If your initial inspection of the valves indicated nothing, then it likely isn't a broken valve (even though the head could snap off and prevent the piston from traveling fully upward). You might want to check those valves again, since the "plastic bag popping out" is a sure sign that something is not sealing on the intake side (unless you *ALSO* have a burnt valve, which means that you actually have *TWO* different problems). If you remove the rockers and inspect the tips of the valve stems, a broken valve will appear obvious (ie: the stem will protrude further than the rest).
A more likely (and common) cause could be a foreign object that has fallen down into the intake system and either made its way past the valve and into the combustion chamber, or is wedged between the valve and the seat and thus preventing it from closing. I experienced the latter once a very long time ago and it turned out to be one of the shroud screws that I must have dropped down into one of the carbs. If the object is large enough, it may hold the valve open far enough to make contact with the piston during its upward travel. I was lucky in that it happened during engine assembly and was detected during hand cranking, but if this is the case with you and you've used the car's starter to crank the engine over, the piston-to-valve contact may have bent the valve. -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of asad ishaque Sent: Sunday, May 22, 2011 5:19 AM To: vw mailing list Subject: Re: [vintagvw] Motor locked up. Hello all, Continuing the uncovering of the mystery...... Well, I had a long chat with the old timer Mechanic whom I was inviting home and also took the starter motor which came off the bug to him. We examined it together and deduced that there was nothing broken or missing off it. We reached the conclusion that we would have to pull the motor to get to the bottom of things. As the clutch felt 'normal' to press and release, we concluded that the likely thoery of a loose and dropped thrust bearing pin would not hold in our case. So on the 20th of May 2011 with the odometer showing 29597 Kilometer (yes, its a Kilometer speedo!) the two of us pulled the motor in our driveway. The findings were: 1. Leaky main oil seal indeed. Lots of oil under the engine but just a light skim inside the bell housing. Only the engine side of the clutch plate had a light coating of oil. 2. Clutch plate lining was good. However, the four rivets holding the center part were coming loose. So we averted another disaster. 3. Nothing wedged between the flywheel and bell housing. 4. Now the motor sat on the ground and was inspected. It just would not turn. We decided to be gentle with it and put a 36mm socket with a standard handle on the gland nut (no breaker bar). It would not turn. Just a bit of a nudge and it came free!! It proceeded to turn anticlockwise without any issues but again at about the same point, it would not go any further. We deduced that for about 20 degrees of the revolution, it does not go round. You can take it the other way round but not thru the 20 degrees. Another thing we noticed. I had stuffed a plastic bag down the intake manifold with the carb off. During part of the revolution, the plastic bag would come flying off!! It should mean that at least one intake valve was not closing. I have yet to reexamine the valve train with the engine sitting on the floor. I am guessing I missed something. I should rotate the engine by hand and see how the valves operate. Maybe its a broken intake valve?? 5. We examined the oil cooler after taking it off. The old timer said it *might* be chocked though he was not sure. He said wed run kerosene oil thru it to make sure. An old school method of checking is to assess the weight. A heavier oil cooler points to a chocked one. I have yet to run oil thru and check. Dont think its likely as we had put on a brand new oil cooler during the rebuild and Ive kept the oil clean. Still, $hit happens. Who knows. The engine now sits on the driveway floor. I shall get my hands dirty again probably tomorrow and let you know the findings. Any thoughts to check other things??? Someone said it may be a broken crank but I tried to rotate the engine with one hand on the crank pulley and one on the flywheel. I cant feel any relative play which probably must be there in case of a broken crank. Also a suspect is a broken or bent con rod. I consulted another VW mechanic who said it is most likely a spun number one main bearing which would need me to repair the block. Hope not. Thoughts, ideas????? Best regards, Asad Karachi, Pakistan. > From: [email protected] > To: [email protected] > Date: Thu, 19 May 2011 00:01:01 +0000 > Subject: Re: [vintagvw] Motor locked up. > > > Thanks to all of you for the warm welcome back!! > > I am most grateful and amazed that I/we (my brother and I) were actually being missed by many. This feels like returning home after a long time to family, our VW aircooled family! > > My Hotmail account is no longer my primary email but I do read the posts every once in a while and do wish I chime into the discussions more often. Can share a lot of the local VW happenings here which would be of interest to all. > > I read all comments and pondered over. Seems like the two top possibilities are something wedged between the flywheel and Bell housing (maybe like you say a TO bearing clip which came loose when I pushed the car while in gear to disengage the starter motor??). Or something to do with the Valve train assembly. Have still not had time to dig deeper into this