Crusted over EGR hole in Plenum on 94Q

[Yogi'sQ45]

I have a 94Q w/165,000 miles. I took the plenum off to replace some injectors and the EGR hole was crusted over with some black stuff. The inside of the plenum was kind of nasty with bits of the black crust all around. I cleaned it out, but I am worried about what could cause this to happen and how to prevent it from happening again.

Thanks in advance for any help.

[qship96]

normal,just needs periodic cleaning...............pcv system dumps oil vapors into intake-using full synthetic oil slows down the deposits

[Q45tech]

EGR only flows at steady cruise rpm shuts off immediately when accelerating at even mild throttle opening.

PROVES you are not exercising the rpms vs steady state.

To act like new everything must be clean as new!

Your highway mpg should improve with EGR back functioning.

[Yogi'sQ45]

How do I make sure I am exercising the rpms vs steady state properly? Yes the mpg has increased, however it is still running a little rough and sluggish. Thanks for the replies!

[96Qowner]

You can't really exercise rpms effectively cruising on the highway. It would carbon-up less if so much of your driving wasn't at steady speed.

What you can do is find yourself a can of BG 44K fuel system cleaner, put it in the tank and go romp on your car some. Floor it and let the motor wind up - it's fun! The only caution ... I would suggest not running the transmission through too many floored shifts - ease up around 6000 rpm and let the transmission shift. Romp as much as you can on that tankful, and then change the oil.

Do that before every oil change, and it will help a lot.

[Yogi'sQ45]

Excellent idea's. Sounds like fun! This weekend I'll get a can of BK-44F "Romp" my car around the rural counties on that tankful and then change my oil with full synthetic. I've never used synthetic oil before, is there a recommended brand?

Thanks a lot, I love this site!

[maxnix]

Most use M1, some Redline, some Amsoil, a few Royal Purple. I think a couple even use Castrol Syntec.