Whats the compression reading I need to get on a 1.6L EFI SOHC?



Thanks for any help!
Brian

 

not sure the exact readings that you need, but i always look for at least 100 on little engines and all of the readings to be within 10 either way.

 

100? I've always looked for something in the 120 range.

But... threw more snooping I found this...

1.6L B6 Compression:

1,324 kPa
13.5 kg/cm^2
192 psi

It also states that all of these readings should be found at 270 rpm. Now 192psi seems weird to me but getting a compression reading at 270rpm is just crazy talk to me! Out of my years as a mechanic I've yet to see anyone or hear of anyone doing this. Maybe I'm wrong or blind?



Brian

BTW My readings where (#1)145psi(#2)145psi(#3)120psi(#4)120psi

 

id expect around 140 psi.
the rotary compression guages would read rpm as well as compression. but i dont think they would
work on a piston engine.

based on your compression readings i would suspect a leaky head gasket between 3&4 cyls
run a cyl leakage test and go from there

 

Alright cool, 140 sounds bout right.Wish I was able to do a leak test on her but I don't have the tools to do so, so I'll just replace the head gasket. Just gotta find someone around here to re-surface my head for me...


Thanks for the help,
Brian

 

pez
i would still have a leak down test performed.
you never stated why you were even checking compression.
other issues may exist.

 

Checked my Mazda Workshop Manual for the B6 engine. The numbers you give are correct. Standard compression is 192PSI, Compression Limit is 135PSI. All are measured with the engine cranking at 270rpm.

 

Reason I did the test was I had a good bit of white smoke coming out of the exhaust. First I figured the rings and then started to suspect the valve seals but after what 3doors said then I might have both. Guess nows the time to do that B6T swap!



Thanks,
Brian