jangell
07-13-2014, 12:13 PM
My 3.0L engine had a bad core plug (aka freeze plug) on the back of a cylinder head, so I went about replacing it.
I first tried to use pliers to pull the plug out through the hole no the edge, but I couldn't get an angle on ie.
I then tried using a screwdriver as a lever through the hole to tilt it out. No go there either.
I found some information about trying to get it to spin by tapping near an edge with a punch and hammer, but this didn't work for me.
Another approach I found online was to hit it with a hammer near an edge to tilt the plug out, and then remoe it with pliers. This worked, although I had to use a four pound hammer to get enough force to break it free.
The only catch with the last method was that once the plug was out, I could see what looks like a slight ledge behind the plug, which presumably supports it. It's very thin, which is why I was able to bash through it (although with quite a lot of force being required), and since the plug tilted out the bottom half of the ledge is still there. I'm wondering if this was really the right way to remove the plug, or if I should have tried other approaches more first.
How do you guys normally remove freeze plugs from DeLorean engines? I'm assuming the 2.8L and 3.0L engines are similar enough that the same process applies.
Before removal:
28893
Tilted out; The punch was placed on the face near the top.
28894
The ledge visible inside the hole. I cleaned out the gunk (a mix of oil and coolant that was left in the engine when I flipped it over on the stand), including some bits of metal that seemed to have come from the ledge
28895
The other reason I asks is that I'm thinking of replacing the rest of the plugs. My question there is, is it worth the trouble to replace them all?. Here are pictures of the plugs on the cylinder heads. There's a little rust on a couple of them, and they generally look fine to me, but some threads on Google suggested that if you have to replace one, you're likely going to have to replace the rest sooner than later.
28896 28897
Lastly, what size are the core plugs? I think they're 36mm (which is what I got when I used calipers to measure them), but I've also found some places selling 36.6mm plugs. My local auto parts stores best match was a 35mm plug, which looked really close at a glance but was far too loose in the hole in the head (as in, it clearly wouldn't plug the hole and could be slid around with my fingers). If I'm going to order a dozen of these I'd like to get the right size. I expect the 3.0L and 2.8L plugs are the same size.
Thanks!
-- Joe
I first tried to use pliers to pull the plug out through the hole no the edge, but I couldn't get an angle on ie.
I then tried using a screwdriver as a lever through the hole to tilt it out. No go there either.
I found some information about trying to get it to spin by tapping near an edge with a punch and hammer, but this didn't work for me.
Another approach I found online was to hit it with a hammer near an edge to tilt the plug out, and then remoe it with pliers. This worked, although I had to use a four pound hammer to get enough force to break it free.
The only catch with the last method was that once the plug was out, I could see what looks like a slight ledge behind the plug, which presumably supports it. It's very thin, which is why I was able to bash through it (although with quite a lot of force being required), and since the plug tilted out the bottom half of the ledge is still there. I'm wondering if this was really the right way to remove the plug, or if I should have tried other approaches more first.
How do you guys normally remove freeze plugs from DeLorean engines? I'm assuming the 2.8L and 3.0L engines are similar enough that the same process applies.
Before removal:
28893
Tilted out; The punch was placed on the face near the top.
28894
The ledge visible inside the hole. I cleaned out the gunk (a mix of oil and coolant that was left in the engine when I flipped it over on the stand), including some bits of metal that seemed to have come from the ledge
28895
The other reason I asks is that I'm thinking of replacing the rest of the plugs. My question there is, is it worth the trouble to replace them all?. Here are pictures of the plugs on the cylinder heads. There's a little rust on a couple of them, and they generally look fine to me, but some threads on Google suggested that if you have to replace one, you're likely going to have to replace the rest sooner than later.
28896 28897
Lastly, what size are the core plugs? I think they're 36mm (which is what I got when I used calipers to measure them), but I've also found some places selling 36.6mm plugs. My local auto parts stores best match was a 35mm plug, which looked really close at a glance but was far too loose in the hole in the head (as in, it clearly wouldn't plug the hole and could be slid around with my fingers). If I'm going to order a dozen of these I'd like to get the right size. I expect the 3.0L and 2.8L plugs are the same size.
Thanks!
-- Joe