# B18 Detonation ?'s
**URL:** https://forums.speedlife.net/t/b18-detonation-s/72955
**Category:** NYSpeed Automotive
**Created:** [September 1, 2009, 2:30pm UTC](https://forums.speedlife.net/t/b18-detonation-s/72955 "2009-09-01T14:30:58Z")
**Posts on this page:** 11
**Page:** 1
### Author:  [@93gspeccivic](https://forums.speedlife.net/u/93gspeccivic)
#### Post date: [September 1, 2009, 2:30pm UTC](https://forums.speedlife.net/t/b18-detonation-s/72955/1 "2009-09-01T14:30:58Z")
My civic hatch has a b18a turbocharged motor in it and i blew a head gasket. As i pulled the head off i found the tops of the pistons to have a thin layer of tar like substance on it, some i could wipe off and some i couldnt. Is this a sign of detonation? how can i clean this off / would i be better off replacing pistons (is this a sign of significant overheating)? Any input would be great!
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### Author:  [@brent\_strong](https://forums.speedlife.net/u/brent_strong)
#### Post date: [September 1, 2009, 2:32pm UTC](https://forums.speedlife.net/t/b18-detonation-s/72955/2 "2009-09-01T14:32:27Z")
Sounds like carbon buildup. Pretty normal.
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### Author:  [@93gspeccivic](https://forums.speedlife.net/u/93gspeccivic)
#### Post date: [September 1, 2009, 3:26pm UTC](https://forums.speedlife.net/t/b18-detonation-s/72955/3 "2009-09-01T15:26:27Z")
how would you remove / clean it before putting it back together?
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### Author:  [@brent\_strong](https://forums.speedlife.net/u/brent_strong)
#### Post date: [September 1, 2009, 3:55pm UTC](https://forums.speedlife.net/t/b18-detonation-s/72955/4 "2009-09-01T15:55:45Z")
Soak a rag in gasoline and wipe them down. I wouldn’t worry too much about it.
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### Author:  [@93gspeccivic](https://forums.speedlife.net/u/93gspeccivic)
#### Post date: [September 1, 2009, 3:59pm UTC](https://forums.speedlife.net/t/b18-detonation-s/72955/5 "2009-09-01T15:59:33Z")
Thanks!
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### Author:  [@deebo](https://forums.speedlife.net/u/deebo)
#### Post date: [September 1, 2009, 4:13pm UTC](https://forums.speedlife.net/t/b18-detonation-s/72955/6 "2009-09-01T16:13:16Z")
detonation would be pitting?
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### Author:  [@reliant\_turbo](https://forums.speedlife.net/u/reliant_turbo)
#### Post date: [September 1, 2009, 4:18pm UTC](https://forums.speedlife.net/t/b18-detonation-s/72955/7 "2009-09-01T16:18:34Z")
if you are concerned with detonation, you should invest in/build some setup to monitor the engine.
a friend of mine uses a bosch sensor and a pair of headphones. you should be able to see the pics and the post.
[http://www.turbo-mopar.com/forums/showpost.php?p=521051&postcount=50](http://www.turbo-mopar.com/forums/showpost.php?p=521051&postcount=50)
another setup that works is here:
[http://www.honda-tech.com/showthread.php?t=1555006](http://www.honda-tech.com/showthread.php?t=1555006)
a little wierd looking but it will tell you if you actually have detonation or not.
Brian
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### Author:  [@Toda\_Party](https://forums.speedlife.net/u/Toda_Party)
#### Post date: [September 1, 2009, 4:24pm UTC](https://forums.speedlife.net/t/b18-detonation-s/72955/8 "2009-09-01T16:24:12Z")
leave the carbon on there, free thermal coating haha.
signs of detonation:
slivers of metal
pitting on pistons/valves/head
slivers of metal on plugs
or the more obvious signs
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### Author:  [@93gspeccivic](https://forums.speedlife.net/u/93gspeccivic)
#### Post date: [September 3, 2009, 12:33am UTC](https://forums.speedlife.net/t/b18-detonation-s/72955/9 "2009-09-03T00:33:42Z")
Thanks alot for the help!
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### Author:  [@Jskrapper](https://forums.speedlife.net/u/Jskrapper)
#### Post date: [September 3, 2009, 5:15am UTC](https://forums.speedlife.net/t/b18-detonation-s/72955/10 "2009-09-03T05:15:02Z")
My piston looks like the pic Toda posted…will Gasoline soaked rags take care of that, or should i JB weld it?
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### Author:  [@boostedhatch](https://forums.speedlife.net/u/boostedhatch)
#### Post date: [September 3, 2009, 8:37am UTC](https://forums.speedlife.net/t/b18-detonation-s/72955/11 "2009-09-03T08:37:27Z")
weld the pieces back on