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General Information => Troubleshooting => Topic started by: zooky on March 08, 2007, 01:33:11 pm
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I just installed a fresh rebuilt 1.6td and fired it up for the first time (well second, first time was less then 1 minute). I let it idle for 1/2 hour, it sounded perfect and was pretty quiet. After the 1/2 hour I started playing with the throttle, it sounded good and returned to idle and was fine. Next, I floored it for about 8-10 seconds and it made a sound like it was misfiring. I got off the gas and it returned to idle, it still idles smooth but now makes a loud rattling noise. What the heck happened? I popped off the valve cover, everything is fine there. I checked the timing and everything is still the same. I am going to have to dig deeper. Any ideas what to look for?? This sucks.
EDIT:
-EGT never got over 300-350
-oil pressure was normal
-engine never got hot enough to turn on fan
-all IP settings were set where Giles set them
-rebuild got all new rings, bearings, valves
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when you had it at wide open throttle was it under load or were you revving it in neutral? if you were revving it in neutral you more then likely wipped out some bearings or something.
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when you had it at wide open throttle was it under load or were you revving it in neutral? if you were revving it in neutral you more then likely wipped out some bearings or something.
neutral. Think I overreved it?
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I just did a full rebuild on a 1.6td. I started it up and put a brick on the accelerator and let 'er rip for: one thousand, one thousand two, one thousand three, one thousand four, one thousand five, one thousand six, one thousand seven, one thousand eight, one thousand nine, one thousand ten............
Sweet chocolate Moses on a Ritz cracker, I’m in shock!
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When I replaced my head gasket I had a loud noise after driving for 8 miles or so. I stopped and opened the hood because I was sure it was major damage, but nothing showed up. After awhile I started it back up and it was quieter and eventually went away. I don't know if it was some kind of injector knock or God's divine intervention but it hasn't come back after 10K miles. I say keep driving it.
Dave
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I have a Giles pump so the govenor mod is done, those revs were waaay up there, if that makes a difference.
I will be dropping the oil pan this weekend to look at the bearings then go from there...
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might sound dumb, but check your motor mounts. mine started making crazy vibrations last week. we popped the hood, pulled the e-brake, put it in gear, slowly let out the clutch and watched the motor mount. it moved like a 1/2 inch or more!
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OK, dropped the pan and checked the bearings. Main bearings are fine. The only thing I found is an indication that the #2 rod bearing spun. The bearing is still in new looking condition but the little tab that sits in that slot is flattened. I am happy I found something but the bearing is still "good" so would losing oil pressure to that bearing cause that noise before the bearing got wiped out? I have to get some new bearings before I can reassemble the bottom end and try it out, its going to drive me nuts in the meantime
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it shouldn't make noise if there's no room to wiggle. Check with plastiguage before putting it back together.
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mmmm rattling noise you say... mine has some weird noise from 1000-1800 rpm. sounds like something is bouncing around in my valve cover... i dont really care though because it runs good enough for me! :lol:
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Next, I floored it for about 8-10 seconds...
Why would you do that?
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Next, I floored it for about 8-10 seconds...
Why would you do that?
try and help seat the rings... best bet though is to get that compound that hillfolk'r was talking about from totalseal. ring land lube or something. supposedly it does a superb job! :wink:
i don't really know if i would 'floor' a freshly rebuilt motor though... but i would definitely give it a few good blips on the throttle and let her idle at around 3000rpm. Does the bentley say to hold wot @ 8-10 seconds???
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The faster you load a new engine the better the rings will seat. Racing engines get frequent top end jobs. Do they spend two or three thousand miles breaking them in easy? I don't think so! It is WFO throttle as soon as the wheels hit the track. What better way to prove the work as well as get those rings seated so the compression is maxed and the blowby is minimal. Don't believe the nonsense that gets repeated since day one about break in procedure. It was written by the lawyers that wanted no liability on warranty not the engineers that built the damn engine!
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it wasnt 8-10 seconds, maybe more like 4-5.
I got it all back together, its about 80% better. I only ran it in the garage, it might get 20% better once I get it outside where the sound is not bouncing off the walls. It sounds 'dieslier' now than before. I havent brought it up to temp yet, its blowing a little white smoke. I havent made any adjustments yet either, not quite sure where to begin. I am going to play with it more tomorrow if I dont have to work...
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it wasnt 8-10 seconds, maybe more like 4-5.
I got it all back together, its about 80% better. I only ran it in the garage, it might get 20% better once I get it outside where the sound is not bouncing off the walls. It sounds 'dieslier' now than before. I havent brought it up to temp yet, its blowing a little white smoke. I havent made any adjustments yet either, not quite sure where to begin. I am going to play with it more tomorrow if I dont have to work...
did you have the injectors rebuilt? maybe that is causing the white smoke... or maybe did you overfill the oil? i know my stupid dipstick isnt the proper one... because i've put in 5L of oil before and it didnt even reach the full mark :shock: didn't take too long to burn off the excess oil though... too much oil is bad!!!
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ok, played around today. Thing has -zero- power. Revs OK but when I put it in 'drive' and hold the brake (not even all that hard) I can floor it and it doesnt even try to go, the RPM's will not go above about 1500RPM.
I checked timing. I am not using the VW transmission, I made alignment marks on all 3 pullys. On the crank alternator pulley and plastic cover I made some "rough" marks, they should line up fine with the marks I made undernieth on the timing belt pulley but I have to gain more access to get to my offical marks. From the looks of things, the IP and cam marks still match and it looks like the crank is off a tooth or two. I wont know until I gain more access.
