Drilling exhaust manifold for EGT sensor

[msimmons]

I plan on installing an EGT sensor (1/8" NPT) shortly in the exhaust manifold of my '03 HO CTD. I would like to install it in the "down" portion of the mani that attaches to the turbo housing. Does anyone have some dimensions that I can use to locate the pilot hole? I understand that there is a partition in the manifold that I want to avoid drilling into.



TIA



Mike

 

[RankRam]

Take a look at my readers rig gallery.

 

[GDouglas]

The partition is in the center of the manifold casting where it dumps down in the turbo. If you drill right between the center point and the edge of the casting you will be alright. By the way the partition runs left to right in regards to the truck orientation

(port-starboard).



Don't worry, none of us likes to drill holes on a new 35k truck, but knowing what your engine is doing is well worth the sweating about it.

 

[Joseph Donnelly]

Why drill down there where chips will fall right onto the turbo wheel? You can drill into the side of the manifold just behind #3 port, and almost everything falls away. A couple chips may fall inside, but they are easy to remove with a magnet on a stick. You will be picking up the heat from #1,2,3.

 

[grabinov]

I driiled my EGT thermocouple port just as Joseph Donnely recommends. I plugged the exhaust with duct tape, made sure the engine was cool, and laid everything out in advance. Then I drilled the whole with the engine running as was suggested by the guys at Diesel Power Products. (As I am learning, this duct tape/backpressure trick is not harmful on diesels the way it can be on a gas motor - it's just like an exhaust brake. )



It sounds hokey, but it works great. The chips run right up the drill bit and never get down in the hole. Same is true for the tap. Just make sure to wear long sleeves, gloves and GOOD eye protection, because the hot shavings will come spraying back at you! And get it done before it gets too hot, or the tap will want to stick.



By the way, to avoid drilling another hole, I used a "boost bolt" from Heath Diesel Products which replaces an intake manifold bolt with a hollow one with a tubing fitting on the end for the boost gauge lead. About $14. 00, and well worth it. It goes in in about 30 seconds.



Greg

 

[Vaughn MacKenzie]

I just drilled mine and let whatever shavings fall into the exhaust just blow out through the turbo. I didn't bother with the magnet or greased bit.



BTW I'm the guy who runs the Bully Box without gauges.



I'm the one everyone's been warned about

 

[JHardwick]

:-laf @ Vaughn



I had a long time diesel mechanic tell me bacically the same thing. He said to be as careful as possible, but not to fret about a few small shavings.

 

[XJSuperman]

I am awaiting my guages... and was told that the turbo doesn;t spool up until 1500 RPM's which is WAY higher than idle... . and at idle the shavings would have been blown out anyway not hurting the turbo at all.

 

[nickleinonen]

Originally posted by XJSuperman

I am awaiting my guages... and was told that the turbo doesn;t spool up until 1500 RPM's which is WAY higher than idle... . and at idle the shavings would have been blown out anyway not hurting the turbo at all.

it will still be turning as soon as the engine fires up. if you want to see that, take off the air piping and have someone start up the engine, you will see the turbo start spinning pretty fast right away

 

[XJSuperman]

Right... but at initial startup it's not(for that fraction of a second)... and whatever I can;t get cleaned out will go right through no problem. I understand if the engine is running (even at idle) so is the turbo... but at idle it's supposed to let the shavings just blow by.

 

[GDouglas]

Oh yea, forgot to mention about greasing the drill bit and the tap to hold on to the majority of the shavings. I guess it is just the usual good shop practice that usually gets forgotten to say when giving instructions. Just the something that is "learned" through the years and never gets mentioned kind of thing. Good luck wherever you decide to place your probe.

 

[Prairie Dog]

Actually I don't like to grease the TAP. I prefer that all the shavings fall into the manifold so that a small magnetized screwdriver can be used to retrieve them. I've found that I can get out every spec of metal this way.

Just a thought,



Scotty

 

[Grunt]

Originally posted by Vaughn MacKenzie

I just drilled mine and let whatever shavings fall into the exhaust just blow out through the turbo. I didn't bother with the magnet or greased bit.



BTW I'm the guy who runs the Bully Box without gauges.

So does this mean you drilled your manifold just to have something to do?

 

[JHardwick]

:-laf :-laf :-laf :-laf

 

[Prairie Dog]

ROFLMAO:-laf

I started mine with the hole open, it gives it a nice deep throaty sound!