28 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHCylinder head crack
Leading reported evidence
Replace without breaking the case
Performed · outcome unconfirmed
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that performed work without a confirmed outcome
1
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Performed · outcome unconfirmed · Original poster
The engine is partially torn apart to replace all of the chain guides that can be replaced without breaking the case.
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion
There is also many ways to repair cracks besides welding( pinning ect) , but for this one I would use Loctite 5900 inside and out and to seal the hole drilled ,it is oil resistant and seals gaps, just press it into the crack and wipe off excess.
Leading evidence: 'Replace without breaking the case' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Repair cracks besides welding( pinning ect)' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
Source reports, not a diagnosis or a success probability. Counts refer to discussions and can overlap.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that performed work without a confirmed outcome
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Performed · outcome unconfirmed
I used JB Weld on a crack like that on my VW T1 and was very pleased it worked and that was 10 years ago.
Outcome qualification: Negation, uncertainty or missing explicit repair resolution overrides the raw extraction signal.
Use there
Performed · outcome unconfirmed
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that performed work without a confirmed outcome
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that contain suggestions
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
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Suggestion
There is also many ways to repair cracks besides welding( pinning ect) , but for this one I would use Loctite 5900 inside and out and to seal the hole drilled ,it is oil resistant and seals gaps, just press it into the crack and wipe off excess.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that contain suggestions
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion · Original poster
If it continues to leak I will probably have to replace the head.
These are separate views of the same evidence. Frequency alone does not establish a fix, and these counts must not be added together.
Repair cracks besides welding( pinning ect)
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Discussions that contain suggestions
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion
There is also many ways to repair cracks besides welding( pinning ect) , but for this one I would use Loctite 5900 inside and out and to seal the hole drilled ,it is oil resistant and seals gaps, just press it into the crack and wipe off excess.
Counts describe captured discussions, not unique people or a diagnosis. Author identities are not reliably stored. Exact duplicate evidence is counted once across matching discussions; one discussion counts at most once per action/state. Multiple repairs reported together remain a combination. Suggestions and failed attempts do not establish a fix. Matches cover whole discussions and can include related faults, model variants and incomplete threads.
28 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
Rennlist: 1 discussions
0 evidence records excluded for query context · 0 excluded by outcome qualification · 1 adjusted by outcome qualification.
0 acknowledgements have no verified action link; they do not establish a repair result.
Generation: 20261026T220748Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources
I have a 03 C4S with around 80k on it. The engine is partially torn apart to replace all of the chain guides that can be replaced without breaking the case. Well.... I found a crack in the cylinder head. The crack is on bank two between the camshaft ends on the flywheel side. It goes all the way through the head and is about an inch long.
I know the best option would be to tear the cylinder head off and send it out to Hoffmans for repair. What are my other options? Does anyone think a machine shop would be able to repair this crack without removing the head?
HELP!
I know little about cylinder head repairs, but my advice on this car is to almost always pick the best option. Anything less might not work or actually be more expensive in the long run.
Don't cut corners on cracked heads on these engines. Have a respected Porsche shop remove the head and send it to Len Hoffman. In the long run, you won't' regret it.
Yeah... I know... Do it right or do it twice.
I have reached out to Hoffmans for a quote. I am going to see what the cost is to refresh both heads as well as fix the crack. I was hoping to wait to do all of this next year winter when I do full rebuild with nickies. Looks like I will just have one less thing to do next year.
I got a response from Len Hoffman. It was not the response I expected but I appreciate his honesty. His response:
"Hi Kris, I can't say for sure what caused that crack, but if it's not causing an issue now, I doubt if it ever will. My hunch is it was from mishandling, but it's possible the casting had stress it relieved. I would advise against welding it as that can introduce distortion that would cause a problem. If it's weeping oil I'd seal it over with epoxy and let it ride."
Looks like were slapping some epoxy on it and seeing what happens! If it continues to leak I will probably have to replace the head. Hopefully, it will at least last me until next winter!
I am thinking of using this:
https://www.loctiteproducts.com/en/p...gcompound.html
Should I apply it to the inside and outside of the head or only the outside? Maybe grind in a little V-groove?
Thoughts?
