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General Information => Troubleshooting => Topic started by: VTPSD on June 11, 2013, 10:36:11 pm
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Hi All,
I just got back from an epic 3000 mile trip with my 91 ecodiesel. It ran great the whole way, but about 1000 miles into the trip it developed a tapping or knocking that is new. The engine has about 240k on it and i dont think has ever been apart. It runs sweet, and has been very quiet for an idi diesel. This new knock is not horribly loud, can barely hear it with the windows up. Almost sounds like a sticky lifter but it does not seem to be coming from the head.
My instinct says it is coming from the bottom end. It starts after the car has been running about 30 seconds and stays there at all engine speeds. I was forced to drive it another 2000 miles to get back home with it in this state and it never got worse or beter. Still there. Running normally and has all of its power. I almost think it is rod knock, and i might just order some new rod bearing and pull the pan and replace them. I am looking for some other suggestions of things I should check.
I am not sure of when it started for sure, but somewhere out in the flats in indiana i decided (for unknown reasons) to see how fast the old girl could do on the flats. I held it wide open in 5th for maybe 30 seconds or less until it topped out and then coasted back down to 70. I drove basically 70 the entire trip. I am not sure this is when the trouble started but when i stopped for fuel in about 100 miles i noticed the ticking or knocking.
Can i re-use the rod bolts in this engine, or do i need to figure out a way to remove the rod bolts from the rods and replace with the oil pan dropped.
Thanks in advance. I feel bad that I hurt the old girl, and want to get it back into shape again.
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i found this video on youtube, mine has a similar sound. Not sure if it helps.
http://www.youtube.com/watch?v=63p-kuHxBEE
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this one is also a similar noise
http://www.youtube.com/watch?v=kFBKHE9rUpc
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The first vid has a "clinking" timbre that makes me think piston contact with a pre-cup or valve. I have a similar sound in my 89NA that makes me nervous.
The second vid sounds like a lifter .
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hmmm, i would say mine sounds more like the second than the first. Do lifters ever go bad suddenly and clatter at all RPMs? What is the way to test them. I was thinking maybe get the engine warm, pull the valve cover and try pushing down and see if i have any play in the lifters?
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The hydraulic lifters can and do crap out, and they are pretty cheap.
Did you notice if the noise was there both on and off throttle, as in coasting in gear?
I'm inclined to think it's a non-critical failure if it went 2K miles of interstate driving
and didn't blow or get worse.
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like this? http://www.youtube.com/watch?v=CC87gNemmUE
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The hydraulic lifters can and do crap out, and they are pretty cheap.
Did you notice if the noise was there both on and off throttle, as in coasting in gear?
I'm inclined to think it's a non-critical failure if it went 2K miles of interstate driving
and didn't blow or get worse.
As far as i can tell the noise is there no matter what the RPM or throttle input. Does it in neutral the same as in gear and under load. Its not loud enough to hear when going fast, so its hard to do the fuel shutoff test, but I am quite sure it is mechanical and not fuel.
I would think a rod bearing would have gotten worse or spun after all that. Is it possible that a precup can drop just a little bit and be kissing the piston? I am inclined to think it would have changed in tone or sound level after all those miles at high rpm.
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I am inclined to think it would have changed in tone or sound level after all those miles at high rpm.
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Agree. Might cut open an oil filter and see if there's sadness inside.
I'd put lifters in it.
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Well I spent some time tonight in the shop trying to find my noise. I couldnt really pinpoint the location, so i started by pulling the valve cover with the engine warm to check lifters. Several of them had a very small amount of play, but nothing outrageous. I am not ruling them out, but nothing looked or felt out of wack to me. ???
Then I pulled the oil pan and wiggled all the rods, everything seemed copacetic, again nothing crazy. There was no evidence of glitter in the oil, but there was some debris in the pan. At first I thought it was metal but upon closer inspection I think it may be stuff that fell in when wiggling the pan off. I checked crank end play, there was some, but seemed to be within the .0147" that the bently says is allowable. The only thing that seemed a bit funny is the main bearing thrust tabs on the middle journal could be wiggled a bit with the tip of a screwdriver. When I slid the crank all the way to one side, you could wiggle the opposite side tab. I actually think this is ok and normal, but i thought it was worth mentioning.
