Rough running.....

[ingringr]

My 94 6.5TD Surburban has been running great since new FSD earlier in Summer. Put a K&N filter in on Tuesday with noticeable power improvement. Last night engine started sounding a little clacky up front and running a little rougher. Puts out codes 18, 54, 75 and 78. I reviewed the codes in TDP reference section but wondering if anyone knows possible significance of this grouping before I dig further.

[ingringr]

Well it seems I have progressed to solving my own problem. Cleaned up some contacts and got the codes down to 78. Sent away for new wastegate solenoid. The loud clicking sound turns out to be the vacuum pump and from reading other threads appears that this may or may not be on the way out.

Continues to be and interesting voyage of discovery.....

[pannhead]

count yourself lucky...i'd take a 78 over a 35 or 36 anytime :D ...good luck