Valve Lifters NOT Moving

[keithems]

my late model a4 [bought used in late 2007] ran well until a month ago, when the problems began -- all of which i've posted in other threads....

yesterday i reopened the valve chamber....

when turning with the hand crank, only #4 exhaust moves -- all other tappets are completely stationary!

so i pulled the head [again!]

#4 intake valve had separated from keeper & retainer, and i just pulled it out from the top

all other valves are not moving, though they can be pried up from the top and tapped down ....

so..... why are the tappets [except #4 exhaust] not moving?

do i have a broken / bent cam? is there any way to avoid an engine teardown?

i'll be compressing springs and removing the valves as soon as i get the tool.....hopefully, that will free up the tappets also?

or am i staring an engine teardown in the face...?

[ILikeRust]

I submit it really is best to keep all of your engine stuff in one thread, rather than keep creating new threads all the time. It gets confusing, because now we've got multiple threads about the same problem on the same engine.

Just stick with one thread. No need to keep making new ones.

[Bold Rascal]

Tappets

Your tappets should rise and fall as the rotating cam lobe upon which they ride allows.

If they are truly frozen in place chances are they are (or most of them) will be at their highest point of travel.

Try a little wd 40 or other oil friendly lubricant cleaner and see if you can gently get them freed up or at least able to spin in thieir holes.

I don't know how the cam is driven in an A4 though I doubt (hope for your sake) that the cam has not failed.

"all other valves are not moving, though they can be pried up from the top and tapped down ...."

If your valves and valve guides are clean, springs, keepers and retaining washer's properly installed you should'nt have to tap your valves down.

Have any pics you can post?

[ILikeRust]

Here is the problem and confusion caused by creating multiple threads instead of sticking with one.

We were already having this discussion over here.

[Bold Rascal]

Thanks Bill

I was wonderring why it was not getting much attention.

It was good answer though, Huh?

[67c&ccorv]

Another possibility is worn lobes on the camshaft as a result of low oil levels and/or failure to change the oil on a regular basis.

[keithems]

with all due respect --

i think it makes sense to stay on topic -- so if my problem is valve related and no longer ignition / no spark, i intend to discuss it in a valve related thread....

that being said...

just returned from the boat

removed valves, springs, keepers, & caps from 6 of the 8 valves.

the lifters all seem to be free -- rotate freely -- and you can move them up & down by hand -- they just don't move at all when i handcrank the motor -- except for # 1 exhaust, which does -- leading me to think the entire cam shaft cannot be broken, else why would #1 move as normal?

valves themselves seem to be in good condition, esp. the stems -- nice and shiny -- smooth, etc.

any other ideas will be appreciated -- esp. re. whether or not i have to teardown further and pull the camshaft, in which case i'm gonna mount an o/b for the rest of the summer and maybe forever -- this is all just not worth it -- i'm a sailor, remember [i have to remember that as well...]

also -- i change oil regularly -- puhleese! -- just changed it a week ago -- [2nd or 3rd time this season -- < 25 hrs ttl ] -- rotella 15w40, with some mmo -- nothing but the best for my a4!

like i said, i will continue to post on all of this here unless the webmaster requests otherwise...

[jpian0923]

I recommend posting a Video to youtube.com and then embed it here for us to see what is really going on.

Verbal descriptions are hard to follow and diagnose.

I posted a video of my "New" engine noise and got a great, dead on diagnosis in short order which enable me to get to work within hours and expedite the repair process.

I hate to not sail as much as anyone else...so, to get to the bottom of this, get a video asap.

Look, we all want to help you...help us help you. Post video here (today!)

[hanleyclifford]

In post #22 on the other thread you indicated it was #4 exhaust that alone was moving. Now you say #1 exhaust alone moves. This needs to be clarified. It is possible for a camshaft to break leaving all lobes outboard from the break motionless.

[ILikeRust]

i think it makes sense to stay on topic -- so if my problem is valve related and no longer ignition / no spark, i intend to discuss it in a valve related thread....

Sure, except now you've posted this same information twice, in two different threads. And people are replying to both. As far as "on topic" - the topic is your engine and the issues you're having with it. If you create a new thread every time you're working on this issue, everyone has to keep track of multiple threads.

Whatever....

the lifters all seem to be free -- rotate freely -- and you can move them up & down by hand -- they just don't move at all when i handcrank the motor -- except for # 1 exhaust, which does -- leading me to think the entire cam shaft cannot be broken, else why would #1 move as normal?

