arriva2450
Cadet
- Joined
- Jul 31, 2012
- Messages
- 11
I bought a "rebuilt" 5.7 merc magnum recently for my boat. The engine came with the intake manifold off, so I was not able to run or test it from the seller.
My mechanic put on the manifold and accessories (ie. starter, alt, risers, etc) and we fired it up for the first time the other day. Seems to idle smooth and accelerate nice, but it is spewing out a you-know-what load of white smoke. Read that some rebuilt engines can do this to burn off greases and other oils used during rebuild, but when is it supposed to stop? Also read that it could be rings, head gasket, or simply the intake manifold gasket (ie. mechanic may not have put it on right, or maybe the rebuilt engine was done bad).
I ran it maybe 30 minutes the first time and it did seem to eventually slow down. Let it sit one day and upon firing seemed to smoke alot again. After maybe 5 minutes seemed to slow down, but then again started smokking real bad.
Is there any way to pin-point what the issue might be? How about if I look at the plugs - will that tell me anything? BTW - seems to have OK power (similar to the engine I replaced which was the same type). Being that this was one rebuilt I was hoping for more, but again it is on par with my previous one (which I cracked the block on from bad winterization).
Oh, one more question. On top of the carb I have a filter housing with two hoses - each hose attaches to one side of the the valve covers. What are these hoses for?? I ask because the hose attachment (that connects it to the valve cover) is broken on one side so basically the hose is free (not connect into the valve cover). There is tons of exhaust (white smoke) coming from this hose, especially when I hit the gas hard. Is this normal?
Any advice would be greatly appreciated.
Thanks
My mechanic put on the manifold and accessories (ie. starter, alt, risers, etc) and we fired it up for the first time the other day. Seems to idle smooth and accelerate nice, but it is spewing out a you-know-what load of white smoke. Read that some rebuilt engines can do this to burn off greases and other oils used during rebuild, but when is it supposed to stop? Also read that it could be rings, head gasket, or simply the intake manifold gasket (ie. mechanic may not have put it on right, or maybe the rebuilt engine was done bad).
I ran it maybe 30 minutes the first time and it did seem to eventually slow down. Let it sit one day and upon firing seemed to smoke alot again. After maybe 5 minutes seemed to slow down, but then again started smokking real bad.
Is there any way to pin-point what the issue might be? How about if I look at the plugs - will that tell me anything? BTW - seems to have OK power (similar to the engine I replaced which was the same type). Being that this was one rebuilt I was hoping for more, but again it is on par with my previous one (which I cracked the block on from bad winterization).
Oh, one more question. On top of the carb I have a filter housing with two hoses - each hose attaches to one side of the the valve covers. What are these hoses for?? I ask because the hose attachment (that connects it to the valve cover) is broken on one side so basically the hose is free (not connect into the valve cover). There is tons of exhaust (white smoke) coming from this hose, especially when I hit the gas hard. Is this normal?
Any advice would be greatly appreciated.
Thanks