Cold start rattle

Hi folks, this is my first post on this forum but I have been reading the excellent articles and advice on here for a long time. Hoping someone can shed some light on a problem I'm facing. I recently purchased a 2006 Cayman S with ~75k miles on it. I've put around 2000 miles on it since and I've noticed a harsh rattle on cold start. It only lasts a second and there are no other symptoms while driving the car. I don't hear this sound on warm starts either. I read a bunch of forum posts about a similar problem being diagnosed to worn out timing chain tensioners(which is my theory as well). However, all the articles I've read so far have referred to this being a common problem on 986 /996 engines. So my question is, has anyone faced a similar problem with 987 engines? Do I need to get this fixed straightaway or is it something I can live with? If I were to attempt this repair myself, is there a tutorial out there somewhere which shows me how to get to the tensioners on 987 engines? Any info would be much appreciated. Thanks in advance!

I wouldn't say it is a problem. I don't know your particular case but every engine is noisier in the firs few seconds after start, until the oil starts flowing. For this reason it is a known fact that 80% of the engine wear occurs during this time. That is one of the reasons why quality oil is important. I have noticed the initial rattle on my 987. It lasts for about 1 - 2 seconds and immediately goes away. Interesting fact is that the previous owner was driving the car with Mobil 1 0-40 as recommended and the rattle was much more pronounced. I switched to Motul X-cess and the initial start rattle is all but gone. It appears sometimes but very rarely and for shorter period. (No, this is not an invite for another oil war. Just personal observation.) I don't think you should be concerned, unless the noise is abnormal or lasts abnormally long time. Enjoy!

Thanks Morde5 for the feedback. The previous owner was running 0-40 as well but I did an oil change after buying the car just to be safe. The engine seems quieter in general with the new oil but it hasn't helped with the startup rattle at all.

The brief rattle on cold startup is usually the valve lifters before they get pumped up by oil pressure. Nothing to worry about.

There are better oils than Mobil 1 . That is an easy way to solve the problem. Amsoil is excellent. Red Line Oil is good too. If you absolutely want the noise to disappear completely you can plumb in an Accusump preoiler into your car. If you do track days with this engine, it would help it to last much longer. You will always have correct oil pressure and flow to the critical components that need oil in the engine. Also with a Porsche you would be wise to check the oil level every week. You never want the coolant and the oil levels to become low.

I have thought about that. Has anybody on the forum done it? It seems pretty involved. If someone has the experience (even with other cars beside Porsche) would be nice to share. Thanks!

Can you provide a video/audio clip of the rattle? I am curious because I have a “rattle” when my engine hits about 3100rpm due to a frequency reacting with one of my exhaust heat shields. I’m wondering if you have the same issue, just with a lower RPM frequency.

Funny you should mention that. I replaced my stock exhaust yesterday with a Fabspeed Maxflo exhaust and when I started the car this morning, I swear the rattle was much less noticeable. However, I wasn't really paying too much attention so I can't be sure. Will monitor it over the next couple of days and get back with a clip if I hear it again.

I suppose that was wishful thinking. Rattle is still very much present. Here's a short clip https://www.youtube.com/watch?v=zGEYG_wy_dI&feature=youtu.be

Just got my 07 S a week ago and heard the same 'rattle / harsh sound' at cold starts after it's been sitting for a day or so... Does not happen when I shut her down, run errands and start her back up... Just on cold starts and it goes away in a matter of 3 - 5 seconds. I took a sound clip of it and asked the owner at the German / Porsche shop I had the oil changed at this morning as it was concerning me and he said the same thing as racergreg... Normal at cold start ups for this engine until the oil gets flowing and nothing to worry about at all.

Hi, did you get to the bottom of this? I have the exact same noise and symptoms. Jack

Change to 5W-40 instead of the 0W-40 that everyone seems to use. Unless you're running the car in northern Alaska in mid-winter, 5W-40 is really what's recommended. I use Pensotin 5W-40, other brands are also probably good - but I like knowing all the fluids in my car are made in Germany.

Did you get to the bottom of it in the end? *Edit: I have a similar issue; rattle after cold start but only whilst moving- reversing out of driveway and pulling away etc. Rang my trusty indie and they said it's probably the exhaust rattling until it warms up and expands. Makes sense seeing as the colder it is/has been, the worse it gets and in my case the noise is only present whilst the car is moving.

Just curious if you had a PPI done before you purchased the car a couple of months ago? Maybe the video series from Flat6innovations by Jake Raby on the detection of bore scoring would help rule out this issue. How cold is the garage where the car is kept on startup? I like many others have noticed startup noise with different motor oils. Is it lifter noise or piston noise. Maybe the timing chains, good motor oil helps quite these startup noises. I use Motul 300V Power 5W40 after a number of other brands caused similar motor noises. This oil seems to work very well for my M97 engine and I change it every 3500 miles without having to add any oil. I check that oil level on every cold startup. Takes what 5 seconds.

I'm thinking it might be the exhaust ; noise only present whilst car moving. Idle doesn't seem to have any change, and the sound goes away when it's been driven for a few hundred yards, presumably because the rattly component has expanded and the fit has tightened. Noise came about only after an exceptionally cold few nights.

This could be a exhaust gasket/ exhaust header bolt issue. Porsche has a heater system along side the exhaust port that is underneath the header manifold. What this does is beyond me but if you take off the header you will see it in the head around the exhaust ports. I'm thinking you hear some of this exhaust coming out of this space until the header heats up and seals the leak, Only takes a few seconds. If you need to change the headers , I highly recommend Soul catless race headers , unless your state requires an exhaust test for your yearly tabs, then use the Soul catted Race headers , they are about $400 more due to the cats in each. Your car will sound much better. Always use new stamped steel exhaust headers gaskets if you buy new Soul headers . John at Soul sent me the woven fabric exhaust gasket, lasted for about 2 months then leaked on start up as you are describing. Mine got worse as time went along and I was racing from a dead stop. At the start line guys could hear my leaky exhaust , sounded terrible. John sent me a set of new steel gaskets. I am still all smiles at every startup.