Messing with cams and chain...nerves and a 3-chain
 

So I am getting ready to pull the cams and girdle on my drivers side bank 4-6 on my '03 3.2. #5 cylinder has no compression and I suspect a busted valve spring. I have been on the internet more than a porn-watching teenager sourcing as much information as I can prior to diving in. (Also have the Bentley and 101 projects)
Lots of information out there on 5 chain motors...not as much on 3 chains. Some stories about loosing time due to chains jumping teeth have me suffering from paralysis by analysis. However, these seem to be related to IMS change projects.
I am only removing cams and girdle and hopefully changing out a valve spring. I will be following procedure I have read about by:
-locking/pinning the crank at TDC
-locking both the cams prior to removal of cam cover using 9686 tool
-marking the chain and sprockets in several locations
-loosening tensioner and removing chain and cams
-doing the spring job (fingers crossed that is what it is)
-reassembling everything back to the way it was prior to removing everything thanks to my marking of the cam and chains
-removing pins and locks
-buttoning everything up and driving off into the sunset.
Is there any reason I cant proceed besides fear?
I have been into other motors and done similar work but I am getting the impression that the flat6 has special physics defying properties not yet understood by modern science...

I would say, as long as everything in locked down, and marked, and assuming nothing moves (shouldn’t) you should be good to go. After some reading it does seem there is a bit of m96 voodoo when rebuilding, but if care is taken it should not be an issue. I say you have all the elements... go for it.

A busted spring does not give a loss of compression. Bent valve or hole in the piston does. May be a bit more wrong with it than you think.

I am trying to remain optimistic...and approaching it from outside-in. I did endoscope the cylinder and the piston looked ok. No metal in oil, etc...The scope I had , unfortunately, did not allow me to look back on the valves. I did take off the exhaust manifold and could see from their back side the two exhaust valves looking to be seating properly. The motor is still in the car and will be until I need to take it to the next level. It would be a lot of unnecessary work to pull the motor only to find out it is a spring....but I am prepared to go there if need be.
Thanks for the replies...

Ottomotion, once I had to replace the seals inside the valve cover on my 987 3.4 CS and lowered the engine and transmission about 2" for the valve cover to clear the frame this should provide you enough space to work around the head.

Good luck!

Thanks for the tip!
:cheers: