Oil pressure switch and thread inside casing

[pauls4685]

Hi hope someone can help please. I have a 1985 water cooled 1.9 van and I'm new to this so here it goes .......
I've had a oil leak from the oil pressure switch, old switch was brown and the new is blue I was told this was right for my van by shop I bought from and from research seemed the be right, anyway went and changed it but the switch will only go so far ( just over hand tight ) and then it just spins and won't tighten up. I've taken it out and checked the thread and there seems to be some metal from inside the shaft on the switch. I've also tried fitting old switch back but this does the same and still leaks. So there seems to be a problem with the thread inside the where the switch goes, can anyone help and tell me my options if any.
Thanks
Paul

[silverbullet]

Find your nearest "Thread Doctor" or similar thread repair man (independant or franchissee)
Its a M10 x 1 thread and needs to be dead square to the boss to seal properly.
Trouble is that any swarf left in the hole from the repair will be pushed by oil flow toward the engine bearings.
Repair is risky, but if the switch pops out then it will be game over in no time.

[pauls4685]

Thanks for your reply, Is it safest to take out the engine and re build to stop anything going to the engine from repair??? I will check out thread doctor or someone similar tomorrow!

[ghost123uk]

Thanks for your reply, Is it safest to take out the engine and re build to stop anything going to the engine from repair??

No. The professionals at this re-thread game are pretty good at not getting any swarf where it shouldn't get. I would for sure do as Ian suggests. Chances are 95% (imho) that it will go just fine

Aside = Re-building a WBX engine is a a costly exercise and fraught with potential "issues" and should only be considered if it proves essential.

E D I T = incorrect html.

[dsmith1974]

Is yours leaking with the new switch in?

Had the same problem with my OPS. When I changed it, the new switch would only tighten so far (not very) and then spin. Luckily it doesn't seem to leak any oil and have so far done about 1K miles without it popping out.

Maybe I'm chancing it and should get a Thread Doctor to do a proper fix.

[pauls4685]

Thanks guys for your replies, I've spoken to a local tread repair guy and his happy to do the job but like you say he can not guarantee not to get any swarf left inside the engine so its my risk!

My other option is that I've spoken to another guy who deals with all VW's for repairs and he said that some of the old beetle oil pressure switches are tapered so he may be able to get one on the same pressure rating or near too and get that to fit/bight but won't know until he takes a look at how much thread is left. So I'm going to get it to him to take a look first.

I didn't try to new switch running as it felt far to loose and didn't won't to risk it, when I took it out it the metal from inside had rapped around it which may have created a seal not sure? like I say didn't try it . The old switch is in there at the moment and that leaks worse than before so presume the new switch has caused more damage.

When I done my research on this repair I was really confidant and also happy it wasn't a push rod but now it's turned into a bit of a nightmare! Just unlucky I suppose.

[silverbullet]

I presume that your engine has just the one switch between the pushrod tubes? It is a "dead" leg coming off of the main oil gallery so the chanhes of any swarf getting drawn in would be pretty small IMO.

[CJH]

I presume that your engine has just the one switch between the pushrod tubes? It is a "dead" leg coming off of the main oil gallery so the chanhes of any swarf getting drawn in would be pretty small IMO.

So presumably, if you drain the oil first, repair the thread, then pour the drained oil back in without the pressure switch in the hole, any swarf would likely be washed out by the flow of oil through the hole?

[silverbullet]

It would need cranking over so the pump purges the gallery. Good idea.

[Oldiebut goodie]

Making a bit of a pigs ear over a simple job . Blob of grease at the bottom, grease on the thread cutter (this will catch most,if not all of the swarf). Turn engine over to force grease blob and any swarf out. No need to make it complicated.

[silverbullet]

Always lead with caveats when giving out advice

[pauls4685]

Thanks to everyone on there advice on this,

My van is now fixed, turns out that there was a small crack in the crank case where the switch screwed in so I had it drilled out to fit a union and then a new switch fitted. This guy in Southend that done the job for me was great, drilled it by hand and done loads of other little bits on my engine and was cheap. The van is running best it ever has!
Cheers again for help and advice.

[CovKid]

Union was a smart idea. Hats off to him.