Valves Knocking at Idle

gregpenn · Post by **gregpenn** » Tue Jun 05, 2018 1:17 pm

65 Monza 140, automatic. Starts fine, no knocking, drive 10-15 miles on highway at 60+mph, engine is hot, pull up to a stoplight and the rattle happens while idling, accelerate and once trans shifts to 2nd no more noticeable noise. Engine is not leaking or burning oil. I tried fuel additive but didn't seem to help. Premium gas does seem to reduce knocking, not completely. Thoughts anyone?
The 140 with powerglide trans is a gas guzzler. I think I'm getting about 19-20 mpg. Is that normal?

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Post by **terribleted** » Tue Jun 05, 2018 1:59 pm

Not normal. Is it really hot? Make sure oil cooler and top of engine not clogged with leave and debris. Timing may be too far advanced as another possibility. Poor fuel may also be the issue 140 especially PG needs premium fuel

gregpenn · Post by **gregpenn** » Wed Jun 06, 2018 6:30 am

Oil cooler and top are clean. I know the mechanic that replaced oil cooler rings for me also advanced the timing. Thanks.

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64powerglide · Post by **64powerglide** » Wed Jun 06, 2018 7:23 am

Better check the timing again.

corvairsince70 · Post by **corvairsince70** » Wed Jun 06, 2018 2:27 pm

Another reason a 140PG will ping at idle is the secondaries are not closed completely. This causes it to run very lean.

66corsaguy · Post by **66corsaguy** » Wed Jun 06, 2018 2:32 pm

I had problems with pinging. I was using premium gas and also add a 1/2 bottle of 102 but still had on occasion.
what got rid of my pinging permanently was my new re built carbs, balanced properly and timing set at 18 I don’t hear any ping anymore.

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Post by **terribleted** » Wed Jun 06, 2018 4:31 pm

Oh concerning fuel mileage I would call your mileage fairly normal and perhaps even good. I have had 110HP 2 carb PG cars that got around the same MPG.

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