Honda crv 07. remove bolt from snapped oil sensor

Harry Bloomfield · 26 Nov 2021

It could be the metal tube, which is what is left of the sensor, is expanding as the extractor is tightened in and jamming it even more.

If you can feel the extractor springing slightly as you attempt to turn it, then it is close to the limit and about to snap. If it has not moved by that point I would be inclined to give up trying with the extractor and try the alternative....

You need a drill sized or ground to match the smaller diameter of the thread. Drill through with that carefully, a little at a time, adding plenty of grease regularly to collect any swarf. Take it out often to wipe the grease, plus swarf off and regrease with fresh clean grease. Then just hope none of the swarf goes inside and your hole was centred on the remaining bits of sensor. Next you try to tease out the remnants of the sensor in the thread with a large sharp sewing needle, if there is any left, plus a pair of tweezers or long nose pliers.

If that doesn't work - all you can do is drill (using grease as above) it and tap it over size with an Helicoil kit, to suit your sensor.

What ever does work, if you have any doubts about any metal getting in, the engine will need flushing with the engine run briefly, to flush the debris out of the oil gallery before the new sensor is fitted - so the oil pressure force it out.

Jonny Vee · 26 Nov 2021

Harry Bloomfield said:
It could be the metal tube, which is what is left of the sensor, is expanding as the extractor is tightened in and jamming it even more.

If you can feel the extractor springing slightly as you attempt to turn it, then it is close to the limit and about to snap. If it has not moved by that point I would be inclined to give up trying with the extractor and try the alternative....

You need a drill sized or ground to match the smaller diameter of the thread. Drill through with that carefully, a little at a time, adding plenty of grease regularly to collect any swarf. Take it out often to wipe the grease, plus swarf off and regrease with fresh clean grease. Then just hope none of the swarf goes inside and your hole was centred on the remaining bits of sensor. Next you try to tease out the remnants of the sensor in the thread with a large sharp sewing needle, if there is any left, plus a pair of tweezers or long nose pliers.

If that doesn't work - all you can do is drill (using grease as above) it and tap it over size with an Helicoil kit, to suit your sensor.

What ever does work, if you have any doubts about any metal getting in, the engine will need flushing with the engine run briefly, to flush the debris out of the oil gallery before the new sensor is fitted - so the oil pressure force it out.

Nothing, I have ordered angle drill to make hole even bigger before attempting the removal by pliers. If this does not work. How the oil gallery is made? Do I have something like another 10mm as safe zone after the sensor thread finish? I mean before drill hitting some aluminium wall again? I will be use same grease but if get to this point will flush the oil through the sensor hole to make sure debris get out.

Not easy to work from below unless I may need to remove bumper and air conditioning radiator making a lot of work into this.

As these tap are not available immediately I have started to measure the the new sensor with tread size pitch and gives me 0.9mm. I cannot find any tap like M10x0.9 but standard one seems to be M10x0.1. or my pitch is wrong or they used a non standard size which seems strange. Any experience on this?

Harry Bloomfield · 26 Nov 2021

Jonny Vee said:
Nothing, I have ordered angle drill to make hole even bigger before attempting the removal by pliers. If this does not work. How the oil gallery is made? Do I have something like another 10mm as safe zone after the sensor thread finish? I mean before drill hitting some aluminium wall again? I will be use same grease but if get to this point will flush the oil through the sensor hole to make sure debris get out.

I would expect the gallery to right angle behind the sensor, so probably no room for error - you should be able to measure how deep you can safely drill, by measuring how long the thread is on the new sensor. Measure and cut a bit of tube which you can slip over the drill bit, to prevent your drill going in too far.

I have no idea what size thread it might be, seek out a local engineering company and see if they can exactly match it. Another way might be to join the owners club and ask if anyone knows, and/or seek out a workshop manual, it might give the specification on that.

Jonny Vee · 28 Nov 2021

Harry Bloomfield said:
I would expect the gallery to right angle behind the sensor, so probably no room for error - you should be able to measure how deep you can safely drill, by measuring how long the thread is on the new sensor. Measure and cut a bit of tube which you can slip over the drill bit, to prevent your drill going in too far.

I have no idea what size thread it might be, seek out a local engineering company and see if they can exactly match it. Another way might be to join the owners club and ask if anyone knows, and/or seek out a workshop manual, it might give the specification on that.

