P38 '97 2.5 DSE Oil cooler pipe leak

Hiya gang, yes its me again!

Ok, got a very (very) slight oil leak from the bottom oil pipe going onto the cooler, mechanic says it may be the o-ring, but cant be sure until its apart. I'm tempted to get a bit oily and do it myself, but here's the rub, apparently the junction where the oil pipes meet the rad can sometimes tend to "weld" themselves together over time so I've been informed, meaning you can strip the threads on the ally and end up needing a new oil cooler rad (or, in my case, second-hand, xmas is coming).
I've just bagged some new O-rings, but my question is... is there a way to avoid the threads getting wrecked, is this common, or does it only happen occasionally?
I am thinking of buying the two pipes and a rad (got some flagged on Ebay), got the O-rings coming too, and then give it a go and any parts I don't use, re-sell, but that seems a little overkill.
I guess what I'm asking is, are there any of you out there who have replaced more than one or two of these parts more than once, and what is your experience, can it be done without wrecking the threads?

The steel/aluminium joint will be a nightmare, unless it has been treated to anti seize during fitting.

Well, that's one vote for "there may be trouble ahead" lol.
No way of telling if anyone has done me a huge favour and stuck some sort of anti-seize majibbins on, so unless anyone comes up with a more hopeful experience, its looking likely that santa may be getting a late "Dear santa, for xmas this year, I want ... " list lol.

General feedback across a couple of similar sites tends to favour the " you are in the S*** " way of thinking.
Seems the "welding" issue is very common, and I'm likely to trash the threads on the ally.
Guess I'll bite the bullet, buy the bits, and see how it goes.
Have had a thought about recouping some of the cost.
If I can get the old rad and pipes off as an intact unit, I might be able to cut the bottom pipe nut off without damaging the threads, and then sell the old rad and one pipe attached. Hmmm, even as I type this, I'm thinking that's not going to work, but hey, cant hurt to try.

Someone has just suggested a rather radical approach.
Coke.
No, not the white powder... the stuff you drink. Apparantly you shake a bottle gently, with your fingers over the end, and direct the spurt of coke over the corroded area, having first tightened the nut slightly to "crack" the corrosion. Leave a while. Repeat with the coke, whilst trying to tease the nut loose. Well, I'm game for a giggle, but I'll have the parts on the bench, just in case.
I'll let you guys know how that one pans out lol!

Your chances of getting either the engine oil cooler or gearbox cooler, if it's and automatic, pipes undone without damaging them are minimal. May have a chance with a manual gearbox cooler in bottom of rad.

Well, I'll buy the bits, and for a giggle give the coke a go, but I'm guessing from all the feedback that at the end of it, I'll have replaced the oil cooler and both pipes, and have a knackered oil cooler covered in coke that I took off lol.

WayneRR4x4 said:

Well, I'll buy the bits, and for a giggle give the coke a go, but I'm guessing from all the feedback that at the end of it, I'll have replaced the oil cooler and both pipes, and have a knackered oil cooler covered in coke that I took off lol.

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Plus gas is better than Coke but still won't help in most cases. If, and they will be, the steel nuts are seized on the alloy, unscrewing them without destroying the alloy threads is practically impossible. Budget for an oil cooler and pipes.

Already on it, got my beady eye on some on Ebay.

Bung some Quicksteel round it and hope?!

Quicksteel?

WayneRR4x4 said:

Quicksteel?

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Yes, it is an epoxy compound. There are quite a few around. It is a putty like substance you mix by rolling in your fingers and then press where required and it goes rock-hard.

I suppose I could try it, can always go to plan "B" if it doesn't work.

PlusGas - there's a decent brew and if that doesn't work nothing will in my experience.

you could go really radical and try battery acid

Or vinegar, bit safer than battery acid might take a bit longer though.

I use steam tape ,plumbers tape ,wrap it round whats left of the threads ,tighten nut on top ,

Well, I think I'm going to try the following, in order..
Coke/vinegar/plusgas/WD40
Quicksteel (been recommended to try Chemical Metal, similar stuff).

Then, if they don't work, I'll try the standard approach of putting second-hand pipes and cooler on.
Once I've got the old ones off (going to take cooler off with pipes still attached), I'm going to try cutting the nut off, (split in half lengthways with my trusty Dremel) see if that's possible, and have a good look at this "weld".

dubbleRR said:

I use steam tape ,plumbers tape ,wrap it round whats left of the threads ,tighten nut on top ,

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According to most of the feedback I've had across a few forums, the threads will be destroyed if I try to take them off in the traditional way.

I did one recently, maybe just lucky. I used plenty of wd40 and repeatedly backed off and tightened gently. Also had to do the gearbox cooler in the same fashion.