Damaged alluminium housing for water pipe! HELP! It still leaks, how to fix this?

[ausdrift]

Damaged alluminium housing for water pipe! HELP! It still leaks, how to fix this?

Here is the problem. Rather than on the R33 this time, this one is on the wife's car, an E46 BMW 3 Series. Long story short I, for reliability, decided to replace the whole cooling system of hoses, plastic pipes, radiator etc (BMW use shitty plastic which fails over time).One of the plastic heater pipes goes into an aluminium housing into the engine and thanks to 13 years of heat cycles it was firmly stuck in and infact sheared when I finally removed the pipe. Despite being as careful as I could the housing was inevitably damaged when I removed the fused-in remaining plastic and this is a major problem as the new pipe and 2 O-rings needs a perfect fit otherwise it leaks. Naturally this is all under the intake manifold system which to remove and refit takes between 1/2 to 1 Days work. I've now attempted to fix it 3 times and am getting quite tired of doing this. Each time it will still end up slowly leaking and usually in the process will swell the o-ring and I need to purchase new ones for stupid prices at BMW. Here is what I've attempted as a fix.

1 - Installed new pipe with some windscreen silicon jammed in between the 2 O-rings. (leaked)

2 - Cleaned area and gave a very light sand to smooth the housing, new O-rings and refit. (leaked)

3 - Cleaned up area, new O-rings and used a stack of RTV silicon gasket (leaks, but less)

Which this most recent fix has it leaking the least, its still not a permanent fix due to its very slow propensity to leak.

I don't want to have to buy a new timing case panel (which incorporates the housing) as even through my cheap online place, its around $500! A used one will no doubt have the same damage, plus doing this is more major engine work which I don't have energy for.

So, my question to you all; What PROVEN methods do you have for this situation? What have you done that has worked? I know it happens that people can damage the water pump surface etc when trying to remove, eg, thermostat, water pump etc so surely there is some wisdom out there. What is a reliable fix?

Thanks!

Oh, as a bonus, an error code has just come up indicating the knock sensor is faulty, so that's gotta be swapped too. Where is that, you ask? Its that cable and bolt to the left of the BMW stamp in the photo below. So I have to take who whole inlet system off agaaaaaaaaain anyway *sigh*.

[Hadouken]

Oh it's one of those couplings. I was scared to death I would break or crack the one on the missus vw.

Anyway.

I would have cleaned both of the surfaces profusely. Then apply rtv and let it cure for 2 hours or so.

I can't see the actual damage so it must be slight.

If that doesn't work and you don't want to replace then um. Cough chemiweld will plug it up.

[WantGTR]

Clean that housing out properly. Get new o rings. Dont have to go bmw. Just go to your local parts shop. They will have a ton of o rings behind the counter. 

Maybe even lube the orings with some motor oil to get them to seat smoothly and not pinch. May even take some days for it to settle. Before the leak seals up.

Failing that google a proper how to on how to do it. No doubt there is a youtube vid or an american bmw forum where what you are doing has been done to death.

Iv got a e39 bmw v8 as a daily. When changing my water pump i disturbed the water pipes that go to the rear of the block from the water pump. I cleaned all surfaces when and reinstalled. Leaks for a few days then stopped. This was 6 months ago and still good. I bought a new set of o rings and other stuff for the rear of the engine but it hasnt leaked again so im not about to go look for trouble if you know what i mean.

 

BMW lyf y0

[Dobz]

Looks nicely scratched up. You need to fill those scratches because that's where it leaks through.

Every burr created by the scratches needs to be smoothed out and the surface cleaned up by using 800 grit wet and dry.

The area needs to be cleaned well using metho and a clean rag then let completely dry.

Cut up and old bank card or similar so you can make a little scraper that can fit in the hole but still has some rigidity.

Skim coat a thin layer of gasket sealant to fill the scratches and let it completely dry.

After that lube up new o-rings and hole with silicone spray and gently insert like a caring lover.

Edited January 9, 2017 by Dobz

[wld093]

Done this repair a few times now.

We change both plastic pipes which come with new o-rings. I clean inner housing with fine emry paper. For the more stubborn corrosion I use a flexible hone on a cordless drill. It's a small one most likely used on master cylinders etc.

After that I use a bit of anaerobic sealant (locite 518) on both o-rings and in the housing. This also helps aid in sliding new pipe in.

The most important thing is you keep the pipe as straight as possible when fitting it into housing.

Attack it with a fresh mind helps. Maybe leave it for a week.

And check that you have plugged the knock sensor plug in can be forgotten sometimes. Have seen people leave the coolant temp sensor plug of whilst doing repair under manifold and wonder why the gauge stops working

Good luck
Ryan

[ausdrift]

Great, thanks everyone there are some good ideas there. I didn't notice that big groove on the inner side of the housing, so perhaps even something like that is making the difference. The leaking is almost nothing, but as I would need to top up 100ml every 40kms or so I think i'll give it another shot to fix. I wasn't able to find anything on youtube either, so this is a good help.

And I wish the knock sensor was only unplugged, but I never undid it and the all the elec clips lock in quite firmly.

[tridentt150v]

If all else fails, I'd remove the timing case and get alloy pipe machined in as a press fit and then weld that sucker!!!

[WantGTR]

Just to make sure, check that the fitting is actually 'clicked' in when you connect it. Bmw have some interesting ways to connectors/joiners