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calexican Samba Member
Joined: June 11, 2008 Posts: 727 Location: El Paso, TX
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Posted: Sun Dec 24, 2017 6:43 am Post subject: Engine noise when not under load. |
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Hello, my first post in the engine world. I have a stock 36 that’s been steadily developing a rattle when the engine is not under load, going down hill, or right before shifting from third to fourth gears and occasionally from second to third. This only happens after it’s well warmed up. Any clues? Doesn’t run hot, and compression is great, no smoke. I recently bought another 36 that I have torn down but haven’t figured out what is worn out and what I should keep. P.O. said it has 60,000 miles on it. After cleaning the pistons I noticed a stamp that said 55... also markings of what number the piston is but not in the right order, which makes me think this motor has been rebuilt before. Everything seems to be genuine VW stuff. I’ve been reading some great posts on this forum and learning a lot. I have the bently book, the idiot book and the haynes. |
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[email protected] Samba Member
Joined: May 17, 2003 Posts: 4863 Location: Harmony, PA
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Posted: Sun Dec 24, 2017 9:22 am Post subject: Re: Engine noise when not under load. |
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A rod bearing going bad will make noise on the way down in the rpm range. Say if you free rev the engine, the engine won't make the noise upon reving up to rpm, but will make the noise coming back down to idle. When the oil thins out from heat, you wouldn't have as much of a cushion of it between the bearing/crank. Maybe put an oil pressure gauge on the engine, and see what you get.
Another thing that would make noise without a load is the flywheel coming loose. You could remove the starter, and rotate the flywheel back n forth with a screw driver, while having someone watch the crank pulley to see if the movements are the same. |
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nsracing Samba Member
Joined: November 16, 2003 Posts: 9437 Location: NOVA
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Posted: Sun Dec 24, 2017 11:55 am Post subject: Re: Engine noise when not under load. |
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Any rattle pretty much that will not go away if other than a loose valve lash is rod bearings. Tear it down fast and see if you can save the crank. |
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Wayne S. Johnson Samba Member
Joined: April 12, 2006 Posts: 1265 Location: GILROY, CA
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vwkirb Samba Member
Joined: January 16, 2007 Posts: 812 Location: Athens, GA
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Posted: Sun Dec 24, 2017 1:12 pm Post subject: Re: Engine noise when not under load. |
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Don't forget transmission noises too _________________ Andrew Kirby |
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mcdragracer Samba Member
Joined: December 30, 2007 Posts: 714 Location: Cally
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Posted: Sun Dec 24, 2017 4:58 pm Post subject: Re: Engine noise when not under load. |
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Cam gear coming loose will make noise at idle but not at higher rpm. |
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jason Samba Member
Joined: August 07, 2002 Posts: 3443 Location: Garage
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Posted: Sun Dec 24, 2017 5:14 pm Post subject: Re: Engine noise when not under load. |
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Mine had a noise when it warmed up also. Sounded like a rod knock. Took it apart and found the cam follower guide in the bottom of the case with the lock tab. |
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Bugsy61 Samba Member
Joined: March 20, 2011 Posts: 256 Location: Peoria, Illinois
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Posted: Sun Dec 24, 2017 9:15 pm Post subject: Re: Engine noise when not under load. |
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Piston to wrist pin clearance, or wrist pin to rod small end clearance to great. |
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calexican Samba Member
Joined: June 11, 2008 Posts: 727 Location: El Paso, TX
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Posted: Mon Dec 25, 2017 10:26 am Post subject: Re: Engine noise when not under load. |
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Good stuff, thanks everyone.
