Thread: Welch plugs replacement Disco 2

If the motor has to come out, then I'd replace all the welch plugs. They are cheap and easy to do when the motor is out.

As to which of the OAT (pink) or the glycol (green) coolants are better for anti-corrosion, unfortunately I have no idea.

There were problems with the early OAT coolants and there was a class action against GM in the USA over engine damage when using Dex-Cool.

See Girard Gibbs LLP- GM Dex-Cool/ Intake Manifold Gasket Class Action

On October 23, 2008, the California Superior Court granted final approval to the class action settlement reached with General Motors in the GM/Dex-Cool class action lawsuit. This settlement affects people who purchased or leased a "covered vehicle" anywhere in the United States other than Missouri. A separate settlement has been reached for those who purchased or leased their vehicle in Missouri, which will offer the same benefits.
The lawsuits were filed on behalf of owners of General Motors vehicles, which were factory-filled with "Dex-Cool" coolant. In summary, the lawsuits alleged that Dex-Cool degraded certain vehicles’ intake manifold gaskets and other engine sealability components, and that in certain other vehicles, Dex-Cool formed a rusty sludge, clogging the vehicles’ cooling systems and causing vehicles to overheat.
The settlement, which covers dozens of GM vehicle platforms spanning ten model years, provides $50 to $800 in cash reimbursement for class members who paid for a covered repair by May 30, 2008, and submitted a claim form by October 27, 2008.

I wonder if Holden used Dex-Cool?

Many Thanks Ron you've been a great help! I will certainly treasure your significant knowledge...and put it to good use! Cheers,

Nick C.

Originally Posted by p38arover

If the motor has to come out, then I'd replace all the welch plugs. They are cheap and easy to do when the motor is out.

I agree if it has to come out but I wouldn't be pulling the motor out just to change welch plugs that are currently OK.

and if you pull it out,,
think clutch etc,,

Originally Posted by awabbit6

I don't know what he's quoted to do them all but I'd imagine it's not cheap. I'd just replace the leaking one and be very vigilant about checking the others. They rarely blow out suddenly and you are likely to notice a significant leak prior to any damage being done. After all, you don't replace all engine gaskets when one gasket leaks. I don't think that welch plugs are any different. If the engine was coming out for another job, then you might replace the ones at the back of the engine while it was out.

I've just done one in my Disco because I noticed a slight weep. Mines a '94 300tdi and the plug I removed really wasn't that badly corroded - just started to go in one spot.

This is just my opinion based on the fact that I tend to lift my bonnet regularly just for a quick visual check and the fact that I rarely have the money to replace parts 'just in case' they fail.

Nick I dont want to Hi-jack your thread but Iam about to replace mine on the defender 300tdi amoungest other things.

Quick question to you Paul did replace all of them on your 300tdi or just the leaking one?Did you leave the motor in the engine bay?

The second welch plug behind the turbo is leaking on mine and Ive pulled the inlet/exhuast manifold ect off just thinking should just change the leaking one or all 3 on the side of the motor.The rear would be a bit hard to change with motor in I would imagine.

But I did purchase four and would be a pain if in a couple of months another would leak and have to do it all over.

Originally Posted by MacFamily

Nick I dont want to Hi-jack your thread but Iam about to replace mine on the defender 300tdi amoungest other things.

Quick question to you Paul did replace all of them on your 300tdi or just the leaking one?Did you leave the motor in the engine bay?

The second welch plug behind the turbo is leaking on mine and Ive pulled the inlet/exhuast manifold ect off just thinking should just change the leaking one or all 3 on the side of the motor.The rear would be a bit hard to change with motor in I would imagine.

But I did purchase four and would be a pain if in a couple of months another would leak and have to do it all over.

Mine was leaking from exactly the same plug - right behind the turbo. I didn't remove the engine and just did the one that was leaking. I considered doing the three of them, but my thoughts were the opposite - what if one of the ones that isn't leaking at the moment doesn't seat properly and the new one starts to leak! That would be more of a pain.

The inlet and exhaust manifolds aren't that hard to remove anyway and I was able to re-use the manifold gasket because it was new last year when I replaced the head gasket.

Thanks Paul that was my thoughts, I replaced the manifold gasket also only six months ago but bought another just in case, must of started to leak after I cleaned up that side of the motor and removed the oil/dirt .Should have left crap there.

I think I will just replace the one for now.Keep the others for spare, was also talking to dave (incisor) the other day he said to use stag to seal with What did you use?

Originally Posted by MacFamily

... was also talking to dave (incisor) the other day he said to use stag to seal with What did you use?

I didn't use anything. I gave the sealing surface inside the block a good clean with wet and dry first. I don't use sealing compounds unless I really have to. I hate having to clean it off the next time I have to work in the same area and I worry about sealer getting to places it shouldn't. I replaced the 'P' gasket at the front of the block at the same time I did the welch plug. Again, cleaned up both surfaces perfectly with wet and dry then back together with no sealer.
I very rarely have leaks after reassembly.