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Lifter Repair 101....
It's beautiful weather outside - and what could be more fun the rebuilding valve lifters?? ;)
As some - if not all, of you recall - I collapsed a valve lifter at a DE last weekend. So - without further delay (as it really takes me a LONG time to work, takes pics - and post - here is "Valve Lifters 101".... So - say you want to replace your lifters? Hear a clack, clack? Well here's what making the noise. In this post you'll see what a collapsed lifter looks like, what an OLD lifter looks like - and what a NEW lifter looks like.. I just got mine (all 12 - for just under $28/ea. from Tim at Mind Over Motorsports (http://www.mindovermotorsports.com/) and knowing that I wanted them this weekend - they came Saturday delivery!!! Anyway - since I'm replacing all 12 - it's probably easier to drop the engine. So... - Step 1 - drop the engine!! ;) http://gallery.rennlist.com/albums/9...2547.sized.jpg - - - - - - - Step 2 - once it's on the floor, take a minute to clean it up. I'm a little neurotic about opening a dirty engine, and starting with 4-5-6 (right) side, spent a little time taking off grit, grime and crap (look at the heat exchanger or lower cover for a comparision). Here is where I started, with the right side engine tin removed: https://rennlist.com/lifter/2s.JPG And after a bit - I got it to the point I felt comfortable taking off the vavle covers without crap falling into the rockers/valves. So, my advice is - take a while to do it right... https://rennlist.com/lifter/4s.JPG - - - - - - - Step 3 - remove the valve covers. Under the PS pump is a pain without the right tools, so here I use a 5mm allen key with a 1/4" socket/extension for leverage. When you unscrew these - use increasing pressure - and they come right out. Try to give one huge TUG - you run the risk of snapping them. https://rennlist.com/lifter/5s.JPG Since that bolt is off center to unscrew, a ball-headed 5mm driver works great! So - now - remove the rest of the cover bolts https://rennlist.com/lifter/6s.JPG - - - - - - - Step 4 - Remove the valve cover. After being on for a long time, some appear to be "welded" into place. Take a rubber mallet - and tap GENTLY on the top right corner of the cover and bottom left. It will move. Next - in the #6 spark plug hole (it's the best for leverage), prise the valve cover off: https://rennlist.com/lifter/7s.JPG https://rennlist.com/lifter/8s.JPG .... (continued next post.....) |
- Step 5 - Remove the rocker shaft. By unscrewing the two bolts - the rocker shaft will come loose. I started with Intake #4, as that lifter had collapsed and the rocker was easily detected as having way to much play...
https://rennlist.com/lifter/9s.JPG Here is a picture of a new lifter - to compare what you will see in the next photos: https://rennlist.com/lifter/1s.JPG Pull the lifter from the end of the rocker. That this one is collapsed - the seal was vaporized and the top protrusion was battered into the lifter body: https://rennlist.com/lifter/11s.JPG And a comparision - old to new lifter. Notice the overall length difference.... https://rennlist.com/lifter/12s.JPG - - - - - - Step 6 - now is a great time to inspect the cam lobes, the rocker pad and the shaft bearing surfaces. Mine are in great shape.. https://rennlist.com/lifter/13s.JPG I thought this was an interesting comparision shot. Top lifter - collapsed. Center - old lifter with a split seal. Bottom - new lifter... https://rennlist.com/lifter/14s.JPG - - - - - - Step 7 - button it back up and torque the rocker shaft bolts to 10ft/lbs https://rennlist.com/lifter/15s.JPG - - - - - - Step 8 - go to the next rocker (and you may want to turn the engine crank a bit if the next rocker is on cam..).. Repeat for all 12...... |
John,
You make it look pretty easy! I would take me a week to do the same :) Rob |
Great thread John!
Thanks for posting the pictures of the good, the bad and the ugly lifters:) Good resource for the future! |
Just curious, how many miles are currently on that engine? Was it abused to have the lifters in that condition, or is that common wear for high mileage?
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You've been a busy guy, John...Nice work. BTW, do 993 lifters just wear out over time, or was it as a result of something else ?
