tappet sound and oil top of piston

Marcus

Supporter
Hi guys,
Reaching out for some thoughts from your good selves re an oiled plug...
Am running an old 302 Windsor standard set-up...
Was told the engine was sound although had sat around unused for a while.... have started running the engine up and she smokes oil a bit and now have some intermittent clicking coming from one bank of rockers....blue smoke getting worse on acceleration...
Pulled the plugs and one cylinder plug shows oil traces...
Inserted a camera and small amount of oil sitting on top of the piston.....no traces of broken ring...
Compression test shows 130psi.....so not sure if this totally eliminates a stuck or broken ring but am hopeful that ring is intact.
So my question is could this be a fault with the valve steam seal.....?
I am a novice when it comes to engines but if compression is OK I am guessing the oil must be coming from above hence the question re the seals..... the on off tapping or clicking seems to be coming from the same bank/cylinder...
Would welcome any advise from you experts to a novice like myself and am hoping that replacing the valve seals is quite straight forward.....
Thanks for anyone able to help with some thoughts....
Kind regards
Marcus
 
I had an issue with valve seals leaking and allowing oil into the cylinder. Have you noticed any evidence of a piece of a valve seal underneath the valve covers? I had a couple of pieces of blue material on mine. Doing a rebuild of that engine, so I cannot speak to how easy it would be to change a valve seal. Someone else will have to comment as to that.

Jim
 
VALVE SEALS AND OR VALVE GUIDES.. IF IT IS AN OLD MOTOR YOU CAN BE SURE THE SEALS ARE AS HARD AS A WEDDING DICK..
CHECK THE VACUUM WITH A GAUGE.. IF IT IS BOUNCING COULD INDICATE A VLAVE TRANE PROBLEM (WORN GUIDES).... SEALS CAN BE REPLACE WHILE THE MOTOR IS IN THE CAR WITH THE PROPER TOOL.

DO YOUR RESEARCH.... I AM NOT A SLOW MECHANIC OR A FAST MECHANIC...I AM A HALFAST MECHANIC :)


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Ian Clark

Supporter
I suppose how long the motor sat around and where (dry indoors or not) would contribute to your issues. Blue smoke on acceleration is oil (usually rings), oil fouled plug could be valve seal, spark plug wire, distributor cap or spark plug itself. Clacking is most likely hydraulic lifter or lifters, although an exhaust leak at the cylinder head can make a ticking or clacking sound.

Did you pull the oil pan and check for sludge or blockage to the oil pump pickup? Did you pre lube the cylinders and turn the motor over slowly by hand (all spark plugs out) to feel for tight spots in the rotation? It's also the easiest time to check for very loose rocker arms as each cylinder comes up to top dead center (indicates bad lifter - stuck or collapsed).

If on pre firing inspection the motor turned over smoothly, then put in new spark plugs, plug wires, oil and filter. On start up it should fire up and run smoothly if the carburetor and distributor are ok and set right. Check the oil pressure and look out for coolant leaks. So there's a few variables. The good news is that if the engine is just a bit tired it's not a lot of money to freshen up.

Cheers
Ian
 
It’s been my experience that intake guides and stem seals tend to leak under high vacuum conditions such as decelerating with the throttle closed.
 

Ian Clark

Supporter
Thanks for chiming in Scott, excellent points. Marcus may get by just replacing the valves seals (without tearing down the engine). Intake guides as you included would be a machine shop job.

Always surprises when lighting up an engine that sat around for a while...

Cheers
Ian
 
Yes absolutely Ian. Hopefully the engine just needs a new set of valve guide seals due to dry rot. have seen valve stems corrode as well when an engine is not pickled going into long period storage or just not being used.
 
Used to be quite common for the OE integral to head valve guides, would stick to the valve stems & lock up while sitting in a repair shop or storage, have also found carbon to flake off piston crown & collect on the lower side of the Vee to make an engine 'knock' every time the piston came to TDC. Plenty of 'old guy' tricks to deal with issues like that.
 

Bill Kearley

Supporter
I would look at the valve guides. Put air to the cylinder s, remove spring/s and check guide play without the air ( use caution ) ha ha, don't drop the valve. Decelerating will suck a lot of oil and smoke. With real bad seals and guides a small amount of oil can drip, mainly from the cooler intake valves.
Warn guides can sound a lot like lifters/valve lash.

Good luck
 
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