valvetrain tick after switch from 0w40 to 20w50

Joined
Dec 4, 2005
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Kingston
The engine is a mid 70's 350 Olds bone stock with unknown mileage (I've put 30k on it since pulling it from the junkyard). It has the stock flat tappet cam and has never been apart. I've run a number of different oils brands and weights, synthetic and non synthetic. I drained the Rotella Syn 0W40 out with 3k miles on it (had not used any noticeable amount in 3k miles) and refilled with 20W50 VR1 Valvoline which I've used last year. My engine has always been slightly low on oil pressure only at a hot idle, and this oil raised the pressure up noticeably but now it has a tick under the drivers side valve cover that I can hear just barely from in the car with the window down. Not sure how a heavier oil can cause that on a hot engine but its there. I think this is the only non synthetic oil I've run in this car other than for winter storage one year. Maybe the synthetic kept it quiet? Any thoughts? I like the higher oil pressure but don't like the noise.
 
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Joined
Jun 17, 2005
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Billings, MT
 Originally Posted By: 72customdeluxe
maybe try a pint or quart of Marvel Mystery oil
If anything, do this just to thin that overly thick stuff out.
 
Joined
May 12, 2008
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Canton, GA
 Originally Posted By: hounddog
Overly THICK oil,LOL Thats why YOU hear something!
Yeah I agree ^^^ too thick,you don`t need it that heavy.
 

caprice_2nv

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Dec 4, 2005
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FWIW, the noise has quieted down after putting some miles on. I've gone 700 or 800 miles since the oil change and the oil still looks perfect and pressure is still the same, just the noise is finally almost non existent again. I've noticed a slight bit of noise before following an oil change that lasted several days of driving, but never this loud before. Maybe it has nothing to do with the oil weight.
 
Joined
May 30, 2003
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Airlie Beach Australia
Hi, caprice_2nv - Those engines loved a diet of 10W-30 when new. IMO a modern 10W-30 would work very well indeed - or just go back to the 0W-40 you were using As long as you have around 3/4bar (without the low OP light on) at a hot idle all will be well - the critical thing is to get normal OP at around 2000rpm
 
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