mystery as my work hours are odd nowadays. I plan to crawl under the car and take a good look with the valve covers off. I did try to turn the crank pulley good though not really in the opposite direction but it did not budge even a fraction of a millimeter. > > I dont know why but have been having this 'gut feeling' it would turn out to be something stupidly simple rather than something as horrid as a broken crankshaft. Lets see, shall share definitely. > > I have invited an old timer Vdub mechanic over to my place tomorrow and would see what he has to say. Id like to inspect the valve assys before he comes to narrow things down. > > Now I'm sitting planning a bit ahead. I did have quite a few things lined up so if I do need to pull the motor, Id have plenty to do. Im thinking maybe this is an opportunity thrust upon me, very politely, by the VW gods! The car lives up to its nickname of 'Trusty', not breaking down on the road to leave me stranded! Below is a list of 'things to do' if I pull the motor: > > 1. Replace leaky main oil seal (have a German replacement in my stash, just arrived from Canada) > 2. Fix some mysterious exhaust leaks. Seem to be from one of the joints as all components are solid. Bug has stopped fweeming lately. > 3. Toss out the J tubes we had used as no decent heat exchange boxes were available. Now I have a pair of good heater boxes in the attic. > 4. Inspect the clutch. Have brand new Brazilian clutch and pressure plate in my stash (a lucky local bone yard find from an unfinished project which ended up with the scrappers. Half price!). > 5. Maybe, just maybe pull the heads off to fix some oil leaks and fix a single stud which was bad after the overhaul several years ago. This was perhaps the only corner we cut, after great contemplation back then. > 6. New piston rings etc if no 5 happens. > 7. Have nice push rod tube seals too in from Canada which can go on if no 5 happens. > 8. Put in a new starter bushing. Btw, folks may find it interesting that some local Dub specialists can change this with the engine on the car. Its a neat trick I can describe. > 9. Maybe I'm forgetting something?? But I know if I put my hands into this, one things going to lead to a lot of things!! > > This is not all. I have a 'spare' 1967 vintage engine and gearbox in my stash too. Engine can be bolted right on till the current unit gets the needed TLC so car is not off the road for long. > > Also, have some issues to sort on the gearbox itself. The nose cone has miles of play in the hockey stick. The brass bushing even comes loose and wiggles around. Sloppy shifter to which I'm used to, unfortunately. Sometimes the reverse gear slips to neutral. Any thougths whether this is due to a bad reverse or may be a consequence of the hockey stick play?? How can I be sure, without tearing the whole box open, something which gives me nightmares as not familiar with the intricacies. > > Some questions: Can I swap the nose cone off the gear box with the unit on the car?? I have a small collection of nose cones now. How hard is it to take the gearbox off?? Its a swing axle 68 bug. Would the rear wheel alignment get disturbed if the gearbox is taken off or played around with?? I also must change all the three mounts while I'm at this. > > All thoughts shall be highly appreciated. > > Best wishes and warm regards to all, > > Asad > > Karachi, Pakistan. > > > > > > > From: [email protected] > > To: [email protected] > > Date: Wed, 18 May 2011 04:08:27 -0700 > > Subject: Re: [vintagvw] Motor locked up. > > > > my friends 63 panel bus had "locked up" right after he turned off his > > engine. upon pulling engine we found a throwout bearing clip wedging the > > flywheel. reinstalled the throwout bearing with new TO clips and driving it > > everyday 20 miles each way. > > > > -----Original Message----- > > From: [email protected] > > [mailto:[email protected]] On Behalf Of No Quarter > > Sent: Tuesday, May 17, 2011 3:30 PM > > To: Air-Cooled Volkswagen Discussion List > > Subject: Re: [vintagvw] Motor locked up. > > > > Hello Asad! Haven't heard from you in a very long time so I'm glad to see > > you're still with us! > > > > It is entirely possible that something has fallen into the flywheel gear > > teeth and wedged itself between the teeth and the bell-housing. > > > > I would just pull the engine and while it's out, fix that starter bushing in > > > > the transmission. > > > > Then to remedy your hard start issues with the increased resistance in the > > wiring causing the solenoid to not want to activate, go here and read up on > > this rather cheap fix: > > http://www.thesamba.com/vw/forum/viewtopic.php?t=421220 > > > > Keep us posted! > > > > NQ > > > > _______________________________________________ > > vintagvw site list > > [email protected] > > http://lists.sjsu.edu/mailman/listinfo/vintagvw > > ----- > > No virus found in this message. > > Checked by AVG - www.avg.com > > Version: 10.0.1375 / Virus Database: 1509/3643 - Release Date: 05/17/11 > > > > _______________________________________________ > > vintagvw site list > > [email protected] > > http://lists.sjsu.edu/mailman/listinfo/vintagvw > > _______________________________________________ > vintagvw site list > [email protected] > http://lists.sjsu.edu/mailman/listinfo/vintagvw _______________________________________________ vintagvw site list [email protected] http://lists.sjsu.edu/mailman/listinfo/vintagvw _______________________________________________ vintagvw site list [email protected] http://lists.sjsu.edu/mailman/listinfo/vintagvw
