I did a compression test today. Tell me what you think.

Cyl. 2 195 PSI
Cyl. 4 185 PSI
Cyl. 6 190 PSI

Cyl. 1 200 PSI
Cyl. 3 185 PSI
Cyl. 5 190 PSI

I have 146,000 miles on the car.

 

You are in fine shape. 185 is standard and minimum is 142.
Mind you these specs are measured at 300 rpm.
But your max. cyl. differential is at the limit for factory spec. (14 psi.)

 

Related question:

I've heard about draining the oil and filling with 2qt new oil and 2qt ATF. Start the car and let it idle for an hour or so. Then drain and put in all fresh engine oil. The idea is that the ATF cleans out things and improves the compression and loosens deposits on the pistons and cylinders.

Good idea?

Dave

 

Haven't heard about this one. I use amsoil synthetic. Been using it since I got the car at 117k.

One thing I did notice is that cly. 2, 4, and 6 all had some minor oil on the threads. where as cyl. 1, 3, 6, had hardly any. Cyl. 1 looked like it never been used. Thats the one with 200 psi.

 

i have heard about that.. i wouldnt do it though cuz ur bearings arent gonna like that..

 

You're fine. 185 is the norm with a max variant of 15.

FYI mine was 195 - 200

 

That's why you still use some regular oil and only idle it.

Dave

 

Yeah, I'd think idling the car for an hour would hurt more than it fixed

 

Man you gotta love these VQ's...did mine last week with 195-200psi all around...110,000 and I beat her death most of the time,but apperently she likes it rough

 

How do you test?

 

To test all you do is remove the fuel pump fuse. Relieve all the fuel pressure by cranking the car until it dies. Than remove each spark plug. Place the compression gauge into each cylinder. Crank the car 5 times to get accuracy. Each time its cranked the pressure goes up.

When I first read the instructions I thought you needed two people to perform the test. But that is quite the contrary. This can be done by yourself.

 

ok thanks. I'll look into doing this.

 

I forget - should all the plugs be out at the same time, or just the one replaced the tester?

 

Just the plug of the cylinder you're testing.

 

^^^ Yep. The instructions say to take all of them out, but I believe taking one at a time is recommended.

 

Also worth noting - the engine should be hot. Cold engines produce artificially high compression.

Dave

 

Lol..yea I found that out the hard way...