Chain tensioner cleaning?

[JFP in PA]

You must lock down the engine at TDC, and install the cam holding tools before releasing the tensioners. But rather than cleaning them, why not install the newer versions which include a pretensioning spring to help reduce start up noise?

[san rensho]

Originally Posted by JFP in PA

You must lock down the engine at TDC, and install the cam holding tools before releasing the tensioners. But rather than cleaning them, why not install the newer versions which include a pretensioning spring to help reduce start up noise?

Yeah, I probably should replace them with the updated versions, but they ain't cheap and I am. I'm not even sure that cleanign them would necessarily make a difference.

I have the clatter isolated to the IMS/crank tensioner and I was hoping to just take that one out and clean it without having to go through the cam lockdown drill.

As an aside, the Pelican DIY for replacing the IMSB doesn't require the cam lock, it just uses set screws to lock the IMS before the tensioners are released, so I thought maybe I could get away with just removing one without the cam lock.

Other than the annoyance, is there any long term damage being done by the start up clatter?

[JFP in PA]

Originally Posted by san rensho

As an aside, the Pelican DIY for replacing the IMSB doesn't require the cam lock, it just uses set screws to lock the IMS before the tensioners are released, so I thought maybe I could get away with just removing one without the cam lock.

Other than the annoyance, is there any long term damage being done by the start up clatter?

Not to be unkind to Wayne's site, but I think more than one person has gone astray after reading it by not locking everything down properly before releasing the tensioners. Once released, there is a lot of valve spring derived load on the chains, particularly on a three chain motor, and bad things happen quickly.

A loose tensioner on start up causes the timing chains to "whip" back and forth a bit, which is not a good thing over time as it can weaken chain links, VarioCam components, and even the actual gear on the IMS shaft itself. Sometimes the noise is a combination of the tensioners and wear on the chain tensioner pads (they have a plastic wear surface) on the main pads, or even the smaller pads between the cam linking chains on the five chain motors. When that happens, just replacing the tensioner will not totally quiet the motor unless the pads are changed also, which is a pretty major undertaking as the motor needs to come out.

[ubii]

Originally Posted by JFP in PA

Not to be unkind to Wayne's site, but I think more than one person has gone astray after reading it by not locking everything down properly before releasing the tensioners. Once released, there is a lot of valve spring derived load on the chains, particularly on a three chain motor, and bad things happen quickly.

A loose tensioner on start up causes the timing chains to "whip" back and forth a bit, which is not a good thing over time as it can weaken chain links, VarioCam components, and even the actual gear on the IMS shaft itself. Sometimes the noise is a combination of the tensioners and wear on the chain tensioner pads (they have a plastic wear surface) on the main pads, or even the smaller pads between the cam linking chains on the five chain motors. When that happens, just replacing the tensioner will not totally quiet the motor unless the pads are changed also, which is a pretty major undertaking as the motor needs to come out.

Just curious JFP, how much labor is typically involved in removing the engine and replacing the chain tensioner paddles (99610525300). Also, how much additional labor would be required, should the chain guides/ramps (99610517552 and 99610517353) need replacing, as well? I actually just had my paddles replaced, while my 986 was in getting an IMS retrofit kit, clutch, and RMS installed. I am curious to see how much labor other mechanics tend to charge for this work. BTW, here is a photo of the old chain tensioner paddles, as you can see the inner set on both banks was pretty ate up.

[JFP in PA]

Realistically, you’d probably be looking at 7-10 hours at the shop’s prevailing rate. The spread comes from the level of the shop’s experience in doing this level of work, how they are equipped, plus these paddles can give you some grief coming apart. It is way easier to pull the engine for this. The guide ramps add maybe another two hours if done at the same time.

[san rensho]

After more investigation, I'm not even sure the sound I'm hearing is chain rattle from a bad tensioner. Today I got underneath the car and put a stethoscope on the IMS/crank tensioner and had someone start the car when it was dead cold and I couldn't hear anything abnormal from the tensioner. I'll try the bank1-3 tensioner tommorrow. Could just be lifter/starter rattle.

[jbox53]

check your water pump for giggles. It likes to rattle and emanate noise when going bad.

[jaykay]

Originally Posted by JFP in PA

You must lock down the engine at TDC, and install the cam holding tools before releasing the tensioners. But rather than cleaning them, why not install the newer versions which include a pretensioning spring to help reduce start up noise?

Thanks for this. I may have fallen into this trap. I have a five chain and had thought that one tensioner out at a time would be okay. Can one make the tools necesary to lock the engine?

I can't believe these weren't designed with a preload spring intially. If it is not too much trouble could you post the PN for the revised chain tensioners?

[JFP in PA]

Originally Posted by jaykay

Thanks for this. I may have fallen into this trap. I have a five chain and had thought that one tensioner out at a time would be okay. Can one make the tools necesary to lock the engine?

I can't believe these weren't designed with a preload spring intially. If it is not too much trouble could you post the PN for the revised chain tensioners?

Sure, you can fabricate all of the holding tools; the TDC lock pin is a 5/16 rod, and the cam holding tools are just metal flat stock cut to a specific shape, nothing more.

The “old style” tensioners have been totally superseded; you can no longer find them. Any dealer can get you the updated version with the pre-load spring, I'd check with them to get the latest part number as they have changed it a couple of times.

[jaykay]

Originally Posted by JFP in PA

Sure, you can fabricate all of the holding tools; the TDC lock pin is a 5/16 rod, and the cam holding tools are just metal flat stock cut to a specific shape, nothing more.

The “old style” tensioners have been totally superseded; you can no longer find them. Any dealer can get you the updated version with the pre-load spring, I'd check with them to get the latest part number as they have changed it a couple of times.

Thanks jfp! ...just went to dealer and the guy has no clue as to which tensioner is the latest and will fit my engine...ahhhh yeah

Perhaps just trying to order will filter out the oldies

[san rensho]

Originally Posted by JFP in PA

You must lock down the engine at TDC, and install the cam holding tools before releasing the tensioners. But rather than cleaning them, why not install the newer versions which include a pretensioning spring to help reduce start up noise?

Locking down the cams is certainly the preferred way and guaranteed not to get you into trouble. However, I cleaned my lower chain tensioners by just pinning the crankshaft at TDC and removing, cleaning and reinstalling each tensioner one at a time. No problems whatsoever.

But the tensioner cleaning made no difference with the startup rattle.