I'd first remove ...

Hi,
I should have followed Pedro's advice of getting a transom plug to pull out the spark plug plastic tubes! I have an 02 s with 67k, and was trying to pull the tube out using a screwdriver as leverage and...the blade broke through taking a piece of plastic straight down. I have not been able to locate. Do I need to get the plastic out, or can it stay in the crank case? Also, any thoughts on how to locate and remove?
Thanks much,
Steve

Are you serious......what do you think will happen to that hard piece of plastic (assuming it is only one piece) when it gets chewed up by the cams and chain ?? Sure it "may" lodge somewhere safe but....
No way I would leave it in there - the potential consequences are too serious to contemplate.
Sounds like the cam box (valve cover) needs to be removed to access the broken piece(s). Even if you get a borscope in there, you still have the problem of removing the plastic bit(s).

I would clean out your shop vac completely then attach a clean piece of small diameter tube and try a little vacuum fishing in the spark hole . If you can, get a bore scope and see if you can locate the piece first. Its definitely time to go sit have a coffee and think this through . Do not start that motor. Removing the cam cover is also a possibility. A small magnet on a string can also be used if the part is steel. Dont worry Steve your not the first mechanic to utter those famous words "oh s--t were did that go" I would give this thread a few more hours and you will end up with more tricks than David Copperfield.

... the tube (what's left of it) and with a boroscope look to try to locate the piece of plastic and remove.
If you still can't find it, depending on the size it's not that big a deal.
That plastic is fairly brittle and thin, so it would get chewed up by any metal part that it gets caught in without harming it.
Happy Boxstering,
Pedro

Pedro Bonilla
1998 Boxster 986 - 311,000+ miles: [www.PedrosGarage.com]
PCA National Club Racing Scrutineer - PCA National HPDE Instructor - PCA Technical Committee (Boxster/Cayman)

---

Racecar spelled backwards is Racecar

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"If you wait, all that happens is that you get older"... Mario Andretti

"Being second is to be the first of the ones who lose" ... Ayrton Senna

Thanks to everyone for your thoughts. I am going to try and locate with the boroscope...and will try the shop vac trick if I can find it. My local Porsche dealer said they will sell me a valve cover "kit" for taking off and replacing for $215.00. I guess that includes the sealant and the special caulking tool...not sure what else. Sounds pretty pricey. If anyone else has any ideas please let me know. I do tend to agree with Pedro...that this piece (about an inch by a 1/4 inch), would be chewed up by any moving metal parts. That being said, I do not want to take that chance....
Thanks everyone for your thoughts, really appreciate it.
Steve

To remove and reinstall the camshaft cover requires some sealant/applicator and new fasteners. Also budget for one or more exhaust system fasteners.

I can't say for sure -- no one can -- but the piece is probably harmless. It can lodge and stay where it is now or be drawn to the scavage pump intake and remain there or possibly get chewed up by the cam chain/sprocket then these pieces/fragments will go through the main scavage pump and be routed to the oil filter housing where they'll remain blocked by the filter element.

It is unlikely very unlikely the plastic piece could cause any chain or chain guide troubles. But try to locate the piece and remove it. If you are unsuccessful then you have to decide if you want to bother removing the camshaft cover. This is not a hard job but of course the job must be done right or leaks (or worse) will ensue. The cover is the upper half of the camshaft bearings and it wants to be installed correctly and torqued down in the proper sequence and to the proper values. New fasteners should be used.

Sincerely,

MarcW.

1. I think the camchains, cam are separate from the combustion chamber. in a 4stroke engine.
2. spark plug tubes mean that it fell in the cylinder. (therefore I don't think it will affect the cam chain or cams in anyway.)
3. Plastic might melt, down, dissolve in the oil, and be some sort of sludge.
4. Plastic, if small enough might just be thrown out the exhaust valves when u start it up the 1st time.....

If u can get it out, with the shopvac, then that would be good..... if not, I don't think I would spend $215 in parts plus labour to look for it.....

I am not a mechanic, nor do I play one on TV.

P

2 years ago I was where you are now... 1999 Boxster, so base model 2.5...
I sat, pondered, got advice etc for a week before deciding that I could not live with the plastic bit in there... I went in to get it. DIY.. After it's over, I would do the same thing again. Some of my personal notes below. Send me a PM if you want to go further into my experience with this. NOTE: IM NOT EXPERIENCED, THIS IS JUST MY STORY AND MY CAR HAS BEEN DOING FINE.
I would not attempt a cam cover removal /re-seal type job without having my hands on a Bently manual and a Porsche workshop manual too. I sourced both before I attempted. I also had a phone conversation with someone who did it themselves before... I just believe in having the full plan together before going head first...
Camp Hold Down Tool
Bently does not mention it but you should use the cam hold down tool that the Porsche procedure mentions in the factory manual. As the back side of the shafts saddles are the inside of the cover, the cover helps “hold” the shafts in… One end is held by the chain drive etc, but the opposite end of the shafts is just sandwiched in by the cover itself… I got this tool for like $60 from Baum tools. There are two types. One with round pins that just insert into cam ends and one with a circle/blade pin and a “trapezoid” pin. The “shaped pins” version is for holding timing. Its more expensive and not needed as the timing chain will be holding any rotation for this job… MY OPINION is you only need the cheaper round pin version to hold the shafts close in to the head when the cover comes off.