Merry Christmas!!! |
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calexican Samba Member
Joined: June 11, 2008 Posts: 727 Location: El Paso, TX
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Posted: Mon Jan 08, 2018 4:40 pm Post subject: Re: Engine noise when not under load. |
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Wayne S. Johnson wrote: |
A common cause for a rattling noise is excessive camshaft end play. My 1300 had a rattling noise at idle, which was caused by 0.037" camshaft end play. |
what is the procedure for fixing camshaft end play? i can move it back and forth quite a bit. |
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calexican Samba Member
Joined: June 11, 2008 Posts: 727 Location: El Paso, TX
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Posted: Thu Jan 11, 2018 5:48 pm Post subject: Re: Engine noise when not under load. |
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Pulled the engine and starting my first rebuild. Inspired by the Grapes of Wrath thread, I've already spent my budget on another engine, so I will try to work both engines into one decent one. |
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calexican Samba Member
Joined: June 11, 2008 Posts: 727 Location: El Paso, TX
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Posted: Wed Jan 17, 2018 1:51 pm Post subject: Re: Engine noise when not under load. |
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I wonder if this Teflon plug was the offending noise? All the other fittings were the clips.... |
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calexican Samba Member
Joined: June 11, 2008 Posts: 727 Location: El Paso, TX
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Posted: Wed Jan 17, 2018 1:58 pm Post subject: Re: Engine noise when not under load. |
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Are these wrist pins too worn? They feel pretty smooth compared to others I have.
Also is this head ok to reuse?
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Danwvw Samba Member
Joined: July 31, 2012 Posts: 8892 Location: Oregon Coast
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Posted: Wed Jan 17, 2018 2:29 pm Post subject: Re: Engine noise when not under load. |
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It's unfortunate that the cylinders got broken like that. It will be ok to use them though. Those pins look good. How do they feel? They normally don't wear, the bushing inside the rod is what wears and that is part of rod sizing and re-bushing that the machine shop does everytime you rebuild one.
There are 80mm big bore kits now for the 36 horse engines I think they require the case to be machined and I am not sure what else. What do yours measure? AA Pistons Stock 36 Check the wrist pin dia too.
You know I think the noise was just the valve train or an old split case transaxle going out if you have one. How does the cam look? _________________ 1960 Beetle And 1679cc DP W-100 & Dual Zeniths! |
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calexican Samba Member
Joined: June 11, 2008 Posts: 727 Location: El Paso, TX
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Posted: Wed Jan 17, 2018 3:39 pm Post subject: Re: Engine noise when not under load. |
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thanks for that information. i can't spend anymore money on this, but it's good to know that stuff is out there for when i have to do this again. i am pretty sure the split case tranny is ok. i actually have other cylinders, but i am not sure about mixing them up, i wanted to use this one because it is vw, the others i have are aftermarket. |
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Danwvw Samba Member
Joined: July 31, 2012 Posts: 8892 Location: Oregon Coast
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Posted: Wed Jan 17, 2018 3:54 pm Post subject: Re: Engine noise when not under load. |
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Be sure and take the bottom end apart and inspect the cam. These cars have been sitting around for years and moisture pitting on the cam can lead to excessive cam lobe wear. Keep your push-rod cam followers matched to their position. _________________ 1960 Beetle And 1679cc DP W-100 & Dual Zeniths! |
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calexican Samba Member
Joined: June 11, 2008 Posts: 727 Location: El Paso, TX
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Posted: Wed Jan 17, 2018 5:11 pm Post subject: Re: Engine noise when not under load. |
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I’m avoiding taking the bottom apart. There is very little, or no end play and I think that was the problem with the last engine, and the case was leaky. I’m going to go with the original pistons and cylinders and put the newer heads on and see what I got. I’ve learned a lot just taking these two engines apart. I will take the leaky case apart at some point and see what that’s all about. |
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calexican Samba Member
Joined: June 11, 2008 Posts: 727 Location: El Paso, TX
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Posted: Wed Jan 17, 2018 5:14 pm Post subject: Re: Engine noise when not under load. |
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“Keep your push-rod cam followers matched to their position.“
Do you mean put them in the same order they came out? I’ve already mixed them all up...oops. |
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Danwvw Samba Member
Joined: July 31, 2012 Posts: 8892 Location: Oregon Coast
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Posted: Wed Jan 17, 2018 5:21 pm Post subject: Re: Engine noise when not under load. |
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You're going to have to have them re-surfaced and I would run a new cam too. You have to take it down! For one thing, it's so easy to do now. _________________ 1960 Beetle And 1679cc DP W-100 & Dual Zeniths! |
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Vanillagurilla Samba Member
Joined: November 21, 2017 Posts: 1061 Location: California
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Posted: Wed Jan 17, 2018 5:23 pm Post subject: Re: Engine noise when not under load. |
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Danwvw wrote: |
You're going to have to have them re-surfaced and I would run a new cam too. You have to take it down! For one thing, it's so easy to do now. |
If he didn't split the case how can he mix up the lifters? |
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