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Hey folks..!
thanks for the comments..!! Just finished up the right upper/lower - and about to finish up the left (which should be easier, as that side lower valve cover I had off a week ago - and it's clean! ;) ) Anyway - Red/Agro1... Great questions! In my case, the engine has 120K miles on it. I don't think it was "abused" by the PO - rather, just "neglected" (which is it's own form of abuse). In other words - it sat for months at a time without even being started/driven. My guess, in this case - it's both the fact that the PO probably neglected oil changes and intermittently drove the car. That - coupled with me stressing it at the track (I think Steve W. and ViberBob are spot on in the other post, about oil changes and oil temps) - that the old lifters just "gave out. It's interesting, in the photo above, that the new lifters have - what would appear - as an improved sealing ring. After pulling the rest of the right side - only #4 intake was collapsed. I suspect, based on what I heard when I drove home after the event - that I'll find the #2 exhaust gone as well.... So - yes and no.. No, I think they are sturdier then what you see in my case, given good mainteniance and normal oil changes - and no - I know it didn't help it when I ran back-to-back at the track... If I didn't run at the track, my guess would be I'd still be running on the old lifters..??? Best to you! John |
John,
I'm sitting here at work......all the SOCAL rumblers have left for the big BBQ.....and I'm thinkin' "John needs some more help" so.......While you have the engine out, you ought to just pop This in. :D :p |
Great post John. Could you tell me in a little more detail how to tell that one has collapsed? I am getting paranoid now!
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Originally posted by Phil McGrath John, I'm sitting here at work......all the SOCAL rumblers have left for the big BBQ.....and I'm thinkin' "John needs some more help" so.......While you have the engine out, you ought to just pop This in. :D :p _________ :roflmao: _____________________ :roflmao: Get behind thee Satan...!!!! You are Always such a BIG help!!!! LOL!!!!!!!!!!! Originally posted by GabiOsz Great post John. Could you tell me in a little more detail how to tell that one has collapsed? I am getting paranoid now! Honestly - you'll know it immediately... Your engine will start "clicking" very loudly.. With a collapsed lifter, my guess is that that are several mm of movement, so when it's "gone" - it will make a distinctive "rapping" sound. Mine collapsed during the last session - and I knew it almost immediately from both the sound and the car felt "different" on power... So - when I pitted - I shut it down, let it cool and re-started at idle. With a lifter gone - like mine - you'll know it when you hear it..?? It sort of sounds like a penny in a tin-can - if you know what I mean??? Best to you!! John |
John,
Great write up! I may never have to do the same job but this type of post inspires me to tackle DIY's in general. I know there is much that can be accomplished with the engine out and I think that the day may come when I will need/want to tackle the job, this will help to that end. Good luck. Jamie |
Great post John, Thanks!
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John, thanks for the great write-up and all the photos, it takes extra time to stop and photograph what you're doing.... very helpful.
I remember when the local dealership had the introduction of the 993 for all of us in the local Porsche club, the car they brought in lost a lifter on the drive down from San Francisco. I watched the technicians do a rapid replacement (lifter flown in overnight) with the car up in the air and just the exhaust valve cover off. I suppose if one were inclined to not remove the engine you probably could replace all of the lifters but you'd have to be a masochist.... Thanks again. Bruce |
Originally posted by CentralCoastC4S John, thanks for the great write-up and all the photos, it takes extra time to stop and photograph what you're doing.... very helpful. ..... I suppose if one were inclined to not remove the engine you probably could replace all of the lifters but you'd have to be a masochist.... Aww - my pleasure... I really enjoy working on these - and yep - you are probably right - I considered doing this while the engine stayed in the car. Honestly, though - I'm glad I pulled it, as it gives me the chance to really go through it - and make some silly "upgrades" ;) On that note - and to my point of pulling it.. When I was doing the left side top earlier today - I noticed some insulation that appeared like a rodent had been working away in years past (it was VERY OLD!). Knowing the PO really didn't care about the car - my "radar" went on "high"... So - when I finished the lifters, had some dinner - I pulled the alternator to peek inside the top of the left bank cooling fins..... Ready????? It's not for the feint of heart....... :grr: https://rennlist.com/lifter/m2s.JPG https://rennlist.com/lifter/m4s.JPG Sooo - I'm pulling the top tomorrow while Alfie does his suspension....... Best to you!! John |
Yikes!! i think we now know where the chestnut stasher lived! :)
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