Hello everyone. I did a compression test on my ride and she passed with flying colors. I did exactly 4 cranks on each cylinder. I was so happy with the results I thought I would share. Also my car has 78k miles and I was so pleased to see how well the engine is holding up for this kind of mileage. The service manual says there should be a minimum of 135psi, but it doesn't say what it should be at it's best sooo I am assuming these are good numbers.

I got... Back
(240)(235)(240)
(244)(235)(237)
Front

Not more than 2% difference between the lowest and highest number. I guess I would be good to go if I ever go for the supercharger.

 

I wonder what the numbers should be at?

 

It's a high compression motor sooo I would think it should be greater than 200psi so your guess is as good as mine.

 

^
I hear you. 135 seems low?

 

Cams contribute just as much or more to compression results as mechanical compression ratio. If the engine uses fairly aggressive cams, even with a high compression ratio, the psi on a compression test can still be low.

Small cam low compression engines can show high psi numbers on a compression test.

All you're looking for is consistency between all 6 cylinders. Ideally the test should be performed with no spark plugs and the throttle wide open but again, all we're looking for is consistency.

The 2% number is great, that's what I would focus on.

 

the throttle being held wide open is a major influence on the numbers reality

you can go more than 4 revolutions to watch for initial, any increase and final compression numbers- 6-7 revs will provide a lot of information

as said- the 2% differance is great- are those canadian numbers? the min allowed is the min the car will still run at...should be a norm range available somewhere for repair techs to work from

Would be interesting to seafoam it and see if it changes compression/reduces it from carbon buildup on the pistons
My honda 2 wheeler owner book talks about that, and requires top end cleaning/decarbonizing on a regular basis to prevent too much compression in an interferance engine and possible valve to piston contact from raised piston height!!

 

Those numbers are psi. And I did have the gas pedal and clutch depressed during cranking. And the spark plugs were out of all cylinders.

A little of topic, but I have the E3 diamond fire sparkplugs.Since I had them out I noticed that there was a little carbon buildup on the plugs. For awhile I noticed extra carbon on my exhaust tips and I think the plugs might be the culprits. So after a little while I am going to get the NGK iridiums again.

 

I suggest removing the E3s & going OEM.

IMHO those plugs are snake oil.

 

the TL -with its already hi energy ignition with coil on plug technology..does not benefit from trick plugs like other cars may

the NGK Iridium is the right part for the job!!

Use a tiny amount of plug thread anti sieze on the middle 2-3 threads, dont want it getting inside the cylinders-- but do want some to keep plugs from sticking

 

I tried them in my 94 Land Cruiser, there was no change of any kind. I took them up on their $ back offer, took almost 3 months to get the $ back.