Ticking lifters = half opened valves?

If a lifter is leaking or clogged it makes a ticking noise. I'm assuming this is from a lack of oil pressure under the lifter plunger and the plunger either bottoms out on the bottom making a "tick" or it comes down a bit and then makes a "tick" when it smacks back up into position...or both. If either of these are true can the valves be fully opening?? Is the lifter shallow enough so that if the plunger is completely compressed in it, the valves will still open slightly?

So, if lifters are ticking is power being lost due to a lack of intake and exhaust flow into the cylinder?

Thanks

The purpose of the hydraulic valve lifter is to enable the idea of a "self-adjusting" valve train. While it's true you will lose lift if the lifters aren't pumping up (or have gone flat entirely!) you typically don't lose more than about .100" of lift at the lobe, and that is livable. Yeah - you lose power, but you don't lose the cylinder.

If the lifter "goes solid" (refuses to pump down for whatever reason,) you will have the opposite problem. There is a real possiblity that you will lose .050"-.100" of lift that would usually result in the valve being closed, and you would lose compression and power - with the effect more noticable at lower RPMs.

Either way, expect to change the lifter(s!). Yes, you need to pull the head to make it happen. No, there isn't an easier way. Yes, it will take you the best part of the day - and you will be better off having a helper to pull the head with both manifolds attached to save knuckle wear. Replace the gaskets, and install the head and manifolds as a unit (it can be done lone-handed, but only if you are willing to put up with a little pain - it ain't easy!)

5-90

EDIT - Yes, lifters not lifter. With all the work involved, it would be just asinine to change only one of the twelve - you're in there anyway, and it's just as much work to change all of them as one of them!

5-90

It is always best to try to clean the lifters before replacing them. I've seen this done successfully many more times than I've seen the lifters needing to be replaced. The best procedure is to pour a quart of automatic transmission fluid into the crankcase (may have to drain a little oil out first), then drive around a little, then change the oil. The ATF is very highly detergent and can clean the crude out of the lifters.

This isn't just a backyard fix, we do this in the shop.

Goatman said:

It is always best to try to clean the lifters before replacing them. I've seen this done successfully many more times than I've seen the lifters needing to be replaced. The best procedure is to pour a quart of automatic transmission fluid into the crankcase (may have to drain a little oil out first), then drive around a little, then change the oil. The ATF is very highly detergent and can clean the crude out of the lifters.

This isn't just a backyard fix, we do this in the shop.

Click to expand...

Interesting.

What do you think about flushing and evacuating the engine ?

I had the dealer evacuate and flush my transmission a few years ago with one of those Bosch units ... it seemed to improve the converter lockup function.

I've been kinda wary having the engine done though ...

If the plunger in the lifter is stuck down...it will make more than a "ticking" noise...try GoatMan's ATF flush trick...it's one of those tried and proven tricks...the detergent in ATF helps to keep varnish out of the delicate spool valves in an auto trans...I have effectively used the trick myself...if it don't help, you aren't out much effort or expense...

Is it one lifter noisy, or is the whole valvetrain ticking?? How much oil pressure do you have?? Have you eliminated other possible sources for the noise??

If it comes down to an internal problem...check the gross lift of the camshaft before going thru the hassle of lifter replacement..if the cam is worn out, it needs replacement too...

bchulett said:

Interesting.

What do you think about flushing and evacuating the engine ?

I had the dealer evacuate and flush my transmission a few years ago with one of those Bosch units ... it seemed to improve the converter lockup function.

I've been kinda wary having the engine done though ...

Click to expand...

The reason you flush a tranny is to get the old oil out of the torque converter and the trans oil cooler lines running through the radiator. A simple fluid change won't do that, so a flush pumps fresh fluid into the entire system. This isn't necessary every time you service the trans, but it is a good idea.

This isn't necessary (or even possible) on the engine because all the oil drains back into the pan every time so a normal oil change gets it all.