Hey guys, brand new to the forum.. but I have a 97 Chevy Tahoe Z71 with a 5.7 engine. After the truck warms up you can hear a ticking under the valve cover, I was told it may be a stuck lifter and try and flush my engine. Would you guys recommend this? and if so what would you recommend to use to "flush" the engine out?
Stuck Lifter
- Thread starter icyjay01
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Do a search on MMO(Marvel Mystery Oil).
Before you run any snake oil through it, doesn't the 97 350 still have adjustable fulcrum rockers? It would be a wise idea to check the adjustment of the valvetrain before assuming a dry lifter is the problem. No amount of oil treatment in the world will make a rocker that's backed off out of adjustment get quiet.
No it wouldn't hurt.
440's sentiment is the same as mine. People around here try to "fix" loose and out of spec valvetrain components with cleaners, thick oils, lucas, mmo, whatever all the time. And while the placebo effect seems very alive around here, really if there is an out of spec lifter or lash adjuster nothing but adjusting it will help.
But, sometimes valve adjustments are difficult. And, it wouldn't hurt of take much time to run a quart of MMO or Seafoam in the last few hundred miles of an oil change. Who knows, and the cost isn't that high in time or money.
440's sentiment is the same as mine. People around here try to "fix" loose and out of spec valvetrain components with cleaners, thick oils, lucas, mmo, whatever all the time. And while the placebo effect seems very alive around here, really if there is an out of spec lifter or lash adjuster nothing but adjusting it will help.
But, sometimes valve adjustments are difficult. And, it wouldn't hurt of take much time to run a quart of MMO or Seafoam in the last few hundred miles of an oil change. Who knows, and the cost isn't that high in time or money.
If you are certain it is a lifter and not the injectors making noise, try running a pint of MMO for the last 1000 miles of your OCI. Since you have a problem a qt would be better but that would mean draining some oil if your oil level is to the full mark. Being a pint over won't hurt anything. If the MMO stops the noise, and in many cases it will, you've saved yourself some time and money. If not pulling the valve covers and checking like others mentioned is the next option.
I would run a pint of MMO the last 1K miles of your current oil/filter change. I am not into snake oils but MMO does help sometimes. Give it a try.
If MMO does not help, you should check with a good mechanic to see if you need a possible valve adjust. depending on the miles, your valves may need to be checked.
How many miles on your SUV? If over 100K miles, it may just need a cleaning up.
If MMO does not help, you should check with a good mechanic to see if you need a possible valve adjust. depending on the miles, your valves may need to be checked.
How many miles on your SUV? If over 100K miles, it may just need a cleaning up.
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I agree with a valve adjustment then a dose of MMO.
Has the design of the Chevy 350 engine changed? When I worked on them they didn't require adjustment during normal service life. Many times if they are making noise it was some dirt. That is why I suggested the MMO first, then look further if that doesn't work. Now if the design has changed it is a different ball game. Also if the car is not running properly, missing, or lacking power along with the lifter noise, I would pull a VC first, and check for problems. JMO
I've had excellent results with Redline oil. It's Group V ester-based synthetic. It has natural cleaning qualities.
I've had two Mazda Miatas with noisy lifter. The first one was pretty noisy overall, and was cured within a month.
The second one has one really weak lifter. On startup, it sounded as if it had a 90 thou. valve clearance, ie, super-loud. It went away after the oil pressure filled up the bad lifter, after say 20-30 seconds. Worrying, even though it did go away.
I've had Redline in it for about 10 weeks now. It's noisy for about two seconds, then quiets down as the oil gets pumped in.
This is Redline 10-40. I may go to Redline 0-40, to build up oil pressure faster.
Another thing: oil consumption and leaks have dropped. Esters have natural seal-swelling properties. So, the cam position sensor O-ring does not leak any more. And the valve guide oil seals don't pass as much. I'm using 40 not 30 to cut down leakage past the valves.
I've had two Mazda Miatas with noisy lifter. The first one was pretty noisy overall, and was cured within a month.
The second one has one really weak lifter. On startup, it sounded as if it had a 90 thou. valve clearance, ie, super-loud. It went away after the oil pressure filled up the bad lifter, after say 20-30 seconds. Worrying, even though it did go away.
I've had Redline in it for about 10 weeks now. It's noisy for about two seconds, then quiets down as the oil gets pumped in.
This is Redline 10-40. I may go to Redline 0-40, to build up oil pressure faster.
Another thing: oil consumption and leaks have dropped. Esters have natural seal-swelling properties. So, the cam position sensor O-ring does not leak any more. And the valve guide oil seals don't pass as much. I'm using 40 not 30 to cut down leakage past the valves.
