Chain Tensioner Replacement Clarification
 

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:

1. Lock the crank at TDC
2. Poke out the little green cam seals
3. Lock the cams
4. 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?

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.

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.

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

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.

http://i70.photobucket.com/albums/i1...psoxszvtov.jpg

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.

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?

http://i.imgur.com/5z547aN.png

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

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.

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

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?

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.

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.

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

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

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.

Watching closely

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

I haven't heard this one yet, is there a reason for the flashers?

On some year cars, the DME will "go to sleep" if the engine is not running, and the data link will be lost. When testing without the car running, leaving the flashers on will prevent the DME for doing this. But if the car is running, you don't need the flashers.

Thanks JFP...!
I will try on Friday once I get back home, right now I am enjoying fresh clams and a nice brew at Philadelphia's airport.
Thanks again!

Drove the car around for an hour, then let it idle, and took a reading, still -9 and -12. Then I had someone else drive and took the reading from the passenger seat, same thing.

Re-opening with new info

Just emailed flat six innovations on this topic, and they seemed to think that the engine was toast because of the .5 second rattle when it starts up. They quoted me $18,000 for a new one. I emailed to them that the car was not necessarily making the noise when it's completely cold or hot, but that it does when it's in between, like around 110 degrees. This is in around 40 degree weather.

Flat six seemed to think that I was on the brink of a catastrophic failure. My theory is that when the previous owner changed the IMS bearing, he messed up timing, because camshaft deviations are holding steady.

Does anyone have the specs for the tensioner tension? Also, if it turns out that I take this apart to replace some chain ramps, and the main timing chain from the ims and the sprockets are worn, do es the engine case need to be split? http://www.pelicanparts.com/techarti...rge/Pic128.jpg

Just emailed flat six innovations on this topic, and they seemed to think that the engine was toast because of the .5 second rattle when it starts up. They quoted me $18,000 for a new one.

Wow. Really?! Gosh, I guess I'll be needing a new engine as well! :eek:

My 2.7L is getting a new IMS/Clutch/RMS shortly and my Indie says he here's a slight rattle on startup for a few seconds. He attributes it to the chain tensioners/ramps, or, more likely, worn out plastic camshaft brakes (Pelican Parts -- $19.95 for the set).

At 70k miles, my '02 986S has a little rattle on startup after a couple of seconds...perhaps 1sec worth. Best independent Porsche shop in the region did the IMS/RMS and it's unchanged thereafter. They didn't seem concerned about it.

Replacing the 3 x hydraulic chain tensioners will definitely help quieten the initial cold start chain rattle (it did on mine), but will not alter the deviation values.

I normally just come here to read and learn from you all but I have to add this, my car is a 2000 S with 33,000 miles. The LN IMSB was done at about 30,000 miles by the former owner and it has the same noise on start up. Just about 1/2 to 1 second then it is quiet. Are we now to assume that this is a problem and should I be worried? Maybe we should do a small survey on just how common this is.

So what I've gathered is that it's the ramps in between the camshafts, however I could be wrong and it's actually the long ramps that are tensioned by the hydraulic tensioners. I don't know if starting like this will damage anything in the long run. I also still am not quite sure how to set the tension on the hydraulic tensioners, or where to find the tool to do it.

Talked to the Porsche dealer technicians today while I had the car in to have a new key made. They told me that to replace the ramps in between the camshafts, it would cost me a total of around $6,500. This includes a replacement of the mechanism between the shafts that actually changes the timing, as well as actually removing the engine to get to it all. So, not a pretty repair bill if it goes in.

On the bright side, the tech said that he had never seen a case like this fail, contrary to the folks over at flat six innovations. I told him about this and he told me that that was crazy. It's apparently perfectly normal for the car to have some startup noise as long as it doesn't persist, but that to keep camshaft deviation values in check, and to switch to a heavier oil. I'm running 0w-40, but he said to move up a step in weight.

Replace the 3 hydraulic tensioners and drive it.

My startup rattle was the WP scraping on the engine block, and the alternator bearing. Both made start up noise until warmed up in a few seconds.

I guess mine wasn't seconds from exploding....glad I didn't get an over the phone diagnosis. Use your head. Check the obvious. Start it without the belt. Same noise?

The tech had looked it over and said not to worry, but he didn't take anything apart. I'll have to check it when it's warmed up completely. I'm still dailying the car, I just felt like a little piece of mind will help. It seems unclear on how or if you need to set the tension on these hydraulic tensioners.

It's a hydraulic tensioner. That's it. The oil pressure makes the tension. Nothing to set.

The tech didn't take anything apart, but at least looked it over. That seems better than over the phone diagnosis and a flat "it's dead, Jim" reply.

Greetings.

I am in a position that I believe I need to change the tensioners. It appears to me that this plunger part is the culprit and I can just change these without removing or replacing the entire unit. Correct?

On a scale of 1-10, with 1 being an oil change and 10 being engine removal, where does this job fall? Roughly how many hours?

Thanks.

Matt, just keep in mind that before you remove the tensioners you will need to lock the crank and the cams as well..

What plunger part are you meaning? The tensioners are 1 piece, you remove & replace with a whole new unit, you dont take it apart.

I would question why you think you need tensioners replaced. Remember, there are 3 of them. Each are specific to their location in the engine and cant be swapped around.

Suggest starting a new thread with the relevant information also, you may not need to replace these.

IIRC, I compressed the plungers and released them submerged in oil when I changed mine.....It is a very long ago and I neglected to make notes.

This essentially prefills the tensioner for the first start up.