[hk968]

Hi Guys,



My 968 just passed the 100,000 mile mark and I am considering having the variocam system inspected during my next shop visit. I have a few questions about this though, maybe you can help:





How many hours would such an inspection take (to be converted into cost at the $100/h shop rate)?



The shop said that the gaskets should be done since the head is already off. Which gaskets are those - head gasket, intake gasket, ... what else?

Should I buy a gasket ser from one of the vendors, or the individual ones?



If the pads and the chain look OK, should I leave them alone or change them anyway? How many hours would that take? Does the camshaft need to come out for that?





Thanks a lot,

hk968

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[mbardeen]

They shouldn't need to take the head off to inspect the variocam assembly, just the cam cover. Inspection is fairly straight forward, just need one of those mechanic's mirror to check the bottom pad.



They probably want to replace all the rubber on the top part of the engine. Cam cover gasket, spark plug hole gaskets, rubber bits under the bolts. This is all quick stuff.



If they bill you for more than two hours, I'd say they're overcharging.

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[flash]

there is no need to remove the head to inspect the variocam. generally people just pull the cam cover and look at the top pad, which only takes about a half hour, and then if they see any signs of wear, knowing that the bottom pad will be twice as worn as the top one, they tear into it if need be. you can try the mirror trick, but you may have to remove the cams though to really see the bottom pad, and at that point you should replace the chain, pads, and belts and such.



still, the head does not need to come off for any of that.



if the head is already off, then inspection is 2 minutes, as the pads would be sitting on the bench.

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[hk968]

Ops, sorry, I didn't mean head, I meant cam cover ....



I will talk to the shop tomorrow, let's see what they come back with ...





Thanks for the anwers so far!

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[durtkillon]

I had mine replaced at 100K, along with a head gasket, timing chain, etc.. Mine started to pit. I was not able to see the pitting before the parts were pulled. From my inspection, all I could see was the tracks that the chain made.



My head gasket on the other hand was trashed at 100K. The gasket was so corroded that there was pitting in the head. The shop had to take 10 thousands off the head to get the pitting out.

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[Cloud9...68]

I can't explain why my variocam pads have held up so well. I replaced them when I bought the car, at about 85K, and the literally looked brand new - not a trace of a nick, groove, pit, or even significant discoloration. When I recently rebuilt the engine, I went ahead and repolaced the pads (and chain) again, but again, there was ZERO hint of wear on the pads - they look like they can go 200K miles (not that I would want to try...). They're just plastic, but they seem to be indestructable in my engine. Again, no idea why...

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[flash]

good synthetic oil?

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[Cloud9...68]

I think the oil is indeed the major factor. Synthetic wasn't around when these cars were new, so I know it ran at least half of its life on dino oil, but checking through the maintenance history when I bought the car, I found it got an oil change an average of every 2500 miles! The <acronym title='previous owner'>PO</acronym> used Mobil 1, and of course I've always used synthetic, mostly Redline, but I've switched around over the years. Always changed it it sensible intervals (about every 5K - probably overkill, but the car did see a fair bit of track use).

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[Langley968]

I wonder if Vario-Cam pads in an engine that has NOT been "pushed" (red-lined / raced) often, would show WAY less wear than one that has. I think that the higher temps associated with "pushing" an engine would be the biggest "enemy" of the (plastic) pads. Last year when I has a new cam cover gasket installed, the top pad was "like new" (at ~ 92,000 miles). I still want to replace them this coming winter because the material they are made of will not hold up with age...

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[kwikt]

    How about these? It was 115,000 miles when changed. I'd say a LITTLE worn and very brittle.

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[Cloud9...68]

[quote name='kwikt' timestamp='1346804271' post='132151']

How about these? It was 115,000 miles when changed. I'd say a LITTLE worn and very brittle.

[/quote]



Come on, those'll buff right out <img src="/forum/images/smilies/968/biggrin.png" class="smilie" alt="" />



Seriously, Holy Crap! <img src="/forum/images/smilies/968/ohmy.png" class="smilie" alt="" />



And to Langley's point about "pushing" an engine: Mine has been fairly heavily tracked (DEs only - no door-to-door racing) for much of its life, and the pads have always held up like they were made of hardened steel.

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[kwikt]

I like my chain ramps extra crispy. I really think i dodged a bullet on this one. Right now I'm pushing 160,000 miles and purring like a kitten or maybe grouling like a grizzly.

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[RS Barn]

After taking apart 60-100 968's (maybe more) I was perplexed at completely different wear rates on cam pads and sprockets. My conclusion was cars that were not driven at road speed but spent alot of time in stop and go and traffic wore out much quicker.

Most of the cabs I looked at had heavy oil staining in the valve area. I think stop and go caused high oil temps and premature wear.



Disclamer: I didn't mean to pick on current cab owners but the first generationbs of owners. They didn't buy cabs with tiptronic to go fast, but to look good around town.

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[Cloud9...68]

[quote name='RS Barn' timestamp='1346872971' post='132184']

After taking apart 60-100 968's (maybe more) I was perplexed at completely different wear rates on cam pads and sprockets. My conclusion was cars that were not driven at road speed but spent alot of time in stop and go and traffic wore out much quicker.

Most of the cabs I looked at had heavy oil staining in the valve area. I think stop and go caused high oil temps and premature wear.



Disclamer: I didn't mean to pick on current cab owners but the first generationbs of owners. They didn't buy cabs with tiptronic to go fast, but to look good around town.

[/quote]

Interesting observation - I guess taking apart a few dozen 968 motors provides insights not readily apparent to the rest of us...

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[flash]

like every other kind of component wear, heat and friction are very likely the demons here. in lower rpm use, the oil sprayed around in there would be less, gravity would tend to pull it away, and you would have increased friction and therefore wear. while higher rpm use would normally add damaging friction, the increased oiling that accompanies it likely mitigates that.

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[RS Barn]

For the cold weather states think of a Radio Flyer sled. When you first sit on sled and try to move there is alot of friction/stiction. Once you get going those two thin rails glide over the snow and don't seem to notice the drag.

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[hk968]

Hi all,



And thanks a lot for all your feedback. I am in contact with pretty much the only shop in the area which can do the work. But they do it so rarely that they need to look into it before they can tell me how many hours it will take. If the difference is reasonable, I am inclined to have the chain and the pads changed - better safe than sorry. But as I said, I don't have the numbers yet ...

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[hk968]

Just to wrap this up:



I finally got the estimate from the shop. The inspection alone will be 1h work time and they will install a new valve gasket. Changing the pads and chain would be 8-9hs. I ordered all the parts necessary for a full change, but I will hold off with that and see what the inspection brings. If everything looks OK, I will at least wait until next spring to do the exchange - especially since the shop is willing to credit me the 1h of work for the inspection if I go for he full service next year.



Now I just hope that things look OK, and that there are no teeth missing on the shafts itself....





Thanks agian for all your advice, I really appreciate this forum, how much information can be found here and how helpful everyone is!

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[gbarrier]

Cam teeth also seem to be a hit and miss thing. When I bought my first 968, it was a tip with 100K on it and there were teeth missing. The second one with about 125K had very good teeth on the cams.

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