Found on this website

https://www.autopartspro.co.uk/hond...1/10578/oil-pressure-switch-sender-unit-valve

Seems like the thread is a 1/8 x 28 BSP

Harry Bloomfield · 28 Nov 2021

Jonny Vee said:
Found on this website

https://www.autopartspro.co.uk/hond...1/10578/oil-pressure-switch-sender-unit-valve

Seems like the thread is a 1/8 x 28 BSP

If that is correct, there is a matching tap here - https://www.avontapdie.co.uk/bspt-1-8x28-tap-set

Other sources might be cheaper.

Jonny Vee · 28 Nov 2021

Harry Bloomfield said:
If that is correct, there is a matching tap here - https://www.avontapdie.co.uk/bspt-1-8x28-tap-set

Other sources might be cheaper.

What about Volkel for full set under £20? I guess I need tap first to cut more remaining metal before going with bottom.

Any suggestion on the right way to use it as would avoid drilling more than 8mm as drill may not be super straight

https://www.amazon.co.uk/gp/product/B00EO4KG5M/ref=ox_sc_act_title_1?smid=A3P5ROKL5A1OLE&psc=1

Harry Bloomfield · 28 Nov 2021

As the depth is limited, as with when drilling, you will likely not be able to go all the way in with the taps without bursting through the back of the oil gallery - so measure and mark each tap for how deep the thread needs to be. Your drilling needs to be just as straight as you can manage, even if you have to get a second pair of eyes to help you get it straight. If you are lucky, the remaining metal of the sensor, will be a softer metal than the block, so that will help you get it straight.

If you can find a drill bit of the correct tapping size, but intended to drill with anti-clockwise rotation of the drill - such a bit might avoid your having to use a tap at all, as the action of drilling might free up the sensor so it unscrews.

Mottie · 28 Nov 2021

Harry Bloomfield said:
As the depth is limited, as with when drilling, you will likely not be able to go all the way in with the taps without bursting through the back of the oil gallery

If you're even considering tapping into the main oil gallery, you really should have the engine out, the block stripped and the oil galleries thoroughly cleaned out afterwards. Just one piece of swarf in that gallery finding its way to a main or big end bearing and your engine will be totally ****ed.

cdbe · 29 Nov 2021

Mottie said:
If you're even considering tapping into the main oil gallery, you really should have the engine out, the block stripped and the oil galleries thoroughly cleaned out afterwards. Just one piece of swarf in that gallery finding its way to a main or big end bearing and your engine will be totally ****ed.

True. Might be time to solder the wires together, fill the hole with araldite and get down to webuyanycar.

Harry Bloomfield · 29 Nov 2021

Mottie said:
If you're even considering tapping into the main oil gallery, you really should have the engine out, the block stripped and the oil galleries thoroughly cleaned out afterwards. Just one piece of swarf in that gallery finding its way to a main or big end bearing and your engine will be totally ****ed.

Which was why I suggested that before he uses the car, he turns the engine over with the sensor removed - so the oil pressure forces any swarf from drilling and tapping out of the gallery.

Mottie · 29 Nov 2021

Harry Bloomfield said:
Which was why I suggested that before he uses the car, he turns the engine over with the sensor removed - so the oil pressure forces any swarf from drilling and tapping out of the gallery.

That more than likely won't happen - it will go along the gallery and you only need a piece of swarf the size of a grain of sugar to wreck the bearing. Would you chance it?

Harry Bloomfield · 29 Nov 2021

Mottie said:
That more than likely won't happen - it will go along the gallery and you only need a piece of swarf the size of a grain of sugar to wreck the bearing. Would you chance it?

The oil gallery will drop down to the sensor, the metal being more dense than oil means it will remain close to the sensor port and simply need flushing out. The OP is in a bit of a fix. Engine out stripped and done properly will cost more than perhaps the vehicle is worth. Yes, it is a gamble!

Old Salt · 29 Nov 2021

Did you buy this car new or used? I think someone has maybe stripped the original thread and then used chemical metal/sealant on this.
You could end up in a world of pain and as has already been mentioned have to helicoil the block.

Jonny Vee · 29 Nov 2021

Old Salt said:
Did you buy this car new or used? I think someone has maybe stripped the original thread and then used chemical metal/sealant on this.
You could end up in a world of pain and as has already been mentioned have to helicoil the block.

Car was used and I have no idea what they have done before. I'm already in a world of pain. Really hope when tap arrive the remaining bit will come off. It's the only car we have and can't afford a new one.

Old Salt · 29 Nov 2021

You’ll soon find out if the original thread is intact, just drill very very carefully keeping it square.

Honda crv 07. remove bolt from snapped oil sensor

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