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View Full Version : Rattling when I punch it... knock?



Sabz5150
08-19-2004, 01:34 PM
I think it's engine knock (Bad Thing), it only happens when the engine's warm and when I get on the pedal. I've got my cam advanced three degrees, timing is adjusted back to compensate. I'm running 89 octane gas in there.

Any clues as how to fix my rattle?

NXRacer
08-19-2004, 01:44 PM
can you tell if its a top end noise or a bottom end knock? Try running the fuel injector cleaner through it and maybe some octane booster and see if that helps. You might be running a little lean due to your timing adjustment.

shepherd79
08-19-2004, 02:25 PM
it couldbe your valves rattle

Sabz5150
08-19-2004, 09:31 PM
I can't tell where it's coming from b/c it only does it when the engine's warm and under load... hence I've gotta be driving to make it happen. NO I will not look under the hood going 60!

I do need to adjust my valves, so I'll take care of that this weekend. As for running lean, how would I remedy this. I've got an adjustable pressure regulator, but that won't do diddly till I get some serious mods going on.

Time for an AFC perhaps?

k-roy
08-19-2004, 11:17 PM
If I were you I would bump up the pressure a few psi and adjust the valves.
Don't you have a regrind? I think your clearences should be a little differant than stock.
Oh and adjust the valves when the car is bone cold, like after sitting overnite.

shepherd79
08-20-2004, 03:33 AM
you can't be running lean. when i got my Air/fuel gauge, my car was running way too rich. so i had to use Apexi to turn it down. even than, i still running a little rich.
your problem is not running lean. keep checking.

thegreatdane
08-20-2004, 03:52 AM
Mine was also knocking some when i floored the pedal at low rpms. (worst in 5th gear going real slow and then flooring it). I changed my injectors, poored some injector/valve/engine cleaner in the tank and changed to a higher octane (currently trying out a gas called "V-power" from Shell). Now it's as good as gone along with a better mpg and it starts much better.

NXRacer
08-20-2004, 07:10 AM
i always notice a slight 'ping' wheni run anything less then plus grade gas.

shepherd79
08-20-2004, 08:18 AM
most likely it is your valve train making noise. adjust the valves and plau with your timing.
it sounds like it is too far advanced.

Sabz5150
08-20-2004, 09:11 AM
most likely it is your valve train making noise. adjust the valves and plau with your timing.
it sounds like it is too far advanced.

When I adjusted my cam timing, I made sure to back the distributor off so that it was at 15 degrees BTDC, where it should be. I can back it off further if needed.

Lemme crack open the valve cover and adjust the valves, if that doesn't do it, then I'll retard the distributor a few degrees.

shepherd79
08-20-2004, 12:49 PM
when you adjust the valves, remember to put the cam gear to stock specs.