I have a 1984 Toyota truck that makes a slight knocking sound or a “duh-duh-duh-duh-duh” sound while running. It doesnt seem to be affecting the way it runs and has been making this sound for a couple years now. Someone suggested i needed a valve adjustment. The trucks engine seems solid and this is probably a minor problem, but i want to provide any necessary maintenance before any serious problems arise. Any advice would be appreciated.
DWIGHT
Comments
It is possible that you do need a valve adjustment, but take it to a reputable mechanic for an diagnosis and estimate before you do it. Collect at least 3 or 4 of these, then compare both the diagnosis and prices before you decide which to go with. Also check on the warranty on the work.
If it isnt a ‘tinny’ sound does it have an air pump (i.e. california emissions) it sounds like an air pump noise! Its not unusual if you have a bad air pump diverter valve
Valves go tic-tic-tic-tic not duh-duh-duh-duh.
Rods go knock-knock-knock.
Pistons go slap-slap-slap-slap.
If runs good, leave it alone.
Valves go tic-tic-tic-tic not duh-duh-duh-duh.
Rods go knock-knock-knock.
Pistons go slap-slap-slap-slap.
Laughing My A$$ Off……..
I have to agree with the fault air diverter valve. This will make that type of noise, and it will be a soft one. It could actually sound like a lawnmower engine with a rod knock…if you’ve ever heard one. It could also be a wrist pin knock. My buddy had a Cavalier with a wrist pin knock…we blew the transmission out of it before the motor….we actually put the motor in another car…Good old American muscle..gotta love it! So..if it’s still running…count your blessings, and put Virgin Mary on the dashboard. That’s an old piece of Jap tin…run it into the ground buddy. Can’t be much left of that sardine can, anyways.
