Norbert Posted March 22 Report Share Posted March 22 Hi, I am thinking about replacing my chain tensioners. The IMS tensioner have an updated external spring design from 2001 (part number: 996 105 180 58). I have been looking all over the internet to figure out whether the updated spring tensioner would fit my '97 2.5. What I found online is: - Porsche stated the part is incompatible. - Many installed the external spring tensioner in pre-facelift cars (before 2001) and reported reduced chan rattle at cold start. I am a bit puzzled here, what's your take on this ? Quote Link to comment Share on other sites More sharing options...
½cwt Posted March 22 Report Share Posted March 22 Someone posted on this and included a YT video in the last 2 or 3 months, but I can't find it at the moment. As I recall, the spring inside it is slightly longer and there is a different taper on the plunger too but otherwise the person in the video found them to be interchangeable. 1 Quote Link to comment Share on other sites More sharing options...
Norbert Posted March 22 Author Report Share Posted March 22 Yes, I also have the impression that the part is interchangeable. But if that's the case why Porsche says it's not? Quote Link to comment Share on other sites More sharing options...
½cwt Posted March 22 Report Share Posted March 22 57 minutes ago, Norbert said: Yes, I also have the impression that the part is interchangeable. But if that's the case why Porsche says it's not? Probably because it as not officially been up issued and you can still get both versions I believe. Quote Link to comment Share on other sites More sharing options...
Norbert Posted March 23 Author Report Share Posted March 23 Amazing, thanks a lot! I can understand logic behind Porsche wanting to sell out the old stock before recommending the newer design. It wouldn't be a nice practice if that's the case but business is business. Quote Link to comment Share on other sites More sharing options...
RedBarediver Posted March 27 Report Share Posted March 27 On 3/22/2024 at 10:41 AM, ½cwt said: Someone posted on this and included a YT video in the last 2 or 3 months, but I can't find it at the moment. As I recall, the spring inside it is slightly longer and there is a different taper on the plunger too but otherwise the person in the video found them to be interchangeable. I saw that video too. I think it was Aaron on Help Me DIY. He has a few very helpful Boxster related videos. I found the one where he did the cam chain tensioners with the engine in the car quite illuminating. 1 Quote Link to comment Share on other sites More sharing options...
Norbert Posted April 9 Author Report Share Posted April 9 I have got the new tensioners and I decided to experiment a bit. I submerged them in oil and pumped them up. As you would expect they become stiff under pressure. I left them for the night and checked them this morning. Even the new tensioners leaked down overnight. In fact I don't see how this design could keep the tensioners under tension with no oil pressure. This is surprising because many people claimed that the startup rattle is due to leaking down chain tensioners. Well, the new ones leak down as fast as the old ones. I start to think that the only thing really matters is the spring tension on startup and not the oil pressure in the tensioner. I am trying to hunt down the startup rattle but I am now sure the new tensioners will not help a lot. I came up with a workaround in the meantime. I installed a killswitch, cutting the petrol pump fuse. Without the fuel pump I crank the engine for 5 seconds every morning. After, I switch on the fuel pump and start normally without any nasty rattle. Quote Link to comment Share on other sites More sharing options...
Daboy3000 Posted April 9 Report Share Posted April 9 Would love to get this sorted on my car, it's such a horrible sound. Quote Link to comment Share on other sites More sharing options...
½cwt Posted April 9 Report Share Posted April 9 1 hour ago, Daboy3000 said: Would love to get this sorted on my car, it's such a horrible sound. Part of the 5 chain M96 engine experience? @TROOPER88 Paul, any thoughts? Quote Link to comment Share on other sites More sharing options...
Norbert Posted April 9 Author Report Share Posted April 9 2 hours ago, Daboy3000 said: Would love to get this sorted on my car, it's such a horrible sound. I guess my temporary workaround with the fuel pump killswtich is permanent. I can recommend it. Quote Link to comment Share on other sites More sharing options...
TROOPER88 Posted April 9 Report Share Posted April 9 19 minutes ago, ½cwt said: Part of the 5 chain M96 engine experience? @TROOPER88 Paul, any thoughts? I have only very, very rarely experienced it tbh. In the past, I have advised those suffering from it to try Mobil1 0W/40 which is the only oil I use. If this does not work, I would be very interested to know what camshaft deviations are on the vehicle in question. Quote Link to comment Share on other sites More sharing options...
Norbert Posted April 9 Author Report Share Posted April 9 6 minutes ago, TROOPER88 said: I have only very, very rarely experienced it tbh. In the past, I have advised those suffering from it to try Mobil1 0W/40 which is the only oil I use. If this does not work, I would be very interested to know what camshaft deviations are on the vehicle in question. I am going to change to oil soon (Mobil 1 0w/40). I wil let you know the results. Unfortunetly, i don't have durametric tool to check the camshat deviation. Quote Link to comment Share on other sites More sharing options...
