spark knocking, pinging
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Joined: Dec 2005
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Originally Posted by muskin
85 ford f150 straight six, what are the things i need to check to fix this.
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Joined: Nov 2004
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From: sunny fla sometimes windy
How far do you usually drive it? If you only make short 15-20 mile trips at say 45mph
you could have carbon loaded up in the cylinders. If so get out on the highway and
open that pig up get to the top speed a couple times for say 3 minutes then 50mph
for 10 minutes then back up to 75mph for 10 minutes basically you want to vary the
speed and times so the combustion temps are spiking and cooling to get it to flake off
and burn!!
you could have carbon loaded up in the cylinders. If so get out on the highway and
open that pig up get to the top speed a couple times for say 3 minutes then 50mph
for 10 minutes then back up to 75mph for 10 minutes basically you want to vary the
speed and times so the combustion temps are spiking and cooling to get it to flake off
and burn!!
Elder User
Joined: Dec 2005
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I didnt consider the carbon factor that could be it. What I do with engines that have alot of carbon in them is, I runem till there good and hot. Take off the air cleaner, with a spray bottle (windex, or other spray bottles) fill it with water. Yes water. With the engine running and its nice and hot do a quick spray down the carb. Keep it running for another minute. Another spray.
This will not hurt the engine. The water evaporates on the surface of the piston and expands flaking the carbon off. The only way it will kill the motor is if your literally pouring water down the carb. Just a spray at a time.
This will not hurt the engine. The water evaporates on the surface of the piston and expands flaking the carbon off. The only way it will kill the motor is if your literally pouring water down the carb. Just a spray at a time.
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Joined: Nov 2006
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Another thing to do is while the motor is running, take a bottle of Marvile Mystery oil or seafoam and take the air cleaner off and start to pour a little in, but keep it running. Then pour a little more in and once it starts to die pour quite a bit more in until it dies. Then let it sit for 10-15 minutes and go back and start it. It'll have white smoke from the carbon for about 10 minutes, but then it should be good. If it is still doing it try it again. I did this to my dads jeep that hadnt ran in a while and there was some pinging and stuff and it really helped it. Another thing we did to get the carbon out of the pistons was, take the spark plugs out and pour a few onces down the spark plug holes and let it sit a day or two, and then turn over the motor so all of the oil is out so it dont blow it up, then put them back in and go.
Hope this helps
Blake
Hope this helps
Blake
Elder User
Joined: Apr 2003
Posts: 673
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From: Maryland
[QUOTE=This will not hurt the engine. The water evaporates on the surface of the piston and expands flaking the carbon off. The only way it will kill the motor is if your literally pouring water down the carb. Just a spray at a time.[/QUOTE]
I was taught to use the garden hose with a slow stream, like pouring a beer. Warm the engine, manually keep the engine speed up and go for it. You can also substitute ATF for the water, same principal just the detergent in ATF does a number on carbon. Bonus smoke show when using ATF!
I was taught to use the garden hose with a slow stream, like pouring a beer. Warm the engine, manually keep the engine speed up and go for it. You can also substitute ATF for the water, same principal just the detergent in ATF does a number on carbon. Bonus smoke show when using ATF!
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Joined: Nov 2006
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From: Quad Cities, IA
Forgive this post if it's not needed, but I would imagine if you have a high mileage engine and you try the water trick, you'd do well to change the oil right after. If any of the water leaked past the rings and into the crankcase, it would wreak havoc on your engine internals.
I'm not saying the water thing is a bad idea, just that I've dealt with leaky rings before and don't want someone trying this and ruining their engine. Hopefully someone will come along shortly to confirm/deny this.
I'm not saying the water thing is a bad idea, just that I've dealt with leaky rings before and don't want someone trying this and ruining their engine. Hopefully someone will come along shortly to confirm/deny this.
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Joined: Dec 2006
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Check the heat riser buterfly in the exhaust manifold. I had to tack weld mine back on the shaft. I was getting high NOx and high HC from a lean mixture, which sounds like advanced timing. Basically, the volatiles were being boiled-off the carburetor. After the repair, it passed California Test-Only smog check with no problem. The pinging under load was noticibly absent as well.
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From: sunny san diego
First do the easy stuff: check for vacuum leaks, leaking emissions hoses and make sure the EGR valve is working, these alone will wreak havoc....then you can move on to the other suggestions.