youtube on acceleration problem and 4th cylinder noise

erio · 05:11 AM

I picked up my engine form a mechanic after head studs replacement(and all nessesary while there), and putting it back in the car by myself.
I have 2 problems.
1. The engine does not have the power. it struggles after 4000rpm.
https://www.youtube.com/watch?v=8ZbkWcZewyc
this is 1st and second gear acceletation. Plus there is this vibration sensation after 4000rpm
is it ignition or fuel related ?
Also
2. There is some noise coming from 4th cilinder.
The mechanical chain tensioners have been rebuild with new seals new spring new piston.
I remember there was some noise from the begining. diagnised as headstuds (4 broken) and chain tensioner.
https://www.youtube.com/watch?v=oK-NFOt5SqM
engine has 97k miles

one more video when altering ignition (didnt positiv affect power)
https://www.youtube.com/watch?v=aSYivYlj7PQ

Before head studs job the CIS was cleaned, presure tested and adjusted
any comment would be apreciated.

crustychief · crustychief's Garage

You don't want to run it more than a minute or two without the alternator fan turning. That is how cooling air gets to the cylinders! The sound is probably valves, I don't have a very good speaker though.

osl · osl's Garage

Difficult to tell from the vid but I would share that my 85 3.2 used to have a distinct ticking noise from one cylinder that several local specialists (both in NYC and the UK) were unable to pinpoint - apart from suggesting general valve gear wear or unspecified errors during a previous rebuild.
My current mechanic immediately suspected incorrect cam timing. And guess what, that's what it was. Cam timing was out on that bank. Now set correctly and the noise is gone. Your noise sounds different based on the vid but still, who knows...

arry911 · 02-25-2015, 11:12 AM

Wonder if it's the camshaft ?

Bob Kontak · Bob Kontak's Garage

Quote:

Originally Posted by arry911

Wonder if it's the camshaft ?

I think osl's thoughts on cam timing makes enough sense for a check.

I also would l like to to see if all the #4 and #5 cylinder valves are following the elephant foot on the rocker properly. If the heads were done, new valve guides? Could one be a little tight not allowing it to seat fully and then the rocker foot "slaps" the valve stem making the noise.