Timing chain tensioners...
 

So... I get that rattle at startup and, based upon my reading, believe it to be those tensioners. Yesterday when I went for a spin it was louder than normal. However, I hadn't driven it in about 6 days.

So... I have some questions, and hope someone can enlighten me.

I thought about taking it to the local indy shop and have them connect a Durametric or the PS## tool thinking maybe it would reveal if there are any tolerances that are out of whack... or whatever information that might reveal in what condition are the tensioners, individually, and if they need replacement. Then I started thinking...

Couldn't the local indy hook up the car and prepare a complete and comprehensive report about all the major/primary components that would reveal what's good... what's bad... and what's on its way out?

How much $$ would be reasonable for an indy to run that software and prepare a report?

While they're "in there" is there anything in particular I should have them look at/test?

In advance, thanks for the help.

Cheers!

Cam deviation values.

My 2001 2.7 Boxster with 147,000km on the clock use to rattle on start up, and yes it was worse if I left the car for more than a day or two between drives. I decided to pull my engine out to check my IMSB and other things that needed attention. But when I pulled the ‘Cam Chain’ tensioners out, 2 of the 3 weren’t working (wouldn’t hold pressure), I also replaced my ‘Variocam Tensioners’ while the engine was out, and though they had some wear I don’t think they were the reason for the ‘Rattle on Start Up’. After replacing the 3 ‘Cam Chain Tensioners’ my car now starts without even the slightest hint of a rattle, last week an O2 sensor failed and I decided to replace both O2 sensors, while I waited for the sensors to arrive (2 weeks as I’m in Australia), the car was left on stands and not started. After fitting the new sensors I started the car and I expected a bit of rattle as it had been sitting for 2 weeks, but again no rattle!
So if the rattle is the only thing worrying you, I’d get the 3 ‘Cam Tensioners’ replaced, they’re not that hard to replace and they aren’t expensive for you guys in the US, I’d start with these as they’re the easiest to get to.

If Durametric dont show extreme values for the timing... then I suggest to replace the oil filter housing before diving to the tensioners. Mine use to rattle and tick until I replaced the filter housing along with switching oil for Liquy Moly. Cheap to try.

Just saying...


Good luck

Oil filter housing I changed out just a couple thousand miles ago. OEM. Sound remained. Thank you. Maybe a different oil... the Moly. I may try that next oil change.

I've looked into swapping out the tensioners, but I'm not positioned to pull the engine. IIRC, it can be done with the engine in the car. So... ~$500 for the 3 tensioners and some 'while I'm in there' parts. Maybe in the fall, as it's baking right now.

Thanks, fellas. :cheers:

The most challenging part of replacing the chain tensioners is pulling the a/c comp to get to the one on top of the motor. It’s a very simple job overall. The Variocam tensioners on the other hand are a different story. I’m going to be replacing my chain tensioners this fall/winter.

To answer your original question: there's not really much that can be reported in via a diagnosis tool. Cam deviations is the only thing that I can think of that really operates on anything other than a ’it's ok/not ok’ basis. Maybe responsiveness of Oxy sensor but everything else is fault code based.

Still worth doing IMO, but don't expect to much.

Do these values essentially tell you how far the chains have "stretched", or guides have worn causing a slight change in the factory parameters?

I use my VCDS for my Audi B 8.5 2.0 to monitor this very value, as they are known for a tensioner failure. Mine has the updated tensioner, however they only have so much adjustment available to offset chain stretch or guide wear before you need to replace the guides and chains. Audi calls it "adaptation" values.

I'm thinking this applies here too.

Thanks

These cars have a deviation spec of +/- 6 degrees; values beyond that range indicate problems in the cam drive that need to be addressed.

Thanks kindly...similar numbers to Audi's "range" of adaptation.