Replacement Of Leaking Welch Plug?

[jezzerrr]

On the turbo side of the block. How the f$$k do you get these things out, and what size is it? I was thinking drill and pull, unless there is a better way, preferably the one where I dont have to pull half the f^%king engine bay apart to fit a drill in. R33 S2 if that makes any difference.

Thanks heaps for any help guys

This one, just above the engine mount -

Edited October 19, 2005 by jezzerrr

[jezzerrr]

bumpity bump! whats the diameter of these things!?

[blind_elk]

If you are VERY careful. you can punch them on 1 side (ie off-centre) so they rotate in the hole, then grab them with pliers / vicegrips / etc and yank them out. I think they are about 32 mm, but if you take the old one in to a Repco store, they should have the right one (they are not a special Nissan-size plug).

My theory is that if one has gone, then the others can't be too far behind. Best to replace as many as practicable in the one job. The plugs are relatively cheap (much cheaper than labour costs).

[Scribble]

I just pulled all of them off my block. Its on a stand though so alot easier (i fear for your sanity when you do the task!). Hit them off center so they spin, or if they do what a few of mine did and actually go into the block just get a nice grip with some combo pliers and yank the mofo's out.

Next question, how do they go back in? just tapped in?

[Mumbo#5]

get a socket of the approx size of the welsh plug (cant remember the one I used) but make SURE that it is a reasonably loose fit (the welsh plugs are designed to squash in, so if the socket is a tight fit good luck getting your socket out ) General rule of them is tap them in so its square, and in far enough for the chamfer of the hole (you'll know what I mean) to be on the EDGE of the plug.

A small demo below with awesome pain shop skills

[SteveL]

Those small ones in the water passage just under the exhaust manifold are 22mm diameter, the rest are 30mm. Getting it out will be difficult with the manifold, etc in place. Pushing it in, rotating and levering out (as suggested) is the 'usual' way, but be careful as the passage behind is big enough for it to get 'lost'. An alternative is to drill a hole in the centre, screw in a reasonable size self-tapping screw and use that to lever on (but getting a drill in there is easier said than done)

Use a (smaller) socket to put the new one in as suggested, but you'll find a surprising amount of force is required given its small size. I use a thin smear of silicone around the outer rim of the new plug to help a little, plus it gives an extra seal, particularly if the bore in the block has been scored removing the old plug (it happens).

Of course, get brass replacements and its quite likely the rest if the plugs in the block will be corroded so consider replaceing as many as you can get to esp if you have to remove the manifold, etc.

[RB30-POWER]

fairly sure there is a proper sealant they recommend on welsh plugs.

cant think of what its called off the top of my head.

i say just wack it off centre and twist it out, if you hit it square on, it can push into the water gallery on some of them and cause more trouble getting it out.

only my thoughts though.

everyone uses a slightly different method im sure.

[Scribble]

I have one left on my block. The one straight down the middle of the thermostat housing. A real little one. I fear this one will push in and be EXTREMELY difficult to get out. As some times welsh plugs dont spin they just push in no matter how you hit them.

[Trust33]

What blind_elk and scribble said.It needs to be spun off center.Tapped from the side.

When putting them back in you can find a socket about the size of the inner width of the welch plugs cupped center and tap it in slowly and evenly i also used lock tight arround the edges of the welch plugs.

Make sure that the area you are tapping them back into is dry and free of forign matter.

[Duncan]

This all sounds really hard to do with the motor in the car.

I replaced a plug on the front of the head it was pretty straightforward while everything was still in.

But what about the plugs on the side and esp the rear? Do they normally get done with the motor in the car by a really patient mechanic?

[Mumbo#5]

i think they use loctite 504 or something around that number anyway. Its what most engine builders use to seal welsh plugs. I wouldnt really wanna use anything else as its a gamble.

[blind_elk]

I did mine while I had the head off for a blown head gasket. I suspect the least you might have to do is remove the manifolds to get easier access to the plugs.

[Trust33]

Lol on the car i did it on it was on the exhaust side and alls that needed removing was the manifold and exhaust pipes.Which gave access to the affected welch plug.But we decided to replace the rest while we were at it.Peace of mind and the fact that if 1 was gone then the others wernt far behind.

[Mick]

yer use some sort of locktight

[Doctor 30]

if a welch/welsh plug goes in the side of the block (turbo side down the bottom behind the engine mount ) and you can't get it out, where will it go?

[Jmaac]

You can freeze them beforehand to shrink them down a little. This way you can get them in easy and make sure that there sitting nicely before it expands to an interference fit. Similar to valve stem guides

Doctor30 try blocking off the rest of the cooling passage and vaccum it towards the opening, otherwise force some compressed air in there or maybe a magenetic part grabber (not sure what material the stock ones are made of). If your game stick your finger in there crank the motor and try and grab it whilst it wooshes past fun fun fun (put the water back in of course) Might even float to the opening?

Dont you just hate it when things never go right? especially when it seems easy or so simple... ahh life!

[GeeTR]

if a welch/welsh plug goes in the side of the block (turbo side down the bottom behind the engine mount ) and you can't get it out, where will it go?

Ouuch, condolences, that’s gota be one of the most f_uck things. I’m not sure on the design of the water jackets. Hopefully its not small enough to jam your thermostat closed :\