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Posted by: CSoso Oct 19 2015, 06:59 PM

Hi All,
I have a 73 base 914 with a 1.7L FI engine. When I accelerate hard, or even medium, I hear a rattling sound from the engine. Otherwise it starts great, runs great, no oil leaks or burning oil, etc. It has better power (according to my calibrated seat of the pants) than my old 1.7L dual Weber car. There are unknown miles on the engine as it was replaced with a "good used engine" 3 years ago by the original owner (stuck wot blew original engine). Engine #'s are correct for a non-smog 73 1.7L engine. Any ideas on cause and fix are appreciated!

Posted by: somd914 Oct 19 2015, 07:08 PM

A few typical items to check as a starters:

- Heat plumbing under the car: make sure none the elbows, flapper boxes, j-tubes, etc are tight and not rattling.

- Make sure heat exchangers and muffler are secure and not rattling such as with internal rust

- Alternator belt: is it tight

- Fan: make sure no foreign objects are floating around the shroud

Does it make the noise if you rev it up while sitting or just under load while accelerating?

Posted by: CSoso Oct 19 2015, 07:19 PM

Thanks! I will check those items. It only does it while under load. Could it be detonation? Thanks again!

Posted by: cary Oct 21 2015, 07:10 AM

Check that the muffler isn't touching the heat shield or the rear valance after everything gets warmed up.

Posted by: '73-914kid Oct 21 2015, 11:11 AM

Sound like gravel in a coffee can? That would be pinging...

Posted by: Bartlett 914 Oct 21 2015, 12:23 PM

it could be a rod knock

Posted by: dirk9141973 Oct 21 2015, 06:57 PM

I have a ping, rod knock under load like climbing a hill ?? is that bad? if I lift just a little goes away

Posted by: wndsnd Oct 21 2015, 06:59 PM

Sounds like pinging. Check timing.