Tap Tap Tap

titus319 · 06-01-2010, 09:27 PM

Oh boy. I've been dreading this moment. I've been a member for a short while, and have enjoyed reading through the forum as a visitor for some time before that. I've preferred keeping on the sidelines, but now I have no choice but to post.

I recently moved from Florida to California, and at the advice and enthusiasm of PCA members on various forums, I decided it would be fun to take the 986 cross-country. At nearly the precise midpoint of my trip, I pull off the freeway for a night's rest and hear a loud tapping noise. A steady, rhythmic tapping. I hit the gas when the light turns green, and the rate of the tapping increases with the acceleration, decreases when I decelerate. Shut her off immediately and had her moved by transport to California. The car still runs, still moves, and was running anywhere from 1-2 hours at 80 mph after the noise began (from what I can estimate, considering my previous stop for gas).

Two mechanics here have identified it as a wrist pin that's come out of place, from what they can tell/see without pulling the engine. Considering all the IMS failure posts I've read, I'm still concerned this problem might be related.

I know better than to ask for a diagnosis based solely on a sound, especially a sound no one here has heard firsthand, but any insight would be appreciated. What am I getting myself into? Does the mechanic's appraisal of the problem hold water? Any other advice?

Thanks, all!

Wayne 962 · Wayne 962's Garage

Wrist pin coming loose? I haven't heard of that happening really on these engines, although almost daily something else seems to start breaking on them! Where is the sound coming from exactly? Left / right, forward back? A small ticking noise is typically a stuck lifter, but your noise sounds louder than that?

-Wayne

cnavarro · 06-02-2010, 05:27 AM

One of the shops I supply in Australia reported seeing "soft" pin end bushings, resulting in the same noise you are experiencing, but I don't understand how one could make such a certain diagnosis without a teardown.

If a wrist pin itself had come loose (like a wire lock piping out), the failure would have likely been a catastrophic one at those speeds. Again, wire locks done typically fail. They are overkill. The only problem really is not installing them properly, or rather completely, whe such a failure could occur.

titus319 · 06-02-2010, 06:25 PM

Thank you both for the replies. Nice to have two experts chime in on the matter, and you've both confirmed what I was thinking, that it could not be the wrist pin. Hadn't considered the possibility of a stuck lifter, so I appreciate that input, Wayne. I went ahead and read up on as many posts as I could on that topic, and am going to proceed working through that solution first. I'll let you know how it goes. Again, thanks.

titus319 · 06-07-2010, 12:45 AM

Follow-up:

I pulled the Boxster out of the first mechanic's shop last Thursday. Considering it might be a stuck lifter, I started out by using Sea Foam as suggested in several threads, and proceeding with an oil change to see if the ticking / tapping would go away, but to no avail. I finally gave up and took the car by another mechanic's shop (one who specializes in Porsche here in Studio City).

He gave a quick listen - maybe 10-15 seconds worth - and very definitively told me it sounded like my IMS bearings were about to fail...true. I asked what the remedy was, to which he answered, "I'll have to pull the engine and do a full rebuild. It'll run you about $5,500, but if the IMS fails and can't use your core, it'll end up costing you an additional $2,000 so we should probably do this soon." All this after only having listened to the car for a few seconds.

Now, I've been dealing with this problem for a couple months now, and I've been doing my share of "worst case scenario" reading. And, since Wayne and Charles' posts above, I've had the opportunity to peruse LN Engineering's website. I don't see why this mechanic claims my motor needs to be rebuilt, and if I'm not mistaken, the motor doesn't even need to come down in order for the IMS bearings to be replaced - just the tranny. I don't like crapping on people publicly, but will gladly disclose this quack's name to anybody who wishes to know privately, or if the forum's members ask me to divulge the shop's name on this thread.

I found a few videos on youtube of 986 and 996 engines with IMS bearing problems / failures, and the sound is identical to what my Boxster is producing:

YouTube - 2005 Boxster 2.7L Noise

more like this, actually:
YouTube - Porsche 996 Turbo X50 Intermediate Shaft Failure!

And then there's this poor guy, who happened to have the video camera on when IT happened:
YouTube - Boxster engine seized

I had a buddy who works on 356s here in LA come take a listen, and while he was also convinced it was a stuck lifter, after taking a look at those videos he agrees the noise is dead-on. A word to anyone who thinks they might have a stuck lifter... anything more than just a slight tick, turn the key to the left, pull it out, and get your car on a flatbed to a reputable shop.

I'm going with one of the certified mechanics recommended by LN to do the replacement as well as a clutch job while I'm at it. The engine has 55,000 miles on it and will be looking at a new clutch in 5,000 miles anyway, so it just makes sense to go ahead and get both jobs done now. The car sat for nearly three years, and it was foolish of me to just take off with it as I did. Had I been more aware of these IMS problems, I would've taken care of them preemptively before heading off on a cross-country trip.

