Chain Tensioner Replacement Clarification - 986 Forum - The Community for Porsche Boxster & Cayman Owners

cornontherob · 02-28-2016, 06:05 AM

Hi all,
So I just bought another boxster and I was wondering exactly how replacing the timing chain tensioners is done. So I read the Pelican Parts article and they basically said that if there's a chatter at startup, that it might be the chain tensioners. The boxster I just bought makes a noise for less than half a second when I cold start it, and I'm not entirely sure what it is. I'll try to get a video and maybe someone here can help me identify it.

In any case, I should replace the timing tensioners just for peace of mind, right? So the pelicanparts article shows removal of the heads for this procedure, while others are saying it's much more simple. What I've gathered from reading around is that to replace them you have to:

Lock the crank at TDC
Poke out the little green cam seals
Lock the cams
Remove and replace each tensioner

I'm asking because it seems suspiciously simple and I don't want to go about wrecking the timing in my new (to me) car. Should I let the stealership deal with it for me? Or is it doable enough?

JFP in PA · 02-28-2016, 06:11 AM

While your procedure is basically correct as far as it goes, I would add checking the cam deviation values before and after to make sure everything is alright. Do the tensioners one at a time, observing that they are not all the same, and be sure to use new crush washers.

cornontherob · 02-28-2016, 06:13 AM

Okay thank you. Here I sold my durametric when I sold my last boxster, telling myself I wasn't going to buy another boxster. Looks like it's time to go durametric hunting again.

banzia · 02-28-2016, 08:42 AM

Hi
In theory it is simple but I recently had a problem while replacing the bank 1 timing chain tensioner from underneath the block... I accidently knocked one of the caps inside the engine and was luck to get it out without having to take engine out

take a look at my post

james
glasgow

jcslocum · 02-28-2016, 12:02 PM

Mine did this also and when I did the IMS bearing I pulled them out and found 1 kinda stuck. I replaced it and the new one was MUCH stronger. As you can see in this pic, the old on on the left goes in much further than the 1 new one on the right with the exact same weight applied.

I don't think you need to do the full lockup things just to replace the tensioner part that I did. Replacing this eliminated the start up chatter.

JFP in PA · 02-28-2016, 01:40 PM

Quote:

Originally Posted by jcslocum

I don't think you need to do the full lockup things just to replace the tensioner part that I did. Replacing this eliminated the start up chatter.

You do so at your own risk.

cornontherob · 02-29-2016, 05:46 PM

I'm definitely going to lock the engine down for my own sanity. Pelican Parts lists 3 tensioners that are available. Do I use these? Are they stock? And does an upgrade version exist as well?

GaryMulcahey · 03-03-2016, 04:24 AM

I am also interested in some of the answers to your questions. Anybody?

flaps10 · 03-03-2016, 08:35 AM

Your procedure is basically correct. I like to remind everyone that there are two TDC positions, each one representing a position for one cylinder head to not be compressing valve springs.

To get the cam plugs I use a sharpened hook to pierce the middle and pull them out, which I'm pretty sure is the exact technique shown in the Pelican Tech article. You need to examine the off center notch in the end of the bottom cam shaft and align it with the machined edge of the cylinder head to see which of the two TDC positions you are locked at.

JFP is correct, to not lock down everything you can is asking for trouble. You've pulled the plugs anyway, it's not a lot of work.

The newer style are supposed to be much better at reducing chain rattle at engine start. That list of three is the entire set. You need one of each if you're doing them all.

I'm curious, how are you going to adjust them to the correct tension? I'm up against this job pretty soon and just want to know what others are doing to set them up.

cornontherob · 03-03-2016, 08:46 AM

I wasn't aware that tension had to be set, thanks! I'll look into it

cornontherob · 03-18-2016, 12:58 PM

Re-opening thread. Got my durametric in the mail today, showing a camshaft deviation of -9° on bank one, and -12° on bank two. Looks like it's chain tensioner time. I have a 1997, so iirc there's no variocam. Do I just replace the oversized Bolt looking tensioners and reset time? Or do I need to rip the head apart and replace the ramps as well?

JFP in PA · 03-18-2016, 01:47 PM

I seriously doubt that changing the hydraulic tensioners is going to solve your problem.

First of all, was the car fully warmed up, as in driven at speed for at least 20 min. before taking the cam deviation values? If not, drive the car and recheck; these values can be all over the place on a cold or partially warmed engine.

A more likely candidate for excessive cam deviations on an early five chain engine would be the small wear paddles located in between the cams; these are a common weakness on the five chains.

jdraupp · 03-18-2016, 02:19 PM

Quote:

Originally Posted by cornontherob

Re-opening thread. Got my durametric in the mail today, showing a camshaft deviation of -9° on bank one, and -12° on bank two. Looks like it's chain tensioner time. I have a 1997, so iirc there's no variocam. Do I just replace the oversized Bolt looking tensioners and reset time? Or do I need to rip the head apart and replace the ramps as well?

Furthering what JFP has said do you have a check engine light with a corresponding code? When you get beyond 6, I believe it's supposed to trigger a code.

JFP in PA · 03-18-2016, 02:38 PM

Quote:

Originally Posted by jdraupp

Furthering what JFP has said do you have a check engine light with a corresponding code? When you get beyond 6, I believe it's supposed to trigger a code.

The actual trigger value is over 12 degrees for a sustained period. Most people that find out they are over 6 but under 12 usually only do so because they looked as the car had not thrown any codes.

cornontherob · 03-18-2016, 02:39 PM

No codes have been triggered. I'm simply using the durametric interface.

JFP in PA · 03-18-2016, 03:07 PM

Quote:

Originally Posted by cornontherob

No codes have been triggered. I'm simply using the durametric interface.

Again, was the car fully warmed up when you tested it????

cornontherob · 03-19-2016, 08:00 AM

It was warmed up, but not fully. It had been sitting for around an hour after being fully warmed up. I'll take another reading once i get the chance to fully warm it up.

Pdwight · 03-19-2016, 08:48 PM

Watching closely

JFP in PA · 03-20-2016, 06:05 AM

Quote:

Originally Posted by cornontherob

It was warmed up, but not fully. It had been sitting for around an hour after being fully warmed up. I'll take another reading once i get the chance to fully warm it up.

Then take the car out for a good 20 min. or so run, and don't turn it off when you get back, hook up the Durametric and test it then.

Gilles · 03-20-2016, 06:32 AM

Quote:

Originally Posted by JFP in PA

Then take the car out for a good 20 min. or so run, and don't turn it off when you get back, hook up the Durametric and test it then.

JFP,

My Durametric instructions state to first turn the flashers On, then to turn On the ignition switch...

But you are metioning that you can connect the cable to take the readings without turning the engine Off.

Most likely I don't know how to use it properly, let alone correctly understanding the readings... LOL