Small block mopar in my 70 duster
Came home a few weeks ago with this thing hitting 240 on the gauge. Pulled into the shop, and what was left of the coolant appeared to be spraying (without pressure, i think) from the freeze plug behind the power steering pump. On the timing cover side, at either the block to plug junction or the corner where the plug goes from horizontal to vertical.
Yesterday and this morning i tore it down to change the freeze plug.
I cleaned everything up, and got to looking closely.
Theres signs of water exiting the weep hole on the water pump.
However, the suspect freeze plug looks like this:
Scraped at the edges and corners with a dental pick and screwdriver, and didn't find any soft spots that i could tell. Especially in the suspect area.
Now, something i found that i didn't remember, is that the upper bolt for the power steering pump bracket goes into a water jacket. This bolt had no sealant, but has been in the engine and untouched for over 15 years. However, looking at the paint damage, its all downhill of that bolt. Thats the only spot on the front of the engine with damage that isn't due to contact.
So, could the bolt have been leaking a little for a long time and just now broke free in such a way as to make it LOOK like the freeze plug? Should i replace both front freeze plugs regardless? Is there a smoking gun im not seeing?
That needs the timing cover re sealed, as far as I can see from the pictures. It looks like trouble higher up, too. The frost plug looks fine to me.
Cooter
UberDork
8/26/21 7:27 a.m.
Streetwiseguy said:
That needs the timing cover re sealed, as far as I can see from the pictures. It looks like trouble higher up, too. The frost plug looks fine to me.
Agreed.
I'm more worried about the timing cover.
Cooter said:
Streetwiseguy said:
That needs the timing cover re sealed, as far as I can see from the pictures. It looks like trouble higher up, too. The frost plug looks fine to me.
Agreed.
I'm more worried about the timing cover.
I agree with the above statement, timing cover gasket and thread sealant.
Is that a loop of gasket sticking out there near the top of the picture?
It certainly could have been that bolt that was leaking. Things move a tiny bit every time the engine heat cycles. It sure doesn't look like there's anything wrong with the core plug (aka freeze plug). Other possible sources of leaks in that area are timing cover, intake manifold and head gasket.
For future reference AutoZone and others will loan you a cooling system pressure tester for tracking down things like this.
You could probably fix that with a 383 or 440.
Pete. (l33t FS) said:
914Driver said:
Is that a loop of gasket sticking out there near the top of the picture?
Sure looks like it.
It is. For some reason i never trimmed it off before painting the engine back then.
In reply to APEowner :
E36 M3. Forgot about those....
Would more pictures help diagnosing it, or are we pretty confident that a timing chain cover gasket, water pump, and thread sealer on all the bolts are the solution? Just want to make sure....
Mr_Asa
PowerDork
8/26/21 2:03 p.m.
Also, you can find coolant dye that shows up under UV.
I usually pressurized the system. Any leak becomes "active" and is pretty easy to find.
Unfortunately its a lot of reassembley and disassembly away from doing a pressure test. Because im dumb and didn't think about it previously, just assumed the freeze plug as it appears from there....
So im trying to make the best of it at this point.
If you were getting an actual spray in the vicinity of that core plug behind the power steering pump odds are it was from that bolt. Changing the timing cover gasket requires cutting the oil pain gasket and getting all of that sealed back up. Personally, unless I saw a pretty solid indication that it was leaking from there I wouldn't mess with that. I also don't see any reason to change any of the core plugs.
That's going from what I can see in the pictures and you're the one actually looking at so I could be off base but that's my inclination.
Cooter
UberDork
8/26/21 3:20 p.m.
The LA timing covers are known to rot out, as they connect your water pump to the cast iron block. After all, the newest cores are nearly 30 years old now.
I would pull the cover completely and check out what is going on at the mating surface.
This whole area is suspect.
Dusterbd13-michael said:
Would more pictures help diagnosing it, or are we pretty confident that a timing chain cover gasket, water pump, and thread sealer on all the bolts are the solution? Just want to make sure....
Take it apart, post pictures, and we will tell you whether we were right or not.
In reply to Cooter :
See also: Ford 3.8/4.2, Ford 3.0, Chevy 2.8/3.1, .... pretty much anything with an aluminum cover.
Fair enough yall.
Any tips to keep the oil pan junction leak free upon reassembley?
Those A engines come apart quite easily. Having said that, it's been a while, but I'm pretty sure there is very little holding the front of the oil pan gasket to the timing cover. I'm not even sure that there are dowels to the block, but most likely. Unbolt, pry carefully, hope the gasket stays on the pan and doesn't get stuck to the cover. Back together, I usually add a light skim of silicone to the top surface of the gasket to take up any gap, and also to use as a bit of a lubricant as you slide the cover back in place. I like yellow contact cement to stick the gasket to either the block or the cover, because it won't move once it's stuck, and that makes life a bunch easier. Just make sure you glue it in the right place, which is generally the side with the dowel pin. You may have to put a small punch through one of the lower cover bolts to pry down against the pan gasket to get it over the dowel (if it's there) or to allow you to get the bolt above or below started. Start all the bolts before you tighten any of them.
It's not rocket science.
