eddyvr4
Leaving Skid Marks
whilst its still fresh in my mind ill share some learnings for those interested in doing same.
my car was blowing a bit of blue smoke on start up and sometimes quite badly at idle and so i thought the valve stem seals would probably resolve that. so far it seems they have, seems no smoke at all now although the blue smoke seemed a bit intermittent so im still monitoring. the old seals were very brittle
i bought the tool that allows the valves to be compressed without removing the head and did the job without removing the engine. about $60 ebay
the basic procedure was
remove air inlet pipework and remove intake manifold (completely)
remove tensioner pulleys and both accessory belts and plastic cam pulley covers
remove main drive pulley and bits so you can access the cam belt tensioner
rotate engine so all cam marks are aligned and drive gear marker is vertically aligned to timing mark.
mark the cam belt at all the 5 timing points (i forgot but makes reassembly easier)
remove drop the belt tensioner
remove belt off cams
make a note of all the camshaft retaining caps before removal they are numbered but i drew a picture with the orientation and numbering as it could be easy to confuse them
remove camshaft caps
make a note of inlet and exhaust cams so they go back in the same location
remove all spark plugs so you can easily rotate engine and find TDC on each piston in turn.
plug all oil drain holes in the head with clean rags so you dont drop stuff into the heads/engine
now you can begin the job.
I borrowed a air compressor but didnt use it to hold the valves shut, we just rotated the engine as we did each cylinder, till the piston was at top of its stroke, then the valves hardly dropped at all, and the new stem seal would basically hold the valve 'up' and allow the spring to go back over. i am not sure if the piston was at bottom of its stroke if you would loose the valve completely into the cylinder. (murphys law says it probably would.)
after each piston (ie 4 valve stem seals) we would carefully rotate the crank back to its start position then start again rotating one way or the other to bring the next piston to the top of its stroke. i rotated back to the start position after each piston, in order to keep the crank in the original position at the end of the procedure, (ie not end up one full rotation out)
changing the seals was an absolute pain in the arse, a tedious procedure that required 2 to 3 people, one to hold the lever down on the spring compress tool, another to frig around with a fine pair of needle nose pliers removing or installing the collets which are miniscule. It is a miracle we didnt drop a single collet into the engine bay as we probably never would have found it again. trying to 'centre' as well as compress the spring with the lever, then feed in the first, then the second collet with a 3rd person holding a torch into the area (as you cast a shodow onto the job with any external lighting). Getting the old seals off was a battle each time as we custom made some tools and used a bent screwdriver to try to hook and prise them up/off, every one was a fight as its quite difficult to get in behind them and lever them up. there is a proper pair of removal pliers that would have helped but i didnt have any. we managed, just.
i am so glad i had 3 of us to do that part the job, it would be possible with 2 but because the 'leave the heads on' compressor tool needs you to constantly apply pressure to compress the spring there is no way you can do any work putting the collets in on your own at the same time. also you need to wriggle the tool around as you hold the spring down to get it centred over the valve to fit the collets. With the heads off, you could use a proper spring compressor that holds the spring down on its own, and do it as a one person job.
take caution to replace the exhaust and intake stem seals as they are a different diameter. 12 of each.
assembly was reverse of removal with the following cautions
oil all the rotating surfaces of the cam and caps at reassembly.
redo the timing/tensioner and check as per a timing belt replacemen procedure (final check being to align all marks, rotate engine pulley twice, all marks should align again) refer to other guides how to set up the tensioner etc
I thought the timing belt/water pump replacement job was challenging enough which i did on my own, i felt this job way harder than timing belt, due to how difficult, fiddly and risky it is trying to get those tiny collets in and out without loosing them, or your mind, (or both) in the process... and the timing belt can be done solo, this job cannot, in the way i did it with the engine in the car and the heads on.
getting the cams in and out is very straightforward, (once the belt is off!) but removing and reinstalling the springs and collets with the engine in the car, and with the heads on is a PITA.
the job took me probably 18 - 20 hrs over 3 days, for what thats worth. i only needed help on the actual seal swapping part, where the spring compressor was being used to remove then reinstall the spring and collets.
there IS room to get the compressor tool in over the rear cylinder bank but more brackets have to be removed than just the ones the hold the intake manifold which are difficult to get at the bolts. the turbo etc can stay on though. Its a very long reach though to lean over into the engine for everyone on the rear bank and do their bit
on starting the car after a few seconds i got a horrible metallic shriek - and thought id stuffed up the cam journals, somehow run them dry. the shock of that noise took about 6 months off my life. walked away for coffee in disgust but found on return it was just a loose accessory belt which was so joyous, i tried to cry tears of happiness but it didnt work, so i just rested my forehead on the roof and took in the relief a bit more old school. bolted back on the strut brace to symbolize a successful end to the job.
