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post #1 of (permalink) Old 03-13-2001, 01:08 AM
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White exhaust valves?

as i pulled the head of my buddies 89 wrangler 2.5L today, i noticed that all the exhaust valves where a whiteish pale color? what causes this? i reported before that the motor was blowing a whiteish substance out the PCV valve into the airbox, so we decided to get a new head for it and try it out, the one on there is really sludged up and i noticed 2 rods where full of crap to the point of no air going threw and that 2 were slightly bent...anyway... any ideas on how this stuff got this way, well anyway thanks for any help!

1988 Wrangler Laredo 4.2L w/5spd Manual
1995 Wrangler 2.5L w/ 5spd / 31"BFG AT's
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post #2 of (permalink) Old 03-13-2001, 01:22 AM
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Re: White exhaust valves?

The white stuff is ash. My guess is your friend had a bad case of "run on" or "dieseling". which comes from burning the carbon in the cylinders on the valves......you get it hot enough and you'll find an ash residue is left behind. It can be caused a few different things a bad fuel mixture (my 1st guess)... the wrong plugs (2nd guess)... timing being a little off,,,,,(etc),,,,,

post #3 of (permalink) Old 03-13-2001, 03:01 AM
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Re: White exhaust valves?

there isn't any residue, i mean they are white!, i don't understand it, i mean its not flaky or anything i mean they are white, like big alkaselzer next to the intake valve, they looked like mabye even backed to white.. thanks!

1988 Wrangler Laredo 4.2L w/5spd Manual
1995 Wrangler 2.5L w/ 5spd / 31"BFG AT's
Sponsored Links

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