Could the crank be off a tooth or two? The belt covers 80% of the pulley so it seems unlikely it could jump. It would also seem odd that the cam and IP would both jump a tooth. Either way, I would expect it would run rough(er). I'll know more when I get more access in a day or two, any thoughts in the mean time?
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If you can't find TDC on the crank, your way out in the long grass. TDC is found on a VW flywheel, lined up with the pointer in the timing hole on a VW transmission bellhousing. Hopefully, you didn't smooch a few valves with your wide open throttle with no engine load experiment.
You might have to pull the motor and put a VW trans on it so you can correctly time the motor using a dial indicator in the pump, the cam lock tool in the end of the camshaft, and the crank zeroed out on the pointer on the vw bell housing.
if the pump timeing is off a few degrees, the engine will run poorly. If the cam and the crank are just a very little off, you'll smack the valves with the pistons.
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Timing diesels is done to a thousandths of an inch at exactly TDC... even a little bit off and you get hard starts, low power, smoke, or all of the above.
There's an official tool you can use to measure the flywheel with the engine out, or there are a couple ways with the engine in... generally stuffing something down #1 injector hole, touching it with #1 piston going one way, then going the other... TDC is right in the middle. There's too much crank rotation at TDC to simply measure when the piston is at its highest.
Or... hillbilly-tune the sucker... a search here and at www.vwdieselparts.com should return lots of suggestions.
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when the engine was out I figured out TDC and made marks on the crank. It purred like a kitten when I first started it, at one point everything was set right. I am thinking that if I did wack a piston the thing would run real bad. It runs smooth but is noisy and has no power under load. The turbo wound spool up before, not anymore that I can hear. If the crank did jump one tooth what would my symptoms be?
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Timing diesels is done to a thousandths of an inch at exactly TDC... even a little bit off and you get hard starts, low power, smoke, or all of the above.
I disagree. With my NA rabbit the cam was off almost a whole tooth and that car had all kinds of power, started like a dream. It did smoke a lot though until I turned the fueling down.
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I've never set up a VW diesel to run smooth at idle and have no power, so its hard to say what exactly is wrong. I usually try to get every thing spot on with all the appropriate timing tools and that seems to work OK.
apearently you can run the cam out of wack a little and not smack the valves. Personally, it too dicey for my likeing.
The TDC mark is on the OD of the flywheel, so at that diameter, a little movement is very noticable. If your trying to find TDC with a scratch mark on the timing belt crank pully, that diameter is a whole bunch smaller and it may be very difficult to achieve accuracy. The cam timing and pump timing are all referenced off the crank being at TDC, so that is your first goal.
I don't know if it is possible to snake something down the injector hole, make it through the small port in the prechamber cover, and then contact the top of the piston. The diameter of the "tool" to do this would probably have to be very small. And i would be concerned about bending it and the prechamber cover while trying to bring the piston up to contact it.
I understand you have a non-vw transmission installed on the engine. Perhaps you can back the trans up enough to sneak the top portion of a cut up VW bell housing in there to verify TDC. I think "hillfolk" cut a junk VW trany so he had the top two bolt holes and the TDC hole from a vw bell housing.
Some where on the interenet there is a procedure to time the motor by ear. Apearently, OK results are achievable through this method. You essentially loosen the pump mounting bolts, start the engine, and then manually move the pump untill the engine sounds the best. I've never tried it, so maybe someone here could elaborate.
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Timing diesels is done to a thousandths of an inch at exactly TDC... even a little bit off and you get hard starts, low power, smoke, or all of the above.
I disagree. With my NA rabbit the cam was off almost a whole tooth and that car had all kinds of power, started like a dream. It did smoke a lot though until I turned the fueling down.
So you had the "smoke" part of my laundry list ?!!! :roll:
Vince
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all my timing marks on everything are dead on, looks like I am screwed.
I guess the head is next although I think it runs too smooth to be a tweaked valve. :?
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Take off your valve cover and see if all the cam followers look good and are intact with their valve adjustment shims still in place. Somtimes, when you wack a valve, the shim will pop out too.
Don't base "smooth running" on every thing is OK. Many years ago, i had an NA 1.6 that had a valve seat failure. It still ran "smooth". The cylinder would cut in and out, but it only manifested its self in an RPM change. It still ran "smooth".
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ok, here are my valve lash results:
limits : .006 - .010
I1 - .007
I2 - .007
I3 - .004
I4 - .005
limits: .014 - .018
E1 - .013
E2 - .015
E3 - .016
E4 - .014
3 out of 8 are a tad too tight. I wouldnt think enough to cause this problem. The results also lean towards no bent valves as a bent valve would not close all the way leaving a bigger gap. I still need to get my hands on a gage to check the cylinder pressure. I may also have access to a borescope to take a peek inside.
The pump was just rebuilt by Giles, is there anything in the pump that could have got crunched? From the research I did it has the symptoms if bad injectors or IP timing, the injectors are overhauled GTD's
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here are the compression test results, pretty good considering the rings are not broken in yet:
#1 - 440psi
#2 - 440psi
#3 - 420psi
#4 - 440psi
Also, I discovered the #3 heat shield was upside down (oops) and there is minor carbon build up on that injector.
This pretty much rules out head and head gasket issues.
Any suggestions?
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Anyone?
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that injector may be fouled up now because of the carbon...
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I would try a different set of injectors or verify the injectors again with the pop and pattern test.
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problem was #3 injector was seized OPEN
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I drove it around for a few weeks after the repair but I didn't like the automatic so I took it off the road to swap in a 5 speed. I had some stuff come up so the swap took awhile but it is almost done now. It runs great, purrs like a kitten. The engine needs to be broken in still but I will wait until I can drive the truck so there is a load on it