Knock in 02 4.6 engine.

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Nov 22, 2016 | 06:43 PM

Greg Rogers

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Fleet Mechanic

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From: Central Michigan

Knock in 02 4.6 engine.

Hi Folks. I just bought a very clean 02 E150 Starcraft conversion van. It has 159,000 miles on it. It has a tick nose that is very constant. The seller told me about it, in fact he said he bought it from the 2nd owner who said it has made this noise as long as he had it. It was supposedly traded in or sold by the 1st owner shortly after the noise started. So the noise has been there for a long time- never getting worse or better. The second owner drove it from Mi to Florida and Texas and then the 3rd owner drove it across country (about 7000 miles). Anyway I was pretty sure it was something simple so I bought it. I know its not a exhaust leak or ready to blow out plugs. Its a constant tick/rap from the center of the engine. I removed the right valve cover and started the engine and can see all is fine there, no noise at all from there. Now I am worried that it might be a wrist pin which would explain why its so hard to pinpoint. You guys got any ideas? Thanks, Greg

Nov 23, 2016 | 05:45 PM

Greg Rogers

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Fleet Mechanic

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From: Central Michigan

Well today I pulled the wires to the individual coils one at a time and determined the noise is on the #1 cylinder. The tick changes alot when #1 is disabled. Now I'm really worried it is a wrist pin or piston. Going to pull the oil pan tomarrow. Boy are things tight on this modular engine in a van!!

Nov 24, 2016 | 07:59 PM

Greg Rogers

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Fleet Mechanic

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From: Central Michigan

Anyone have any ideas??

Nov 25, 2016 | 11:42 AM

z31freakify

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From: Las Cruces New Mexico

Might be a sticky lifter, run some seafoam on the oil and see if it goes away.

Nov 25, 2016 | 09:42 PM

wtroger

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These are known to have an issue with piston slap. It's up to you but if it has been running for a long time like this then I would just drive it.

Feb 27, 2017 | 06:49 AM

Greg Rogers

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From: Central Michigan

I forgot I started this thread. I have found out what the problem was. Some one changed the spark plugs and dropped a 1/4" socket down the #1 spark plug hole!!! It ended up cracking the piston and put a perfect indentation of the bottom of socket on the piston and a indentation of the top of socket in the head. I think it was the small socket that was used to take off the coils. I think it was a accident and as soon as they tried to start it it hit once and stopped. Then I think they took the spark plug out and fished it out of the plug hole with a magnet. I put in a used piston/rod along w/ new gaskets chains,etc. Now runs great- no noise. Previous owner wanted me to call him when I got it figured out so I did. He said that made sense since the knock started after he had new plugs installed... Wow...