Hi Guys
I'm in the process of rebuilding my 996 3.4 at 82k and I'm just cleaning up the cam assemblies, check out the wear on the plastic vario chain pads, if you have similar mileage, might be time to get that top end refreshed

Sorry, another thing to worry about!!

Thanks Lee

 

Hmm, based on those pics at only 82k, do you know the full history of the motor?(oil contamination, OCI,type of oil, track abused, etc)

And what led you to rebuild it?

 

I bought the motor from a breaker as my original motor had a major failure so no history, decided to refresh it whilst it's out partly because of the history, had it bore scoped and leak down tested when I bought it, luckily everything looks ok as I have it fully stripped doing replacement on all bearings , gaskets, chains , rings etc, having cylinders re rounded and strengthened, new ims, new water pump and aos, these vario pads do get quite bad!

 

This hasn't been my experience unless oil type and change intervals have been neglected. My guides at 115k looks way better than yours that you posted as an example

 

Your probably right, I think maybe long intervals between oil changes.
Luckily no damage has been done to important parts and I now have the chance to change all worn stuff
Main and big end bearing coming out are strangely very good in comparison to the pads??

 

Your probably right, I think maybe long intervals between oil changes.
Luckily no damage has been done to important parts and I now have the chance to change all worn stuff
Main and big end bearing coming out are strangely very good in comparison to the pads??

 

Your experience has been my experience, too. The pads on the VarioCam actuator that came out of my 02 Boxster with over 200K miles on them didn't look very bad at all. The tech was so unconcerned about the condition of the pads he advised me no need to pull the other camshaft cover and replace the actuator as a preventative action.

 

Wow sounds like you have done really well there!!
I wonder why mine are so bad? Maybe Porsche adjusted the material on later engines as this is a 99 engine? I don't have history on the engine but everything else looks good , mains , big end etc
and the oil I drained out looked reasonable, the engine was clean inside, no debris, sludge etc
It doesn't look like a neglected engine.
So glad I stripped it now, who knows how much longer they would have gone before breaking up??
I suppose when metal chains push agains plastic , eventually the metal will win?? Especially the vario pads, the actuator pushes them hard against the cam chains to alter the cam timing when the solenoid is activated, there must be quite a force to deal with aswell as the chains moving at high speed , even with oil lubing the situation , I can understand it in a way!

Maybe the oil is the key, can you tell me which oils you rate guys?? I was thinking of using the dt40 jake raby recommends??

Thanks!

 

The chains ride against the plastic all the time. If there was any real wear the guides would not last a day.


Ignoring just a bad pad my WAG is what shortens the life is lack of use.


The oil drains away over time, then the engine is started and until the oil pressure builds in the tensioners, which happens pretty quick, the chains slap against the pad. This brief but repeated slapping starts to tear up the pad and it can go downhill pretty quick then.


IOWs, the pads can take the rubbing (sliding on a film of oil) but they can't take the slapping, the impact of the chain from uncontrolled chain slop.


I have run almost exclusively Mobil 1 0w-40 oil my Boxster (now with 282K miles on its original engine and one actuator guide and all the other chain guides), though recently I switched over to Mobil 1 5w-50 (not a typo for 15w-50!). Since it doesn't get that cold where I live and drive but it gets plenty hot (facing another 100F+ high today where I live) I just decided to run 5w-50 year 'round. The next time the Turbo goes in for an oil/filter service I'll have the service department use Mobil 1 5w-50 oil in it too.


I change the oil every 5K miles and use the car quite a lot and regularly. Neither car sits more than a few days unused except in very rare and special occasions like I'm away in one car on vacation or business, or out of the country on business, or the car is in the shop for an extended time. (The Boxster was out of action around 30 days a while back getting repaired from a minor traffic accident.)

 

Old thread, but I'm hoping to still get experienced replies.

I just had my vario cam tensioner replaced on bank 1 after a CEL came on. The car was running fine and I brought it in right away to a very well respected indy shop whose lead mechanic was the #1 rated Porsche tech years ago. Anyway, I just got the car back and it's running great. Quieter than ever (and it wasn't loud before, just normal startup chain sounds). The mechanic suggested doing both sides as preventive work, but at about $3,500 per side, that's a lot of coin, so I did the one side.

My question is: for anyone who replaced one side, did the other go bad soon after? long time later? never?

The top chain paid was very well worn, especially for a 39k mile car. I've only had the car for 2 years and 3k miles. I change the oil regularly and have UOA done every time. Nothing bad shows in the oil reports.

Should I worry about the other side? Do it preventatively? Or just keep an ear on it and continue doing oil analysis and frequent changes and maintenance?

The car has had all suggested maintenance done, from IMS to AOS to water pump. So it should be good to go without turning in to an expensive paper weight at any moment! lol

 

The other side won't be far behind unfortunately the plastic on the original pads goes brittle then chips away in little pieces, the newer ones are a revised nylon type material which wear more evenly , that said 3.5k per side, wow I think they having your pants down there !! It's only a valve cover off job not even the head , it can be done in a few hours !!

 

I assume they're dropping the engine for this job at that price? That a lot of money to install such a cheap part(s). I'd get another estimate if it were me. And yes, you'd want to change the both banks. Remember, it's always more expensive to do it right the second time!

 

On the `99 it's not just a valve cover, the cover holds the cams in place. So you need to lock down the cams, lock in the timing, then remove the cams to replace the tensioner assembly (which is $1,300 alone) and then put it all back together. I trust the shop owner - he's a friend and our kids play together. If he said it took them 14 hours (which includes lowering the engine, removing the bumper and muffler) then I believe it. He said the `99 is the worst. The rest of the years, it's just a cam cover, as you said.

The cost to do the other side at the same time was a lot more as they would drop the entire engine. Doing it this way they just lowered it. So I felt it was still going to be thousands more to do both sides, so I just did the one side. In looking at the chain pads, they're not horrendous. And the chain tensioner not failed, i'm sure this would not have been an issue.

 

Yes, I know all about 5-chain cam installation and timing. A lot different than the 3-chain engines. You have to lock cams and put the engine in TDC on both configurations as well as securing the cams. There are a lot more Porsche special tools involved with the 5-Chain too.

Is he charging you $3500 for the other bank too?

 

Sorry misread your post. Got too many thing going on at the moment.

My personal opinion is you'll have the same wear on Bank 2 of the engine that you experience on Bank 1.