Question:
Question about valve tapping?
sha1gon
2009-04-27 08:14:20 UTC
I have a valve tap which only happens when my engine is cold. After the engine has warmed up the sound goes away or at least gets low enough so you can't hear it anymore.

This sound basically happens in the mornings after the car has been sitting all night, or when I'm leaving work and the car has been sitting outside all day.

Is there something I could put in next time I do an oil change that could help this problem? I've heard of a few additives that can help clean/unstick any stuck lifters/rings etc.

Also, if it came down to it...is it a big/expensive job to replace hydraulic lifters? The car is a 1999 Chevy Malibu 3.1 V6 and only has 110,000km's on it.

Help/input appreciated.
Five answers:
Randy p
2009-04-27 08:26:04 UTC
STP oil treatment
Country Boy
2009-04-27 08:37:54 UTC
The next time you change the 5W-30 motor oil try one of two things: #1. Switch to Mobil1 or Valvoline full synthetic. The detergent additives are very aggressive in these two brands of synthetic oil. #2. If you don't want to spring for full synthetic oil, pick up a quart of Rislone and substitute it for one quart of your regular 5W-30 next time you change oil. Rislone is a high detergent oil additive that cleans piston ring grooves, hydraulic lifters and helps dissolve gum, varnish and sludge.



Havoline, Valvoline, Kendall, Mobil and Brad Penn tend to have better detergent properties than other brands. Make sure you're using an AC-Delco or Wix oil filter also.



GM's roller hydraulic valve lifters are quite expensive. All you would really need to do is replace the one that's clattering when cold. Nowadays GM lifters are nonadjustable and thick molasses STP oil treatment has no detergent properties. It will actually slow down the ability of the hydraulic plunger inside the lifter from pumping up when tou start the car.
What to do?
2009-04-27 08:37:27 UTC
The tapping is caused by a lifter not filling up with oil quickly on startup. The cause is the passage is blocked by oil residue. There are several products in the auto stores, I recommend Berryman Chemtool. You add it to the oil when you're going to have an oil change. You can't run around with this stuff, it's solvents, and it's just to clean the gunk out just before you drop the oil. If that doesn't work, it's a real hairball to pull a lifter due to the amount of stuff on top of the engine.
vicki jean
2009-04-27 08:34:34 UTC
try something like stp oil treatment..that should stop the lifter from making noise..try a heavier weight oil..do not put in 5w30..stay w/10/40...yes its very expensive to have lifters changed..but i dont think that would help your problem..try adjusting the lifters..u may have a bad rocker arm or push rod..chevy 3.1 is not the best of engines,you have to give them alot of maintanance....car person from the usa
ken k
2009-04-27 08:24:20 UTC
if you are using the proper weight oil you should not have any problems/use 5 w 30 and it should clear up/dont fall for the old if 5w30 is good 10w is better. you need lubrication and the 5w is it. do not use 10w40 its only for cabs or police cars/change oil every 3500 miles


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