alrite...so i have a D16Z6 swap on an eg tha I bought a few days ago. The car drives fine but for some reason it didn't feel like it was at its full potential. So I decided to do a compression test. Cylinder 1 was at 150, cylinder 2 was at 150, cylinder 3 was at 140 and then cylinder 4 was at 0, it was'nt holding any pressure. So i did a couple of research and almost everyone said to add oil into the cylinder and see if compresssion goes up, if it does then the rings are bad and if it doesnt then the valves are either burnt and stucked. So i added oil and there was no compression....so I took off the head and send it out to the machine shop. They pressure tested it and the exhuast valves were not holding pressure. It pretty much needed a valve job...which I agree and paid $200 bucks. Got it back, installed the head with new gaskets and before starting it i did another compression test and guess what.......same f;;;king results. Still no compression on the 4th cylinder...........any ideas...........? the only thing left is an valve adjustment which i didn't even bother to do cause i'm f;;king frustrated...if anyone knows pleaes let me know........thanks

 

Did you by ay chance put a straight edge on the deck of your block while the head was off. Did you check cylinder four for cracks in the walls and such. Is there any possibility that there is a broken connecting rod and the piston is not moving? This would obviously make a great deal of noise but could have been masked with a little rigging done by previous owner.

 

The motor is still in the car and all I did was remove the head... What I notice was that the block had p07 pistons. I rotated the crank several times to check If the pistons were moving up and down and they all were..I also covered up the cyilnders with my hands to see if it had pressure as well as vaccum as I rotated the crank and they all did... There wasnt and signs of chips or scratches on the walls as well

 

no leakdown test?

 

Did the car smoke when you had it running?

 

Holy sh*t..... It wAs the Fu*king rocker arm assembly... Tooooo tight on both the intake and exhuast valves on that piston...And wAs keeping them stuck Open. I went back ad re-adjust all the valves now it runs great... Compression actually bumped up 160 in all cylinders.. Which was pretty werid but it's Idleing smooth and running good.... Thanks for all those who helped

 

Theres a possibility of bent valves as these are interference motors.