My oil tank cap has thick yellowish sludge and after having the oil changed its on 2001 Ford Expedition

still building up and now she's having trouble starting (2-3days later). Now I've notice white smoke and she's driving a little rough. The check engine light is on and I was told she's misfiring. What work should be done?? First I was told a major tuneup and now a valve job.... Not to mention almost 2yrs ago the engine was replaced and oil changes had been maintained.

by in San Diego, CA on February 24, 2012
2 answers 2 comments
ANSWER by , February 24, 2012
it sounds like it has overheated and you are mixing coolant and oil. have a leak down test to check the cooling system first before doing anything. Roy
COMMENT by , February 25, 2012
Okay thank you I will ask for the test. Will a leak down test detect a cracked or leaking head gasket and comfirm the need of a valve job? And can you tell me if valves 3&4 are "misfiring" would that mean a valve job should be done? Costing more than $2,500.00 or is that fair? Thanks again I wish I had your knowledge or Oprah's bank balance. AB
COMMENT by , February 25, 2012
yes, this test will confirm a head issue and yes, it could also be the missfire code. 2500 sounds like a good starting price. Roy
ANSWER by , February 25, 2012
check the warranty on the engine replacement ,seems like the engine was overheated and caused damage to the head or head gasket ,inspection needed