sign of blowby? Sounds of air leaking.

Sat Jul 12, 2014 5:26 pm

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




Thoughts?

Re: sign of blowby? Sounds of air leaking.

Sat Jul 12, 2014 9:14 pm

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

Re: sign of blowby? Sounds of air leaking.

Sat Jul 12, 2014 9:52 pm

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

Re: sign of blowby? Sounds of air leaking.

Sat Jul 12, 2014 10:49 pm

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

Re: sign of blowby? Sounds of air leaking.

Tue Jul 22, 2014 1:51 pm

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?

Re: sign of blowby? Sounds of air leaking.

Wed Jul 23, 2014 9:01 am

havoc1482 wrote: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.

Re: sign of blowby? Sounds of air leaking.

Thu Jul 24, 2014 11:56 am

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.