Welcome Guest [Log In] [Register]
Posted ImageWelcome to the all new Geo Metro Forum. We hope you enjoy your visit.

You're currently viewing our forum as a guest. This means you are limited to certain areas of the board and there are features you can't use and images you can't see. Registration is simple, fast, and completely free. If you're already a member please log in to your account to access all of our features:

Join our community!




Username:   Password:
Add Reply
Compression numbers on rebuilt engine; 110 psi on rebilt engine
Topic Started: Feb 2 2013, 03:17 AM (1,208 Views)
Michael_B
New Member
[ *  * ]
Rebuilt the engine in my '95 Geo Metro 1.0L and just did a compression check. I have about 3000 miles on the engine right now. I get about 110 psi on all cylinders dry and around 115 psi wet. This seems low to me or is this normal? I had 140 psi on all cyliders before the rebuild. I know compression should be around 190 psi. Thanks for your help.

Update...

I did forget to hold the pedal to the floor when testing. :smackface I will test again.

Yes the engine was warm when tested. I drove 7 miles before I tested it.

Rebuild...

New...
-bored .020" over
-oversize pistons
-oversize rings
-rod and main bearings
-valves (all)
-valve guides (as needed)
-water pump
-oil pump

The odometer said 215,xxx but the engine may not have been original to that car. The engine was never bored out before. Engine did not use oil before the rebuild and is not now either. I had a local machine shop bore and hone, deck the engine block and install the pistons on the rods, grind valve seats, valve guides as needed. I disassembled and assembled the engine myself. I obtained info on where to have the ring gaps in relation to eachother from off this site. I took no shortcuts. Not purposely anyway.

Car runs just fine. There is no black or blue smoke out the tailpipe.

My compression testor is brand new. From Sears and only used it three times if that.
Edited by Michael_B, Feb 3 2013, 12:24 AM.
Offline Profile Quote Post Goto Top
 
Deleted User
Deleted User

Did you just put in a new set of rings?

Or, did you bore the cylinders and install oversize pistons and rings?

How many total miles on the engine?

Was it using any significant amount of oil prior to your working on it?
Quote Post Goto Top
 
Vkhelldog
Member Avatar


Did you try another tester to be sure it isn't off?
Offline Profile Quote Post Goto Top
 
Memphis metro


Did you have the eccelerator pedal to the floor when you tested? What does rebuilt mean to you? Just asking. Means a lot of things to a lot of people. All new valves? Any machine work done? New rings?
Offline Profile Quote Post Goto Top
 
Smidgen
Smidgen

All the above Plus. Was the car warm when tested?
Offline Profile Quote Post Goto Top
 
lelio
Lelio

yeah does the car run well ? if it has ac does it choke it way down ? i rebuilt mine didnt bore it just honed it and i had 180 on my comp test on all cylinders , so i bet you didnt preform the test right or something is wrong . i would think you should see black smoke if u messed up those rings and plenty of it .
Offline Profile Quote Post Goto Top
 
Michael_B
New Member
[ *  * ]
I did forget to hold the pedal to the floor when testing. I will test again.

Yes the engine was warm when tested. I drove 7 miles before I tested it.

Rebuild...

New...
-bored .020" over
-oversize pistons
-oversize rings
-rod and main bearings
-valves (all)
-valve guides (as needed)
-water pump
-oil pump

The odometer said 215,xxx but the engine may not have been original to that car. The engine was never bored out before. Engine did not use oil before the rebuild and is not now either. I had a local machine shop bore and hone, deck the engine block and install the pistons on the rods, grind valve seats, valve guides as needed. I disassembled and assembled the engine myself. I obtained info on where to have the ring gaps in relation to eachother from off this site. I took no shortcuts. Not purposely anyway.

Car runs just fine. There is no black or blue smoke out the tailpipe.

My compression testor is brand new. From Sears and only used it three times if that.
Offline Profile Quote Post Goto Top
 
Coche Blanco
Member Avatar
Troll Certified

If it's 110 even on all three, run it for another 7,000 before you worry about compression.
Offline Profile Quote Post Goto Top
 
Stubby79
Member Avatar


Timing belt off by a notch? I'd assume it'd be noticable if it was, but perhaps not.
Offline Profile Quote Post Goto Top
 
mikeallen2112


Yeah I'm guessing it has to do with you not holding it at WOT. Also just because your comp tester is new doesn't mean it's perfect. I had to rent 3 different ones before I got one that would work correctly lol
Offline Profile Quote Post Goto Top
 
1 user reading this topic (1 Guest and 0 Anonymous)
« Previous Topic · Engine Tech & Diagnostics · Next Topic »
Add Reply