Sealant
Porsche recommends using Loctite 5900 silicone sealer to re-seal. I used exactly that. Dealers sell it in a 30ML (not full 300ml) tube. I suggest this size tube as it has a sharp point to lay a super small bead. Special (small) gun is used to dispense from this tube. You will need the gun. I was lucky to borrow from a Mercedes tech I know.

The Procedure
Various model years might be different from mine (1999 2.5). REVIEW THE FULL PROCEDURES PER BENTLY AND FACTORY MANUAL AS IM LEAVING THINGS OUT. Mostly telling you the issues I had that were not in the books.

I did not use new bolts, but did replace any plastic ends caps, oil extraction pump o ring and any other plastic / rubber bits that seal…

To reach each of the bolts, I needed various wrenches/ sockets / extensions to get “around” the obstacles… On one bolt, I had to use a small stubby gear wrench ratchet end and tighten by hand as I could not get a socket or torque wrench in the tight spot. Make a chart of which wrench / extension combo works for each nut.. Identify the nut number by the numbered tightening pattern per Bently or Porsche procedure. Do this before you take things apart. Much better to know what you are doing on re-assembly when you have wet silicone…

When you “lay the bead” it should be 1mm. Don’t overdo it. A little works great. The Loctite 5900 instructions say something like “re-assemble within 5 minutes..” The Mercedes tech that advised me said it’s actually best to let it cure 10 minutes before you mate the pieces together again, so don’t rush and botch something..

Tighten bolts according to the pattern in the manual… I first did hand tight, then went back through the pattern for the full 10lbs (I think it was) of torque.

I had trouble working the oil extraction pump back in.. I then used a heat gun on the engine in that spot and it slid in. Maybe I just got lucky, but next time I will put the pump in the frig and heat the engine and see if that helps more…

If you don’t need the car immediately then I would go for it. Take it slow and if you hit a roadblock, you can always backup… I personally don’t think it’s a “dangerous” DIY job if you follow the books…

camshaft cover bolts. For some reason they are not supposed to be reused.

Even when in the case of my 02 Boxster the dealership's service department had to go back into the engine once again on its own nickle (to replace the VarioCam actuator (which required removing the cams)) even though the tech had just been in the engine a few days earlier and there was less than a hundred miles on the engine since he was last in there, new bolts were still used.

Were I to do this camshaft cover R&R job I'd not risk my time, the other parts, the engine, by reusing the old bolts.

They are not expensive, certainly not compared to what else is at risk.

Sincerely,

MarcW.

MarcW,

Can you look up the torque values for the Camshaft cover bolts? I don't imagine they are very high.....

My theory,....

The only reason why they would want new bolts for a camshaft cover, is because they want to sell you new bolts at $5/each to cover the 'free' coffee and biscotti in the service department.

Heck, you need new camshaft cover bolts? but can reuse engine mount bolts? Something is wrong with this picture.

P

cover bolts would bring in it would overlook the engine mount bolts as another profit center?

There is nothing under the camshaft cover that requires periodic servicing so on the vast majority of cars there'll never be any reason to touch the camshaft covers at all. (I note my 02 didn't need any attention under the passenger camshaft cover until at almost 240K miles the VarioCam solenoid/actuator needed replacement.)

And the same applies the motor mounts. Save the one mount on my Boxster that failed -- I forget at what mileage but IIRC it was under 100K miles) the engine mounts have not been touched.

Frankly, Porsche could charge $100/each for the motor mount and camshaft cover bolts and still the profit would not rise above the noise level.

And lastly the camshaft bolts are I think stretch bolts, which makes a good case for *not* reusing them.

The tightening procedure is:

1st Step: Tighten to 20NM (15 ft lbs). Use the tightening proper sequence. (I won't take the time to type the sequence in unless you ask me to.)

2nd step: Tighten each bolt another 60 degs., +/- 2 degs. (Follow the same sequence as in step #1.)

3rd step: Tighten each bolt another 60 degs., +/- 2 degs. (Follow the same sequence as in step #1.)

With the above tightening sequence no one can say what the final torque is. And I will point out the camshaft cover contains the top half of the camshaft bearings. Proper tightening is obviously critical to ensuring a long and trouble free camshaft life. A leak from the camshaft cover is the least of one's worries. The real concern is which camshaft bearing has too much or possibly too little clearance (if the tightening is uneven or the bolts are not tightened down to the right final torque value)?

Sincerely,

MarcW.

