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-   -   Valve Rattle??? (https://67-72chevytrucks.com/vboard/showthread.php?t=171393)

woodyjim 09-03-2005 01:56 PM

Valve Rattle???
 
Hey, I'm getting a rattlle on accelleration (hard, easy, doesn't matter) and when going up an incline. I'm running a stock 305 on 87 octane "liquid gold".
It is definitely a rattle, not a knock. Any suggestions? :confused:

cliffsta 09-03-2005 02:02 PM

For me, one or two things made my valves quit clattering during the summer. When I got the truck, I switched to Valvoline MaxLife oil rather than El-Crappo cheap stuff. 2, I went to the dealership and ordered the fresh air duct that goes from the air cleaner to the opening in the grill, cause mine was gone since long before I began driving it. Which did it, I don't know. :lol: But my valves quit clattering and they haven't clattered since.

red86chevy 09-03-2005 04:55 PM

check your timming. If you can retard it a little it will help significantlly(SP?) Also 89 or higher octane "liquid gold" would also help. But it doesn't cost to bump your timming back a little.

cliffsta 09-03-2005 07:43 PM

Quote:

Originally Posted by red86chevy
check your timming. If you can retard it a little it will help significantlly(SP?) Also 89 or higher octane "liquid gold" would also help. But it doesn't cost to bump your timming back a little.

Yeah, that woulda been my best suggestion. Timing might be too aggressive for the octane gas you run.

KShortell 09-03-2005 09:29 PM

I've been wondering how well that MaxLife works. I've been running the regular Valvoline. I'm considering using Valvoline's MaxLife next time around. I do have 137,000 some odd miles and 19 years on this original engine.

cliffsta 09-04-2005 01:43 AM

MaxLife works great for me. I really think that is what elliminated my valve clatter. I don't really got any other big "oh wow it made $100 bills fart outta the exhaust" stories, but the truck runs very well with it in it and of course the elimination of the clatter. :)

woodyjim 09-04-2005 02:38 PM

Thanks alot Guys,
I'm sure this info will help. Any suggestions on a starting point (how many degrees) to retard the timing? I'll try the oil too, but my fresh air duct is in good shape. Would "Octane Boost" or = help?
Thanks again! :gi:

red86chevy 09-04-2005 05:31 PM

First of all I would check your timming and see where it is at. With vacuum advance disconnected and pluged. Compare that with what the engine specs call far. If it is high at all I would bring it down to where the manufacturer suggests. (this should quiet down the rattling) If is is already correct, you could lower it a couple of degreese but you will notice a powerloss.... 89 octane would probably take care of it though. I would not buy octane booster b/c it only raises your level about .5 octane so IMO you would be better off to take that money and use it toward 89 or 93 octane.

Is your engine computerized?(1987 or up) If not I would check the timing and if it is 8 degreese or more BTDC I would bring it down to around 4. However if you are worried about loosing power you'd be better off to go with the gas.

Jeremy


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