JND72 Posted 27July, 2017 Report Share Posted 27July, 2017 Has anyone replaced the hydraulic chain tensioners on their 996? I've had my C2 '98 manual coupe for 9 months. For the first time the other morning when I started it up, it made the most horrendous clattering sound. I switched it off straight away and went a bit pale! I reluctantly got out of the car and jumped into the other, fearing the worst but hoping it wasn't terminal... After a call to my local P specialist, they reckoned it was likely the chain tensioners, and if allowed to run a bit longer the noise would have gone away as the oil pressure cam up. Sure enough this morning I gave it another try, slightly noisier than usual, but then settled down to the usual ticker. Drove to work, all good.Some internet searching has identified this to be a common trait of these motors, but I'm inclined to get them replaced as the car is due for its service in a week's time anyway.Has anyone else had this start-up clatter, or replaced the chain tensioners? I drive my car at least 3 times a week (sometimes 5), and this was the very first time I have experienced the noise. Was a particularly cold morning for Brisbane that morning. Is there anything else worth doing at the same time as the tensioners?Otherwise loving the car and appreciate the help and info on the forum. Link to comment Share on other sites More sharing options...
P-Kay Posted 27July, 2017 Report Share Posted 27July, 2017 Mine use to do it when not driven consistently. Some mornings were worse than others.Personally, I would change the chain runners as I understand they wear. Slippery slope, as if you are going to take off the cam covers........change the chains too as they have most likely stretched and while you're in there? Food for thought.... Link to comment Share on other sites More sharing options...
Stephen Tinker Posted 27July, 2017 Report Share Posted 27July, 2017 I replaced all 3 hydraulic tensioners on my Boxster S @ +/- 95,000 km- 2 tensioner are relatively easy to get to but the 3rd is behind the A/C compressor...The engine has to be pinned at the crankshaft and also the camshafts have to have the locking tool inserted to stop ant movement of the cams when the tensioners are removed. OPC Brisbane could probably replace them for $1,500 - 1,800.Before replacing the tensioners, check the condition of your oil - I found as the oil aged, the noise @ startup increased - especially if the car had not been started for a week or so. I found Mobil 1 was the worst culprit for chain rattle even after only 5,000 km.Replacing the chain wear pads (the plastic wear material was upgraded in 2002) and chains is a whole different scenario - the engine will have to be removed and the you may as well replace the AOS, hydraulic actuators etc etc - big dollars..... Link to comment Share on other sites More sharing options...
firstone Posted 28July, 2017 Report Share Posted 28July, 2017 My research on this showed an improved tensioner is available that is spring loaded to maintain tension until hydraulic pressure is made. Link to comment Share on other sites More sharing options...
Stephen Tinker Posted 28July, 2017 Report Share Posted 28July, 2017 They have always been spring loaded, but the newer tensioner pistons have a tapered top edge compared with the original square sectioned edge.The other wear point is the springs behind the piston, which tend to sag with age (a bit like me...). Link to comment Share on other sites More sharing options...
JND72 Posted 28July, 2017 Author Report Share Posted 28July, 2017 Sounds like a slippery slope!Service is being done Monday week, and car has done just on 5,000 km with Mobil 1....Will see how it goes after that.Might wait until a clutch change before pursuing further. But adding jobs to that list sounds like big $$$Thanks for the info Link to comment Share on other sites More sharing options...
firstone Posted 28July, 2017 Report Share Posted 28July, 2017 I was quoted $350 per tensioner fitted. I was encouraged to try 10w 50 to quieten it first. My hoist is ready to use now so I will try that and report my findings. Link to comment Share on other sites More sharing options...
80XTR Posted 3August, 2017 Report Share Posted 3August, 2017 Like Stephen Tinker, I replaced mine with the updated tensioners and the noise has gone away and never really came back on startup. I did a few things whilst I was messing around with the engine - didn't remove it, but I did tackle IMS, AOS, mounts and a few other minor things along with the tensioners etc. Link to comment Share on other sites More sharing options...
Pokiou Posted 4August, 2017 Report Share Posted 4August, 2017 ahhh so that starting up noise is the chain tensioners... my sr20det 180sx used to do that lol.. .never thought that id have that in the 996. Btw that doesnt affect performance does it ? Link to comment Share on other sites More sharing options...
Stephen Tinker Posted 4August, 2017 Report Share Posted 4August, 2017 Btw that doesnt affect performance does it ?They say not - there has been a lot of discussion regarding startup rattle over on 986 Forum going back years You usually find its a combination of both the hydraulic chain tensioners and valve lash (tappets) pumping up, especially if the car has been sitting for several days... Sounds awful.If I have been on holiday and left the car siting for a few weeks, I pull the fuel pump fuse and spin the engine on the starter motor for 5 seconds to pump up the tensioners / valve adjusters which helps reduce the startup noise. Link to comment Share on other sites More sharing options...
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