Clackety clackety clackety clack

[evan9eleven]

Hi Steve and everyone! Thanks for putting up this forum. As much as I love hanging out on PP, it is really a treat to have a forum dedicated to giving expert Porsche technical advice. We are all lucky to have this resource!

I put up a post on PP a while back regarding some engine noises I'm experiencing. I received lots of great feedback and will finally get to spend some time working on the car this weekend. So, before I get out the wrenches... I thought it might not hurt to also get some tips here as well! My SC motor was rebuilt 4K miles ago by a very well respected shop (one of the best in Norway they say) before I owned the car, and the same shop did my PPI. At the time the PPI was done the engine had gone 2K miles since rebuild and I've driven it another 2K after I bought the car. The PPI shop mentioned hearing some engine clatter but didn't specify a reason. I asked and they speculated it might be a chain tensioner, and that the car wasn't fully warmed up when they listened to it. I thought it was odd that a fresh rebuild would be making clackety noises, but well, it does. The car goes like a top, but given that this is my first aircooled P-car I though posting a video might be a good idea. In the video the engine is fully warmed up, and the oil cap is removed until the end of the video-- the noises are easier to hear with the slow no-oil-cap idle. You'll need good speakers or headphones to hear it. The engine had 156K miles on it when it was rebuilt, below you will also find the parts list, most of which is fortunately in English. Pretty sure it was top-end only. I have also attached a video of the clatter I hear when shutting off the engine in case that helps.

I used a couple of long handle socket extensions to use as listening devices and spent a good 15 minutes trying to get closer to the source of the sound with the car idling. I believe it is on the passenger side of the engine. Here is a summary:

Upper right valve cover: loud rhythmic clacking
Upper right valve cover nuts, especially at cylinder nr. 4: loudest most distinct clacking
Lower right valve cover: less loud but still very clear clacking
Left side valve covers: no clack
Timing chain covers: chain-running-on-sprockets noise, no clack
Block underneath near sump plate: mechanical noises but no clack

Suggestions I've received so far include checking rocker shafts that may have walked out, rockers themselves, valve adjustment, timing chains and ramps, etc. Also suggested were problems with valve guides and springs, but I guess those are engine-out items anyway. The engine has oil-fed tensioners. I've stopped driving the car and will probably have to skip the P-Club fall drive. Bummer. Any tips greatly appreciated!

[Steve]

Hi Evan,

Thank you for your kind words about our forums, we simply wanted to offer a more focused alternative for people needing technical assistance and exchange ideas. Further, I needed a place where I could provide unbiased advice and the benefits of 40 years of experience without worrying about any words having a possible negative effect on someone's enterprise. Sometimes such things are not welcome as I found out.

The success here depends on participation.

I'm very sorry to hear about your engine misfortunes as a properly built engine should not have any such issues. Sometimes the most highly reputable shops make mistakes and its all about how such problems get resolved. Given your initial detective work at isolating the source & location of the noises, I think its time for your shop to pull the valve covers to inspect everything VERY thoroughly.

I think they did you no favors with a possibly flawed PPI as this should have gotten their attention and required a removal to see what was making the abnormal noises. There IS a big conflict of interest here since they may not have wished to admit a problem with one of their rebuilds and frankly, you should have had the PPI done elsewhere to maintain objectivity.

I would not run the engine until the problem(s) is found and resolved and further, I would ask the shop what kind of warranty they gave the PO about their work. You may need to employ that person to help, if that becomes necessary.

One observation I have is that he may have paid far too much for a "rebuild" that had used parts in it.

Hope this helps,

[evan9eleven]

Hi Steve,

Thanks for your reply. I think that I am realistically on my own here, as the PO sold me the car as-is and the shop that did the work is 7 hours drive from me. The rebuild was done just over two years ago, so I don't know if I would have much recourse with them anyway even if I wanted to have them look at it- after all, they replaced only what was absolutely necessary and not more during the rebuild, so it would be easy to blame the remaining parts. I sincerely doubt they will do much for me now. Yes, their PPI was crap.

I also live just slightly further from civilization then Mars, so the nearest qualified shop is 2.5 hours drive. I am mechanically inclined, have a lift and all manner of standard metric tools, and have tremendous tenacity and patience for troubleshooting. Knowledge and experience... well everyone has to start somewhere. I did a split case rebuild on a 1970 VW bus motor in my apartment once though!

I agree that the PO got taken for a ride on the rebuild but he clearly wanted the car to run again with a bare minimum of investment, and he wasn't about to tackle the job himself. I expected to be rebuilding this engine eventually to do it right, but was hoping that could wait a while. No such luck perhaps.

So, all that said... valve covers off, any tips on how you would approach the inspection will be much appreciated. I wish I was down the street from you, I'd be there in a heartbeat!

evan

[Steve]

Hi Evan,

Well sir,.....given the situation, its time to get your hand dirty by digging in and rebuilding the engine yourself so you know precisely what you have. This will give you peace of mind and ultimate reliability. From your description about where you live, you surely don't want to be fixing this by the side of a road without any tools or resources and without trustworthy documentation about whats in that motor, its only a guess.

I would start by pulling the valve covers to see if everything is normal. Naturally, you will need things like the Bentley SC manual at the very least and hopefully, all of the factory workshop manuals & supplements through your model year.

[evan9eleven]

Thanks Steve. I've got the Bentley manual as well as Wayne's and Bruce's books as a start. Perhaps I'll consider the factory manuals as well.

I love that you're offering performance consulting now, I will very likely take advantage of that when the time comes!


evan

[Steve]

[evan9eleven]

A little update. Drained oil warm and pulled valve covers on the right (noisy) side to find all rocker shafts in place and not leaking. Rockers seem fine and all valves 4-5-6 are in adjustment as the .004" feeler just fits. Double checked ice cold and its the same. Springs appear ok as far as I can see, and they are almost impossible to compress. No debris in valve covers.

Pulled the sump plate and screen as well, found what appears to be a 1mm x 4mm piece of gasket material, and a 1mm piece of something amber colored and brittle. Nothing else in the oil, in fact it looks very clean after just 2000 miles.

Considering pulling the chain covers next. Advice?

[Steve]

[evan9eleven]

[Steve]