Dave Lindfield
New member
Hi,
I have a Searay 250 sundancer with a Mercruiser 5.7ltr V8. When I was out on the lake travelling at 20 knots the engine bay filled with smoke from the breathers, I assume. The engine got noisy and now there is a knock, only under load. I stopped when it happened and I went back slowly after letting it cool. The engine didn't over heat and the oil pressure is fine. There was no knocking on the way back at 5 knots.
I let the engine fully cool when I got back. Then started it, no knocking. I let it warm up and gave it a few revs, no knocking. So I took it back out, at up to 6 knots it was fine, but as soon as I put a load on the engine it started knocking. It sounds like a bearing, but I thought it would knock on a cold start, it doesn't.
Can anyone shed some light on this before I lift the engine?
Could it be bearings? Water coming in the intake manifolds? Detonation? Or something else?
Thanks in advance!
I have a Searay 250 sundancer with a Mercruiser 5.7ltr V8. When I was out on the lake travelling at 20 knots the engine bay filled with smoke from the breathers, I assume. The engine got noisy and now there is a knock, only under load. I stopped when it happened and I went back slowly after letting it cool. The engine didn't over heat and the oil pressure is fine. There was no knocking on the way back at 5 knots.
I let the engine fully cool when I got back. Then started it, no knocking. I let it warm up and gave it a few revs, no knocking. So I took it back out, at up to 6 knots it was fine, but as soon as I put a load on the engine it started knocking. It sounds like a bearing, but I thought it would knock on a cold start, it doesn't.
Can anyone shed some light on this before I lift the engine?
Could it be bearings? Water coming in the intake manifolds? Detonation? Or something else?
Thanks in advance!
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