It is possible to replace broken valve springs and defective Valve Stem Oil Seals without removing the cylinder head. In most cases, this operation requires two special tools and a compressed air source. In the absence of compressed air, however, a length of nylon rope can be used to keep the valves from dropping into the cylinder during this procedure. To get started take out the spark plug in that particular cylinder and also ignition coil assembly. Following that, remove cams (if applicable), lifters as well as housings. Then turn the crankshaft until it positions a piston at top dead center on the compression stroke in that affected cylinder. Screw an adaptor into hole for sparkplug and connect an air hose for compressed air supply to it. Feed some compressed air into cylinder to hold valves in place. Or if there is no compressed air take another step by keeping a piston about 45 degrees before TDC on its compression stroke and pass through a long piece of nylon rope via spark plug hole. Now rotate crankshaft in normal rotation direction until it feels slight resistance against it. Put clean rags around holes next to valves so they won't tumble away with pieces or tools down into your engine block. Use valve spring compressor tool to press down on spring and release keepers; remove them first then retainer next spring followed by guide seal rotator The condition of the stem must be checked out for any damage or eccentric movement for checking bind while moving valve up and down vertically within guide Reintroduce air pressure or turn crankshaft round until valve stays closed Repositioning of the valve rotator consequently needs lubrication on stem once more while inserting new guide seal Dust off accumulated debris from guides; finally install new seal then put back retainer, spring together with keepers Detach the hosepipe or pull out rope eventually Replace cam(s), lifters along with housing(s) afterwards start driving your car listening for any unusual sound which may come about and look for oil seeping.
