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#1
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Quote:
If it had been the original lifter with a stuck piston the valve would have closed and the worse senario if any would have been some lifter noise because of the additional valve lash resulting. Clear as mud? I find this difficult to describe. I feel it is probably accurate all the same. |
#2
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On VWs I've worked on I was always advised to put the lifters in a cup of oil to "prefill" them.
Wouldn't the action of opening the valve make the lifter bleed down? -J
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1991 350SDL. 230,000 miles (new motor @ 150,000). Blown head gasket ![]() Tesla Model 3. 205,000 miles. Been to 48 states! Past: A fleet of VW TDIs.... including a V10,a Dieselgate Passat, and 2 ECOdiesels. 2014 Cadillac ELR 2013 Fiat 500E. |
#3
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Here's the factory procedure on testing OM60x hydraulic lifters, complete with nifty cross-section cutaway drawings... see attached PDF file.
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Check out my website photos, documents, and movies! |
#4
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Hey, that pdf says to use a magnet!
Sixto 87 300D |
#5
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They quote no lifter leakage all. In the real world I do not know if that is factual. If so pumping them up before installation might give valve/piston interference. Although this seems to be eliminated by the short range of automatic adjustment action of that particular design of lifter. This was intentional to make them quieter on start up I suspect.
On a valve job for those engines there must be either various custom height lifters available as the valve on seat stem protusion measurement result may be critical. I suspect some lifters may have had their skirts ground down or the valve stems over the years as it is reported the last cylinder on some of these particular engines (606) have been reported with deep valve recesses on the last cylinders seat insert.. Changing out to a new seat would be the proper and really required repair. Also when the edge of a valve is reground it extends the stem a little higher as well. Seems to me that to do a decent valve job on that type of head you have really to pay attention. Last edited by barry123400; 09-28-2012 at 05:52 PM. |
#6
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It's physically not possible for a fully-pumped lifter to press the valve far enough to contact the pistons. It's simply not designed that way.
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#7
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I know that this is an old thread, but I thought I'd share something I learned the hard way.
When using a drill press or clamp to squeeze the piston, ensure that the piston is pushed straight down. In other words put no side load on the piston or you will destroy the lifter. You know that you killed it when the piston becomes easy to depress. If you can easily do it with your thumb, your lifter is ruined.
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1986 300SDL 1987 300SDL 1997 F-350 Powerstroke Turbo Diesel 1969 32' Luhrs Perkins HT3.54M Turbo Diesel WVO & biodiesel when I can get it (there is a de-facto ban on biodiesel in CA - ask the Water Quality Resources Board why underground storage isn't allowed for biodiesel - heck, you can drink the stuff ![]() |
#8
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The internal spring alone perhaps allows this to slowly take place. I guess what I am really thinking is some modern lifters look somewhat more complex in illustrations than the simple ones I took apart so many years ago. My guess is that if there is no oil already in a given lifter all you have to overcome is an internal spring that may not be very strong. So if you where to finger push an empty lifter in a bath of oil. On the pistons upstoke it will intake oil when you remove the finger pressure. You will then only be able to finger push the lifter piston down the second time as far as the accumulated internal oil inside allows. Constant finger pressure continued the oil may very slowly bleed back out perhaps. The bleed down may be quite slow though with only finger pressure. Finger test is not adequate as it does not compare with lifter in service pressures. The lifters are designed to constantly adjust to provide near to zero valve lash. My guess is say you mark and extract a set of lifters. Take some transmission fluid and pump them up and let them sit a day. This may get rid of any varnish internally. Then test them in motor oil. You hold pressure till they drain down. Then pump them up and check their ability to stay up time wise in comparison to the others. At onetime lifters where so cheap you just grabbed a complete set if you had one or two in the engine that would not hold. Now if the oil feed passages are badly sludged up there may be inadaqate oil reaching the lifters for them to function well should always remain a consideration if all the lifters you remove test well. I guess you could even just have one or two feed passage sludge problems as well. So perhaps the first step in dealing