hydralic tappet noise

firecadet613 · January 7, 2002

My grandpa told me he thinks its the hydraulic tappet making a slight clicking noise in my engine while it's at idle. He told me to just put in a cleasner in my oil and it should clear up the deposit? What should I put in? My truck has 81,000 miles on it and I have been considering synthetic.

Thanks,

CMNTMXR81 · January 7, 2002

I doubt a cleanser will help your problem as it isn't a cleanliness issue. It's an issue of insufficient oil pressure and/or too much slack in the valvetrain. A faulty lifter could be also be working in tandem with bad oil pressure in one or more lifters.

A lifter not up to proper pressure essentially leaves too much slack in the valvetrain resulting in the ticking sound all the way from the lifter itself up to the pushrod and rocker arm assembly while it slaps against the valve stem that it should be pushing.

CMNTMXR81 · January 7, 2002

Another thought that comes to mind seeing as though you have a 95 with CPI is that on the fuel delivery side there is a tappet acutated set of tubes that are nicknamed "the spider" that is wore, could be making some excess noise.

firecadet613 · January 8, 2002

Ok I believe the noise has gotten a little louder. It appears to be coming from the bottom/passenger side of my engine. It is loudest at 2350RPM, it gets almost unnoticable at 3000RPM. Could it possibly something else? Any long term ill effects?

95Yukon · January 8, 2002

if you're sure it's not just pinging (does it only under load when you are driving it) but a mechanical sound (if it does it when parked or in neutral) and its coming from the bottom rather than the top end, sounds like it could be an engine bearing, which is not good, especially if it got louder that quickly. Check your oil for contamination (coolant will look greyish/white or foamy on the dipstick, and the level may also be higher than it should be.) Even if it looks okay, get it changed and see if there is any difference in that noise. If it is contaminated, you may have another problem which is messing up your oil, thinning it, and causing the noise. I wouldn't drive it in the meantime until you can diagnose it or pinpoint where it coming from and what could be causing it.

Torque converter to flywheel bolts also can cause some wierd noises if they come loose, and hard to tell where its coming from a lot of times.

When you rev it, does it sound like a light constant ticking which increases with engine speed, or more like shaking a can of marbles when it hits that rpm where its the worst? Does it have an oil pressure gauge, and has it dropped lower than usual lately?

Are you sure it isn't a cracked exhaust manifold or bad manifold gasket? Those tend to tick louder under load at lower rpms and quiet down at cruising speed. Just a thought..because engine bearing knocks will be heard generally from either side of the engine, while exhaust ticks will be louder on that one side. (unless its internal piston skirt slap or a wrist pin, which may also favor one side over the other)

firecadet613 · January 9, 2002

My truck just had its oil cooling lines replaced. It has an oil pressure gauge and that is in check. Oil pressure is normal. From your description it sounds like it could be a bad/cracked exhaust manifold/gasket. Is there anything I can do to check those?

Thanks!

CMNTMXR81 · January 9, 2002

I answered you PM and said the same thing. Sounds like an exhaust leak either at the manifold to head or the manifold into the Y-pipe/collector.

firecadet613 · January 9, 2002

Well I talked to my brother about it last night, and he told me what he does to fix sticky lifters. He said toss in a quart of ATF, run it for a day or two, but not more than 200 miles and then do a complete oil change and that should take care of it. Well I tossed in a quart of ATF last night, here's hoping it goes away.

firecadet613 · January 10, 2002

Well just had it by Midas, no exhaust leak. They told me there it might be a bad rocker arm, rod, or lifter. I had to take it by another shop to get them to finish up replacing the lower ball joint (they didn't tighten a bolt down all the way). The mechanic there said it sounds like it could be a rod bearing. The noise gets louder when my engine warms up, if that helps. So far the ATF hasn't made an improvement.

95Yukon · January 10, 2002

Usually a bad lifter or rocker will be louder on the one side where the problem is, from the slack in the valvetrain on that side. It will sound like its coming from the top end under the valve cover. You may want to pull the valve cover on the side which is louder and do an inspection for slack or anything obvious. Start it briefly with the cover off and let it idle while looking at the rocker arms. If the noise is coming from there, it will get much louder with the valve cover off and you may even be able to pinpoint which one is the problem by just looking at which one is opening and closing in time with the clacking noise.

If the noise isn't any louder with the cover off and everything checks out in there, I would suspect a rod bearing is on the way out. (its hard to diagnose without actually hearing it) If you do find slack in one of the rockers, look for signs of a bad rocker arm or push rod. If not, it could also be the lifter which opens it.

Be prepared if you take covers off and run it, there may be a little oil spatter, but won't be too bad at idle.

Edit: that's if your comfortable doing that.. I tend to think of things in terms of what I would do, and don't always think that some folks might not want to go wrenching into their engines on their own. If you are getting mixed opinions, you should try to take it to someone who has experience using an engine stethescope and has experience enough to know exactly what it is and where it is coming from. If you don't like their answer, by all means get a second opinion from another without telling them the first opinion you get, see what they say, and go from there. Definately look for a confident answer as opposed to a guess. If you let them tear into it, and they guess wrong, you'll be getting the dreaded phone call to let you know how much more it will cost than originally quoted, and be left to decide to spend the money or have them put it back together the way it was.

Let us know what you find out.

firecadet613 · January 11, 2002

Well dealership won't get a look at it until Monday. Just changed out my oil that had some ATF that I added into it, it was in there for 2 days, like 75-80 miles. That didn't help. The oil looked perfectly fine, no foaming or anything. Does that take out the possibility of an engine bearing? I put in regular dino oil, I'll switch it to synth when I get this all fixed. Noise is still there, still the same. It sounds like it could definatly be a lifter slapping against a valve. My engine almost ran out of oil when my oil cooling lines burst, I take it the lifters, rocker arms, and pushrods would run out of oil before the bearings?

Thanks!

95Yukon · January 11, 2002

The oil being clean takes out the possiblity that it was being caused by bad oil. I didn't realize you ran it out of or low oil when the lines burst. Did it run long like that? True the top end would lose oil first, but also doesnt require nearly as much as the lower end. Its more like a drip as opposed to a constant pressurized flow the bearings need. If there was no pressure for any length of time, you may have done some bearing damage. Let us know what the dealer finds out. Keep your fingers crossed.

firecadet613 · January 11, 2002

When the lines burst the engine was full of fresh clean dino 5W30. It only lost pressure for maybe a second or two, gauge shot to zero, then back up to 50, started going down & i shut it off. It was two seconds from the time it shot to zero to the time I shut it off. My fingers are crossed hoping for no bearing damage, I will keep you all posted.

Thanks again.

firecadet613 · January 14, 2002

Well it's a bad rod bearing on the #2 cylinder, at least that is what the diagnosis is so far. The dealership and warrenty company want me to authorize a $400 teardown authorization, which will be billed to me if the warrenty company decides to reject the claim. I do not know what I am going to do as of yet.