Almost two weeks ago, my mechanic advised me that the root cause of my blown exhaust gaskets was a damaged intake valve spring. I was summarily told that the only fix was to replace the head itself.

Finding the heads was a difficult task, and after a couple dead ends I've finally found a pair on a compatible car but they're stuck good.

I've searched the net a bit and found a handful of odd remedies, including using a mixture of ATF and acetone as a penetrant, and breaking the head free by loosening everything and trying to turn it over, but all of this seems a bit like automotive quackery. Furthermore, most of those threads seem to peter out before a resolution is reached, so I can't be sure which one of these fringe theories actually worked.

Any help is welcome. I'm within a hair's breadth of breaking the bike out of storage. Hell, it's unseasonably warm (read = "above freezing") so it might not be a bad way to go.

 

I've been reviewing all the head removal information myself - I am pulling my engine because I've done most of the easier to get at seals and gaskets (cam coverts, banjo bolts, oil pressure sender, etc) but each one I fix reveals another leak. While I've seen all kinds of interesting tips and tricks on replacing them in the car, I suspect that yanking the motor will actually save time in the long run.

Point... oh, yes, I'm going to pull the heads off and see what I've got going on in there. Likely will replace valves, springs, seats, etc. so I'm getting ready to deal with exactly the same issue.

The best method to remove the heads appears to be obtaining or building one of these: fabricated to apply even force against the head studs to break it loose. Kirby's Book suggests that you can use several smaller plates to essentially do the same thing but with a lot less fabrication effort.

BTW, if anyone knows where I might get find one of the big plates already built I'd be prepared to pay a reasonable amount to rent or buy it. Making one would be a bit of effort and I don't feel the need to have that experience but I'm ready to embark. Want to share the pain?

But something of a red flag here is that you don't have to just "replace the heads" because of a bad valve spring. It would be a hack of a fix but it would be pretty simple to just replace the one spring - there isn't anything majick about the V12 heads. Doing what is generally called a "valve job" on these things doesn't require anything a good machine shop wouldn't have. You might not need to replace valves or seats in which case you can get away with not even using a machine shop.

Not sure I'd recommend that you don't do it "right" by installing all new components and having everything properly machined, especially with the engine's penchant for dropping valve seats. I certainly wouldn't suggest just taking a used head and popping it on without doing some of the same work it would take to repair the heads you've already got unless you KNOW that your replacements were overhauled *properly* not too many years ago. Otherwise you're just trading old, beat up components for more old, beat up components.

Even if your replacement heads are mechanically sound the seals are going to be old and seals deteriorate when just sitting. Springs also.

On a completely different note - nice bike! I've recently discovered the wonder of electrically heated gear and riding in the cold has just lost much of its pain. Had to wonder - how (and WHY) did I live without it for so long?

 

Oh, yes, I knew I'd seen better info on building one of the "full size" head pullers. Check this post out. Also info on the small versions.

 

I read a post some time ago and he stated he had a head puller tool he would rent with a deposit. Hopefully he will come along soon.

 

I found the post and revived it
It was calvindoesknow

 

Far be it from me to question this mechanic, but that sounds a bit far fetched to me. I replaced all of my gaskets, not because of a weak spring, but because they were, well, blown. Just like any gasket could go bad over time. But a weak INTAKE spring? Making a exhaust gasket go bad? Please guys, tell me if I'm missing something here.

 

It's why I do ALL my own work and always will. If you can't do it yourself, find a new mechanic and change the exhaust gaskets. Pulling the heads sounds like a good way to put money in his pockets.

 

'zacktly. Not saying head work isn't needed - but that doesn't make sense as to why the head gaskets are blown. There doesn't have to be a reason - those things can get pretty gnarly after lots of years. The studs aren't the only things in the heads that deteriorate.

 

Well, the heads are off. Didn't need the "big, metal plate" although I've found out that my mechanic actually has the "big, metal plate" so that was an option the whole while.

That particular shop was my old standby. Gave them a lot of business - usually in the winter or when I don't have time or access to the facilities to do something particularly invasive (dropping the tank to get at a fuel pump or anything transmission-related) - and the CSR I'm dealing with is one of maybe two people who didn't recognize me (even though I hadn't been there since '09,) ask where my Mark VII is, and make a crack about the Jag.

I'm not a fan of this CSR at all. I had to pull teeth to actually talk to the man doing the wrenching, and when I did he recommended a valve job - so that's the direction we're going.

If it weren't the middle of damn winter I'd be the one elbow deep in that engine.