So this is the info I’ve gathered:

 

1. Take off damaged oil return line and clean thoroughly around sump etc.

2. mark depth of damaged threaded hole and transfer to drill bit

3. drill with 11/32 bit (grease bit and vacuum as I go, also go in and back out to clean swarf out as getting deeper)

4. ffs don’t drill too deep

5. use appropriate tap to accept m10 bolt

6. use new gasket and some gasket sealant and install new line

6. drop oil, strain oil and refill

 

And in regard to the tap I need to use a taper lead tap first then a bottoming Tap as it’s a blind hole? This is the really unclear part for me. 

We all do things differently. I'd skip some of that list because the material is super soft, not much is being removed and spraying out a hole is better than vacuuming. I'd just use one cheap tap even if it's a bit harder to start cos it'll do most of the thread and the bolt will cut the very last part of the thread as you do it up. You shouldn't get any sh*t in the oil but if you aren't sure then drop it. I wouldn't though.

 

You use different taps so you can start the hole easily and straight and then finish it up with a full depth pitch cut to the very end. Imo not entirely necessary for aluminium repairs but meh. If you've got em then use em.

 

I think you'll be fine with it. Do what you think you need to as a little extra care and prep can only make it go better.

Have you measured the depth of the hole? is it blind or does it continue into the sump. With the correct gasket material and sealant the bolts wont need to be very tight and not even many threads engaged. 

 

If you can go deeper and pickup 3 or 4 threads that would be enough.

Ok great thanks for input. 

 

Today and tomorrow are the first opportunity to get some proper time to work on this. I have another car for the week so pressure is off a bit. 

 

Will keep you posted. 

 

I was under the impression it’s a blind hole but haven’t checked depth yet. 

 

Its only the lower bolt hole that has a damaged thread the top one is fine. 

 

Are the metal gaskets like the one that was in there ok or is there a better alternative?

It should be blind, here's hoping there are 3 or 4 threads at the bottom of the hole that a slightly longer bolt can pick up. Did you consider a mobile thread repair bloke?, it's only a phone call & if he says 'nick off' nothing lost he might only want $80 AND it's got warranty

I just tried to tighten it up again without the metal gasket in there and it tightens up pretty tight. Didn’t want to press my luck but I was surprised...

 

But blind means closed doesn’t it? So a longer bolt won’t work.

HAVE YOU MEASURED IT!!!!!. The depth that is.  Insert a wire to see if its blind.

 

Screw the bolt in without the fitting and see if it stops.

Edited September 1, 20188 yr by arronm

hopefully the bolt was to short & only stripped the outer 1/2 of the thread leaving some thread at the inner part of the hole

Lol try something, we're all dying here 

For those interested this is what I’ve pulled out. 

 

Real piece of crap part as you can see it just split in two at the top rib. A car with 90,000kms on it only. Very disappointing. 

 

Getting to the turbo end of the drain line is easy enough. One bolt very easy to get to once you unbolt the coolant reservoir and the other much more challenging but can be done from underneath the vehicle with two extensions in my case. They aren’t torqued down that tight so not too bad just a little awkward. 

 

contemplating cutting the ribbed section off, connecting with some hose and tightening down with a couple of hose clamps. 

 

I have ordered a replacement but could probably return that if the hose join does the job.