I've had a leak for some time now. It's wet in the same spot as when my timing cover gasket blew out but I'm sure that's not where it's coming from.
I noticed the leak after the truck had sat for about a week and it was pretty wet down there. I drove the truck earlier then put UV dye in the radiator after it cooled off and ran it for a little bit so it would be at operating temp with the thermostat cycling that dye into the block.
I got down there with a black light and only saw fresh coolant in one spot, on the forward bolt that attaches the driver motor mount to the block and it had dripped on the starters power cable. The rest of the engine was dry since I ran it for a bit.
So onto my question, is there a coolant passage in the bolt hole for the driver side motor mounts front bolt. I didn't see any glowing behind the motor mount and the only fresh wet spot was around that bolt.

 

I would HOPE the bolts would not go into coolant passage. It would be p*** poor casting design to say the least. I know ther are freeze plugs on the side, but I don't know if there is one by the motor mount or not. I would suspect that there is before I would think the bolt goes into coolant passage.

 

According to my black light and the UV dye, the freeze plugs in front of, behind and under the motor mount were dry. That's what's confusing me.

 

The bolt may indeed go into the cooling jacket. I don't remember if I got coolant flow when I pulled the mount to change the leaking freeze plug....... let the engine cool, pull the bolt, see if anything comes out. (may wanna have your RTV, and a spare finger ready, to seal up the bolt, and stick it back in.)

The freeze plugs there are really difficult to see though.... mine was leaking at the very bottom, due to crap being held in place against the steel plug... it rusted out, and started leaking.

 

I think I found the leak. I let it sit overnight and went out there a few minutes ago and found something that gave me a frowny face.


How hard is it to change that freeze plug?

It's had a slow leak for years and I assumed that the timing cover leaking was the cause and didn't think to check for a leak after fixing that.

 

Tedious, but, not really a bad job, provided you have a warm, dry, place to work.

Disconnect battery.
Remove Starter.
Remove brace from engine mount to bellhousing.
Support motor with a floor jack, or some such.
Remove engine mount bolt.
Remove bolts engine mount to block.
Knock out old plug.
Take bath in coolant.
Dry floor.....
Put a thin bead of RTV around new plug.
Drive in new plug. (I used a six inch extension, and a large socket as a driver)
Reassemble.
Refil cooling system.

 

Sounds doable.
Wouldn't the RTV just shear off when I drive the new plug in?
When you knock the old one out, don't you just put a punch on one side to kick it sideways in the hole?

 

Yeah, a lot of the RTV will scrape off when you drive the plug in, but, the edge that actually has the interference fit is tapered, so, some will stay where it needs to be.

Mine was rusted so bad, I kept poking holes in it....... Eventually I got it to the point where I could grab it with a pair of channel locks, and lever it out. It was actually easier than I expected it to be.

 

I always go with brass core plugs over steel.

 

I plan on going with brass. I'm going to change that motor mount too because I believe it's the cause of my whooping sound from the left side of the engine.
I wonder what the deal is with that one freeze plug. It's gotten me, heyyou and aim.