| Removing carbon buildup [message #229059] |
Sat, 09 November 2013 15:18  |
biggreen
Messages: 347
Registered: June 2011
Location: Northeast Florida
Karma: 1
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I'm not able to use my GMC as much as I would like so it sits in the garage. I start and run it to operating temp a few times a month, and take it out for a short drive when I can. I know it needs to be run good and hard, but due to a number of circumstances, that has not happened lately.
I started it today and see some carbon near the tailpipe, and a slight noise like a faint knock in the engine. From experience, I know this is carbon build up in the combustion chambers.
Years ago I had a 79 Cadillac with a 425 that knocked like crazy from not being driven far. Took it to an old mechanic buddy of mine and he trickled transmission fluid down the carb at about 2500-3000 rpm and the pile of carbon out the tailpipe was unbelievable! And the knocking stopped.
Anyone heard of this trick, and is it recommended still? Anything better come along? Mine is a 77 with a 403 with 53000 miles. Thanks.
R.D.
Northeast Florida
77 ex-Palm Beach 403
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| Re: Removing carbon buildup [message #229061 is a reply to message #229059] |
Sat, 09 November 2013 16:39  |
Dennis S
Messages: 3046
Registered: November 2005
Karma: 2
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| biggreen wrote on Sat, 09 November 2013 15:18 |
I'm not able to use my GMC as much as I would like so it sits in the garage. I start and run it to operating temp a few times a month, and take it out for a short drive when I can. I know it needs to be run good and hard, but due to a number of circumstances, that has not happened lately.
I started it today and see some carbon near the tailpipe, and a slight noise like a faint knock in the engine. From experience, I know this is carbon build up in the combustion chambers.
Years ago I had a 79 Cadillac with a 425 that knocked like crazy from not being driven far. Took it to an old mechanic buddy of mine and he trickled transmission fluid down the carb at about 2500-3000 rpm and the pile of carbon out the tailpipe was unbelievable! And the knocking stopped.
Anyone heard of this trick, and is it recommended still? Anything better come along? Mine is a 77 with a 403 with 53000 miles. Thanks.
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Seafoam down the carb and in the gas reportedly reduce the buildup.
I also recall JimB has used it and mentioned it favorably on his pose.
Dennis
Dennis S
73 Painted Desert 230
Memphis TN Metro
[Updated on: Sat, 09 November 2013 16:40] Report message to a moderator |
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| Re: Removing carbon buildup [message #229064 is a reply to message #229059] |
Sat, 09 November 2013 17:06 |
GMCNUSA
Messages: 283
Registered: August 2006
Location: Indianapolis, IN
Karma: 0
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| biggreen wrote on Sat, 09 November 2013 16:18 |
I'm not able to use my GMC as much as I would like so it sits in the garage. I start and run it to operating temp a few times a month, and take it out for a short drive when I can. I know it needs to be run good and hard, but due to a number of circumstances, that has not happened lately.
I started it today and see some carbon near the tailpipe, and a slight noise like a faint knock in the engine. From experience, I know this is carbon build up in the combustion chambers.
Years ago I had a 79 Cadillac with a 425 that knocked like crazy from not being driven far. Took it to an old mechanic buddy of mine and he trickled transmission fluid down the carb at about 2500-3000 rpm and the pile of carbon out the tailpipe was unbelievable! And the knocking stopped.
Anyone heard of this trick, and is it recommended still? Anything better come along? Mine is a 77 with a 403 with 53000 miles. Thanks.
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Starting your engine and running it for a little while is harmful. Let it sit until you can drive it at highway speeds for several miles. This is Dick Paterson and many other mechanics advice. JWID
Larry Dilk
Indianapolis, IN
76 Eleganza II
Patterson 455,Turbo City TBI,
Just LOVE It!
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| Re: Removing carbon buildup [message #229069 is a reply to message #229059] |
Sat, 09 November 2013 19:08 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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I have done it to a few engines but I usually run enough ATF to kill the engine. Then let sit overnight to soften up the carbon. The next day when you start it, the engine will smoke a lot for about 10 minutes. Most of the ATF will vaporize and not burn as it goes through the engine.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: Removing carbon buildup [message #229085 is a reply to message #229059] |
Sat, 09 November 2013 21:39 |
Bob de Kruyff
Messages: 4260
Registered: January 2004
Location: Chandler, AZ
Karma: 1
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| biggreen wrote on Sat, 09 November 2013 14:18 |
I'm not able to use my GMC as much as I would like so it sits in the garage. I start and run it to operating temp a few times a month, and take it out for a short drive when I can. I know it needs to be run good and hard, but due to a number of circumstances, that has not happened lately.
I started it today and see some carbon near the tailpipe, and a slight noise like a faint knock in the engine. From experience, I know this is carbon build up in the combustion chambers.
Years ago I had a 79 Cadillac with a 425 that knocked like crazy from not being driven far. Took it to an old mechanic buddy of mine and he trickled transmission fluid down the carb at about 2500-3000 rpm and the pile of carbon out the tailpipe was unbelievable! And the knocking stopped.
Anyone heard of this trick, and is it recommended still? Anything better come along? Mine is a 77 with a 403 with 53000 miles. Thanks.
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Seafome is the best.
Bob de Kruyff
78 Eleganza
Chandler, AZ
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| Re: Removing carbon buildup [message #229118 is a reply to message #229059] |
Sun, 10 November 2013 09:24 |
Ultravan Owners
Messages: 443
Registered: March 2013
Karma: 0
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As a retired mechanic I have tried lots of things.
I started off using ATF when I was younger.
Also working for other shops over the years and on my own I have tried different additives from many different companies. To this day still use BG Products - because I know they work!
The one product a use every year in everything we have with an engine is 44K.
Unlike Seafoam or Trans fluid - this stuff does more than clean carbon build up inside the cylinder.
It is not a quick fix - it works over a longer period. It takes a full 18 to 20 gal tank of gas to be used.
Read about it yourself, find a supplier near you and try it.
You have nothing to lose.
http://www.bgprod.com/blendr/magicPill.html
http://www.bgfindashop.com/44K.htm
Tony
Tony (Ontario Canada)
Marie and I are blessed to have had a 2nd chance to buy our farm.
Still hoping and more importantly praying to be able to build a garage.
Our 1970 Ultravan #520 has an Olds Toronado 455 in back.
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| Re: Removing carbon buildup [message #229120 is a reply to message #229059] |
Sun, 10 November 2013 09:34 |
Cadillackeeper
Messages: 464
Registered: October 2012
Location: Fort Lauderdale
Karma: 1
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A nice 12 ounce can of coca-cola feathered down the carb does some clearing.I never would have believed it until I seen it....
77 455 Elaganza II and 67 Animal, Built 500 Powered Eldo
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| Re: Removing carbon buildup [message #229135 is a reply to message #229120] |
Sun, 10 November 2013 10:43 |
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Bill Freeman
Messages: 122
Registered: March 2004
Location: Colerain, NC
Karma: 1
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I run the engine about 1000 to 2000 rpm while trickling plain water into the carb. Pour just slow enough that the engine doesn't stall. It steam cleans the carbon from the combustion chambers.
A good hard run down the road at high rpm in a lower gear will sometimes work as well as the water trick, but it's probably harder on an old tired engine.
Bill Freeman
78 Royale 73 Sequoia
Colerain, North Carolina
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