top of the cover will show you the way). There you go, your twin cam AJ6 3.6 exposed. Don't expect it to look like on the photo. You will see the rust, butter-like goo, probably seized components. Now it is your Glory Hour -sssprayyyy! Everything, any gap, bearing, seat, spring, timing chain link you are able to reach - with one and only true WD40. Do yourself a lunch break until fumes will finally vent out. Then come back, grab a syringe and flush everything with engine oil - preferably fully synthetic 5WXX or 0WXX (cheapest possible). Flush down the timing chain(s) use as much as you want, but bear in mind it will overflow on the off side of the engine (translation for non-UK visitors - offside: where the exhaust shield is located). pour the oil down through the timing chain channel 2 litres should be enough to make it much over the dipstick max level (assuming that there was century old oil inside to start with). If not - top it up. Cheapest fully synthetic will be the best.
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11. Not it's time to remove spark plugs. Try it gently. really gently if seized - use Liquid Wrench penetrant (again, WD40 next to it looks like a rubbish - see XJS ToolBox section). After removal of the spark plugs (hopefully in one piece) spray some WD40 into each cylinder. Wait 10 minutes and pour down 20-30ml of fully synthetic engine oil into each cylinder with use of syringe. Leave it for now and return to CAM SHAFTS. With use of scraper, file (NOT wire brush) remove any excessive rust from the CAMS. polish the contact surfaces with 3000k sandpaper (see photo from the beginning of this article for refernce).
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12. This is distributor cap (again, if you don't know that I guarantee you will hurt yourself shortly). Remove and clean contact points from white oxide (if you're on budget repair and don't have new one yet). Biggest problem for everyone - how to connect HT leads back in the right sequence. You can note it prior to disassembly. You will also find the guide in separate gallery (that's how difficult that seems to be...)
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13. Lucky number 13. Often forgotten and usually snapped-off during the resurrection ops - Distributor. Remove the arm (I-shaped thingy from the top also known as a finger in EU). Seal off the vent pin hole if you have one (visible from inside). Now again, Glory Minutes - spray WD40 until it will overflow. Then pour down the same fully synthetic oil until it will start to look like a pond in Dartford industrial area. Cover with the Cap and leave it for now.
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14. Time to get sweat. Make sure that the spark plugs are removed/not present in the cylinder head. Jump under the car, with use of 3/8 breaker bar and suitable socket (match the size yourself, each VIN has a different one) try to spin the flywheel each way few degrees gently. If it doesn’t move - check if your car is manual and left on the gear... Change breaker bar to ratchet. Spin the engine counter-clockwise. As long as you can, until your forearm will look like you've overdosed with wanking.
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15. Reinstall the battery.
16. Find the inertia switch and lift the round pin up until you will see the orange shank (you've just disconnected fuel pump)
17. Pour down the oil on the cam shafts one more time and reinstall the cover. DO NOT reinstall the spark plugs.
18 TURN ON IGNITION KEY AND CRANK THE ENGINE for 2 seconds, then 3 seconds, then 5 seconds, then 10 seconds. then wait 5 minutes and spin again for 10seconds. Repeat until your battery dies. You should hear the engine spinning up faster and faster.
19. Recharge battery
20. Fill up the tank with fresh petrol. 20litres should be enough. IF YOUR CAR HAS NO CATALYTIC CONVERTER - mix fuel with 2-stroke engine synthetic oil. Doing so with CAT-equipped car will send the eco-friendly-magic-can straight to hell.
21. Fill the coolant system with distilled (exactly distilled - NOT tap) water and any radiator flush product safe to use on aluminium. Now try to test water pump condition by pulley spin if it’s spinning roughly or with grinding noise – you’ve got additional £119 project to complete. Spin until moving freely.
22. I bet you forgot about inertia switch that must be pushed down.
23. Check if auto transmission is on Parked.
24. Reinstall the drive belt.
25. Reinstall the spark plugs, HT leads and distributor cap.
26. Drain excess of engine oil to make it read correct level on the dipstick. Check if oil is present in automatic transmission (should be way above max level on dipstick.
27. Ask your boyfriend to assist with JumpStart application. Do not engage starter motor yet. Turn off and on ignition 10 times with few seconds lag (you need to pump goo-fuel out from the fuel rail), then fire it up and start spraying, push the acceleration pedal half way down.
28. When you hear the engine whining sound and revving up - release the acceleration pedal immediately, but not entirely. let it run for no more than a 2-3 minutes. Shut it down. wait 5 minutes - you want to avoid damage/heat build-up on jamming components and cylinder head. Start the engine, this time without JumpStart spray (if not working - spray again). Repeat cycle 5 times then change the engine oil and filter while still warm - use cheapest semi-synthetic 10w40. Top up to max level on dipstick.
29. Now it's time to get the white oxy hedgehog out of your cylinder head. Hedgehog may be huge, huge enough to block coolant channels causing severe overheat of cylinder head and later on - your own. The chances are really low if your XJS was found with coolant in expansion tank. If your "barn find" XJS was found with coolant in the expansion tank - the chance that it was parked there yesterday is almost guaranteed (loser).
30. With your "radiator flush" and deionised water in the cooling system, with the new engine oil and all consumables including air filter and HT leads installed. With the grim reaper’s breath on your neck and without thermostat in the thermostat housing – start it up and… LISTEN. Don’t look at the gauges, just listen, cylinder top of the engine will give rattle when overheating. Check the temperature with your palm across the rocker cover, pump the radiator’s top hose by squeezing it. Any hot spot or rattle from the cam shafts – shut it down immediately. Run the engine with 5 minutes on / 5 minutes off intervals – for the next hour. If ok – increase the running time. Check the automatic transmission’s dipstick on hot running engine (level should be somewhere between cold and hot marks) – don’t engage the drive gear yet. Run it until the evening, top up with fresh fuel and leave it overnight. Drain the coolant system next day, reinstall new thermostat and refill with G05 concentrate + deionised water. You’re all done with the engine now. Well done, champ. Now you are ready to resurrect your gearbox…