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chevy 350 valve lifter noise

My 98 Tahoe makes valve lifter noise when I do a cold start like overnight. It is persistent but not extremely loud. Thing is, it goes away after about one minute of idling, then doesn't come back. How bad is this? Should it be fixed, or ignored for now?
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Comments

  • edited December 2007
    We had a similar post some time back, and most of the regulars concluded that when the valve lifters on type of engine wear, the oil drains from the valve gear, and upon startup, they are noisy until the oil pressure builds up, when it disappears. Nothing to worry about; my Chev Impala with th 305 V8 did this for several years. Don't put heavy oil in your engine, as some might be tempted to do. That will create many other problems, including rapid engine wear at startup. You might also notice a small puff of smoke from the exhaust after startup; that is some oil draining past worn valve guides into the cylinders, resulting in some oil burning. This is also nothing to worry about unless it is severe. If you need to go for a smog test, make sure the engine is well warmed up, since the burning oil will make you fail the test.
  • edited December 2007
    I've been using synthetic 5w30, which is the weight that it calls for. I've been tempted to go to the 0w30 in the winter, to get that lifter lubed quicker.
  • edited December 2007
    If the engine is quite worn, and has large clearances, the 0W30 might make it WORSE, since this stuff is extremely thin and slippery. Synthetic oil manufacturers often issue a warning about valve lifter noise when using synthetic in an older engine. If I were you, I would go back to a regular 5W30 mineral oil for one oil change to see if it improves. If not, you need one or more valve lifters replaced if you want to get rid of the noise. Most people just keep driving and put up with the noise. Your engine is not in danger. Replacing valve lifters on your engine is not difficult.
  • edited December 2007
    Thanks. Dino juice makes it worse, in the sense that it takes longer to go away in cold weather. I assume this is a viscosity phenomenon. Last questions. (1) I have been waiting till it goes away to engage a drive gear, assuming this would protect the engine. It takes about a minute. Is this necessary or desirable?
    (2) How much might it cost to replace a lifter? It's a 1998 Chevy 350. (3) I guess one would do that if the noise didn't go away, right?
  • edited December 2007
    Most engines with hydraulic valve lifters make some clattering noise during warmup. This is rather harmless, unless it persist after the a few minutes and when warmed up. Yes, an equivalent 5W30 dino oil is thicker than synthetic at very low tempertures (they are equal at 0 Celsius), and flows slower. So your 5W30 synthetic is probably the best compromise. If it takes only a minute or so for the noise to disappear, you're OK, the engine is not in danger. If the ticking persists, you should have it fixed for sure. Sometimes you can get this noise if the lifters are sticking because of not enough oil changes. In that case, the noise would persist, but could possibly be cured with a can of valve lifter additive. GM used to sell it themselves. But, I assune you have maintained the vehicle well.

    I have not replaced a lifter for a long time, so you would have to get a quote. (Best go to an independent shop who know GM engines. The dealer would charge you a fortune.) It's done after removing the intake manifold, which then allows access to the valve gear. The lifters themselves are cheap.

    Since you have little to lose, you can try a can of valve lifter additive, and see if it makes any difference.
  • edited December 2007
    What the guys are saying about using 5W30 in winter in this engine is right.

    The 5W30 you read off the oil filler cap is what GM recommends year round.

    I have the 5.3L in my 2002 Tahoe 4x4 (130k miles) and the lifters are noisy on the initial start up (lasts maybe 45 secs) but only during the cold months. (Up here in Ontario that can last 5 months)

    In the spring I switch to 10W30 for the rest of the year as I tow a travel trailer down to South Carolina and sometimes to Florida. (Can't afford to store the tt there or stay all winter, darn it)
  • edited December 2007
    the lifter has as spring inside to make them push on rod to open valve. also the hole for oil to pass through the lifter is as small the ball in a ink pen. if just a small chunk of dirt get in lifte the holes get cloged. put oil cleaner in engine follow directions. and change oil put more in next time you change oil remember you might have to put less oil because of the cleaner. the problem you get from sticking
    lifters the valve is not opening you are not getting the proper air fuel mixture and you could burn a valve .yes you can run for a long time like this BUT----- thicker oil will stop flowing through small holes and take longer to thin out stay with 5/20 or 5/30
  • edited December 2007
    Remember, this problem goes away after a few minutes of engine running--faster in warm weather. It does not reappear on a start the same day. So, I think it is draining down, then refilling on start, rather than being plugged. I suspect wear, not dirt.
  • edited December 2007
    Melott,

    You are most likely mistaking valve train noise with piston slap on cold start due to hyper-utetic (sorry, no spell check) pistons that GM uses.

    We have the same issue with our engine and on a previous chevy.

    Search the web and you'll find that Chevy is aware of the issue. There is no fix.

    -Matt
  • edited December 2007
    Is this damaging; can the damage be reduced by idling till it goes away before takeoff?
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