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Jim Bear Samba Member

Joined: March 25, 2006 Posts: 670 Location: Watkinsville, GA
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Posted: Sun Jun 01, 2014 7:34 pm Post subject: '74 Engine knock... |
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Hey folks. I went to move the bus so the kid could shoot hoops. The bus had not been started in a week as I was away with the family. I gave it three pumps of the accelerator and turned the key and it made some clunking sounds that were unfamiliar and startling. It barely caught and then died. I turned the key, checked the oil light (on) and then committed again. This time is started smoothly and stayed running, but there was an unsettling slight knock emanating from the engine. I backed it to where it needed to be and let it run for a minute. It idled fine, but the knock was still there. I shut it off, shot hoops with the kid, and tucked the fear into the back of my mind. I will head out tomorrow to assess further and really take a look and listen. My question is how should I proceed? Suggestions and insight welcome. Thanks in advance. _________________ "You're either on the bus, or you're off the bus." ~kk
'85 Vanagon Westy - George In the Stable 2020-?/'74 Weekender - Ophelia In the Stable 2007- ?/'69 Beetle Convertible - SOLD 2017-2020/'67 Beetle - September SOLD 2013-2016 /'67 SO42 Westy - Sage SOLD 1996-2001 /'69 Transporter - Baby Blue SOLD 1995-1995/'72 Westy - Nelly - SOLD 1990-1995--STOP FRACKING |
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Danwvw Samba Member

Joined: July 31, 2012 Posts: 8895 Location: Oregon Coast
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Posted: Sun Jun 01, 2014 7:38 pm Post subject: |
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Well if it has set for a long time perhaps a valve seat stayed stuck to a valve! Wonder if you may have the later hydraulic lifters in it? _________________ 1960 Beetle And 1679cc DP W-100 & Dual Zeniths! |
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busdaddy Samba Member

Joined: February 12, 2004 Posts: 52746 Location: Surrey B.C. Canada, but thinking of Ukraine
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Posted: Sun Jun 01, 2014 8:08 pm Post subject: |
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Danwvw wrote: |
Wonder if you may have the later hydraulic lifters in it? |
Me too.
Also check your oil level to see if it's way too high and smells like gas. _________________ 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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Jim Bear Samba Member

Joined: March 25, 2006 Posts: 670 Location: Watkinsville, GA
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Posted: Sun Jun 01, 2014 8:34 pm Post subject: not hydraulic lifters |
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It does not have not hydraulic lifters. I'll check the oil in the AM. It only sat for a week and was driven locally quite a bit prior. _________________ "You're either on the bus, or you're off the bus." ~kk
'85 Vanagon Westy - George In the Stable 2020-?/'74 Weekender - Ophelia In the Stable 2007- ?/'69 Beetle Convertible - SOLD 2017-2020/'67 Beetle - September SOLD 2013-2016 /'67 SO42 Westy - Sage SOLD 1996-2001 /'69 Transporter - Baby Blue SOLD 1995-1995/'72 Westy - Nelly - SOLD 1990-1995--STOP FRACKING |
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korfmach Samba Member

Joined: February 28, 2014 Posts: 264 Location: Fort Collins, CO
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Posted: Sun Jun 01, 2014 8:40 pm Post subject: |
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Jim Bear--no disrespect intended toward your mechanical assessment skills...but I just went through the whole valve process on my '74. Thought for sure it was solid lifters since it was bone-stock... then found out that it was hydraulics all around--someone had replaced them at some point in the dark, distant past. Check your pushrod length--I think that is the only way to tell for sure without disassembling the whole valvetrain.
Sorry if this is a dumb-ass post and you've already verified your lifters...my engine had (to all external appearances) stock solid lifters and I was very surprised to fine out they weren't. _________________ 1989 Westy
2016 Golf TSI
Gone, but not forgotten:
1974 Dorper Baywindow, "The Bleeding Trout"
1998 Jetta TDI, "Trixie"
1987 GTI, "Heike"
1974 Thing, "The Luftwaffel"
1974 Ghia
1966 Ghia |
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Jim Bear Samba Member

Joined: March 25, 2006 Posts: 670 Location: Watkinsville, GA
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Posted: Mon Jun 02, 2014 5:51 am Post subject: Confirmed solid.... |
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Solid lifters for sure. I will have a chance to get out and dig on things in a bit. I am first going to adjust the valves and note issues/changes from last adjustment. Then, we'll see... _________________ "You're either on the bus, or you're off the bus." ~kk
'85 Vanagon Westy - George In the Stable 2020-?/'74 Weekender - Ophelia In the Stable 2007- ?/'69 Beetle Convertible - SOLD 2017-2020/'67 Beetle - September SOLD 2013-2016 /'67 SO42 Westy - Sage SOLD 1996-2001 /'69 Transporter - Baby Blue SOLD 1995-1995/'72 Westy - Nelly - SOLD 1990-1995--STOP FRACKING |
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Jim Bear Samba Member

Joined: March 25, 2006 Posts: 670 Location: Watkinsville, GA
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Posted: Thu Aug 14, 2014 8:32 am Post subject: All is good. |
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False alarm. Checked everything out and been running strong since...no noise. _________________ "You're either on the bus, or you're off the bus." ~kk
'85 Vanagon Westy - George In the Stable 2020-?/'74 Weekender - Ophelia In the Stable 2007- ?/'69 Beetle Convertible - SOLD 2017-2020/'67 Beetle - September SOLD 2013-2016 /'67 SO42 Westy - Sage SOLD 1996-2001 /'69 Transporter - Baby Blue SOLD 1995-1995/'72 Westy - Nelly - SOLD 1990-1995--STOP FRACKING |
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Wildthings Samba Member

Joined: March 13, 2005 Posts: 52301
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Posted: Thu Aug 14, 2014 9:08 am Post subject: Re: All is good. |
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Jim Bear wrote: |
False alarm. Checked everything out and been running strong since...no noise. |
I would recommend still doing that valve adjustment. What you have described so far sounds like a classic loose valve seat. The engine has been running fine, but once let sit for a while the seat will come out on start up causing a nice bang as the piston collides with the valve. The seat is now jammed most of the way back into place so you get some valve train noise for the excessive lash. Slowly as you run the engine the valve pounds the seat back more fully into place, the lash tightens and every thing seems fine. Ignored though you may soon have a rod ventilating your block. Please check your valve adjustment and watch for any further changes. |
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williamM Samba Member
Joined: August 07, 2008 Posts: 4342 Location: southwest Arizona
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Posted: Thu Aug 14, 2014 9:47 am Post subject: |
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x2 wild has a good point- check all you valve adjustment screws for one that is extended more than the others.
Those heads were known for that
.[img][/img]
Check both spark plugs for any debris or metal bubbles stuck to the electrode- need a magnifying glass. _________________ some days I get up and just sit and think. Some days I just sit.
opinion untempered by fact is ignorance.
Don't step in any! |
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SGKent  Samba Member

Joined: October 30, 2007 Posts: 42439 Location: at the beach
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Posted: Thu Aug 14, 2014 10:04 am Post subject: |
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williamM wrote: |
x2 wild has a good point- check all you valve adjustment screws for one that is extended more than the others.
Those heads were known for that
.[img][/img]
Check both spark plugs for any debris or metal bubbles stuck to the electrode- need a magnifying glass. |
a loose seat, weak spring or stuck valve is the most common. Loose pieces of carbon in a cylinder can also knock. I would follow the advice more than one poster has given and check the valve stem height to see if there is anything noticeable. _________________ "Most people don't know what they're doing, and a lot of them are really good at it." - George Carlin |
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