compression test result questions

[iceman30]

Ok, I tested my compression yesterday, and got the following results...I have a few questions from it.

cyl 1 = 180
cyl 2 = 165-170ish
cyl 3 = 190
cyl 4 = 180

My car is a 96 TSi awd, with 115k on it, I was glad to see most of the numbers around the original of 178. My only real question was how number 3 was 190???

Any way I was glad to see that I have a healthy engine.

Thanks

 

[L2RTSiAWD]

probably some carbon build-up on the cylinder.

 

[13secGST]

i have a related question that might sound kinda stupid but...how many times are you supposed to crank the engine before you stop...like how many times does it have to shoot up?
An auto teacher told me 4 when I had my honda but I got low #'s like 120-130...then he told me it doesn't matter...so I figured I shouldn't listen to him.

 

[allwheelTSI]

Originally posted by 13secGST
i have a related question that might sound kinda stupid but...how many times are you supposed to crank the engine before you stop...like how many times does it have to shoot up?
An auto teacher told me 4 when I had my honda but I got low #'s like 120-130...then he told me it doesn't matter...so I figured I shouldn't listen to him.

just spin it over for about 2-3 seconds.

 

[larryd]

Exactly, compression builds really fast. If it doesnt reach compression after 3-4 seconds its not going to.

 

[iceman30]

I would say we cranked it for about 5 seconds

 

[iceman30]

So short of pulling the head what else can be done if anything to clean the combustion chamber?

 

[tsunari]

I can not recall where exactly I found them, but there are some good articles online dealing with cleaning your combustion chamber without tearing everything apart. It mainly involves spraying some type of cleaner through the sparkplug holes and letting it just soak in. . .

I do believe they were using carb cleaner. But don't quote me on that.

 

[tsunari]

.

 

[pneumo]

Mopar Combustion Chamber Cleaner. aka, MCCC. Many DSMers have used it with good results.

 

[alex1090]

you are generelly supposed to let the motor turn over 6 times.