Ski Boat Forum

Repairs and Maintenance => Engine Repair/Maintenance - All Ski Boats => Topic started by: phil on May 09, 2014, 06:48:24 PM

Title: what is this, freeze plug?
Post by: phil on May 09, 2014, 06:48:24 PM
hey guys,
we fired up the 82 skier for the first time today and water was coming out of the side of the block. in addition it appears a couple of caps(freeze plugs?) were laying in the bilge and water was coming out of these holes. the block was drained and back filled with rv antifreeze before winter storage.

what is going on? the bigger hole in the picture is where water is coming out.
Title: Re: what is this, freeze plug?
Post by: Daximus on May 10, 2014, 08:55:35 AM
I can't tell from the picture, but that sounds like a classic case of freeze plugs doing their thing. Hopefully your block isn't cracked.

Title: Re: what is this, freeze plug?
Post by: RonT on May 10, 2014, 11:47:59 AM
Picture isn't really that clear but it looks & sounds like your freeze plugs have either popped -or- rusted out of the block. you will need to repair this. Most important is to monitor the oil dipstick for milky oil, that will indicate more serious problems. If the oil stays clean then we simply have to address the freeze plugs. you will need to get creative with a tool to clean the block bore (wire wheel, mini sanding drum) and then replace the freeze plugs. There are some creative rubber plugs out there if the hole is too large for the std. plug to fit. Others have used JB Weld to hold the plug in, either is more permanent and should not be considered a "freeze plug" when done. Keep me posted
Title: Re: what is this, freeze plug?
Post by: Mike Harry on May 11, 2014, 06:46:30 AM
Ron, I put brass plugs in my block (and that's what I believe in)... I was just wondering what you use in the shop. Its hard to tell in this picture, but I would guess that's not brass, there is quite a bit of rust in there.
Title: Re: what is this, freeze plug?
Post by: Gonzo on May 11, 2014, 07:10:42 AM
the plugs are definitely not brass. Should I get the brass plugs then?
Title: Re: what is this, freeze plug?
Post by: Mike Harry on May 11, 2014, 08:54:39 AM
They wont rust out.............. That's my opinion and I have always used them. They are a little more $$$ but you never have to worry about what you have going on.

Now there may be some spec that Im not aware of as to why you shouldn't use them on a marine engine, that's why I directed the question toward Ron.......... but I run them in anything and everything and have never had this issue.
Title: Re: what is this, freeze plug?
Post by: RonT on May 11, 2014, 09:12:31 AM
Brass IS the preferred plug, Marine Power uses these in their engines, Indmar did not, that was just one reason I switched to Marine power in 1996. My first concern is the cast iron block freeze plug bore, I have seen the std. steel plugs rust so bad they fall out of the block as soon as the engine starts the first time of the year & the water pressure blows them out. Cleaning the block bore is next & inspect to see if its still round, I have seen them so rotten that the new plugs fit loose and won't press in and stay. 
Title: Re: what is this, freeze plug?
Post by: Gonzo on May 11, 2014, 09:47:26 AM
I was also looking into the rubber ones. I see they are sold at O'reilly auto parts. What is your opinion on the rubber expansion plugs?
Title: Re: what is this, freeze plug?
Post by: Mike Harry on May 11, 2014, 12:08:53 PM
Try brass first........ problem with rubber plugs is they DO plug the holes but WILL NOT do the work as freeze plug should. The freeze plugs are in place so they will burst out before cracking the block, rubber plugs will not burst out and COULD cause cracking issues under freezing conditions.