Antifreeze in my exhaust manifolds

[Glasplyer]

Tell me it is alright to have antifreeze in my exhaust manifolds. A newbie here and was draining fluids (not antifreeze in engine) from exhaust manifolds...nothing but antifreeze! My understanding was that salt water circulated through the exhaust manifolds through a heat transfer unit. Am I wrong? Or...is this bad news...my heat transfer unit is severly corroded through and antifreeze is leaking into the salt water or ????? help! Not liking this! At least my exhaust manifolds or exhaust sytem will not freeze up ???? Help!

 

[Don S]

Re: Antifreeze in my exhaust manifolds

What are you working on, year, make, model?????
I assume it's has a closed cooling system, and it's probably a Mercruiser of some unknown year and model, and may have the exhaust manifolds included in the cooling system.

 

[jerryjerry05]

Re: Antifreeze in my exhaust manifolds

PIctures always help.Jerry

 

[Glasplyer]

Re: Antifreeze in my exhaust manifolds

Does make sense to let you know what year make model...1975 Glasply 21 footer...302 C.I.D.

 

[mthieme]

Re: Antifreeze in my exhaust manifolds

Yup, that's a closed cooling system. This is a good thing.
Anti-freeze in the manifolds would be normal in this case.
You might consider flushing it out and putting in new antifreeze.

 

[Bondo]

Re: Antifreeze in my exhaust manifolds

Ayuh,...

Your manifolds are freshwater,+ Only the Risers see the expelled Raw water...

I can see the line from the H/E going right to both Risers... The hoses with the "T" fitting...

 

[Glasplyer]

Re: Antifreeze in my exhaust manifolds

What a relief...thought i was in for some major repairs! I can see the lines from the H/E and the T fitting's. Trying to see the logic of this engine.
The only 'slight' problem now...is i opened the water plug on the side of the exhaust manifold and found loads of teflon tape around the plug (for seal). Now i can't wrap enough tape around the plug to stop it from leaking. Oh well...look into a larger plug or retapping the drain (would worry about metal shavings getting into the exhaust manifold...would that be a problem?).

Its great to have all this expertise (and the willingness to help) on this forum! Im an old retired Navy Lieutenant Commander (and do not know a 'whit' about boats...rode a carrier (Hornet) for two years and was on destroyer tenders for a year), hospital and school administrator. This is entirely new to me.

Again, thanks for your help!

 

[Bondo]

Re: Antifreeze in my exhaust manifolds

(would worry about metal shavings getting into the exhaust manifold...would that be a problem?).

Nope,.... Not really...

Are the Bad threads in part of the drain fitting, or the cast iron itself,..??..??

If it's the cast iron,...
Those are tapered Pipe Threads,.. Probably 1/4" pipe, or possibly 1/8" pipe...

 

[Glasplyer]

Re: Antifreeze in my exhaust manifolds

...if its the cast iron...it is tapered....

don't know if it is the drain plug or the cast iron. It is a really loose fitting. Can't tighten the bolt down...can't apply enough teflon tape...like something is stripped...either the cast iron or the plug...and is leaking antifreeze. The opening is at least 1/4 inch.

 

[jerryjerry05]

Re: Antifreeze in my exhaust manifolds

From the rust on top of the manifolds.They are probably WAY old.It might be possible to go to the next size plug.Of course they are pipe plug fittings and need the correct taper tap and plug. If not then the manifolds are available to replace.Those manifold do go bad and rust out just like the regular FWC ones they just last longer.Jerry

 

[bomar76]

Re: Antifreeze in my exhaust manifolds

don't know if it is the drain plug or the cast iron. It is a really loose fitting. Can't tighten the bolt down...can't apply enough teflon tape...like something is stripped...either the cast iron or the plug...and is leaking antifreeze. The opening is at least 1/4 inch.

I guess investing less than $1.00 in a new pipe plug to see if that works is out of the question, right?

 

[Glasplyer]

Re: Antifreeze in my exhaust manifolds

Thanks for all the input. Went down to the local Anchor Marine mercruiser dealer (Port Angeles, WA). He looked up the plug...a brass 1/8 in pipe fitting. Guess the guy felt sorry for this newbie. After my tale of 'woe' he said..."just take the fitting, if it doesn't work...come back we'll figure something else out". Didn't charge me for the plug. The thread was different than the plug the previous owner had installed...the old was a steel (nonpipe) coarse thread. I gambled and put in the new fine threaded tapered brass plug...works like a charm. No leak...firm fit. Now on to winterizing the rest of the cooling system.

Thanks guys for all your input!