Any further suggestions / ideas / tips / insights are welcome and appreciated.

-Reynold

K. McClain · 06-07-2010, 11:56 AM

Quote:

Originally Posted by titus319

Any further suggestions / ideas / tips / insights are welcome and appreciated.

-Reynold

I'd buy a lottery ticket! You are one lucky son of a gun if it doesn't need a rebuild.

titus319 · 06-07-2010, 03:08 PM

Quote:

Originally Posted by K. McClain

I'd buy a lottery ticket! You are one lucky son of a gun if it doesn't need a rebuild.

Forgive me... am I mistaken? A full failure of the IMS hasn't occured - the car is still running. As I understand it, the IMS bearings can be replaced at any time (and is recommended with every clutch change), without any other repairs having to take place. As the car is still operating otherwise, this should be my only repair, correct?

K. McClain · 06-08-2010, 05:09 AM

The experts can probably answer this better than me, but if the IMS bearing is failing it throws a lot of metal bits all through the engine. Pull your oil filter and check for metal and I'd have an oil analysis done also.

Wayne 962 · Wayne 962's Garage

Quote:

Originally Posted by titus319

Forgive me... am I mistaken? A full failure of the IMS hasn't occured - the car is still running. As I understand it, the IMS bearings can be replaced at any time (and is recommended with every clutch change), without any other repairs having to take place. As the car is still operating otherwise, this should be my only repair, correct?

I just put this up not less than 30 minutes ago, and it hasn't been fully edited or vetted, but I think it applies to your car 100%. Sounds identical to what is the issue with the 996 discussed in the article. Here is the link:

Pelican Technical Article: Intermediate Shaft Bearing Replacement and Upgrade (IMS) - 986 Boxster (1997-04) - 987 Boxster (2005-06)

As for having someone look at it, you should bring it by Callas Rennsport in Torrance. If you take it there I can stop by and take a look too (just had lunch with those guys today, and borrowed some tools!)...

-Wayne

Wayne 962 · Wayne 962's Garage

Oh, and don't run the engine any more if the sound is like that in the video. That dunderhead decided to rev the engine to see what would happen and turned it from a $500 fix to a $10,000 fix. Check out the article, it's very complete. If your car has that problem, we may even be able to work out an arrangement where your car is one of the test vehicles for the new kit!

-Wayne

Wayne 962 · Wayne 962's Garage

Quote:

Originally Posted by titus319

more like this, actually:
YouTube - Porsche 996 Turbo X50 Intermediate Shaft Failure!

The 996 Turbo doesn't have a ball bearing on the intermediate shaft - it's a completely different engine and a completely different design. I listened to the audio on that video - most likely not having anything to do with the intermediate shaft itself, but probably with the chains or tensioners.

-Wayne

Wayne 962 · Wayne 962's Garage

What did the other shop that you took the car to have to say about the noise?

-Wayne

titus319 · 06-19-2010, 02:26 AM

Ok...

I wanted to have her back in my hands before posting a follow-up. I got some so-so feedback on Valley European by some of the members of this forum, and many unsolicited positive referrals for TRE in Van Nuys. So, I gave the guys at TRE a call, and they matched the low price being offered by Valley Euro. The price was neither here, nor there, however.

A couple of days after dropping it off with Jeremy at TRE, I get a call from him letting me know that my car was ready to go, and that his effort would only cost me a couple hundred bucks. An oil change with cheap, thin oil, and ATF; a 20-mile drive; and another oil change with quality oil, and the noise is gone. That's it... a sticky lifter. A very LOUD, sticky lifter. The girl is home.

I've had several mechanics inspect the vehicle since this mess began over two months ago, and gotten everything from slipped cylinder sleeves to snapped wrist pins, to being told that I needed a comprehensive rebuild of my motor. It's good to know that there are still honest, quality mechanics like the guys at TRE still around, who have their clients' best interest at heart. These guys are the real deal - they weren't out to get me to agree to an expensive repair I didn't need, and now they've earned a customer for life.

I'm grateful to this forum and its users for the support and guidance.

Wayne 962 · Wayne 962's Garage

Boxster lifter noises are pretty obvious to those who have heard them before. I suspect the other mechanics just aren't familiar with the Boxster too much. Glad to hear the problem is solved!

-Wayne

titus319 · 06-20-2010, 04:26 PM

I wish that was the case, Wayne. The mechanic here in Studio City that told me I needed to have my engine rebuilt after only taking a few second's listen is a very well known and established shop - one who had several Boxsters up on lifts the day I went by. Two of the other mechanics were also Porsche specific, and also very well known. It is what it is.

I'm glad the problem is solved too. Thanks again to all for the help and recommendations.