Freeze plugs on bottom of intake?

I bought this car with 58K miles on it and it looked like the coolant was never changed so I flushed it a few times and replaced all hoses (I think) and the coolant. This was a couple years ago. Now with 90K miles, the coolant still looks rusty so I ran some flush through it again. Now I'm noticing a coolant leak (steady dribble) that looks like it's coming from a 1" diameter plug on the bottom of the intake between #3 and #4 cylinder. Is that a freeze plug and does it make sense that it could be leaking due to the poor care that the cooling system had in it's early days? This is on an 89 DX automatic with only 95K miles. If it is a freeze plug, I guess you can get these from Honda?
Thanks for any help. Pat

I'll just add something on taking the freeze plugs out. Since the block is on the car, try to knock it in the middle so it folds as much as you can get it. It will take a little prying on it to get it to come out the hole. Might not have much room to work with.
Neglect of changing the coolant causes rust. Rust causes plugs, radiator & block to deteriorate.

Edit- Sometimes you can hit the freeze plug on one side to get the other side to move outwards. Then pull the plug out with some pliers. If the block was out of the car, then you would drill a screw in the plug & pull it out with a slide hammer.

I know it won't be easy to replace since it's still in the car, but the leak is too bad to ignore it. I've never heard of freeze plugs on the intake, but I guess thats what they are??? To make sure that's whats leaking, I put silicone on it yesterday (I know that won't hold long, especially with heat) and will put water in it today to see if it leaks because before it was just a steady dribble. If it still leaks the same, then it's probably the hose just below that short rubber "U" shaped hose on top.

I've learned my lesson, never buy a car if the coolant looks rusty. I thought I could flush it and be back to normal, but thats not the case... Thanks!

I just reveiwed my first post:
and where I said 'between #3 & #4 cylinder', I really meant 'between the #3 and #4 ports on the intake bottom'. Hopefully that makes sense... Sorry about that....

The carburated engines have several lines going to the carb. They are relatively small and a pain to change since they are below the intake. Chances are, one of these small lines is leaking. I do not recall any coolant passages anywhere near the runners of the intake manifold. Take off the carburetor airbox and you should be able to see much better below the intake manifold. There is a large water pipe running along the back of the engine to which some of the carb coolant lines connect. Trace any small lines from this pipe to the carb and check for leaks along the way. These little pipes are relatively cheap from the dealer, or you substitute some proper size hose of your own. Hope this helps.

I replaced that large pipe and many of those small hoses a while back, but there is a good chance I missed one. Hopefully there aren't any coolant passages in the intake meaning the leak is not coming from the plug, but from one of those little hoses I missed before...

Well I just added water back in the systen and now I have no leak meaning that the silicone is sealing the &$^( leaking plug... Crapola!!! Guess I'll find out more tomorrow when the dealer is open, but for now I'll see how long the silicone (house silicone, not car silicone) I put on yesterday holds. Then I may try some high temp silicone for cars and see what happens. At least that will buy me a little time to get my ducks lined up... Thanks!

Main problem is the radiators rust real easily since they're aluminum cores. I wouldn't say don't buy a car with rusty coolant. Just flush it, put a new radiator and hoses, etc. and you should be good as new.

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Originally Posted by SteveDX89

Main problem is the radiators rust real easily since they're aluminum cores. I wouldn't say don't buy a car with rusty coolant. Just flush it, put a new radiator and hoses, etc. and you should be good as new.

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I don't think you meant to say radiators rust easily because they have aluminum cores did you?

Quote:

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Originally Posted by Blkblurr

I don't think you meant to say radiators rust easily because they have aluminum cores did you?

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I did. That's what I've heard, at least. If I recall correctly, using anything other than distilled water will cause them to rust. I guess I'm wrong though.

hmm, in for answer on aluminum core rust

I know the aluminum radiator doesn't rust in itself. The rust in the block from neglect of the cooling system looks as if it does. Tap water & alkali eat away aluminum.

Aluminium in contact with salts or alkali chemicals will corrode very
fast. Aluminum is more vulnerable to electrolytic corrosion than either copper/brass or cast iron because aluminum is a highly reactive metal. When the corrosion inhibitors are used up and the pH of the coolant drops to 7 or below, aluminum becomes a sacrificial anode and is eaten away.

This same type of corrosion can also occur even when the coolant is in good condition if the engine does not have a good ground connection. Voltage from the charging system will flow through the coolant to ground, creating electrolysis corrosion that attacks the components in the cooling system.

I've been running only distilled water the past couple of weeks and have changed it out several times. I finally added about 20% antifreeze and a bottle of water pump lube/rust inhibitor that I've had for a few years. I'll probably run this for a few weeks to a month, then flush a couple more times with distilled water and refill 50-50 coolant-distilled water.

Surprised that the silicone is still sealing one of the plugs on the bottom of the intake, but I'm not complaining... :)

Well the silicone held for a while, but started leaking at the freeze plug again. I'm going to silicone it again with hi-temp RTV because even IF I could get the old plug out, I'm not sure I could get a new on in without pulling the intake/head. Always something... :(

Well this time the silicone didn't hold very long. Looks like I need to work on getting a freeze plug and hopefully figure out a way to install it without pulling the intake... :(

I found JB Weld in a stick like clay so hopefully this will be the ticket I need. Only time will tell, but I'm more hopeful with this. It's like putty that you just work in there and smash it in real good.