help please, oil light flicker at idle

[Davezj]

i would first try and clean the area with carb cleaner, sprey point blank range at the crack and the surounding area to get rid of all traces of oil.
then get a new oil sensor and some RTV sealant which is designed to wrok in an oil environment. work the RTV into the crack so it is filled. then put RTV on the sensor threads and screw it in not to tight.
leave it to set for 30-45 min and test to see if it seals. the beauty of the RTV is it will move and expand with the metal expansion.
if it does not seal then try something else. it will cost next to nothing to try and if it seal the sensor might work. i say might work as the GND for the sensor is connect via the threads soo the RTV could insulate the sensor depending how tight it is screwed in. so you might get you oil pressure sensor to work and plug the leak.


here is thought out load, get a stong band clamp and tighten that up anround the boss of aluminum that the sensor thread is in after the RTV is worked into the crack. this should pull the crack back together, befor screwing the sensor. it should help.

[elnevio]

I have got some of the Wurth high temperature sealant (like this) that I reckon would do the job. Not sure the boss is deep enough to get a decent band around; but still worth a go.

The thoughts and ideas are much appreciated!

[adaxo]

Maybe something like this will do clamp it tight? http://www.ebay.co.uk/itm/10-x-6mm-M...S-DJDdDp3TilXg

[elnevio]

Will this carb cleaner do the job?

http://www.halfords.com/motoring/eng...-cleaner-500ml

[Confused]

Those little aerosol cans will do the job, but they run out VERY quickly, as it's mostly propellant in the tin!

Brake cleaner is practically the same stuff as carb cleaner, and I use a LOT of it!!

A much better option would be to get yourself a Brake Cleaner Spray Bottle, and a 5 litre tin of brake cleaner from your local motor factors.

This will last a long time, you can adjust the spray pattern. A worthwhile investment (and it also makes a good "in the middle of the job" hand cleaner, when sprayed onto your hands and wiped off with a paper towel!)

[elnevio]

This is why I come on here to ask questions!

[elnevio]

Progress report! Yes, actual progress!

Cleaned off as much as possible with brake cleaner (thanks @Confused for the buying tip).

Then I used a Mikalor-style clamp, size 18-20mm around the boss:

20160506_143612-1.jpg

More than half of the clamp was on the boss, so I'm hopeful it will be okay.

Than I whacked in as much Wurth 250 Special Sealant that I could, hopefully forcing lots into the crack:

20160506_143915-1.jpg

I also coated the thread of the new sensor with plenty of sealant.

Screwed the new sensor in until resistance felt, then another turn - although (and I couldn't get a pic of this) the sensor feels like it is almost butted up to the edge of the clamp (which obviously sits a couple of mm proud of the boss), which should help keep the clamp in place anyway.

And tightened the clamp quite a bit, as you can see in this pic, if you compare it to the above pics:

20160506_144601-1.jpg

I am hopeful that this will fix the issue.

I say hopeful, because I've not tested it yet! Too scared!!

The sealant says not to put parts into service for 30 mins, but the cure rate is about 1.5mm per day, and I think I'd rather not risk there being any sealant that hasn't gone off. It would *probably* be okay (well, as okay as it's going to be), but if there is a problem, then I will then have a real problem.

[Davezj]

If this does not fix it the the only thing to do really is get someone to weld it while it is still ion the car, not an easy thing to do as access will be a bit tight.
You could get them to weld the hole up completely and fit the pressure sensor on a sandwich plate under the filter.


Sent from my space-aged gizmo

[Confused]

Looking good, Nev - certainly worth a shot - just keep a beady eye on that oil pressure light, and if it comes on again, stop the engine and pull over immediately.

Glad that the tip about the brake cleaner worked for you - looking at the before and after photos, I reckon you'd have needed to use about 10 aerosol cans to get it anywhere near that clean! I bet you've only used ~500ml of brake cleaner at the very most?

[elnevio]

I didn't use a great deal to be honest. I used more cleaning up other bits and pieces!

I've decided to leave the grand restart until next Thurs/Fri when I'm next at home.

So until then, I have Schrödinger's Car!

[WOODY72]

Bugger, i'll have to come on here again next week for the result!

[Davezj]

So until then, I have Schrödinger's Car!

Schrödinger's Car, i like that

you will need a big box for that.

[elnevio]

Schrödinger's Car, i like that

you will need a big box for that.

The big box might be a coffin!

Alas, the attempt had been unsuccessful.


I think the next stop will have to be the aluminium welding option.

[Davezj]

if it can't be welded in situe then you might as well replace the oil pump when the engine comes out.

[carfanatic]

@elnevio I don't know much about this sort of thing but I had heard of this. http://www.ebay.co.uk/itm/EPOXY-PUTT...IAAOxy8g5RmIWg or this http://www.ebay.co.uk/itm/JB-WELD-WO...oAAOSwNSxU6uWG
Oh and I can't really explain why but I would have placed the screw tightener next to the crack.

[adaxo]

Pressure must be to high for silicone to hold in, weld bugger and fit sensor on sandwich plate, hope this works.

[elnevio]

Yes, the screw tightener had to be placed in such a way that I could get to it in order to tighten up - there's a lot of things in the way!

I've been speaking to a welder who might be able to help, but ideally the part needs to be removed. However, he might have a go with the car in situ. The problem lies with the oil and also the access. The crack could do with widening before welding, such as with a 1mm cutting disc, so that he can get the welding rod in.

He also suggested the possibility of Araldite (or similar, I suppose). I will sleep on it, and may decide that this is actually the best course of action, seeing as plugging the gap appears to the way forward.

[elnevio]

Pressure must be to high for silicone to hold in, weld bugger and fit sensor on sandwich plate, hope this works.

I might not have been able to get the silicone all the way into the thinnest part of the crack. The leak was not as bad this time, but still too much. It's not a case of the clamp just needs a touch more tightening.

[Confused]

Clean it all up again, and fill the crack with chemical metal.

Then, tap out the thread again - it's 1/8 npt I think.

My dad has used chemical metal to repair imperfections on cylinder heads and blocks, so it'll withstand the heat and oil.

Otherwise weld it up, and start again with the hole.

[lkedweaver]

Hi i hope you sort this problem out but welding will be very difficult in a tight space hopefully it won't go up or bits of slag or bits of splatter go's in pump. Jb weld mite work just need to v the crack out a bit. it sticks most things together very well and you can tap drill and grind it and fine with high temperatures. Might be next step before welding