280ZX (S130) Forums Dedicated to 79-83 ZCars

Cylinder PSI

Thread Tools
 
Search this Thread
 
Old 06-19-2013, 02:08 AM
  #26  
Registered User
 
pnoyslimm's Avatar
 
Join Date: Mar 2013
Location: Kansas City
Posts: 72
Resurrecting an old thread and high-jacking it!

Tonight i did a compression test on my stock F54 block with a P79 head. I tested with a stone cold motor, disconnected the EFI from the fusible link, unplugged the coil from the distributor and did each cylinder one at a time 3x both wet and dry, with the other spark plugs still in. These are the "average" results i got from a 180,XXX mile motor;

CLY DRY WET
1 140 140
2 150 150
3 150 150
4 150 150
5 150 150
6 210 250

WTF is going on with cylinder 6?!?!

I did a comp test in hopes of finding out if my head gasket was blown. Just recently, the past 2 days, the car has been expelling out clouds of white from the exhaust at idle and with load.
I was like andwhen i saw the smoke.
First i thought maybe its from a bad cat converter and the many quarter and nickel size holes that are in the exhaust piping. Then i thought maybe its condensation or trapped rain water is what im burning off in the exhaust??? but i havent driven in the rain or crossed any water puddles lately...and now an unusually high compression test reading in the 200's?!?!
The past week i have been losing a qt of coolant ever other day, sometimes a little more depended how much i drove that day. i figured the cause was from a damaged and leaky radiator drain tap...but NOPE!
Since the steady lost of coolant i have been noticing gunky and dried up coolant leak trails coming from the thermostat housing and right by cylinder 6, at the corner where the head meets the block.

Which brings me back to my 1st question, "WTF is going on with cylinder 6?"

I know i may have some valve(s) or lifter(s) issues, due to the loud metal on metal tapping from the valve cover, which has gotten louder since ive had the car(5 months but only has been on the road for 2 months). im pretty sure the motor has never been fully maintained and still has original engine gaskets..so before i invest in either a new exhaust system or do a full engine gasket replacement. i would like to hear any comments or ideas that anyone has to offer.

Last edited by pnoyslimm; 06-19-2013 at 04:17 AM.
pnoyslimm is offline  
Old 06-20-2013, 01:51 PM
  #27  
Registered User
 
Twiggs280zx's Avatar
 
Join Date: Aug 2012
Posts: 201
My PSI was 120 on cylinders 1,2,3,5,6 and 4 was only 90. That and the BS vacuum chop job led to my rebuild.
Twiggs280zx is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
nismodrifterx
300ZX (Z32) Forums
6
09-11-2012 08:33 PM
nandocruz
300ZX (Z32) Performance / Technical
4
11-29-2009 12:59 PM
BoKnows
240Z, 260Z, 280Z Performance / Technical
1
09-05-2005 09:03 PM
v0va
300ZX (Z32) Forums
23
08-11-2005 06:09 PM
doityourself
240Z, 260Z, 280Z (S30) Forums
0
03-24-2003 12:26 PM



Quick Reply: Cylinder PSI



All times are GMT -7. The time now is 10:46 PM.