I have another thread going, but the focus of that was the poor running of the engine and the idle problems. Now, after doing a bunch of stuff to the truck, and getting it going sort-of, I discovered two freeze plug leaks, the front and the rear (on this inline 6). So now I'm wondering, is it possible to change those plugs without removing the engine? It makes a difference. I'm not really an auto mechanic, and I don't have a lot of tools. But I have a mechanical aptitude, and if it can be done, I can do it. But I need to know how to proceed. Someone with experience with the engine would know.

I have to decide on a course of action. Has anybody changed those freeze plugs?

It's a 1990 F150 with a 4.9L fuel injected engine.

~~ Nehmo

 

Possible? Yes. Not much room though.

You'd need to remove the old freeze plugs, cleaning out the holes very well afterward. Find a socket that will fit the new plugs. Using that as a punch, tap it in with a hammer to just beyond flush with the new caps.

 

You seem to be recommending using metal, brass or steel, replacement freeze plugs(size 1 45/64") . I was planning on using the rubber ones with the tightening nut.
There's no way I could directly get a hammer to strike in there. I could, possibly, use some sort of extension, like a long socket extension, to tap it.
But even with the rubber plugs, this is going to be a problem. I get worn out just thinking about it. :-)


~~ Nehmo

 

I have done the rubber plugs before, but they are kinda a tempory fix (always leaked a few weeks later even with sealant on them). It is a tight place under the manifolds and installing metal core plugs will be harder than the rubber ones. Pulling the manifolds off will open the area up and make it alot easyer to replace them.

Also do not forget the rear core plug that's behind the flywheel/flex plate! If others are rotted out then most likely that one will be bad too. Only way to replace that one is pull the tranny out. Been there and done that...... also replace the rear main seal while its apart(didn't the 1st time around and had to repull tranny).

 

I just did my freeze plugs on '96 4.9l (straight 6) You'll have 5 on the passenger side of the block. I did four of them by just turning the tire to gain more room. I used a "punch" in the middle of every plug to put a hole in them; I then used a long self tapping bolt to screw in the hole; Small pair of vice grips to hold on to the bolt; Then a long small headed flat head screwdriver to knock out one side of the freeze plug at the lip next to the block. Example: knock in freeze plug at 12 o'clock and 6 o' clock comes out towards you it will swivel at 3 and 9 o'clock. Pull it out with pliers at the 6 o'clock area. The vice grips and the bolt are so the freeze plug does NOT fall into the block!! The only one I had trouble getting to is the one behind the back exaltst manifold; you'll have to remove the manifold to get to that plug (sorry). Do not use the the rubber plugs. Napa has regular plugs for about $2.00 each. Also use "Indian head" gasket stuff. It will help sill the plugs to the block with no linkage. You will also find 2 on the block behind the fly wheel (tranny and fly wheel have to be removed). And one on the cylinder head just above the tranny. That one should be ezy to get to.

Hope that helps Good luck,

MSK

 

With the removal of just 5 nuts, 1 bolt and a handful of screws, this is all the clearance you'll need.

Even the hardest plug (behind the exhaust manifold) is accessible through the wheelwell.

And with the right tool, reinstalling is simple.

Total time from start to finish: 2½ hours.

 

I never had luck with any of the quick install ones not leaking, despite trying expandible rubber and copper ones. They both would leak. I used Indian head shellac to install them but next time might try "the right stuff" which is what local engine builder CLAIMS he uses to install freeze plugs.

 

I have used the Dorman expandable rubber plugs, with no issues. Would not really recommend that for all of them, but, for 1 or 2 might work for you. Install them dry, no sealant.