If not drain plugs what is it?

[tlcnate]

I am at the tail end of a partial engine break down to fix water intrusion problem. I tagged and photographed almost everything as I disassembled making assembly much easier but I am stuck on a minor issue (it's the simple stuff that gets complicated!) I hope someone here can help. I have a hole I thought was for a blue drain plug but I stripped the threads on three plugs before I decided maybe it isn't for that. I've cleaned the threads and was considering using a tap to fix the threads but they look clean so I think this may not be a drain. The hole is directly above the oil pressure sensor that shuts down the gasoline pump if it detects no oil pressure.

I managed to get a plug into a similar hole at "9 O'clock" of the problem hole and you can see it just at the edge of the photo. This does NOT mean it is meant to be there. Here is a photo showing my drain plugs (one I am sure belongs there):



On this photo you can see the thumb head of the port side drain just under a spark plug wire and above a water hose. The other plug is the one that n the first photo is off at 9 O'clock at the edge of the photo so that may not belong there. If it does not then I imagine this hole and the one above the oil pressure sensor must take some sort of bolt although I've looked through my bags of removed parts and I can't figure out if I have a left over bolt. I have several extra "head bolts" because I bought all new bolts for the project.

Your help is greatly appreciated. I am this step away from restarting the engine!

 

[alldodge]

:welcome: to iboats

What engine are we working on? What is the serial number, year, type, size, give us something

Add pics

 

[mr 88]

if not drain plugs what is it

Those threaded holes could be for brackets or something like that . Do the holes go all the way through or do they stop.If you try to put a pick or something similiar and it bottoms out after a inch or so I wouldn't worry about it.My computer locks up when I sign in and the only way I can reply is to start a new topic.

 

[alldodge]

Those threaded holes could be for brackets or something like that . Do the holes go all the way through or do they stop.If you try to put a pick or something similiar and it bottoms out after a inch or so I wouldn't worry about it.My computer locks up when I sign in and the only way I can reply is to start a new topic.

Your kidding right ?? :facepalm:

 

[tlcnate]

:welcome: to iboats

What engine are we working on? What is the serial number, year, type, size, give us something

Sorry about that. I t is a Mercruiser 5.0 V-8 model year is 2000. Engine serial number is OL695968 and Engine model number is 44M11025N1

 

[Fun Times]

Those threaded holes could be for brackets or something like that . Do the holes go all the way through or do they stop.If you try to put a pick or something similiar and it bottoms out after a inch or so I wouldn't worry about it.My computer locks up when I sign in and the only way I can reply is to start a new topic.

Moved your reply for you.

 

[alldodge]

Sorry about that. I t is a Mercruiser 5.0 V-8 model year is 2000. Engine serial number is OL695968 and Engine model number is 44M11025N1

I thing that is a blind hole used to mount other items, but not on your motor. It appears to have black paint on it, meaning it was never used.

The thread is probably an 1/8 NPT

 

[tlcnate]

Those threaded holes could be for brackets or something like that . Do the holes go all the way through or do they stop.If you try to put a pick or something similiar and it bottoms out after a inch or so I wouldn't worry about it.My computer locks up when I sign in and the only way I can reply is to start a new topic.

The hole I am having problems with has about 3/4" of thread and then goes in about eight inches. I used a magnetic parts pickup wand and it goes in deep. The other hole where I have the blue plug only goes in about an inch and stops. Is it OK to do direct email or is the preference here for the discussion to continue publicly for the benefit of other people?

 

[Fun Times]

That's just an extra accessory hole that you shouldn't have to worry about..... You'll know for sure when you start the engine tough.

Good luck.

 

[tlcnate]

I thing that is a blind hole used to mount other items, but not on your motor. It appears to have black paint on it, meaning it was never used.

The thread is probably an 1/8 NPT

I am thinking maybe I go ahead with engine start and see if water oil or gas goes shooting out into a small geyser :lol: If not then I guess I am good to go. Weather is turning so I won't be able to work on this for a few days. I will come back and post results.

