sign of blowby? Sounds of air leaking.

[havoc1482]

Dropped the pan today to have a looks-ey before I changed my oil, and I turned the crank and heard this:




Thoughts?

[John *.?-!.* cub owner]

sounds pretty normal to me. with the engine cold, you will here air hissing past the ring gaps as you move the piston slowly.

[havoc1482]

Wasn't cold tho lol. I warmed it up a little so the oil would flow out better. I do that will all my machines/cars

[Eugene]

What did the compression tests or leak down test tell you?

[havoc1482]

I took a sparkplug compression test. It wasn't warm, but wasn't exactly cold, it was run for a little bit about 45 minutes prior. I got 90, 90, 90, 85 in cylinders 1-4 respectively. I was taking it by running it using the starter, and not actually firing the engine, was that the correct procedure?

[Denny Clayton]

I took a sparkplug compression test. It wasn't warm, but wasn't exactly cold, it was run for a little bit about 45 minutes prior. I got 90, 90, 90, 85 in cylinders 1-4 respectively. I was taking it by running it using the starter, and not actually firing the engine, was that the correct procedure?

Yes. Remove all 4 plugs first and crank the starter while testing each cylinder until the gauge no longer rises.

[Matt Kirsch]

Compression's a little low but there's still plenty of life left as long as it has good oil pressure and doesn't smoke too much for your liking.

But I agree, the hissing sound is normal for an old engine with some wear in it. Once it fires off and starts running it seals up pretty well.