Honda D Series Forum banner

1 - 7 of 7 Posts

·
Registered
Same as above
Joined
·
5,975 Posts
Discussion Starter #1 (Edited)
The engine:

D16z6 block
Oem bearings
Oem oil pump
Fjt 138.56mm rods
76mm vitara pistons
Arp headstuds

Head:
D15b head
D15b cam
D16y7/y8 cam gear

Timing and idle is dead on.

Compression test results are #1-150, #2-180, #3-120, #4-180.

Im getting ready to open it up but just curious if there's possibly a less serious problem than blown out ring lands that could cause the difference in compression. Should i look into valve lash or a blown head gasket first or just proceed with pulling the pistons out?

It doesnt burn oil. Just a few drops of oil in the catch can. Smokes a bit from the valve cover. Doesnt overheat.
 

·
my name says Guest, but Im really a MEMBER
Joined
·
10,488 Posts
Okay, did a second wet compression test increase the numbers?
Leak down?

Valve lash unlikely to only effect 2 cylinders, but anything is possible. Unless you have reason to believe you did it wrong or just did a valve adjustment, it would be far down my list. Well dependent on what a wet compression and leak down showed.

Without a wet compression and leak down it's a guess as to what the problem is.
 

·
Registered
Same as above
Joined
·
5,975 Posts
Discussion Starter #3
Wet compression test increased numbers. But oil will plug any small leak right? Weather it be a small gap between the valve and head, head gasket, or rings right? Does the severity rule anything out? Like the 60psi variance?

Also plugs looked fine light brown and dry.
 

·
Registered
95 ej2
Joined
·
731 Posts
The oil will be forced down into the rings though and as long as the numbers go up your rings should be good but a leak down test is faster then trying to guess all the rest.
 

·
my name says Guest, but Im really a MEMBER
Joined
·
10,488 Posts
conventional theroy if your compression number go up with oil you have a lower end sealing issue. A leak down is going to be the more conclusive.

compression = quick easy lets you know there's a problem. Leak down tells you where.
 

·
my name says Guest, but Im really a MEMBER
Joined
·
10,488 Posts
I dunno I trust something this important on HF. I personally would be using mac, matco, or snap on. Don't get me wrong I have a lot of HF tools, but I'm not going to trust there tools for something as important as the cause of low compression.
 
1 - 7 of 7 Posts
Top