Getting desperate I pulled each rod cap and inspected the bearings since I already ordered the parts in a fit of rage the other night. The pictures below show the bearings. The bearings that are more copper colored came out of the rod side and the non discolored ones came from the cap side.
(http://i1103.photobucket.com/albums/g472/danapcurtis/Diesel%20Jetta/DSCN0871_zps955a613e.jpg)
(http://i1103.photobucket.com/albums/g472/danapcurtis/Diesel%20Jetta/DSCN0872_zpsf0717bbc.jpg)
(http://i1103.photobucket.com/albums/g472/danapcurtis/Diesel%20Jetta/DSCN0873_zps33aa5803.jpg)
(http://i1103.photobucket.com/albums/g472/danapcurtis/Diesel%20Jetta/DSCN0874_zps68363c06.jpg)
any thoughts?
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Google "testing hydraulic lifters" it's a leak down rate kinda thing.
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If those are rod bearings that is how they wear. Mains are opposite. They don't look good to me.
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If those are rod bearings that is how they wear. Mains are opposite. They don't look good to me.
yes those are rod bearings, so you are thinking they look worn?
I am replacing them anyhow since its apart and they are cheap.
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Don't really look bad now that I can see them on a non-phone screen.
I'd plastigauge with the new bearings just to be OCD but I think they are fine
Unless the journals look crappy.
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Is it possible that a precup can drop just a little bit and be kissing the piston? I am inclined to think it would have changed in tone or sound level after all those miles at high rpm.
IMO, they can loosen up and rattle, kissing the piston with each combustion event. At some point, they crack apart and spread the love.
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Is it possible that a precup can drop just a little bit and be kissing the piston? I am inclined to think it would have changed in tone or sound level after all those miles at high rpm.
IMO, they can loosen up and rattle, kissing the piston with each combustion event. At some point, they crack apart and spread the love.
im sure hoping that the noise will cease after lifters and rod bearings are new......but that precup is in the back of my mind. Its so consistent, that I doubt that is the issue. I cant imagine it getting hammered millions of times and not getting any worse.
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Might be, I hope not.
I've been driving these things for a long time and never heard of pre-chamber problems till I started reading
online. My personal opinion which could well be BS is that it's a bad rebuild/abuse/high turbo pressure issue myself.
I don't doubt it happens and anything can happen with a large enough sample size. But it isn't something to expect on a good
stock original motor, and I've put as many or more miles on em as anyone. If the boost is cranked or the head has been monkeyed with, that I can't say about.
It's why I value a virgin VW built motor highly.
You could pull the head. I know it's grief but it's not that bad a job really once the junk is out of the way.
I have had twice, what I believe to have been pieces of really really hard carbon dislodge in these motors after having had crappy
injectors in em and not being rung out very often, both times hot
at low RPM, and make an ungodly bad tap tap tap tap tap noise. Sound for all the world like it was about to come apart.
Few minutes later it cleared up and was gone. One of those motors I had a chance to pull the head off later
and there was a hint of some irregular banging in one cylinder on the piston top and head. It was slight but it was there.
Both motors lived a long life after. These things are tuff.
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Too late to try this now but next time maybe? In the past, to hunt down noise, I have rigged a contact microphone to a tape recorder and headphones so I can listen and make a recording while driving. By moving the mic around, I can localize the source most of the time. By playing back into an oscilloscope, I can measure the frequency and amplitude of the noise.
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I put a mech stethoscope on my 89 today, but it isn't making the particular tone, just lifter noise today. :-\
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My hearing is so lousy and these SOB's are so noisy, I have a hard time really picking out anything to be honest.
I never new the lifters were as apt to crap out as they are till I had a gasser and then was able to pick up a similar
noise on the diesel, even then I wasn't sure. But it shut up and ran better with fresh ones.
Always figured when I'm rich (ha-ha) I'll build a mile long retaining wall with a straight road next to it so I can drive along
it with the window open and hear reflected sound.
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I don't think the precup would make it 2,000 miles. Mine only lasted about 2 miles of slightly less performance than I was used to and 1/2 mile with a noise before throwing it out.
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I put my new rod bearings in tonight and gave it some fresh rotella. I think the noise is still there, but the motor might be a bit quieter overall. I am pretty sure its a lifter. I found a couple that had a 5 thou gap after being run and bently says replace anything with 4 thou or more gap. I am going to assume its safe to drive until the new lifters arrive. The sound really does seem to be at cam speed, not crank speed.
