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Whaanga Samba Member
Joined: May 07, 2016 Posts: 627 Location: Rochester, NY
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Posted: Sat Apr 10, 2021 8:30 pm Post subject: The Sad Tale of a Particular Type 4 Engine |
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Hello -
I'm helping my friend prepare to install a rebuilt type 4 engine in his 73, auto trans bus.
He called me last summer and said he had been on a trip that took him about 150 miles from home. On the way back, he heard a 'click' from the engine, he lost power, and when he pulled over, he reported oil all over the engine bay.
He tells me he checks the oil at every gas fill and on this particular trip, he was confident that he had the proper amount of oil in his engine. He also reports that he had a knowledgable professional help him with a valve adjustment about 800 miles prior to the 'incident.'
He had the bus towed home and basically put it away so he could regroup and make plans.
Once he got home. we found pieces like this scattered in the engine bay:
Two weeks ago we pulled the engine and tranny and were able to get a close look. Here's what we saw:
As we worked to separate the tranny from the engine, we could rotate it enough to line up two of the drive plate bolts for removal. But the engine would not rotate all the way around to remove the third bolt. We had to pull back the bell housing just enough to squeeze a 13mm box wrench in-between the housing and the torque converter.
Once separated, we began to tear things down and found more evidence of problems. We found that the cable from the T stat to the flaps was broken. But we also saw that someone had installed the 1/2 flap BELOW the frame guides so that it was completely frozen and unable to move as seen here:
When we pulled the valve covers, we found that the intake valve on #2 cylinder was frozen and that the rocker arm was able to move way too far:
We also found this odd little wire inside the intake for the #4 cylinder:
Lastly, here is a photo of the inside of the engine looking at the piston:
SO -- My question is - what the heck happened here? I have a fair amount of experience with car work, but less so with engine rebuilds (and diagnosing engine failure). I would be very grateful to hear your thoughts ....
Thanks _________________ Late 1973 Bay w/a transplanted 914 Engine |
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69BahamaYellow Samba Member
Joined: April 22, 2011 Posts: 537 Location: Talbott, TN
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Posted: Sat Apr 10, 2021 9:02 pm Post subject: Re: The Sad Tale of a Particular Type 4 Engine |
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Head of valve broke off and blew through a piston. Rod then broke free from piston and beat a hole through top of case. Maybe you can salvage a few parts for your next engine. Sorry to see this happened to you..... |
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Wildthings Samba Member
Joined: March 13, 2005 Posts: 50349
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Posted: Sat Apr 10, 2021 9:31 pm Post subject: Re: The Sad Tale of a Particular Type 4 Engine |
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Pretty much a boat anchor or lawn ornament. Maybe you can save two of the rods and a few other miscellaneous parts? |
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busdaddy Samba Member
Joined: February 12, 2004 Posts: 51145 Location: Surrey B.C. Canada, but thinking of Ukraine
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Posted: Sat Apr 10, 2021 9:45 pm Post subject: Re: The Sad Tale of a Particular Type 4 Engine |
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Bummer, the "odd little wire" was the oil ring expander at one time. _________________ Rust NEVER sleeps and stock never goes out of style.
Please don't PM technical questions, ask your problem in public so everyone can play along. If you think it's too stupid post it here
Stop dead photo links! Post your photos to The Samba Gallery!
Слава Україні! |
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timvw7476 Samba Member
Joined: June 03, 2013 Posts: 2205 Location: seattle
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Posted: Sat Apr 10, 2021 9:57 pm Post subject: Re: The Sad Tale of a Particular Type 4 Engine |
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that wire would be what's left of an oil control ring assembly.
when checking valves, doesn't hurt to drop the 1/2 side bottom tin & see that
the thermostat is STILL there & tugging on the cable. Maybe check the routing of cable & the nylon wheel directing cable up to flaps. Flap failures are usually catastrophic, but you get engine ping before they sign off.
At highway speeds you won't here a thing. Gotta have gauges, oil pressure,
temp as well, to catch that kind before it lets go like that.
I'm not a fan of extra instruments so I trace my thermo cable routing when oil
change or valve adjust time arrives. |
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Abscate Samba Member
Joined: October 05, 2014 Posts: 22668 Location: NYC/Upstate/ROW
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Posted: Sun Apr 11, 2021 12:02 am Post subject: Re: The Sad Tale of a Particular Type 4 Engine |
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Good news is you can drill as many holes as you like to get the engine and transmission separated. _________________ .ssS! |
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borninabus Samba R&D Dept.
