massive engine noises

[joel210]

I have posted about a month earlier, tried to fix it but got no where. So here is what happened and what I have done. One day the car started to run horrible, sounds like it is missing at idle, pulling about 5-10 inch of vac at idle. Also no acceleration, can barely hear the turbo spool up. Used to be really loud spool up. But this is what really concerns me, it has this knocking tapping noise that sounds like it is coming from the head, that make the car sound like a diesel enging. It is really loud. Now this is what I have done, changed the oil and filter. I even cut open the oil filter to find it perfectly clean, saw no metal flakes or anything. The stock oil press gauge shows normal, and the aftermarket oil press gauge show about 18 lbs at idle. Then I have replaced all of the lifters with the new style with the bigger opening, and still no luck. I have checked the compression, and it is good all the way across. Checked the cam timing and the two white marks line up, also checked the ignition timing which is also good. Looked at the spark plugs for detionation, but all appeared to be in great shape. Does anyone have any idea's? Here are a list of mods that are done to the car: Hacked can with K&N, buscher racing apr, HKS electronic boost control, 16g small turbo, hks catback exhaust, tmo stage 2 chip, about 1000 miles ago the car overheated and had the head milled and all the vavles reseated and valve steam seals replaced, the shop I had the work done put the complete head back together. But the car ran and sounded great after I had all the head work done. Any help would be great. Thanks in advance. Depressed DSMer. Joel

 

[oddrob]

You checked the cam timing, did you check to see if the crank was lined up when the cam marks were in line? Did you run a leakdown test as well as a compression test? That may tell you more. Pull the plugs and do a visual inspection of the piston crowns as well, see if you see anything.

 

[joel210]

Cam timing shows to be right on, I will run a leak down test to see if I can get any more clues on what it is. The plugs looked great when I pulled them. Is there any way to test oil pressure up at the head? if so, how many lbs. should there be? thanks joel