need advice, think I popped a piston :(

[n2ojunkie]

OK I took my m109 on a 280 mile road trip this weekend, used it as the rv I turned it into and everything was great. Well about 20 miles from home I stopped for a cold drink and heard a knocking sound, Thought at first it was a rod but the thumping is coming back out the intake. I drove it home and it wasnt to bad, not really low on power, a little but not to bad.

I took the filter off and it was LOUD. Well I have ruled out a rod knock. I m stuck between a intake valve, or a piston. Anyone else have something to look at? I would like to do a leak down test but not sure how. Would I have to pull all the injectors to do it? Thanks and I"ll keep you updated but it will be awhile before get to it. but would like to have an idea on what to look for and to check.

 

[gimpyrobb]

Have you adjusted the valves yet?

 

[big block 88]

What fuel/fuel mix are you running? Is your IP turned up?

 

[Jersey4x4]

I have the same problem but mine is making the sound out the exhaust and I think it is the head gasket between 2 cylinders and mine the exhaust valve is open when the piston of the other cylinder comes up on compression it sounds like yours is doing it when it comes up on the intake side of the other cylinder.

OK I took my m109 on a 280 mile road trip this weekend, used it as the rv I turned it into and everything was great. Well about 20 miles from home I stopped for a cold drink and heard a knocking sound, Thought at first it was a rod but the thumping is coming back out the intake. I drove it home and it wasnt to bad, not really low on power, a little but not to bad.

I took the filter off and it was LOUD. Well I have ruled out a rod knock. I m stuck between a intake valve, or a piston. Anyone else have something to look at? I would like to do a leak down test but not sure how. Would I have to pull all the injectors to do it? Thanks and I"ll keep you updated but it will be awhile before get to it. but would like to have an idea on what to look for and to check.

 

[deathrowdave]

I think U have popped a head gasket . Mine left town passenger side against the fire wall. Progressivly got louder and louder until old faitful started leaking water . Got my gaskets for SS member M35Tom . Have a good time replacing not too hard just heavy and U will need a special wrench to remove and install the heads.

 

[n2ojunkie]

Ok thanks, ill check the valves first, then look at the head baskets. I did have oil around the oil fill cap which I never had before. I assumed ( hate that word lol ) that I broke a piston and the blow by pushed it out there.

I run straight diesel from the pump. But I did pour about a gallon of UMO from my bike into it before the trip upnorth. First time I've done that and noticed nothing different. But that's one gallon with a full tank of fresh diesel, so I don't think it even noticed it.

I have turned the IP up a little but not a lot. It smokes taking off and clears up going down the road so I didn't think it was getting to much fuel. And no I have no pyrometers on it so idk the temps. It is a non turbo and runs strong.

 

[n2ojunkie]

ok got a chance to look at it. I just finished putting it all back together. The 3rd valve from the rear of the engine was really lose. The lock nut was tight but im talking .250? I checked the pushrod and it was nice and straight, it spun freely.

I adjusted it and got it really close. I did it by feel. and started it up just to listen and watch it. Everything sounded and looked good. The only thing that bothers me is that the adjusting screw is almost all the way in. Like I said pushrod is straight. so what else could it be? I havent drove it just had it running in the driveway for about 30 sec. but the knocking is gone and it sounds like its new.

 

[davidkroberts]

if everything is running okay then leave it alone, I know your worried about it and I would be too but If the noise is fixed and everything is running normally then call it good enough and quit

 

[73m819]

on the push rod, did you CHECK the ENDS, .250 (1/4") is a lot with the adj. nut still tight. you LOST .250 somewhare
also is the rocker like the others, NO BENT

 

[n2ojunkie]

Ya I checked them, the lifter end was nice and smooth and shinny, the top was nice and clean also. No grooves or gouges.

Its just that I was looking at every other rocker and they all have alot more of the adjusting screw showing.

I thought at first the valve was stuck open alittle, but I tapped it a couple of times and it still stayed the same. I know its closed because the noise is gone but it just seams like somethings still wrong. I would think cam lob wore out.but it idles and revs up fine. and I can watch the valve move and it looks just like all the rest. (yes I know hard to see .250 difference right? ) Oh I also but a straight edge between the two valve springs just to see if the seat height was off and it was the same.

 

[73m819]

what about the contact point on the adj. screw, just try to think where 1/4 can go, there is not a lot of place in the valve train that this can go

 

[n2ojunkie]

no I didnt pull it all the way off so I didnt get to check that part. Ya I know, The rocker arm didnt look bent either.

I Know its not in the valve or pushrod, unless somehow the pushrod colapsed. I looked at it and it looked spot welded on the sides. So unless those let go and it jammed it in and made it a little shorter.

Just fyi I am a car guy I have rebuilt many different engines just never messed with a diesel, well not this far into one anyways lol.

 

[Nonotagain]

If you have access to a dial indicator, I'd check the lift between the pair of both intake and exhaust valves on that head.

Either the cam, the lifter, or the rocker arm are going away.

For now just check the lift between the two cylinders and report back.

 

[rlwm211]

If you want to check a pushrod., you can pull the one you are concerned with and another that is apparently 'normal' and compare their lengths. If the pushrod got compressed it would be rather obvious.

RL

 

[n2ojunkie]

Are the lifters easy to get out? can I just pull it up threw the head threw the pushrod hole? If its the pushrod I would think the adjustment i made would be ok. a lifter would be alittle different. I only put maybe 500 miles a year on it so I'll see how its runs around town for awhile. Thanks for all the help guys.

 

[rlwm211]

You would know if the lifter is collapsed if you measure the pushrod against another.

RL

 

[AMGeneral]

Are the lifters easy to get out? can I just pull it up threw the head threw the pushrod hole?



Pretty sure the multifuel has a flat tappett cam,basically you have to pull the cam to swap em.

 

[73m819]

HAD to be something sudden, because that is how the OP described the on set of the noise, not a bit of noise getting louder over time like a cam or lifter wareing. what ever is the cause, at the moment of the start of the noise, is when the .250 (1/4) clarence got made. So again, I would look at the push rod, the lifter TOP, the rocker, the adjuster, top of valve, you DO NOT gain 1/4" of clearance all of a sudden and NOTHING IS WRONG

 

[n2ojunkie]

Ya I know, ill pull the cover off it again maybe tonight and take a couple pushrods out and compare them. I have calipers but nothing long enough to measure them with, so ill just have to compare them.

Even if it is a flat tappet cam I should be able to out one new lifter in right? I know about they wear together but a new one should be ok right? Can I get it out without pulling the head?

 

[houdel]

Have you found the problem yet?