hello everybody i am new to this forum site. looks like alot of people with some helpful information.

i recently took in my girlfriends sisters 2001 honda accord DX into my shop for repair. its a 16valve non-vtec SOHC 4 CYLINDER. engine code f23a5.

she brought the car to me with a leaking water pump, and therefore i replaced the balance shaft belt, timing belt, tensioners (2) and the water pump, tensioned everything correctly and reinstalled all the components.

heres where im kinda at a stand still. even before she brought the car to me, it sounded like she had a bad knock coming from the top portion of the engine more towards cylinder #1 or the cam gear... i turned the accord on after install and she ran perfect, no belt noise once so ever, however the knock is still there.....it only occurs between idle and about 1500 RPM and thats if i really tap the gas quick, with a slower progressive idle increase the noise doesnt really occur.

ive checked valve lash on only cylinder #1 today just because the engine was still a bit warm, ill check and adjust once more tomorrow while its cold, however the lash really didnt seem to bad, 1 intake 1 exhaust was a bit loose but still felt a TINY bit of drag on the feeler gauge (.010 for intake and .012 for exhaust)

SOOO QUESTION BEING- what are some other sources of a knock sound (almost like a diesel) can cause this? maybe rods? maybe the timing belt is to tight?.....also wen checking valve lash iv heard mixed stories...alot of repair manuels say check it at TDC for each cylinder while techs have told me to check valve lash with the base circle of the cam facing up directly above the rocker? any truths behind this.

thanks for the help!!! ALX

 

The Helm shop manuals say to check all 4 valves when the cylinder is at TDC of the compression stroke. Personally, I think it makes very little difference which part of the base circle you're on.

Measure valve lash when the engine's cold, like you said.

You said the noise depends on throttle? Sure it's not a tiny leak in the exhaust manifold gasket?

 

If the rattle noise goes away after the engine is warmed up I'd bet it's piston slap.
There was a service bulletin about it.

 

yes i have thought about replacing the exhaust manifold gasket because the honda dealer had told her there was a small leak at the manifold and at the catalytic converter however i couldnt find anything...

and yes from what i recall when i pulled the car in, the noise did not occur (she had been driving it around earlier that day) . what causes piston slap? ill look around the forum site for the article.