My hearing is so lousy and these SOB's are so noisy, I have a hard time really picking out anything to be honest.
I never new the lifters were as apt to crap out as they are till I had a gasser and then was able to pick up a similar
noise on the diesel, even then I wasn't sure. But it shut up and ran better with fresh ones.
you hit the nail on the head with that one. I know there is a new noise, but the engine is so loud to being with its very hard to pinpoint the noise when under the hood, even with the hose to the ear trick or the screwdriver to the ear trick.I can hear it better when standing back from the car, then the louder clatter can be heard over the normal clatter.
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the plot thickens....I put in new INA lifters today. Let them soak for several hours and installed. Started the car and let it idle for several minutes. It was still pretty noisy, but if i revved it a bit the lifter noise would go away, then return at idle. Once warmed up it sounded exactly as it had before
Still sounds like lifters to me, but not sure. Maybe there is something very broken inside, but i think not since it ran completely quiet for a few breif moments during warm up.
I am wondering if i am not getting adequate oil pressure. The buzzer does work, but I think I will try to get a gauge installed and check the pressure at the head. Is this a common issue with these? Oil pump seemed healthy when I had it out last week. Starting to get frustrated, I would really like to have a motor that didnt have that extra little ticka ticka ticka...
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is it possible that i didnt soak them enough? if that is the case should i pull them out and soak them again? grumble.....
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I put in a set a couple weeks ago. I was kinda disappointed that the lifters didn't just run silently - seemed as bad as before I changed them.
But they have been getting much quieter over time.
I also have a gauge, yet to install. ::)
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Well, I guess that is good to hear. It sounds exactly as it did before. Bummer, but maybe it will improve. Nothing in the valve train showed any signs or abnormal wear or low oil pressure, so i dont think that is the issue.
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Piston slap?
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Piston slap?
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its possible...but I am hoping no.The noise remains constant when coasting downhill and no power applied, bores looked really nice from the bottom when I was in there, and the noise seems to be at cam speed, not crank speed. But I am not ruling it out. If its piston slap, its just going to get driven until it doesnt drive anymore. The noise started suddenly, and has not worsened at all since, 3000 miles later.
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Vacuum pump? I'm grasping at straws here obviously.
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So if you chop throttle at speed in gear, still there or can you tell?
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So if you chop throttle at speed in gear, still there or can you tell?
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yes very clearly, on the way down a steep hill you can shut the key right off and still hear it, does not change with load at all.
I used my stethascope on the vap pump and it seems pretty quiet. I think its a vane type, not a piston type.
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drove it all the way into work (35 miles) and still making the same old noise. I am wondering if the head isnt getting oil, or a passage feeding a lifter is blocked? Could intermediate shaft bearings somehow make a similar sound? The timing belt looked to be tracking very well and the IM shaft seemed to run just fine. Grasping at straws here.
Kind of defeated at this point.
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http://www.youtube.com/watch?v=FAOAGDsZs7c&feature=youtu.be
video of said clatter, engine fully warmed up
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Yeah, sounds like lifters... I'd give it a couple weeks and make another recording the same way. Play em side-by-side.
Turbo sounds sweet. ;D
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Sure does.
Did you eyeball the cam lobes good and check stems for funky wear?
It don't take a lot to make noise.
Low head oil pressure is possible, only on way to check.
What kinda oil?
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I didnt see any strange wear on the cam lobes, but i didnt check them besides a quick eyeball. Oil is 15w-40 rotella T. Maybe the oil pressure gauge will shed some light. I cant believe it would take this long for new lifters to quiet down.....
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Mmo made my ticking lifters on my Eco go away... Your also sucking air into your ip looked like bubbles in your fuel lines. I would get different fuel filter from 86 Jetta w/o warmer aka aiR sucker.
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Mmo made my ticking lifters on my Eco go away... Your also sucking air into your ip looked like bubbles in your fuel lines. I would get different fuel filter from 86 Jetta w/o warmer aka aiR sucker.
im about to try something like that, even though it makes no sense that new lifters would need it. Maybe a little oil passage is blocked with something?
