QuestionQUESTION: Yes Im new to car repair and things and my lifters are making a rattling noise right under the head i was wondering if it were the lifters how do i go about adjusting them and 2 if its not the lifters what do i have to do to fix the noise because im pretty sure the sound that its making isnt just a sound its probably messing something up real real bad
ANSWER: Heya,
In most cases late model Chevrolet lifters are not adjustable but thats not to say the noise can be corrected externally. Lets assume A: That it IS a valve train noise that you are hearing and B: The engine is a 3.4 liter V6. I am assuming its a 3.4l due to lifter noise being fairly common.
If a general state of wear and tear has caused excessive play in the valve train there is no solution other than a motor tear down. Trying to figure out which lifter, which cam lobe, which pushrod or rocker is the culprit is not an easy task and can be very time consuming and technical. Remove the oil fill cap and flip it over. Is there a whitish residue? Is it covered in sludge or varnish deposits. Sometimes the cap is like a window into the general state of the lubrication system. If service intervals have been missed or skipped you might just have a lifter that sticking and not pumping up. Obtaining a engine cleans product like "Sea-Foam" (my personal fave) or Kleen Flo engine cleaner might break up those deposits and make a happy lifter!
The lifters could als be making noise due to water intrusion into the lifter galley from a leaking intake gasket. Google "GM intake gasket" and be prepared to sift through thousands of disgruntled GM owners with this complaint. Water causes corrosion and the lifter won't seal and pump up properly giving the valve train that extra play. Replacement of these gaskets and an engine flush can solve this problem as well.
The valve rockers are mounted to the aluminum cylinder head with an 8mm bolt and tightened down to a specified torque. If the rocker bolt is not torqued adequately or over torqued it can damaged the aluminum threads and the rocker bolt will start to pull out. The reason I say this is that maybe that composite intake manifold gaskets was leaking and the rockers need to be loosened the remove and replace this gasket. It is not uncommon for technicians to take a shortcut and not use the proper equipment to install them causing this problem. The rocker bolt holes can be drilled and heli-coiled with lock-tight making a fair-excellent repair. The rear studs can be a problem due to access but lets not hope that is your problem.
In a nutshell:
The rockers are probably not adjustable depending on the chev engine you have.
Try an engine flush or friction modifier and additive to free up sticky lifters
Remember : Never attempt repairs that exceed the value of the vehicles!
Wayne
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QUESTION: Ok ive tried seafoam once before and still no fix the Lifters still knock its a pretty loud knock you can hear it when you open the hood and i think my car is a 3.1 v6. So theres no at home solution that i could do To fix this problem becuase i was hoping to get a few more years out of it ? thanks
AnswerHey,
It sounds like your problem may be a wear issue. Other than an expensive tear down there really isn't much else you can do. You can try increasing the viscosity to take up that extra play. If you are not experiencing any driveability issues it may not be of a major concern anyways. Assuming that it is lifter noise the valves are still opening ok and not creating any compression problems or it would run rough. Everything else being said you may still get years of service out of it.
Hope that was helpful
Wayne Howie
