Hilux 4x4 Forum

Good day All

I need advice on how to drill the hole for the EGT sensor,

some say, you just drill it with the engine running, revving it a bit to help blow the metal shaving out so that they don't go through the turbo. others say use a magnet after you drilled the hole.

I know the safest way is to remove the manifold and then drill the hole, but can it be done any other way?

regards

While you at it why not drill another hole and install a water/meth injector to lower the EGT? I'm thinking of doing it, as I've read of so many turbo diesels that crack heads from too high EGT's.

Raymond, I drilled mine with the motor running. You can see the bits of iron being blown out. Its very small bits, I have seen bits of carbon which are bigger that pass through just fine. Just start with a very small bit and go up step by step size wise. 11/32 is the the imperial bit size of the biggest hole you should make. Assuming you are going to tap it to a 1/8 27tpi npt which is commonly used for egt sensors. The one madman sells is a 1/8 npt 27tpi.

1. Start engine
2. spray some cutting fluid.
3. start drilling with a 1mm
4. 2mm
.
7. 5mm
.
10. 8.5mm (this is the biggest metric bit you should use don't do a 9mm)
11. 11/32 bit (if you dont have one you can try tapping the 8.5mm hole. its just harder and not good for your tap and if you break the tap off in the manifold. then you are screwed).
12. tap hole with 1/8 27tpi npt tap. liberally apply cutting fluid to tap, clean tap regularly
13. you can use a magnet too if the motor is not running

Raymond I also drilled whilst the engine was running, very similar to Johan above. Just be sure to use a good quality drill bit and cutting fluid, makes the task very manageable.