I have a 90 as well with 240,000 miles on her. It will occasionally tick and as you've seen in the other reply there is some good info bout this. As to when mine ticks I use it as an indicator that I need to get around to changing the Oil. I tend to use 10w30 or 10w 40 oils I also put in a can of CD2 (V-8 Size) in with each oil change. I've had my truck for around 4 years and when I got it ticked bad and I changed the oil two times inabout 2 weeks. Since then it has been much better. I think it just needed to be cleaned out a bit. Over all this truck has definately been one of the best I've ever had! (And one of the cheapest!) <img src="/forums/images/graemlins/kewl.gif" alt="" />