Engine: 289 Valve Tap? Things to check?

[Geigs]

My car is almost ready for the road after all these weeks, but while on a test drive, a tapping noise was noted. A call to the previous owner suggested that most likely it was just carbon deposits since it has not been driven in several years. For the record, all the fluids were changed before the test drive. Plan to decarbon it, but does anyone have any other suggestions? Only has 42,500 miles on it.

[41 Frank]

First thing to check would be valve adjustment. Carbon build up because it has not been driven for several years? Carbon only builds up if car is driven. Seriously though, since these cars have mechanical lifters a periodic valve adjustment would be normal maintenance. I have also ran into fuel pumps making a tapping noise.

[Warren Webb]

While your at it remove & clean out the oil pressure relief valve. It's probably the most overlooked maintenance item.

[Mike Van Veghten]

What Frank said.

Mike

[studerodder]

Probably the fuel pump. If you bought an airtex pump from SI it is definitely the fuel pump.

[Geigs]

To close the loop on this topic, he decarbed the engine and the noise went away. It starts, runs, and drives without issue. Turn the key and drive away. Thanks for all the suggestions.

[Mike Van Veghten]

"Decarbed the engine"

Please do tell. What is this miracle action ?
Sounds a bit fishy to me. Carbon ISN'T formed on an engine that isn't running..!

Mike

[Tom Bredehoft]

Back in the '50s, it was sort of a common practice to de-carb an engine. You got the engine hot by driving around a while, stopped at home, removed the air filter and with the engine at high idle, dribbled water into the carb. The theory was that the water would be absorbed by the carbon (sure it would) and then turn to steam, loosening the carbon from the head and valves, and it would be blown out the exhaust pipe.

Either that or take it out on the highway and wind it out in second gear, high revving the engine under load.

Both recommended solutions for the build-up of carbon inside the combustion chamber. I'm not at all sure either of them did any good.

[dictator27]

removed the oil filter and with the engine at high idle, dribbled water into the carb.

Removed the oil filter? Proof reading required, Tom!

Terry

[Dan Timberlake]

"Carboned up" would not have been my first guess.
However I've had two running engines that had the carbon on the piston or head seemingly swell up after sitting for a couple of years and produce "symptoms."
One was a 1980 Ford fairmont 6 with ancient valve seals and > qt per 1000 mile oil use. I gave it to my dad when we got another car, and it sat in his yard until he wore out the other car some more.
When we tried to start it, it cranked a fraction of a turn and stopped. Some work with a breaker bar on the crank bolt revealed it could roll it a fraction of a turn backwards, but no further forwards. With the head off the carbon build up was significant, and quite flat. Decarb with a putty knife, fresh valve seals, and away it went.

To build our house I got a small generator. I put all kinds of gasoline thru that poor thing for several years, including my dirt bike premix at the end of the season. When we got power to the house the generator got stowed in the garage for several years. When I had occasion to use it again it ran with a distinct and alarming rap and I shut it off. So it sat for a few more years. One day I was starting to disassemble the engine from the generator to inspect the splined coupling, when I got to thinking about that FORD and decided I should pop the flathead cylinder head off first. Once again the carbon build up was extensive, and flat. The valves were QUITE loose in their guides too. Putty knife decarb, copper coat on the used headgasket, and it started and ran fine.

[Geigs]

Yes, what Dan wrote. I believe that was the case.