In the other thread, you said #4 exhaust would move. Which one is moving - #4 or #1? #1 is the cylinder closest to the flywheel/forward end of the engine; #4 is closest to the reversing gear/aft end of the engine.

If the lifters move up and down freely but do not move when you rotate the engine, then the only explanation I can think of is you have a catastrophic failure of the camshaft. It could make sense if #4 exhaust moves but no others do - that could indicate that the camshaft has snapped just forward of that valve. The camshaft is gear-driven directly off the aft end of the crankshaft. So if the camshaft were to break just forward of the #4 exhaust valve, the small aft portion would still rotate and make #4 exhaust go up and down, but the rest of the shaft would just sit there.

I hate to even suggest that this is a possibility, but if the lifters are free to move up and down but don't do anything when you crank the engine, I don't know what else could be the cause. It's a pretty simple mechanical system - if they're not moving, something is broken.

Was it running well before? Did it make any awful noises and suddenly stop working or something?

[keithems]

i'm sorry if i said #1 -- it's the #4 exhaust [closest to reversing gear end]

here are last week's pix again, hopefully sized a little better

you all can adjust the size by pushing your crtl + [larger] and crtl - [smaller] keys together





i'll try to get new pix today, but given where the motor is, i doubt they'll be any better.

only difference now is the springs and valve, etc, are out of there; the lifters are all freely moving and turning and all look very shiny and good

only problem continues to be that none except the last one [#4 exhaust] move when i hand crank the flywheel

also -- here's the url for the relevant diagram in the a4 parts manual

http://www.marinedieseldirect.com/ca...ors=&comment1=

as you look at it, pls remember that everything looks good, except the camshaft, which obviously i cannot see -- i'd normally assume the camshaft or timing gear is broken -- except that one valve is moving -- leading me to think somehow the lifters are not aligned with the cams or the cams have gotten ground down / sheared off.

believe it or not, the engine was running fairly well when this happened -- it was just what don calls a "soft" shutdown -- as if the ign switch had been turned off -- we did hear one brief metallic sound, but no banging or anything, as i'd expect from some major component breaking / failing.

so really all i need to know at this point is why....is it the camshaft? is it something i'm gonna have to pull the motor to get to? [as seems likely]

in which case, i'm done with the a4 for now; maybe i'll get to it in the winter, maybe i won't

anyone have a nice saildrive / longshaft o/b they want to sell?

[keithems]

In post #22 on the other thread you indicated it was #4 exhaust that alone was moving. Now you say #1 exhaust alone moves. This needs to be clarified. It is possible for a camshaft to break leaving all lobes outboard from the break motionless.

thank you -- that sounds like what's happened

[keithems]

Sure, except now you've posted this same information twice, in two different threads. And people are replying to both. As far as "on topic" - the topic is your engine and the issues you're having with it. If you create a new thread every time you're working on this issue, everyone has to keep track of multiple threads.

Whatever....



In the other thread, you said #4 exhaust would move. Which one is moving - #4 or #1? #1 is the cylinder closest to the flywheel/forward end of the engine; #4 is closest to the reversing gear/aft end of the engine.

If the lifters move up and down freely but do not move when you rotate the engine, then the only explanation I can think of is you have a catastrophic failure of the camshaft. It could make sense if #4 exhaust moves but no others do - that could indicate that the camshaft has snapped just forward of that valve. The camshaft is gear-driven directly off the aft end of the crankshaft. So if the camshaft were to break just forward of the #4 exhaust valve, the small aft portion would still rotate and make #4 exhaust go up and down, but the rest of the shaft would just sit there.

I hate to even suggest that this is a possibility, but if the lifters are free to move up and down but don't do anything when you crank the engine, I don't know what else could be the cause. It's a pretty simple mechanical system - if they're not moving, something is broken.

Was it running well before? Did it make any awful noises and suddenly stop working or something?

ditto thank you to you, bill

also see my answers above

based on both hanley's and bill's posts, i'll assume i have a broken camshaft and the engine will need to come out and be rebuilt...

[keithems]

i have to ask...

is it possible to remove & replace the camshaft & timing gear by removing flywheel and housing ONLY? can this be done with motor still installed in boat?

here's the diagram again -- or it's on p.78 of the a4 parts manual if you have one [tried to upload mine, but was unable]

http://www.marinedieseldirect.com/ca...ors=&comment1=

i do have another camshaft from the previous engine.....

[jpian0923]

Not possible. Oil pan has to come off.