white residue on plugs

[trogdor4x4]

I have found white residue on almost all eight of my plugs. Does anyone have an idea of what it could be? The motor runs fine except at highway speeds (not enough power to go up hills at steady speed or to go against a head wind and it pings sometimes) and sitting at stop lights (the engine bogs a little, but frequently, I have noticed it does it more the warmer the motor is). I don't know if my symptums are related or not.

Please help I acually have time to work on it this weekend. Thanks

 

[mountain4x4]

You are burning LEAN. Check your fuel pressure, under load as well as idling, check fuel injector spray pattern. Make sure fuel and air filters are not clogged. Verify O2 and MAP sensors are OK. If your engine has some mods, you may need to bump up the fuel pressure. This is best done with a wideband O2 sensor so you get the correct A/F ratio in open loop operation (over 3/4 throttle on Chevy TBIs I think).

Lean burn can damage your engine, make sure you solve the issue quickly. If you are modded and can't pay someone with a wideband to tune it, read up on how to read your sparkplugs. Dyno facilities with tailpipe sniffer A/F readers don't work well if you have a cat. The sensor needs to go upstream of the cat.

 

[zeroz400]

If the insulator isnt white then you are not running lean. If it is whitsh-grey, it is oil.; Either you have low compression or leaking valve seals.


Later

 

[mountain4x4]

It's pinging under load, low power on the highway, and has white plug deposits... lean.

 

[Mad-Dog]

that is aluminum from your pistons because the fuel mixture is lean and preignition is happening (not good).
fatten up the mix and install a fresh set of plugs

 

[4X4HIGH]

Mad-Dog took the words out of my mouth. He is absolutely correct. The specs you are seeing is actually aluminum from the pistons from running too lean and pinging.