My mechanic said to do STP oil additive and ignore the noise, or have engine flushed. Says I cannot cause further problem ignoring the lifter clatter. Is this right or should I have it taken care of? (01 Olds Bravada)
I am susprised he did not try to sell you a repair. What type of further damage did your mechanic predict?
If I could hear it I could say ignore or fix, STP or engine flush will not buy you anything postive.
STP? I don’t think so. STP oil additive actually thickens your oil and it does not contain any detergents, so if anything, this goo might make the situation worse, rather than better.
I would suggest that you add 1/2 a can of Seafoam to the oil, and then change the oil within a day or two. Seafoam will frequently free-up a sticky lifter, and for far less money than tearing down the engine. Just be sure to change the oil within 100-200 miles after you add the Seafoam to the oil.
And, in the future, I would suggest that you schedule your oil changes more frequently, in order to avoid a recurrence of the problem.
I have had good results with CD2 detergent additive, not the thick honey version, for quieting a noisy lifter. Worth a try before you spend bigger bucks.
A little lifter noise will not harm your camshaft but a lot can do that.
If the lifter quiets down after the motor warms, I’d ignore it. It might not be a lifter; could be a worn rocker arm pivot assuming that you have an OHV engine.
STP is the wrong thing to use for a clattering lifter. Try a can of Sea Foam, Berryman B-12, or even Marvel Mystery Oil.
You did not state if one or more lifters are rattling or if this rattle is constant or not. The rattling could be caused by faulty lifters (they must all be replaced) or by a number of gummed up or stuck lifters (a cleaner may fix that).
Your mechanic is incorrect that rattling lifters cannot cause further damage. If left alone loose lifters will also destroy cam lobes. That rattling is actually sledge hammer blows being applied to the cam lobes and when they beat through the hard coating of the cam lobes the camshaft will not last long.