Did a compression test on the KA

[grimm199]

Did a compression test on the 96' 240sx tonight. It was a cold test. It ran MUCH better than I expected! Although cylinder #3 is the lowest, it isnt bad. These are the numbers, from the front cylinder towards the back.
Cylinder #1- 185
Cylinder #2- 190
Cylinder #3- 180
Cylinder #4- 185
I didn't think to put a little bit of oil in #3 at the time, may do it tomorrow.
But I am still VERY happy with this, and this engine has 155k-156k on it! :D
She's all ready to be tested.
http://i1122.photobucket.com/albums/l539/grimm199/photo-36.jpg
Cylinder #1
http://i1122.photobucket.com/albums/l539/grimm199/photo-32.jpg
Cylinder #2
http://i1122.photobucket.com/albums/l539/grimm199/photo-33.jpg
Cylinder #3
http://i1122.photobucket.com/albums/l539/grimm199/photo-34.jpg
And Cylinder #4
http://i1122.photobucket.com/albums/l539/grimm199/photo-35.jpg
I shouldnt really be worried about #3 should I? Just figured I would post this on here, showing off my healthy engine. :p

[ForceFed]

I think the rule of thumb is 10-15% balance across all cylinders. Anyway your numbers are fine. Did you do 4/5 hits on each cylinder or just crank till the gauge stopped?

[grimm199]

We did a 10 crank I think it was. Should I do it again with 4 or 5 cranks to get more accurate results then?

[Fredward]

the recommendation is no greater than 14 psi apart. the standard is 179 psi and the low is 151 psi

straight from the FSM

[fliprayzin240sx]

Shit, my KA pushed 140-150 across the board. Idiot previous owner decided that it would be a GREAAAAT idea to run the car with no thermostat.

[grimm199]

Now that I know I have a very healthy engine, I am contemplating either saving up and turbo the KA, or just saving money, and then buy a lower mileage Kouki and then turbo that one. Either way, I will buy a Kouki eventually, most likely for my second car.

[Walperstyle]

curious to the wording of the first post.

When you do a compression check, it does't make your car run better. Its just a process of testing what kind of compression you have.

what problems were you having before?

[Corey121]

This might be a dumb question, But how does running without a thermostate lower your compression per cylinder?

[fliprayzin240sx]

This might be a dumb question, But how does running without a thermostate lower your compression per cylinder?

Engine doesnt get up to operational temp, piston rings doesnt seal in properly and adds extra wear and tear in the long run. Theres a reason that when you check your compression cold, you get a lower number when compared to an engine that is up to temp.

On my car, my guess was the water temp sensor on the car was replaced at one point. They used the wrong sensor, Autozone/Advanced auto has one water temp sensor for all S-chassis, so I think thats what they replaced it with. Engine showed that the car is overheating and figured taking the thermo out would cool it down. Well it did, it kept the temp down on the gauge but its the wrong reading.

[grimm199]

So which is it better to do it on, a warm or cold engine? I have heard them both and there seems to be no right or wrong answers. My step dad was telling me we need to do it on cold, but I didnt know if the numbers in the FSM were from a warm engine or not.

[fliprayzin240sx]

You can do it cold but accurate number is when its hot. Personally, I hate burning my fucking hands with hot spark plugs so I do it cold. Its not really that far off to be honest. Cold is usually off by 10-15 psi, unless your engine is doo-doo like mine. Mine would only gain compression when I drop a cap full of oil to help seal the rings better.

[grimm199]

That is what I was telling him. But they were still fantastic numbers so I am not going to worry about doing it while warm.
curious to the wording of the first post.

When you do a compression check, it does't make your car run better. Its just a process of testing what kind of compression you have.

what problems were you having before?

And I meant that it made much better of numbers than I thought it would. I figured it would make around 150 or something, but I was very suprised.