My 06 GP has 265,000 miles on it, but a couple of weeks ago, there was a clicking noise coming from the valves at the rear of the engine. I removed the valve cover and found that none of the valves seem to loose. All the valves look to have oil at the end of the pushrod, but I can manually apply oil to the valves and the clicking will go away. I still am having trouble identifying exactly which of the valves the noise is coming from, but I believe it to be one of the middle two.
My thoughts are that either the lifter is not performing properly or the pushrod is clogged and not enough oil is making it to the valve. Does this make sense or are there other things that I am not thinking about that could cause this?
With that, I'm at a bit of a standstill about what my next course of action is. I really do not want to get to the point of tearing the motor down to the lifters, but I am considering removing the pushrods and trying to blow them out with compressed air or cleaning them somehow. With that, I have a couple of questions:
1) Is removing the pushrods as simple as removing the rocker arm bolt, and pulling them straight out?
2) I thought I read that you need to replace the rocker arm bolt with a new one once the factory one is removed. Is this the case?
3) Is there anything I can use to clean the pushrods better?
4) Is there anything I can run through the engine (i.e., engine cleaner) that is effective at cleaning the lifter/oil system?
Thanks for any advice, suggestions, and comments.