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I put my lifters in 2200 miles ago (April 25). They are much quieter than when I installed them.
There might be one that occasionally gets louder, but when I installed the head gasket last "winter", I found one lifter completely collapsed... that valve or pocket may have some issue.
I will be installing some gauges, so I can tell if the pressure is off. I also hear a brief loud clatter when turning into the street just after starting the engine (< 2min running), so maybe a baffle is missing or the pump is weak.
I can recommend inspecting the old lifters closely for any signs of abnormal wear - I probably should have done the guides (lifters had slight eccentric wear at the stem contact point), but I was eager to get the car back on the road and had no idea if the rest of the engine was worth the effort. (bought used)
I only changed the collapsed lifter when I had the head off. After a month of loud lifters, I presumed that some others were bad and changed them all in April, including the recent replacement. There was very little travel in any of the old lifter plungers, just slightly more than a new lifter. Now I can say, it is worth the time & $ to change them all and know that they are all ok, rather than just one known failed part.
Overall, I'd say the engine is not as quiet as my ex's TDI, but quieter and smoother running than it was before. Maybe it gets another 2-3 mpg, but hard to say if related to seasonal changes more than lifters.
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A little update, In an act of desperation i poured in some marvel mystery oil, and i swear the ticking it got a bit quieter, although still there for sure.
I installed an oil pressure gauge and tapped into the head. It makes about 60psi when cold and driving, about 20psi cold idle, and maybe 5psi hot idle. Driving around at 50-55mph in 5th it is between 15-20psi. Is this normal readings when taking at the head? Seems a bit low. Of course the pint of MMO could be thinning it out some too.
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I should add that the low oil pressure light does not come on, but it does appear to work. Do oil pumps wear out on these things ever? its got 250k.
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I have never had a 1.6 with numbers as low as yours. On first cold start even at the head my pressure shoots up at idle until it warms up. Never got even less than 10 hot idle at the head with my used engines, you are almost ready to trigger the alarm sensor on the head.
I believe the bently wants 29psi at 1900 rpm with sender in the oil filter flange.
My fresh engine in my 79 rabbit right now, td block, does that at idle hot. Cold start at idle is 100+
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A little update, In an act of desperation i poured in some marvel mystery oil, and i swear the ticking it got a bit quieter, although still there for sure.
I installed an oil pressure gauge and tapped into the head. It makes about 60psi when cold and driving, about 20psi cold idle, and maybe 5psi hot idle. Driving around at 50-55mph in 5th it is between 15-20psi. Is this normal readings when taking at the head? Seems a bit low. Of course the pint of MMO could be thinning it out some too.
Those numbers (especially the hot idle number) are a bit low and do indicate an engine with some decent wear for sure. I think the hot idle pressure should be more like 25+PSI. I could see some lifter ticking at hot idle if the pressure is that low.
Chances are you can drive it in the condition it is in for a good long time yet, but if you want to fix the issue the first place I'd be checking would be the intermediate shaft bearings. They can flake away if the timing belt has ever been overtightened in the past and a bad one will cause the oil pressure at the head to drop quite a bit. The oil pump itself is not usually an issue.
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the strange thing is the lifter tick is completely consistent no matter what the oil pressure is.
At this point, I'm driving it until something gets bad. Its not worth chasing my tail on it any longer. I am going to move the gauge pickup to the port down by the filter just for giggles. Will probably swap oil out for 20w-50 and drive drive drive. Still a good chance the road salt will kill it before the engine blows.
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the head oil pressure should be 25psi hot? I was thinking it would be lower than that normally? My reasoning for that is the switch up there closes at .25 or .3 bar to illuminate the oil pressure light. That would be 3.6-4.3 psi before the light comes on. Anyways, its probably boned, oh well.
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The spec is not measured at idle, IIRC it is something like 28psi hot @2000 rpm.
I don't think vw actually cares what it is at idle as long as there is something there.
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do you know if spec is measured at head or at filter area?
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That spec is at the head, with the oil at operating temps.
VW doesn't have an idle spec, as long as the head port sees more than 5psi ALL THE TIME it is good to go. You get 40psi while cruising? You're sailing.
What oil do you have in there? I don't really like the idea of the 20w50, for the 20w part.. the 20w on a cold start (not cold temps just not a hot engine) you could see like 150 psi with that!
