Intermix repair/Camshafts/Threaded plugs
07-04-2009, 06:22 AM
#16
Three Wheelin'
Jasper: You need to read his other posts about his intermix problem/head repair and then cam expansion plug damage and blow out after engine rebuild and reinstall.He's documenting this saga and giving great detal to his problems with detailed photos.
07-04-2009, 08:29 AM
#17
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In the case of the Boxster (or at least some Boxsters) the bolts in the tool are replaced with socket head cap screws like the ones you show in the tool in your picture.
07-04-2009, 11:42 AM
#19
Drifting
Thread Starter
Thought i should mention that with these mods the two factory tools, 9634, which is the cam hold down tool I made, and 9612, which is the cam alighment tool, will no longer fit without modification.
By the way, Doug Dornbush make a much prettier tool than i did as you can see from this picture. And note that his tools uses hex head bolts that should not go into the expansion bolts. I thought I was being clever using the round headed hex driver bolts, not so!
By the way, Doug Dornbush make a much prettier tool than i did as you can see from this picture. And note that his tools uses hex head bolts that should not go into the expansion bolts. I thought I was being clever using the round headed hex driver bolts, not so!
07-04-2009, 03:54 PM
#20
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Excellent info Dharn55. I am suffering same intermix failure as you. Will be attempting similar repair. Engine should be coming out this weekend if I get time.
I am closely following your saga, and believe me I am a #1 fan!
Tim S
I am closely following your saga, and believe me I am a #1 fan!
Tim S
07-04-2009, 04:24 PM
#21
Drifting
Thread Starter
sehorntx - Let me know if there is anything I can do to help. I have developed somewhat of an expertise on this. Once you drop the engine pull out the sparkplug tubes, start on 1-3, actually #1. Now that you know what to look for you should able to see the crack (assuming it is the same crack/area) without removing the cam cover. Here are some pictures of the crack again. You can see where it runs down the sparkplug chase. This is the part that you should be able to see with the cam cover on. The rest of the crack is not visible until you pull off the cam cover, cams and the tappet holder.
07-04-2009, 05:58 PM
#23
Drifting
Thread Starter
That is an expansion plug. I am not sure if it is an oil passage or a coolant passage. therer are lots of thee plugs in the head and block. You see them in most engines. Two purposes, one is to close off openings that were required in the manufacturing/casting process, the second is the concept of "freeze plugs." the idea of freeze plugs was to allow the plugs to give way before the block/head cracks when the coolant freezes. These used to be called welsh plugs. With modern coolants/antifreezes, freeze ups are much less common, but you still see these plugs in almost all engines. Jake Raby of Flat 6 says that when he builds engines he trys to replace as many of the plugs as possible with threaded plugs. It would be a big project and would require breaking down the entire engine.
I am not too worried about these plugs, except at the cams. And quite frankly, if I had not pressed on the plugs in the end of the cams, one might never have come out. But the cams are a high pressure oil passage. Jake says he has seen quite a few of the cam plugs come out, refers to it as "mode of failure #11." another tech here on the site told me that he had never seen one come out, and he is very experienced. However, he also said he had not seen a cracked head until he checked a set he had and found the same basic crack that I had. I think a large percentage of the time when engines have failed the techs never really knew why, particularly when Porsche policy has always been not to tear down the engine, or to disclose the source of the problem. Most of the time when an engine fails, whether due to an IMS, intermix, cracked cylinder, etc. the engine is just repalced with the core sent back to Porsche. Of the local techs I talked to about my problem, none even knew there were plugs in the end of the cams.
Someone like Jake Raby is specifcally involved in analyzing why engines have failed and how to prevent it in the future on engines they build. So their experience and perspective is alot different from a tech working at a dealership/shop. Almost everyone I talked to when I first had the intermix, techs and others said "new engine, no other option." And that was not the case, but was the standard approach, and encouraged by Porsche. And it is alot more profitable for Porsche to sell a new/reman engine for $14,000+, and to conceal the real problems, than to fix the engines (although what they really do is take them back to Germany and "reman" them, i.e. fix them and send them back out.
Now that many of the cars are no longer covered by warranty, and Porsche has jacked up the price, particularly of the 3.4 (remember that 3-4 years ago a 3.4 reman was only about $8,000, and now they are $14,000+), and parts are available, more people are tearing down the engines, finding the source of the problems and fixing them.
I am not too worried about these plugs, except at the cams. And quite frankly, if I had not pressed on the plugs in the end of the cams, one might never have come out. But the cams are a high pressure oil passage. Jake says he has seen quite a few of the cam plugs come out, refers to it as "mode of failure #11." another tech here on the site told me that he had never seen one come out, and he is very experienced. However, he also said he had not seen a cracked head until he checked a set he had and found the same basic crack that I had. I think a large percentage of the time when engines have failed the techs never really knew why, particularly when Porsche policy has always been not to tear down the engine, or to disclose the source of the problem. Most of the time when an engine fails, whether due to an IMS, intermix, cracked cylinder, etc. the engine is just repalced with the core sent back to Porsche. Of the local techs I talked to about my problem, none even knew there were plugs in the end of the cams.
Someone like Jake Raby is specifcally involved in analyzing why engines have failed and how to prevent it in the future on engines they build. So their experience and perspective is alot different from a tech working at a dealership/shop. Almost everyone I talked to when I first had the intermix, techs and others said "new engine, no other option." And that was not the case, but was the standard approach, and encouraged by Porsche. And it is alot more profitable for Porsche to sell a new/reman engine for $14,000+, and to conceal the real problems, than to fix the engines (although what they really do is take them back to Germany and "reman" them, i.e. fix them and send them back out.
Now that many of the cars are no longer covered by warranty, and Porsche has jacked up the price, particularly of the 3.4 (remember that 3-4 years ago a 3.4 reman was only about $8,000, and now they are $14,000+), and parts are available, more people are tearing down the engines, finding the source of the problems and fixing them.
07-04-2009, 05:59 PM
#24
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Dharn55,
I am with you brother right down in the trenches! Will lean on you quite a bit if you dont mind. While I'm a mere private in this army, you're the seasoned colonel! Will definitely be interested in the manufacture of special tools! Got the email specs for one tool already.
Tim S
I am with you brother right down in the trenches! Will lean on you quite a bit if you dont mind. While I'm a mere private in this army, you're the seasoned colonel! Will definitely be interested in the manufacture of special tools! Got the email specs for one tool already.
Tim S
07-04-2009, 05:59 PM
#25
Drifting
Thread Starter
sehorntx - I was trying to send you a PM with some info, but it seems that you are not set up for one. If you send me one with your email i can send you some info.
