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VanagonPDX Samba Member
Joined: April 25, 2012 Posts: 114 Location: Portland Oregon
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Posted: Mon Oct 03, 2016 1:31 pm Post subject: Intermittent Engine Knocking |
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I have this knock that has become a constant source of fear, or at the very least uncertainty. I know the hydraulic lifters will often loose their oil if sitting for a while, causing the engine to knock until they get pumped back up. But this seems to come even after driving for a while.
Last week I did an oil change (Delo 15W40) and used a Manh filter from GoWesty. My understanding was that this filter should resolve the lifter knock associated with them flattening out. Today, I drove to Bend (~30min drive at 55mph) and it was quiet the whole way. Then, got back to Redmond and stopped in at a store and it was knocking, and knocked the rest of the way home. Any ideas? Could it in any way be associated with poor fuel flow? (I ask as my pump is cavitating as of yesterday and is another project I am trying to resolve, as I replaced the white block filter last week as well). |
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candyman Samba Trout Slayer
Joined: December 20, 2003 Posts: 2694 Location: Missoula MT
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Posted: Mon Oct 03, 2016 1:35 pm Post subject: Re: intermittent Engine Knocking |
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Is it a knock or a tick? Lifters tick, not knock. Rods knock and then bam! Do you have any exhaust leaks? |
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VanagonPDX Samba Member
Joined: April 25, 2012 Posts: 114 Location: Portland Oregon
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Posted: Mon Oct 03, 2016 1:47 pm Post subject: Re: intermittent Engine Knocking |
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Definitely sounds like what I have always associated with the a noisy lifter. In the past, every so often, it would have that knocking sound when I had let it sit a bit, then would take it for a run and it would stop. This sounds the same, but is popping up after being ran a little while - almost as though the heat from the engine it lowering the viscosity and thus letting it knock. But, 15W40 is a decently heavy oil. |
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candyman Samba Trout Slayer
Joined: December 20, 2003 Posts: 2694 Location: Missoula MT
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Posted: Mon Oct 03, 2016 1:52 pm Post subject: Re: intermittent Engine Knocking |
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An exhaust leak can certainly sound like a lifter tick. Check around for any exhaust leaks. An exhaust leak before the o2 sensor can cause your engine to run rich, look at you tail pipe for excessive black soot. It helps if you have a stethocope |
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VanagonPDX Samba Member
Joined: April 25, 2012 Posts: 114 Location: Portland Oregon
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Posted: Mon Oct 03, 2016 2:00 pm Post subject: Re: intermittent Engine Knocking |
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She definitely has an exhaust leak, but this seems to be in addition to that sound. I suppose the heat could be causing the leak to become louder/sound different with the pipes increasing in temperature.
Would a rod knock be intermittent? Some days she sounds fine, then others, this knocking sound. I just drove to Portland this weekend, did fine, but coming back was low on power. I chalked that up to this fuel issue that is causing my fuel pump to whine.
I really hope this is not an engine issue. I just bought this vanagon about two months ago and have already replaced the transmission |
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bluebus86 Banned
Joined: September 02, 2010 Posts: 11075
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Posted: Mon Oct 03, 2016 2:02 pm Post subject: Re: intermittent Engine Knocking |
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sticky lifters make noise. a filter change from fram to mahle fixed it for me, but it was only noisey for a few blocks, the filter stppoed that.
try many oil changes, dirty oil can clog lifters. if that fails, you can pop them out and clean them. and pump them up.
do not mix the lifters, rockers nor pushrods, all go back in same spot, in same orientation. lable with marked tape to prevent screw ups.
hopefully with some oil changes and clean living this will resolve, else pull them
good luck, may this be an uplifting experience for you and your van. _________________ Help Prevent VW Engine Fires, see this link.....Engine safety wire information
Stop introducing dirt into your oil when adjusting valves ... https://www.thesamba.com/vw/forum/viewtopic.php?t=683022 |
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Howesight Samba Member
Joined: July 02, 2008 Posts: 3274 Location: Vancouver, B.C.
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Posted: Mon Oct 03, 2016 2:11 pm Post subject: Re: intermittent Engine Knocking |
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Poor fuel flow will not induce lifters to pump down, period. These issues are unrelated.
The Mann oil filter will also do nothing to prevent lifter leak-down, although it is definitely the proper filter to use. The only time you need to worry that lifter noise is indicative of a serious problem is when you have no lifter noise while driving, but at some point during the drive, lifter noise commences. In that case, you have a serious problem.
It is very common for lifter noise to occur if you start the engine from cold, run it very briefly, (say, to car jockyey on your driveway, as many often do), and then run the van the next day or a few days later.