Thanks everyone for your help!

 

[alldodge]

The hole I am having problems with has about 3/4" of thread and then goes in about eight inches. I used a magnetic parts pickup wand and it goes in deep. The other hole where I have the blue plug only goes in about an inch and stops. Is it OK to do direct email or is the preference here for the discussion to continue publicly for the benefit of other people?

Going in 8 inches isn't a blind hole. Get an 1/8 NPT brass plug and install it. Yes open forum comment is best for all others looking at the thread

 

[tlcnate]

Going in 8 inches isn't a blind hole. Get an 1/8 NPT brass plug and install it. Yes open forum comment is best for all others looking at the thread

I will do that and repost in a week or so when I get this done. Thanks everyone. I've been wrestling with this for days and I have solid guidance in minutes. I should have posted earlier. By the way this photo shows why I did the partial tear down:


Pretty ain't it?

 

[Bondo]

I will do that and repost in a week or so when I get this done. Thanks everyone. I've been wrestling with this for days and I have solid guidance in minutes. I should have posted earlier. By the way this photo shows why I did the partial tear down:


Pretty ain't it?

Ayuh,.... Welcome Aboard,.... Did ya find the Reason for the water in the oil,..?? What's the back story,..??

That blue plug don't belong in that hole,... Nothin' lives in that hole, in yer application,...

 

[thumpar]

You need to remember these blocks had a ton of applications with different fittings needed. What exactly are you trying to do?

 

[JustJason]

That blue plug don't belong in that hole,... Nothin' lives in that hole, in yer application,...

I agree. On the basic 350 cooling water drain system you have 4 drain plugs. 1 on the bottom side of each manifold. And 1 on each side of the engine block, just above the oil pan/block seam.

Give my signature a read when you get a chance.... Just because you found it that way, doesn't meant it is supposed to be that way.

 

[tlcnate]

Ayuh,.... Welcome Aboard,.... Did ya find the Reason for the water in the oil,..?? What's the back story,..??

That blue plug don't belong in that hole,... Nothin' lives in that hole, in yer application,...

The exhaust manifolds were corroded. The previous owner said he'd installed all new exhaust manifolds and elbows when all he really did is paint them a pretty black color.





This is the surface of the exhaust manifold where it meets the elbow. Note the chunk missing on the edge of what is supposed to be a smooth surface.

This one is the surface at the engine black on the exhaust port:



At 5 O'clock you can see the hole I've been dealing with on the OP. All these surfaces are now shiny and smooth. I replaced the manifolds, elbows, gaskets, etc. Also had a valve job done since they were all corroded from the water intrusion.

This is my first boat and I have been working on it with a wrench on one hand, a SELOC repair manual on the other and wishing I had a third hand to hold my beer.

Everyone's been very helpful here. Thanks!

 

[tlcnate]

You need to remember these blocks had a ton of applications with different fittings needed. What exactly are you trying to do?

I am reassembling after partial tear down. I just want to put the thing back together. Now I am thinking maybe there was nothing there to begin with since I did a step by step record of the tear down procedure and I don't see any mention of removing something from this location. I thought maybe I had missed something. I did miss a step in another location with some wiring but I was able to reconnect them thanks to color coding.

 

[Volphin]

That's either a water or oil gallery. Pop a 3/8 brass plug in it as suggested.

 

[asm_]

No Title

There you go...

Nice clear picture for you to show that hole isn't mean to be plugged.

 

[K-2]

There you go...

Nice clear picture for you to show that hole isn't mean to be plugged.

I agree.
On a older car engine with a manual transmission one of these screwed into the hole
.http://www.lategreatchevy.com/full-s...1958-1964.html
Is that the hole you put the magnet stick into?
I never knew the hole went in that far, it must poke through into the area in front of the flywheel, not an oil or water area.
Do you have a 1/2"-13 tap? See if that's the right size.