A dose of MMO or Rislone with a good HDEO like Rotella, Delo, Mystik, or Delvac would probably help if its a lifter. I did the MMO flush on our 3.1 GM V6 and it helped a lot. A full run with Mystik JT8 semi syn 10w30 and Rislone finished it off and now its dead quiet.
Adjusting the valve lash on a 350 is easy as cake, but you can try this first as a cheap fix.
Adjusting the valve lash on a 350 is easy as cake, but you can try this first as a cheap fix.
I had a noisey lifter on a 4.3 v6 basiclly the same motor, 1 pint of trans fluid cleaned it out and stopped the noise. trans fluid cleans as good as MMO, and won"t burn off as easy. I used 1 pint of trans fluid every oil change in the winter. my 2 cents.
PDF: How to Adjust Your Chevy Valve Lash
That was the instructional I found that accurately described all the need-to-know information for adjusting valve lash. He claims that the standard GM specification is good for 100,000 miles. I have two Chevy 350 engines: 150K and 250K. Both needed valve adjustment.
Rather than rotate the engine 8 times I find it easier to rotate it only twice by making a chart from the original instructions.
So do both. Run some MMO then find the time to adjust the valves.
That was the instructional I found that accurately described all the need-to-know information for adjusting valve lash. He claims that the standard GM specification is good for 100,000 miles. I have two Chevy 350 engines: 150K and 250K. Both needed valve adjustment.
Rather than rotate the engine 8 times I find it easier to rotate it only twice by making a chart from the original instructions.
So do both. Run some MMO then find the time to adjust the valves.
What weight oil are you rnning? What is specced? I ran 10W-40 in my cav middle of last year and it didn't like it, it had a very loud tappet and lifter noise. I changed to 5W-30 PP and it went away.
If it is just a dirty lifter sticking and/or not fully pumping up Seafoam will take care of it within say 100 miles. MMO will as well but the Seafoam will do it faster. I have used both and both are excellent for this scenario/problem. I just prefer the Seafoam these days.
No additive however can fix mechanical failures or a rocker out of adjustment. I agree it makes sense to try the additive first. $10 + an OC vs the $$$ of a valve lash adjustment( assuming you would pay to have it done ). Seafoam and MMO won't hurt anything so give one a try before going through the hassle and $$$ of checking the adjustment.
No additive however can fix mechanical failures or a rocker out of adjustment. I agree it makes sense to try the additive first. $10 + an OC vs the $$$ of a valve lash adjustment( assuming you would pay to have it done ). Seafoam and MMO won't hurt anything so give one a try before going through the hassle and $$$ of checking the adjustment.
Originally Posted By: NHHEMI
If it is just a dirty lifter sticking and/or not fully pumping up Seafoam will take care of it within say 100 miles. MMO will as well but the Seafoam will do it faster. I have used both and both are excellent for this scenario/problem. I just prefer the Seafoam these days.
No additive however can fix mechanical failures or a rocker out of adjustment. I agree it makes sense to try the additive first. $10 + an OC vs the $$$ of a valve lash adjustment( assuming you would pay to have it done ). Seafoam and MMO won't hurt anything so give one a try before going through the hassle and $$$ of checking the adjustment.
I agree, I never tried Seafoam for engine cleaning but many swear by it. Pulling a VC to check can be a PITA, which is why I suggested the MMO cleaning first. My brother ran Chevy 350 V8's for years and years, some close to 200,000 miles w/o a valve adjustment. A little bit of dirt can cause lifter noises too, so cleaning isn't going to hurt. If the condition remains the same, then pulling the VC would be my next step. OTOH, I've had friends over the years drive over 100,000 miles with lifter noise, didn't care, and didn't want to do anything about it either.
If it is just a dirty lifter sticking and/or not fully pumping up Seafoam will take care of it within say 100 miles. MMO will as well but the Seafoam will do it faster. I have used both and both are excellent for this scenario/problem. I just prefer the Seafoam these days.
No additive however can fix mechanical failures or a rocker out of adjustment. I agree it makes sense to try the additive first. $10 + an OC vs the $$$ of a valve lash adjustment( assuming you would pay to have it done ). Seafoam and MMO won't hurt anything so give one a try before going through the hassle and $$$ of checking the adjustment.
I agree, I never tried Seafoam for engine cleaning but many swear by it. Pulling a VC to check can be a PITA, which is why I suggested the MMO cleaning first. My brother ran Chevy 350 V8's for years and years, some close to 200,000 miles w/o a valve adjustment. A little bit of dirt can cause lifter noises too, so cleaning isn't going to hurt. If the condition remains the same, then pulling the VC would be my next step. OTOH, I've had friends over the years drive over 100,000 miles with lifter noise, didn't care, and didn't want to do anything about it either.
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