In the short term, the best fix is to add as much as a quart of Marvel Mystery Oil just before an oil change and run it that way for a few days or a longish drive. Don't do this in high ambient temperatures or just before high-rpm driving, since the MMO thins out the oil a lot. At oil change time, add one quarter of a quart to your new oil fill. MMO works to clean out the gum and varnish in the lifter check valves, making them work as the factory intended. _________________ '86 Syncro Westy SVX |
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bluebus86 Banned
Joined: September 02, 2010 Posts: 11075
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Posted: Mon Oct 03, 2016 2:16 pm Post subject: Re: intermittent Engine Knocking |
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Howesight wrote: |
Poor fuel flow will not induce lifters to pump down, period. These issues are unrelated.
The Mann oil filter will also do nothing to prevent lifter leak-down, although it is definitely the proper filter to use. The only time you need to worry that lifter noise is indicative of a serious problem is when you have no lifter noise while driving, but at some point during the drive, lifter noise commences. In that case, you have a serious problem.
It is very common for lifter noise to occur if you start the engine from cold, run it very briefly, (say, to car jockyey on your driveway, as many often do), and then run the van the next day or a few days later.
In the short term, the best fix is to add as much as a quart of Marvel Mystery Oil just before an oil change and run it that way for a few days or a longish drive. Don't do this in high ambient temperatures or just before high-rpm driving, since the MMO thins out the oil a lot. At oil change time, add one quarter of a quart to your new oil fill. MMO works to clean out the gum and varnish in the lifter check valves, making them work as the factory intended. |
the correct filter does have the backflow valve that rapidly pumped up lifters that when using the fram which lacks that valve would take several blocks of driving to pump up. this is my expereince. _________________ Help Prevent VW Engine Fires, see this link.....Engine safety wire information
Stop introducing dirt into your oil when adjusting valves ... https://www.thesamba.com/vw/forum/viewtopic.php?t=683022 |
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VanagonPDX Samba Member
Joined: April 25, 2012 Posts: 114 Location: Portland Oregon
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Posted: Mon Oct 03, 2016 2:23 pm Post subject: Re: intermittent Engine Knocking |
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Howesight wrote: |
The only time you need to worry that lifter noise is indicative of a serious problem is when you have no lifter noise while driving, but at some point during the drive, lifter noise commences. In that case, you have a serious problem. |
Well... that is not comforting, as that is sort of what I am working with. Quiet this morning, drove to Bend and back (~40 miles total at 55mph), and then stopped in at Oriellys for a fuel filter and noticed a fairly audible tapping/knocking sound. I just finished swapping out the fuel filter (which did not resolve my cavitating fuel pump), and started it up - the engine was quiet as could be. There is a definite exhaust leak at where the two manifolds connect with the J pipe. My optimistic side is hoping that the heat of the run is just causing the metal to expand and make the sound louder, and is not a knock at all. (Sadly, I don't think this is what i am hearing). |
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VanagonPDX Samba Member
Joined: April 25, 2012 Posts: 114 Location: Portland Oregon
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Posted: Mon Oct 03, 2016 6:41 pm Post subject: Re: intermittent Engine Knocking |
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Took a metal rod and placed it against my ear and then against the engine around the end of each cylinder. One cylinder definitely has a louder knock than the other three. Like a little jackhammer doing some work in there |
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candyman Samba Trout Slayer
Joined: December 20, 2003 Posts: 2694 Location: Missoula MT
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Posted: Mon Oct 03, 2016 7:32 pm Post subject: Re: intermittent Engine Knocking |
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VanagonPDX wrote: |
Took a metal rod and placed it against my ear and then against the engine around the end of each cylinder. One cylinder definitely has a louder knock than the other three. Like a little jackhammer doing some work in there |
Bummer. Next step pop the valve covers and check the valves, esp on the on cylinder that seems to be making the noise. Then i suggest a leak down test
Still worth doing a run if MMO to see if that helps
Last edited by candyman on Mon Oct 03, 2016 7:46 pm; edited 1 time in total |
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Wildthings Samba Member
Joined: March 13, 2005 Posts: 50352
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Posted: Mon Oct 03, 2016 7:38 pm Post subject: Re: intermittent Engine Knocking |
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bluebus86 wrote: |
Howesight wrote: |
Poor fuel flow will not induce lifters to pump down, period. These issues are unrelated.
The Mann oil filter will also do nothing to prevent lifter leak-down, although it is definitely the proper filter to use. The only time you need to worry that lifter noise is indicative of a serious problem is when you have no lifter noise while driving, but at some point during the drive, lifter noise commences. In that case, you have a serious problem.
It is very common for lifter noise to occur if you start the engine from cold, run it very briefly, (say, to car jockyey on your driveway, as many often do), and then run the van the next day or a few days later.
In the short term, the best fix is to add as much as a quart of Marvel Mystery Oil just before an oil change and run it that way for a few days or a longish drive. Don't do this in high ambient temperatures or just before high-rpm driving, since the MMO thins out the oil a lot. At oil change time, add one quarter of a quart to your new oil fill. MMO works to clean out the gum and varnish in the lifter check valves, making them work as the factory intended. |
the correct filter does have the backflow valve that rapidly pumped up lifters that when using the fram which lacks that valve would take several blocks of driving to pump up. this is my expereince. |
I don't have one to cut open, but I would think that most any filter you could find to screw on there is going to have a anti-drain back valve. The base level Fram filters are cheap and the filter element and the two valve functions may not work all that well though.