with noisy lifters may be to put a synthetic oil change in place or a real cleaning additive in the oil supply. In the old days it was adding a quart of automatic transmission fluid to the oil and running the car in service for awhile. This seemed to loosen up crud and varnish in the lifters and oil feed passages many times. I know a lot of members know this type of issue. I just posted it if perhaps a few did not. A list of common problems experienced with lifters in my opinion. The cylinder and piston varnish up to the point the internal spring is unable to push the piston in the lifter upward. The arrangement for the check valve to enable the ability of the lifter to hold oil well enough is shot. Broken spring internally or whatever arrangement is used to enable the piston internally always to have upward internal movement available even with no oil present. Very low force levels required for this. Most common perhaps is the piston and cylinder have just worn so much the required time to retain the oil internally in service just does no longer exist. These are the ones you typically manage to pump up in a drill press and they compress down again much faster than average as the oil is leaving far faster than the design paremeters allowed. Or at worse they will not pump up. you cannot totally duplicate test conditions as a lifter experiences in actual service. Still in general the slow hand testing will reveal most the common issues. One last thing that crossed my mind. As the engine oil heats it thins. So it may be better to use a thinner oil for testing at times. A cheap quart of say 0-20W oil cold may be hopefully about the equivalent of normal hot engine oil. If they pass in that viscosity oil they are probably just fine. This testing is not rocket science remember. Anyone can really do it that has access to a drill press. Last edited by barry12345; 09-07-2014 at 08:09 PM. |
#9
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Reading the procedure that Dave posted, it looks like the piston can be removed and the valving mechanism inside cleaned/inspected.
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Respectfully, /s/ M. Dillon '87 124.193 (300TD) "White Whale", ~392k miles, 3.5l IP fitted '95 124.131 (E300) "Sapphire", 380k miles '73 Balboa 20 "Sanctification" Charleston SC |
#10
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I just replaced all my lifters with new in the box ones. I just put them in not doing anything special. I still got a tick/clack, how does that preset procedure go?
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1993 MB 300D 245K died. ![]() |
#11
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Turned out to be the head gasket had started to fail at the front oil galley, and debris from the gasket was blocking the oil passages to the lifters. Lack of oil at the lifters caused ticking even with brand new lifters installed. The fix was to remove the head, carefully clean all the oil passages, and replace the head gasket. It was silent afterwards. While I was in there I also replaced the crank seal and converted to a pressure-operated wastegate. Photos are here: http://www.w124performance.com/images/OM602_head/ ![]()
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#12
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Do not be surprised to have an oil feed problem to the lifters. We had one at one time we could not solve. There had to be a crack into the oil passage somewhere was our final unfound conclusion. This was a german engine but not Mercedes. |
#13
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Either one (or more) of your lifters are bad, or one (or more) are not getting sufficient oil pressure, or something else is making your noise. Ticking lifters are a classic sign of failure of the head gasket at the front oil passage for OM601/2/3 engines.
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Respectfully, /s/ M. Dillon '87 124.193 (300TD) "White Whale", ~392k miles, 3.5l IP fitted '95 124.131 (E300) "Sapphire", 380k miles '73 Balboa 20 "Sanctification" Charleston SC |
#14
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Too funny, Winmutt was quoting me!
For the record, Yes I did simply use my fingers/thumbs, and very gradually I was able to get the oil out of that lifter. Once I was able to get a little action in the piston, and some air entered, it became much easier to get the oil out. I find myself now replacing the head AGAIN, this time installing a used #17 head. It turns out that #20 head was internally cracked. Machine shop that did the work did not catch this, I ended up building my own hot-tank and pressurized the head via the exhaust manifold. Crack was confirmed by air bubbles escaping from the coolant passage at the front of the head. I recently completed bleeding down all the lifters for this head installation, this time I used a small vice. One lifter bled down with far less pressure than the rest of the lifters, so that one will be replaced with a different used lifter.
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Respectfully, /s/ M. Dillon '87 124.193 (300TD) "White Whale", ~392k miles, 3.5l IP fitted '95 124.131 (E300) "Sapphire", 380k miles '73 Balboa 20 "Sanctification" Charleston SC |
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