I agree with what Len said, but I would not take a chance on the crack not growing. Find the very end of the crack and drill a hole at the end to stop the crack from growing. This is a common practice to "stop cracks in their tracks" !!. There is also many ways to repair cracks besides welding( pinning ect) , but for this one I would use Loctite 5900 inside and out and to seal the hole drilled ,it is oil resistant and seals gaps, just press it into the crack and wipe off excess. Epoxy will NOT stop crack growth..
I know what caused this crack, and Skip probably does, too.
The biggest issue with this one is an oil leak, when the engine is hot, and the oil is thin.
I not experienced enough to give advice on this issue particular with a head, but I'll comment on what Porschetech3 said. In a prior career I was an aerospace engineer (actually worked in submarine design). Did a lot of stress analysis. The stress concentration of a crack is pretty much infinite. The stress concentration of a round hole is 3. This is why if you ever go by an old bridge with cracks in the girders you will see repairs with a drilled hole at the end of the crack.
I appreciate the conformation, coming from an Aerospace Engineer !!
It's harder to get " Attaboy's" when you get put in the "vender catagory" as Jake says , I miss that..
for those that have not done variocam pads recently that threading accepts the cam lock tool. Im assuming someone forced something or it was a poorly made tool?
Thanks for all the replays guys. I am going to drill a hole at the end of the crack, carve out a little v groove, put some 5900 or Drei Bond on it and call it a day. Well see what happens! Worst case, I don't mind tearing it apart again.
Jake, I am very curious as to which tool and procedural failure would cause this crack. I'm guessing the single cam lock tool while attempting to rotate the engine? Or maybe using the dual cam lock tool as a counter while tightening / loosening the intake cam bolt? When you mentioned a tool causing this failure it brought back a faint memory from my instructor in M96 class saying something about cracking the head in this area, but I cant remember and have long since lost that notebook...
[Image-only post; no author-written text. Original image references:]
https://cimg2.ibsrv.net/gimg/rennlist.com-vbulletin/1228x659/camlocking_tool2_5efef831c3b63302bc4581be2b46ada59d8e1889.png
https://cimg2.ibsrv.net/gimg/rennlist.com-vbulletin/1228x659/camlocking_tool1_f1ad6462c02689de3cb0b2204e73c8186485b21f.png
B3, thanks. I know which tools are used there. I have a .2 so the first picture does not apply. I was asking under what
specific
circumstances would the tool in the 2nd picture OR the tool like that but only holds the intake cam; cause that crack shown on my head.
I provided both a 5-chain and (your) 3-chain heads for reference to "the tool" that Jake is probably referring to in this scenario.
My prediction:
1. cam locking tool was left on by mistake.
2. engine was rotated using a large wrench... high torque put stress on the locking tool
3. head was cracked near the mounting point.
Haha got me with my sniper edit... tried not to sound like an ***...
That what I was thinking as well. One of the tools had to have been left in while the engine was rotated. I just didn't know if Jake or anyone else had an experience of yes if you do X,Y,Z it WILL crack.. For example if you do not use the camshaft bridge hold down tools shown in your pictures, the camshafts can crack in half. I was hoping to expel another golden nugget out of Jake..
Another possibility was the vein cell adjuster bolt was not loosened enough during the cam timing procedure. The high torque energy was then transmitted to the end of the camshaft. With the locking tool in place, the energy exerted on the camshaft from rotating the engine caused the camshaft to turn and thus cause stress on the locking tool which in turn caused the crack.
I was thinking about that also. But what puzzled me is that in my experience and from what Jake says in his rebuild video series is that usually the half moons on the camshaft will break if excessive force is applied while the camshaft is locked. Maybe the previous builder DID break a cam and also cracked the block??
Good point! Quite a few over the years here on RL have "ate crow" and admitted to breaking the ends of the camshaft during timing procedure.
Here's the deal, the vein cell adjuster can transmit a great amount of torque. If a person doesn't loosen the vein cell bolt enough, the camshaft can still try to rotate. If you're not watching the timing chain carefully during the timing procedure while the cam locking tool is in place, that high torque energy can be transmitted to the end of the camshaft. It's highly probable that the technician was forcing the engine to rotate but forgot to watch the chains during timing. The camshaft rotated enough to cause stress on the heads, but didn't break the ends (i.e. moon shaped mounts). The crack is the result.