Joined: May 18, 2006 Posts: 4538 Location: Arizona Highways
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Posted: Sun Apr 11, 2021 2:16 am Post subject: Re: The Sad Tale of a Particular Type 4 Engine |
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not the dreaded "you need an entire new engine" click again! _________________ 88 Van WBX, A/T - 13 JSW TDI 6M/T - 2012 Touareg TDI Sport |
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Wildthings Samba Member
Joined: March 13, 2005 Posts: 50349
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Posted: Sun Apr 11, 2021 7:34 am Post subject: Re: The Sad Tale of a Particular Type 4 Engine |
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The left side thermostat flap is in the proper failsafe full cooling position, driving as much air as possible over the heads and down through the oil cooler. |
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sjbartnik Samba Member
Joined: September 01, 2011 Posts: 5998 Location: Brooklyn
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Posted: Sun Apr 11, 2021 9:19 am Post subject: Re: The Sad Tale of a Particular Type 4 Engine |
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Wow I think that would have been a little bit more than a "click"
This is the head of one of the valves. Obviously it has come off its stem - this is called "dropping a valve"
The valve head dropped off into the combustion chamber and 69BahamaYellow concisely described what happened next.
Ouch.
There are many possible causes for why a valve may break like that, usually involving being run hot for a long time. Improper valve adjustment can contribute - valves transfer heat to the cylinder head while they are at rest in the valve seats. If valves are adjusted too tight, they spend less time in contact with their seats and therefore can transfer less heat to the head. _________________ 1965 Volkswagen 1500 Variant S
2000 Kawasaki W650 |
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Wildthings Samba Member
Joined: March 13, 2005 Posts: 50349
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Posted: Sun Apr 11, 2021 9:29 am Post subject: Re: The Sad Tale of a Particular Type 4 Engine |
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About the only warning one would get that this is about to happen is the valve adjustment being very tight prior to adjustment because the valve stem was stretching and/or the valve seat was receding into the head. There may have been some funny noises in the exhaust and a slow loss of power over the last few hundred miles as well. |
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cmonSTART Samba Member
Joined: July 15, 2014 Posts: 1915 Location: NH
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Posted: Sun Apr 11, 2021 9:47 am Post subject: Re: The Sad Tale of a Particular Type 4 Engine |
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sjbartnik wrote: |
Wow I think that would have been a little bit more than a "click" |
No kidding! This guy must have some seriously nice sound deadening installed! _________________ '78 Bus 2.0FI
de K1IGS |
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mikedjames Samba Member
Joined: July 02, 2012 Posts: 2743 Location: Hamble, Hampshire, UK
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Posted: Sun Apr 11, 2021 10:06 am Post subject: Re: The Sad Tale of a Particular Type 4 Engine |
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My T1 did that, the engine noise changed a bit, and I lost power . Came to a stop after half a mile of trying to work out what the new noise was, with pieces of piston lying in a cylinder and a hole in the top of the engine.
The valve head that fell off was so mangled by the time I stopped that it took a while to recognise it. _________________ Ancient vehicles and vessels
1974 VW T2 : Devon Eurovette camper with 1641 DP T1 engine, Progressive carb, full flow oil cooler, EDIS crank timed ignition.
Engine 1: 40k miles (rocker shaft clip fell off), Engine 2: 30k miles (rebuild, dropped valve). Engine 3: a JK Preservation Parts "new" engine, aluminium case: 26k miles: new top end.
Gearbox rebuild 2021 by Bears.
1979 Westerly GK24 24 foot racer/cruiser yacht Forethought of Gosport.
1973 wooden Pacer sailing dinghy |
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Whaanga Samba Member
Joined: May 07, 2016 Posts: 627 Location: Rochester, NY
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Posted: Sun Apr 11, 2021 10:52 am Post subject: Re: The Sad Tale of a Particular Type 4 Engine |
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Thanks for the comments - I appreciate the chance to learn. This engine had some plumbing that I don't recognize. It connects directly into the heads. Can anyone tell me what this piping is and what is the function? And why does my engine not have it?
_________________ Late 1973 Bay w/a transplanted 914 Engine
Last edited by Whaanga on Sun Apr 11, 2021 6:09 pm; edited 1 time in total |
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Wildthings Samba Member
Joined: March 13, 2005 Posts: 50349
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Posted: Sun Apr 11, 2021 11:19 am Post subject: Re: The Sad Tale of a Particular Type 4 Engine |
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It is the remnants of the factory air injection system which injected a small amount of fresh air into the exhaust to give a cleaner burn. It was used on '73 and '74 engines. |
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Abscate Samba Member
Joined: October 05, 2014 Posts: 22668 Location: NYC/Upstate/ROW
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Posted: Sun Apr 11, 2021 12:14 pm Post subject: Re: The Sad Tale of a Particular Type 4 Engine |
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You might have remnants of an extra pulley on the crankshaft , which spun an extra fan belt turning a big pump sitting on the rear of the engine, on top of the fan shroud.
Usually that’s a cymbal crash ffff, not a triangle ppp
_________________ .ssS! |
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