Drilling holes in exhaust manifold

[3VILC]

Hi guys,
Now I remember reading about this a while back but I can't for the life of me find it now.
I read a few people had had some success with drilling a hole in their exhaust manifold (for an EGT probe) with the manifold in-situ and I think just having the engine running to push any excess filings thru the turbo.
Is this correct and is it a good idea? Or should I just tap the dump pipe and settle for post turbo as most seem to have done with this engine.

Cheers,
Clive

[kbushnz]

I have done it and no issues to date...
Drilled it with the engine running and also a vacuum cleaner to suck away the swarf...Nice and slow..
Then with engine off I tapped it with grease on the tap... Stopping and cleaning tap off every turn or two and re greasing...
Then when completed, cleaned out the hole and ran engine again...
Any tiny bits will soon exit out the tail pipe...

[trucked]

Hi guys,
Now I remember reading about this a while back but I can't for the life of me find it now.
I read a few people had had some success with drilling a hole in their exhaust manifold (for an EGT probe) with the manifold in-situ and I think just having the engine running to push any excess filings thru the turbo.
Is this correct and is it a good idea? Or should I just tap the dump pipe and settle for post turbo as most seem to have done with this engine.

Cheers,
Clive

If i get what your trying to say, any foreign objects running through the turbo is a terrible idea to me. bearings and turbo vanes tend not to like foreign objects and metal filings are like a grinding paste.

Drilling and tapping the egt after the turbo would in my mind be a much better alternative without taking anything off, if your set on putting the egt pre turbo, take the turbo and manifold off and do it properly.

[rob-mu]

I have seen heaps of turbo manifolds that have been drilled and tapped without being removed with no issues so I wouldn't be scared off doing it as long as you do it like kbush says

[SamLogan]

there is no point putting a egt gauge after the turbo as it will tell you nothing. There is a temp drop across the turbo and you will never accurately be able to measure that so if you are doing to the hassle of installing one put it in the collection point in the exhaust manifold. When you drill the hole put oil on the drill bit as well as that can help hold all the swarf together.

Sam

[suzolla]

Why not just run it while you are tapping as well, then virtually no shit will get in.
Cheers
Tim

[1hamish1]

Hi guys,
Now I remember reading about this a while back but I can't for the life of me find it now.
I read a few people had had some success with drilling a hole in their exhaust manifold (for an EGT probe) with the manifold in-situ and I think just having the engine running to push any excess filings thru the turbo.
Is this correct and is it a good idea? Or should I just tap the dump pipe and settle for post turbo as most seem to have done with this engine.

Cheers,
Clive

If i get what your trying to say, any foreign objects running through the turbo is a terrible idea to me. bearings and turbo vanes tend not to like foreign objects and metal filings are like a grinding paste.

Drilling and tapping the egt after the turbo would in my mind be a much better alternative without taking anything off, if your set on putting the egt pre turbo, take the turbo and manifold off and do it properly.

Ive always done it in place. Drill bit with grease on it, go slow and clean it every 1mm or so it goes in and reapply grease each time to the drill bit until it breaks through. Same goes for the tap, grease on the tap 1/4 or half turns at a time, remove clean and reapply grease and go again. At the end stick a magnetic screw driver through the hole and I guarantee if your patient with the process there will be almost nothing in there it all comes out with the grease. Anything in there is easily removed with a magnetic screw driver. Careful where you put the hole as directly above the turbo flange means any swarf drops down. Keep hole close to centre of manifold but over a piece where the swarf (if any) will be easily removed. I have done it many times and get no swarf in the manifold and I am very particular with my vehicles. Pre turbo is much better than post especially if your planning turbo swaps. Turbo efficiency and post turbo readings especially when changing turbos can be confusing, you really don't know what your seeing.

[klompy]

Is the hole best kept central in the manifold or is it ok in the plate used to blank of the egt pipe.

[tweake]

Is the hole best kept central in the manifold or is it ok in the plate used to blank of the egt pipe.

its ok in the egr port BUT you need to make sure the probe tip is in the centre of the runner. if its still in the egr port instead of the runner it will read colder. i found out the hard way

[Moriarty]

Run the engine while drilling, partially block the exhaust pipe to add to the pressure and that will blow the swarf back out past the drill. (in theory!!) then the grease trick with the Tap. no need to up the rpm, you dont want the turbo spinning to quick if bits DO migrate down past the turbine.

[wax]

I just use grease on the drill. it works fine I have done it a few times