Mechanics

PREIGNITION KNOCK

2002 Ford 500 • 6 cylinder 2WD Automatic • 11,000,000 miles

I have 2002 ford windstar with the large v6 (vulcan) and I noticed that it has recently started pinging or knocking under acceleration. It does it when the engine is hot, not when it is cold. The problem occurs under light to moderate acceleration or just after the automatic transmission shifts. I've taken it to a diagnostic center and they have checked the EGR valve and associated systems, polled the computer for error codes (none found). I have no check engine lights or other warning lights.

Their best guesse was bad gas. I've changed brand/gas station and have run a half tank of premium through it and while the knock has diminished, it is still there. What could be causing this problem?
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Hopk6344
June 8, 2011.




If the engine is pinging/detonating and the EGR valve is not doing its job it will cause a high combustion temperature and NOx will sky high and cause it to ping. Don't always rely on the computer to give you something when there's a problem within the engine management system it'll be nice though if it does
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Tiny
Rasmataz
Jun 13, 2011.
Thanks. I hope this turns out to be the problem. It's highly inconvenient buming a ride to work when you have a 45 mile commute.

Tiny
Hopk6344
Jun 13, 2011.
Well, replacing the EGR solenoid and cleaning the injectors/combustion chamber seemed to fix the problem. I picked the van up yesterday, and stress-tested it by accelerating up a steep hill from a dead stop. No pinging or preignition noises. It still seems odd that the solenoid would not have tripped a error code on the computer. I'll monitor it closely over the next month to make sure it's not a temporary improvement. Thanks everyone for your suggestions. I'll be using this service again!

Tiny
Hopk6344
Jun 14, 2011.
Thank you for letting us know that your problem was resolved successfully with help from our expert contributors.

Rivermikerat
Jun 25, 2011.

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