1999 E300D. Long story short. Bought car with broken GP. Tore it down and put it back together over the course of around 7 months the way time goes. When I got it back together the engine was very loud much louder than normal. I checked everything. Eliminated the injectors, timed IP, made sure cams were in time. Now I have it down to the lifters and I can't push the lifters in using my hand. Is there a chance they could have became stuck being out of the car for so long and not working right now? The noise seemed like it was coming from the whole engine and I was kinda suspecting lifters but have read were they aren't a problem area on this particular car. But also most of them aren't sitting on the shelf for 7 months. Please let me know if I should be able to push the lifter in and out. All of mine seem stuck.