I feel pretty happy after i got through the job, but not sure id ever take it on again in that way though! I can understand now the comments ive read and heard about mechanics wanting the engine out to do such a job. i empathise with that now.
my car was blowing a bit of blue smoke on start up and sometimes quite badly at idle and so i thought the valve stem seals would probably resolve that. so far it seems they have, seems no smoke at all now although the blue smoke seemed a bit intermittent so im still monitoring. the old seals were very brittle
i bought the tool that allows the valves to be compressed without removing the head and did the job without removing the engine. about $60 ebay
the basic procedure was
remove air inlet pipework and remove intake manifold (completely)
remove tensioner pulleys and both accessory belts and plastic cam pulley covers
remove main drive pulley and bits so you can access the cam belt tensioner
rotate engine so all cam marks are aligned and drive gear marker is vertically aligned to timing mark.
mark the cam belt at all the 5 timing points (i forgot but makes reassembly easier)
remove drop the belt tensioner
remove belt off cams
make a note of all the camshaft retaining caps before removal they are numbered but i drew a picture with the orientation and numbering as it could be easy to confuse them
remove camshaft caps
make a note of inlet and exhaust cams so they go back in the same location
remove all spark plugs so you can easily rotate engine and find TDC on each piston in turn.
plug all oil drain holes in the head with clean rags so you dont drop stuff into the heads/engine
now you can begin the job.
I borrowed a air compressor but didnt use it to hold the valves shut, we just rotated the engine as we did each cylinder, till the piston was at top of its stroke, then the valves hardly dropped at all, and the new stem seal would basically hold the valve 'up' and allow the spring to go back over. i am not sure if the piston was at bottom of its stroke if you would loose the valve completely into the cylinder. (murphys law says it probably would.)
after each piston (ie 4 valve stem seals) we would carefully rotate the crank back to its start position then start again rotating one way or the other to bring the next piston to the top of its stroke. i rotated back to the start position after each piston, in order to keep the crank in the original position at the end of the procedure, (ie not end up one full rotation out)
changing the seals was an absolute pain in the arse, a tedious procedure that required 2 to 3 people, one to hold the lever down on the spring compress tool, another to frig around with a fine pair of needle nose pliers removing or installing the collets which are miniscule. It is a miracle we didnt drop a single collet into the engine bay as we probably never would have found it again. trying to 'centre' as well as compress the spring with the lever, then feed in the first, then the second collet with a 3rd person holding a torch into the area (as you cast a shodow onto the job with any external lighting). Getting the old seals off was a battle each time as we custom made some tools and used a bent screwdriver to try to hook and prise them up/off, every one was a fight as its quite difficult to get in behind them and lever them up. there is a proper pair of removal pliers that would have helped but i didnt have any. we managed, just.
i am so glad i had 3 of us to do that part the job, it would be possible with 2 but because the 'leave the heads on' compressor tool needs you to constantly apply pressure to compress the spring there is no way you can do any work putting the collets in on your own at the same time. also you need to wriggle the tool around as you hold the spring down to get it centred over the valve to fit the collets. With the heads off, you could use a proper spring compressor that holds the spring down on its own, and do it as a one person job.
take caution to replace the exhaust and intake stem seals as they are a different diameter. 12 of each.
assembly was reverse of removal with the following cautions
oil all the rotating surfaces of the cam and caps at reassembly.
redo the timing/tensioner and check as per a timing belt replacemen procedure (final check being to align all marks, rotate engine pulley twice, all marks should align again) refer to other guides how to set up the tensioner etc
I thought the timing belt/water pump replacement job was challenging enough which i did on my own, i felt this job way harder than timing belt, due to how difficult, fiddly and risky it is trying to get those tiny collets in and out without loosing them, or your mind, (or both) in the process... and the timing belt can be done solo, this job cannot, in the way i did it with the engine in the car and the heads on.
getting the cams in and out is very straightforward, (once the belt is off!) but removing and reinstalling the springs and collets with the engine in the car, and with the heads on is a PITA.
the job took me probably 18 - 20 hrs over 3 days, for what thats worth. i only needed help on the actual seal swapping part, where the spring compressor was being used to remove then reinstall the spring and collets.
there IS room to get the compressor tool in over the rear cylinder bank but more brackets have to be removed than just the ones the hold the intake manifold which are difficult to get at the bolts. the turbo etc can stay on though. Its a very long reach though to lean over into the engine for everyone on the rear bank and do their bit
on starting the car after a few seconds i got a horrible metallic shriek - and thought id stuffed up the cam journals, somehow run them dry. the shock of that noise took about 6 months off my life. walked away for coffee in disgust but found on return it was just a loose accessory belt which was so joyous, i tried to cry tears of happiness but it didnt work, so i just rested my forehead on the roof and took in the relief a bit more old school. bolted back on the strut brace to symbolize a successful end to the job.
I feel pretty happy after i got through the job, but not sure id ever take it on again in that way though! I can understand now the comments ive read and heard about mechanics wanting the engine out to do such a job. i empathise with that now.
