Soft Camshaft
Thread Starter
Instructor
Joined: Sep 2008
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Soft Camshaft
I was in the Chevrolet garage yesterday, there is a 2007 vette in for repairs. It has soft camshaft lobes. The car has 36,000 miles. How many others are out there with potential camshaft problems?
Paul
Paul
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From: Northern, VA
St. Jude Donor '15
"In honor of jpee"
I don't know what soft cam lobes are? Was there any further explanation/definition? First time I've read of it here, so I'd guess no, it's not a big or frequent thing/occurrence.
Melting Slicks
Joined: Oct 2005
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From: Pasadena, CA
Oh yes absoutely!!! My 05 had a soft factory cam, and I suspect that there are many many more out there. The clue to me was subtle lifter noise around 2,000 RPM. Mine became evident at approx. 45,000 miles. Here's a pic to prove there was a problem. What was more dissapointing was that GM was not willing to admit there was a problem and give me a break on the repairs. Although I had proof of maint. records etc, I had to pay 5k out of my pocket for repairs. Kind of reminds me of the frustration I went through with the Chevy Vega I bought new in 1973... : 
Last edited by Jimbeaux; Aug 21, 2010 at 10:36 PM.
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From: Charleston SC
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From: Howell Michigan
St. Jude Donor '09-'10-'11
A soft cam improper heat treat would have happen much sooner than 45K miles. A soft cam looks like this photo and this one happen with only about 3K miles.
Melting Slicks
Joined: Oct 2005
Posts: 2,617
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From: Pasadena, CA
Just my opinion, but I doubt your cam in your photo was due to improper heat treat. This type of damage looks like an engine that was stored where the lifter roller corroded to the cam lobe. Leaving old oil in the crankcase before storage can do this.
A soft cam improper heat treat would have happen much sooner than 45K miles. A soft cam looks like this photo and this one happen with only about 3K miles.
A soft cam improper heat treat would have happen much sooner than 45K miles. A soft cam looks like this photo and this one happen with only about 3K miles.
Last edited by Jimbeaux; Aug 22, 2010 at 12:37 AM.
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Joined: Nov 2002
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From: BROOMALL PA
Soft Cam ?
I manufacture cams for a living. They are not for the Auto industry but for automated machinery from can seaming to packaging machinery etc. The first photo looks to me to be a failure from too hard a cam surface. I know this seems strange but when the hardening process is not tempered properly the steel becomes too brittle and chucks of steel falling out as seen the in first picture can result. I have had failures just like this in our products . When the cam surface is too hard and the tempering process was not done correctly.
The sencond photo is typical of a cam surface that is soft. The scoring is typical of wear marks.
Last edited by PHLGUZZ; Aug 22, 2010 at 12:59 AM.
Melting Slicks
Joined: Oct 2005
Posts: 2,617
Likes: 13
From: Pasadena, CA
I manufacture cams for a living. They are not for the Auto industry but for automated machinery from can seaming to packaging machinery etc. The first photo looks to me to be a failure from too hard a cam surface. I know this seems strange but when the hardening process is not tempered properly the steel becomes too brittle and chucks of steel falling out as seen the in first picture can result. I have had failures just like this in our products . When the cam surface is too hard and the tempering process was not done correctly.
The sencond photo is typical of a cam surface that is soft. The scoring is typical of wear marks.
Thread Starter
Instructor
Joined: Sep 2008
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Thanks all.
Not much to worry about I see. I did not ask if the camshaft was OEM or aftermarket. The way the discussion went I assumed the shaft was OEM. Over the years and I have heard about "soft cams" and having had one, I thought here I go again.
Paul
Not much to worry about I see. I did not ask if the camshaft was OEM or aftermarket. The way the discussion went I assumed the shaft was OEM. Over the years and I have heard about "soft cams" and having had one, I thought here I go again.
Paul
Team Owner
Joined: Jun 1999
Posts: 41,793
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From: Houston,Texas USA
Oh yes absoutely!!! My 05 had a soft factory cam, and I suspect that there are many many more out there. The clue to me was subtle lifter noise around 2,000 RPM. Mine became evident at approx. 45,000 miles. Here's a pic to prove there was a problem. What was more dissapointing was that GM was not willing to admit there was a problem and give me a break on the repairs. Although I had proof of maint. records etc, I had to pay 5k out of my pocket for repairs. Kind of reminds me of the frustration I went through with the Chevy Vega I bought new in 1973... :
Team Owner
Joined: Jun 2005
Posts: 46,295
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From: Northern, VA
St. Jude Donor '15
"In honor of jpee"
very interesting discussion. I've never seen one with chunks out of the lobe itself but I have seen excessive scoring and significant wear, usually in race cams. But it can happen to stock cams. Thanks for the photos and explanations from all, a learning experience for sure.
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From: Howell Michigan
St. Jude Donor '09-'10-'11
Could you share the photos of the other lobs that are pitted? 
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Flat tappets are much crueler to camshafts, and required copious amounts of ZnDP to make them live.
Melting Slicks
Joined: Oct 2005
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From: Pasadena, CA
Every lobe has a roller lifter sitting on it, so if there were corrosive conditions you should expect multiple pitted lobes. The car may have been sitting on the dealer lot since Sept of 2004 before you bought it.
Flat tappets are much crueler to camshafts, and required copious amounts of ZnDP to make them live.
Flat tappets are much crueler to camshafts, and required copious amounts of ZnDP to make them live.
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