I would recommend to the OP that he add some MMO and then run a thin synthetic oil like a 5w40. The MMO will help clean the gum and varnish from the engine and the synthetic will keep more from forming. Vanagon lifters just like thin oil, especially when cold, as well. |
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VanagonPDX Samba Member
Joined: April 25, 2012 Posts: 114 Location: Portland Oregon
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Posted: Mon Oct 03, 2016 8:17 pm Post subject: Re: intermittent Engine Knocking |
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Wildthings wrote: |
I would recommend to the OP that he add some MMO and then run a thin synthetic oil like a 5w40. The MMO will help clean the gum and varnish from the engine and the synthetic will keep more from forming. Vanagon lifters just like thin oil, especially when cold, as well. |
Worth a shot. I will pick up some MMO tomorrow and dump it in there and see what happens. I live in eastern Oregon, which gets real cold, like -5 at night, in the coming month or so. I ran the 15W40 thinking its high viscosity would keep knocks at bay, not make them them more likely. |
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thummmper Samba Member
Joined: November 25, 2009 Posts: 2015 Location: Meadow Valley, California Republic
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Posted: Mon Oct 03, 2016 8:35 pm Post subject: Re: intermittent Engine Knocking |
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crankshaft end thrust excessive |
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VanagonPDX Samba Member
Joined: April 25, 2012 Posts: 114 Location: Portland Oregon
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Posted: Mon Oct 03, 2016 8:49 pm Post subject: Re: intermittent Engine Knocking |
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thummmper wrote: |
crankshaft end thrust excessive |
...Go on. |
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mightyart Samba Member
Joined: March 24, 2004 Posts: 6188 Location: Portland, Oregon
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Posted: Mon Oct 03, 2016 9:04 pm Post subject: Re: intermittent Engine Knocking |
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VanagonPDX wrote: |
thummmper wrote: |
crankshaft end thrust excessive |
...Go on. |
How many miles on your engine? _________________ My Art:
http://www.instagram.com/flynn8552/ |
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candyman Samba Trout Slayer
Joined: December 20, 2003 Posts: 2694 Location: Missoula MT
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Posted: Mon Oct 03, 2016 9:04 pm Post subject: Re: intermittent Engine Knocking |
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VanagonPDX wrote: |
thummmper wrote: |
crankshaft end thrust excessive |
...Go on. |
You can do a simple quick and dirty check if endplay is excessive by grabbing the pulley and push in and out. You should not be able to detect endplay by this method (even though there is factory spec endplay). If you have excessive endply you would also have low oil pressure issues, esp at hot idle |
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VanagonPDX Samba Member
Joined: April 25, 2012 Posts: 114 Location: Portland Oregon
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Posted: Mon Oct 03, 2016 9:09 pm Post subject: Re: intermittent Engine Knocking |
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mightyart wrote: |
VanagonPDX wrote: |
thummmper wrote: |
crankshaft end thrust excessive |
...Go on. |
How many miles on your engine? |
The low low number of 214k
I like to think that being the third owner, and having receipts dating back to purchase, that she was well taken care of. But, that is a fair amount of miles. |
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mightyart Samba Member
Joined: March 24, 2004 Posts: 6188 Location: Portland, Oregon
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Posted: Mon Oct 03, 2016 9:18 pm Post subject: Re: intermittent Engine Knocking |
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You get play in the camshaft from wear, so it could very well be,
crankshaft end thrust excessive
If it is then it's tear down time, or drive it till it dies.
Check the basics first. _________________ My Art:
http://www.instagram.com/flynn8552/
Last edited by mightyart on Mon Oct 03, 2016 9:21 pm; edited 1 time in total |
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Wildthings Samba Member
Joined: March 13, 2005 Posts: 50352
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Posted: Mon Oct 03, 2016 9:19 pm Post subject: Re: intermittent Engine Knocking |
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VanagonPDX wrote: |
Wildthings wrote: |
I would recommend to the OP that he add some MMO and then run a thin synthetic oil like a 5w40. The MMO will help clean the gum and varnish from the engine and the synthetic will keep more from forming. Vanagon lifters just like thin oil, especially when cold, as well. |
Worth a shot. I will pick up some MMO tomorrow and dump it in there and see what happens. I live in eastern Oregon, which gets real cold, like -5 at night, in the coming month or so. I ran the 15W40 thinking its high viscosity would keep knocks at bay, not make them them more likely. |
Not sure why thin oil seems to work better than thick oil but it seems to both keep the lifters from leaking down and helps them pump up faster. As others said, if you start a cold engine and drive it only a short ways, you will probably have lifter noise the next time you run it, thick oil just seems counter productive as far as the lifters are concern.
Last edited by Wildthings on Tue Oct 04, 2016 2:47 pm; edited 1 time in total |
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