Porsche recommends single use of nearly every bolt from caliper bolts to the drain plug. That doesn't mean there is a good reason or that there is a reason we care about.

Porsche get away with allowing the reuse of the obviously very safety critical lug bolts to be resused?

Really, if the bolts were reusable, I think Porsche would allow for their reuse. The tiny tiny bit of money Porsche makes from insisting these be replaced can't be that much and in fact it is probably only a break even sale on Porsche's side if even that. I bet Porsche would be better off not stocking the parts and leaving that tiny bit of money on the table.

Sincerely,

MarcW.

In any case, I believe that Porsche does recommend replacing the lug bolts on tire changes, which for many is more often than oil changes.

I have no problem with disagreement. That makes things interesting. And from that we learn. It's all good.

that were designed to deform when they were tightened so they could only be used once. And others that can be reused. So are we mixing the 2 types up and glossing over the differences in these discussions?

Pedro? Marc? I seem to remember you both have some machinist background.

stretch type fasteners.

The camshaft cover bolts are simply torqued to a value and that's that (well they have to be tightened in the proper sequence I'm sure).

But based on a pic I have of the camshaft cover bolts from my Boxster it looks like the bolts are treated with some micro-sealer (much like the IMS end plate bolts are) on the thread and the underside of the head and reuse of these may result in oil leaks from these bolts.

Sincerely,

MarcW.

Looking at where the oil should be, I think leaks on the camshaft cover are due to failure in the gasket material used, not due to any type of threadlock on the bolts.

I believe the gasket/o-rings/endseal is what prevents the leaks in the camcover.

P

located.

The mating surfaces which the bolts clamp/hold the camshaft cover to the head are adjacent to high oil pressure (possible 6 bar) that is fed to these bearings (plain bearings sans even any inserts). While it looks like these flat surfaces receive some sealant that is used to seal around the perimeter of the camshaft cover to head sealing surface the micro-sealant on the bolt threads/underneath their heads is added protection against an oil leak and one that could be fed by a high pressure oil supply.

Even the IMS bearing end plate bolts were treated with a similar thread/bolt head micro-sealant and for fear these bolts could pass oil. These bolts were not subject to high pressure oil but simply oil splash from oil being slung about inside the crankcase.

Sincerely,

MarcW.

Cam shaft cover bolts are 10 ft-lbs

The tightening procedure Mark W describes is the second half of the Cylinder Head to Crankcase

Thx, Ollie...

Ok, I got the Bentley Service manual off the shelf. Camshaft Cover bolts are M6 x30mm as stated on p15-5

I have a box of 100 M6x16mm zinc coated bolts in the garage, grade 8.8 (lowest grade I could find at local fastener place in bulk) - I use them as shear bolts in a big Honda Snowblower to protect the auger transmission.

Mounted a nut in my vice, and put a washer on it, and set my torque wrench to 145in-lbs (about 12ft lbs)

Tightened and loosened it 20x, no signs of failure. Dry fastening.

Reusing it a couple times, won't lead to failure.

Peter

PS. MarcW, The camshaft I think is in it's own carrier, independent of the cover. At least it was when I checked valve clearance on a motor.



Edited 1 time(s). Last edit at 02/28/2011 07:05PM by Petee_C. (view changes)

that shows my Boxster's cover upside down and the bolts next to it. Note please the presence of some thread sealant. Much like that of the new bolts that come with the IMS cover.



I do not understand why people insist on second-guessing Porsche about these items.

Sincerely,

MarcW.

Didn't realize that the camshaft saddles were part of the valve cover on a Pcar. I suppose that would make it harder to seal it out against leaks.

P

Not by any means telling anyone they shouldn't replace the bolts. I just diddn't on mine 2 years ago. I did however, place a really small ring of the loctite silicone (same sealant as the mating surface) around the last few threads under the bolt head. When you pull the cover off and clean the old sealant, you should notice that some of the silicone from the factory was actually in the threaded area of the bolt holds. I had to pick some of it out with a toothpick. So, they may have even shot a very small dab around the threaded area.

ALSO, you must circle with the 1mm bead every bolt hole. Dont miss the interior ones on each side of the shaft saddles in the middle of the cover. Its more than just the exterior border...

Petee_C
I see you have the Bentley book. Just note that it does not mention this "special" tool. Dont forget to consider this before you remove cover. See my notes above. As the shafts are to some degree held down by the cover itself, I think it's possible for spring pressure to push out the ends opposide the chains. Again, my car is a 99 2.5.

Just my $.02. Im just a shadetree guy at very best but think adding this to the Bentley procedure might make good sense. Not sure why they dont mention it... Not in my copy anyway.

Also, when you replace the oil extraction pump, be mindfull of it's orientation. If I remember correctly there is a 'right side up" and an "upside-down." I think they are opposide for each bank.... It think it might affect the direction of flow. So, make note and dont copy the other bank if you forget as it could be wrong...