some valve lash in my ka24de

[needmorenissan]

okay my car just got a fresh rebuild new bearings, new piston rings, headgasket, oil seals. Compression tested my car a month ago and got 170s across the board. Now two weeks ago i tested it again cylinder 4 was down to 120 which is kinda weird cause i just got new piston rings and everything so idk. So i was wondering if valve lash could cause the compression to go so low so soon its not my headgasket im not leaking any and not losing any antifreeze so thats good so idk could it be valve lash? im getting a ticking sound from my valves so i know i have it but could it cause a loss in compression? so please tell me if u know . thanks by the way its a dohc
Modified by needmorenissan at 12:08 PM 7/21/2009

[needmorenissan]

does anyone know?

[Cone Junky]

Did you get any head or valve work done?I had a similiar problem on my rebuild. After the valve grind and cutting new seats in the head, the valves sunk into the head enough to cause them to be constantly open.

Best way to narrow it down is with a leak-down tester. If used correctly you could pinpoint rings, intake/exhaust valves, or headgasket for the loss of compression.

[480sx]

Technically it is POSSIBLE that shim/bucket clearance is out of whack causing your problem. Not really making a lot of sense going on what you have told us, but still possible. Easy check, just pop the valve cover off and use a feeler gauge to tell. Follow FSM directions, and get back to us.

[eastcoastchaos]

ticking would be from valves with too much clearence which will not cause a loss of compression, if it's even the valves making the tick. do another compression check, then right after the bad cylinder put a little oil down the spark plug hole and check again. If the comp jumps up a lot then your rings are probably bad or installed with the end gaps lined up which is bad. If comp doesn't change much then your down to either valves or head gasket. If your oil looks milky and coffee like it's probably the gasket, if not then look at valves. valves are easy to check and with the right tool you don't have to pull the cams to swap shims because there over bucket shims.

[needmorenissan]

okay the head work didnt do that much just the milling of a couple thousandths of and inch off the head to make it flat again thats all, the fsm said .012 to .015 on the intake side for valve clearence and cylinder # 4 was .024 and .013 so its definitly over and the exhaust side was supposed to be .013-.016 and it was .010 and .011 so its kinda tight. the leak down test is not done yet but i will do it this week to narrow down if its the valves, and i did the cylinder test with the oil and it was 120 before and 120 after so i know its not that the piston rings