Just got the news about my '98 V70 AWD (217K miles). Burned valve on #3 cylinder. I am wondering two things: Can this have happened by running the car a quart low on oil at interstate speeds (Daughter was driving when the check engine light started blinking, but oil light did not come on)? Also, is a valve job a DIY for a mediocre mechanic? I love the car--best car I have ever had. Bought it in 2004 with 54K miles. About $1800 work in the last year (new heater core in February, wheel bearings in May, climate system blower motor last weekend). Hate to part with it. Looking for wisdom, as I am not objective about this car I love. About $2500 for my shop to do it; they say I should look for a new car. Thanks, as always!