Ran Motor Without Drain Plugs....

[Big6ft6]

Hi All, What should I be inspecting after running my 4.3 mercruiser with the four engine drain plugs removed? I accidentally left the drain plugs out of the motor (two on exhaust and two at bottom of block) and fired her up at the lake. I probably ran the motor for 5-8 minutes, mostly at idle, before the bilge pump kicked on alerting me to the problem. With a racing heart and a pit in my stomach I replaced the drain plugs (luckily they were in the boat with me) fired her back up, and things seemed to be OK for the remainder of the outing, but I could hardly relax and enjoy the trip.

I'm terrified that some damage was done. What should I be worried about/looking for? Based on the cooling water flow path as I understand it, it seems possible the engine was still getting at least some water through important areas, but for sure no water was being injected in to the exhaust with the manifold drain plugs removed, right? Would that have possibly burnt something things up? Exhaust baffles?

Appreciate thoughts and ideas.

 

[Rick Stephens]

Go boating.

I've never done it that long, or at the lake since I always test in the driveway, but you and I didn't hurt anything except pride.

 

[Scott Danforth]

you may have toasted your exhaust rubber hoses and the flappers if no cooling water got to them.

 

[rad1026]

Wouldn't hurt to pull your rubber exhaust hoses and just check your flaps. Doesn't take long and it would sooth your mind if there is no damage.

 

[tank1949]

Check shutters and exhaust bellows just to be sure. Rubber loves cold water when hot gases are around.

 

[Big6ft6]

Thank you all! I will pull the rubber and check flappers, should do that anyway, one thing I haven't looked at since I bought the boat.

 

[crazy charlie]

you didnt do anything too terrible and you didnt do it for too long.Look on the bright side,your block is probaly clear of all rust and sediment.Was there a bunch of crap in the bilge??

 

[harringtondav]

I'm predicting you will be OK. The water bleeding out the drain ports is small compared to the amount your raw/sea water pump delivers. I flubbed years ago and let my 4.3 idle on muffs after a re-start in Nov to fog. The impeller froze to the pump hsg. No water for 5-7 min. Exhaust flappers and tubes were fine.