Compression Test EA82

[nathan.chase]

Hey all,

I just checked my compression on my 87 GL D/R SPFI. The car has 220k and no rebuild that I know of. I wanted to check up on my results to see what you think. What is the compression range supposed to be?

 

Passenger side

Front .... back

170 178

Drivers

158 170

 

I added oil to the lowest one and got 175 PSI afterwards. I suppose this could just be rings, is this an issue, worth rebuilding an engine for? what are good readings for this engine?

 

 

 

 

 

My procedure:

1. warmed up car

2. disconnected wires to fuel pump and let the engine run out of fuel

3. Remove all sparkplugs

4. Prop throttle wide open (depress pedal all the way as alternative

5. Disconnected wires to ignition coil, disconnect wire from coil to distributor cap.

6. Put battery charger on battery

7. installed compression reader on each cylinder and cranked engine ~8 times, 4 was too few.

8. dropped alittle oil into low compression cylinder and retested to diagnose bad rings.

 

Hope this is helpful to those about to do a compression test.