TROOPER88 Posted April 9 Report Share Posted April 9 6 minutes ago, Norbert said: I am going to change to oil soon (Mobil 1 0w/40). I wil let you know the results. Unfortunetly, i don't have durametric tool to check the camshat deviation. What area are you? Call by anytime if you would like me to plug your car in. Quote Link to comment Share on other sites More sharing options...
Norbert Posted April 9 Author Report Share Posted April 9 2 minutes ago, TROOPER88 said: What area are you? Call by anytime if you would like me to plug your car in. Up north Sheffield. Quote Link to comment Share on other sites More sharing options...
TROOPER88 Posted April 9 Report Share Posted April 9 23 minutes ago, Norbert said: Up north Sheffield. There is sure to be a member close to you who can help you out with PIWIS or Durametric Quote Link to comment Share on other sites More sharing options...
Daboy3000 Posted April 9 Report Share Posted April 9 1 hour ago, ½cwt said: Part of the 5 chain M96 engine experience? I had a 2.5 with 103k about 12 years ago and it never did it. Had the starter motor squeal though! Quote Link to comment Share on other sites More sharing options...
Nobbie Posted April 9 Report Share Posted April 9 28 minutes ago, Daboy3000 said: I had a 2.5 with 103k about 12 years ago and it never did it. Had the starter motor squeal though! The 2.5 5 chain I’ve just scrapped had 165k on it, used 5W 40 Titan Supersyn and never rattled on startup. I did measure the cam deviation which was well within limits at 3 degrees. The disabling the fuel pump trick sounds like a good cheap solution👍 Quote Link to comment Share on other sites More sharing options...
TROOPER88 Posted April 9 Report Share Posted April 9 7 minutes ago, Nobbie said: The 2.5 5 chain I’ve just scrapped had 165k on it, used 5W 40 Titan Supersyn and never rattled on startup. I did measure the cam deviation which was well within limits at 3 degrees. The disabling the fuel pump trick sounds like a good cheap solution👍 That’s amazing Regular oil changes? Quote Link to comment Share on other sites More sharing options...
Norbert Posted April 9 Author Report Share Posted April 9 57 minutes ago, Nobbie said: The 2.5 5 chain I’ve just scrapped had 165k on it, used 5W 40 Titan Supersyn and never rattled on startup. I did measure the cam deviation which was well within limits at 3 degrees. The disabling the fuel pump trick sounds like a good cheap solution👍 I wonder why you scraooed it. Quote Link to comment Share on other sites More sharing options...
½cwt Posted April 9 Report Share Posted April 9 1 hour ago, Nobbie said: The 2.5 5 chain I’ve just scrapped had 165k on it, used 5W 40 Titan Supersyn and never rattled on startup. I did measure the cam deviation which was well within limits at 3 degrees. The disabling the fuel pump trick sounds like a good cheap solution👍 It would be interesting to know what that data is on @the baron's at over 210kmiles. Quote Link to comment Share on other sites More sharing options...
Nobbie Posted April 9 Report Share Posted April 9 1 hour ago, Norbert said: I wonder why you scraooed it. I bought a newer Boxster and didn’t fancy selling a car with a chassis that looked like this. A shame as the engine was still running perfectly. Hopefully it will find a home in a car with less rust. 1 Quote Link to comment Share on other sites More sharing options...
the baron Posted April 10 Report Share Posted April 10 I use Millers 10/50 oil as recommended by Hartech who rebuild these engines, (my 996 had an engine rebuild) my 2.5 Boxster had a rattle at start up, when I switched over oils from Mobile 5/30 to Millers 10/50 the rattle has gone. 2 Quote Link to comment Share on other sites More sharing options...
½cwt Posted April 10 Report Share Posted April 10 7 hours ago, the baron said: I use Millers 10/50 oil as recommended by Hartech who rebuild these engines, (my 996 had an engine rebuild) my 2.5 Boxster had a rattle at start up, when I switched over oils from Mobile 5/30 to Millers 10/50 the rattle has gone. Have you even had the cam deviations read on the 986? Quote Link to comment Share on other sites More sharing options...
Norbert Posted April 10 Author Report Share Posted April 10 4 hours ago, ½cwt said: Have you even had the cam deviations read on the 986? I am not sure I understand how the cam deviation is connected to the startup rattle? Quote Link to comment Share on other sites More sharing options...
½cwt Posted April 10 Report Share Posted April 10 1 hour ago, Norbert said: I am not sure I understand how the cam deviation is connected to the startup rattle? This was related to another comment made in the topic. @TROOPER88 was impressed at the figure from a 160k+ mile can and I know @the baron's car is over 210k miles. So, sorry I was Quote Link to comment Share on other sites More sharing options...
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