I see 70+psi at idle and 80+psi just off idle on a cold start (25c ambient) at the head on 15w40.
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I moved my gauge to the oil filter gauge down to the lower port. Still has low pressure. Barely 10psi at idle, maybe less when hot. Still cruises at about 20 when hot. Bummer. I took the timing belt off and played with the IM. Doesnt seem to have any strange play. I couldnt find any flecks in my oil last time I drained it. Going to replace oil with fresh and fresh filter. Is there anything else I can check before I give in and tear the motor all the way down. Is there a seal in the Vacuum pump that could leak oil pressure? The slot that drives the oil pump is worn like a bow tie. Can this cause issues? Wish I had never messed with it, just driving it and turned up the music!!
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bow tie slot is normal. There is a seal inside that gear area of the vacuum pump that could help you. Could be numerous things, if you didn't pull the im shaft out then you can't rule out the bearings.
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i will check vacuum seal. Seems like IM shaft bearings are most likely culprit. Looks like that is a motor pulling job. I am going to try and rule out any other small thing, and then have to start planning on a tear down. Kind of lame, got way to much other stuff to do in the summer season. Dont have time to be wrenching on my daily every single day. ::)
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make sure the oil pressure gauge you used is accurate before tearing into it.
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guess i dont really know if its accurate. Could pressurize it with my compressor and regulator set at a certain psi. Strange thing is, buzzer and oil pressure light work, and the only time i have ever seen either come on is when cornering left very very hard (i.e. tires breaking free) while ripping over a mountain pass and a quart low on oil. The lights never on even under the hottest idle? Bugger. Should change oil and just drive. Probably go another 100k with the radio up. Im just not that kind of pearson ::)
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Probably go another 100k with the radio up.
Most likely so if it's stock and you keep the oil changes up with good oil.
15w40 Rotella or the like for me, coast to coast, drive easy when it's cold, let the turbo
cool when it's hot, on and on they go. And use a Mann/Mahle or other known good filter.
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What is the range of your gauge? A gauge is most accurate in the middle of the scale. Try a 0-30 psi gauge for high pressure and a 0-15 psi gauge for idle pressure. Get the oil up to temp before hooking up the gauge so you don't peg them with cold oil.
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gauge is 0-100 psi, no worries about pegging it with my engine the way it is now. When cold it might get up to 60psi. At least for the last 100k miles the car has been on a strict diet of 15w40 rotella T with mahle filters, and that is what I have continued to use for it. Its been very well taken car of by a vw diesel nerd of many decades. I think its most likely that my curiosity will get the best of me and I will have to pull the motor and replace the main bearings and intermediate shaft bearings and perhaps oil pump/pump bushing. Its just really hard to climb that mountain in the morning and watch the boost gauge be at 10psi and the oil pressure at 15psi......seems bad.
Another thing I noticed with the lifters. The lifters seem to be more noisy on the driver side of the head. The old ones have a bit of circular wear at that side as well. The new lifter that wont shut up also seems to be on that side of the head. I wonder if that means something on the driver side of the block is spilling out more oil pressure. Im just to curious not to find out. :-\
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I also have a 0-100 psi gauge I installed a while ago. At rest, the needle does not sit at zero, super accurate yeah ;D. I meant to check it with a 0-15 psi gauge for hot idle but never got around to it. I'm gonna do it soon!
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another update:
-took my vac pump out and apart. It looked fine,the oil seal at the end of the shaft appeared to be in tact. Maybe a bid old, but nothing that would be causing my massive pressure loss.
-messed around with the oil pump shaft. The bushing seems nice and tight at the top. I did twist it back and forth a bit and there seems to be quite a bit of play before i can feel the gears touch each other. I think I am feeling gear backlash, and it seems like quite a bit. Bentely specs between 2 and 8 thou. I know people say these pumps never wear out, but it does feel a bit loosey goosey. Is the ABA pump the one with the larger gears? Price seems about the same, is this worth a try?
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can anyone direct me to where I might find the oil seal that lives in the bottom of the vacuum pump shaft. Might as well change that out and see what happens.
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I think it's # 068145117B
IIRC, I got mine from the dealer. ~$10
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thank you! Highly doubt that this is my issue, but easy enough to change.
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Was the culprit discovered?