EGT and Boost

[britannic]

Did GM provide tap points on the air intake and exhaust manifold for the EGT and boost gauges and if not, any tips on doing the job properly?

[Toddster]

Nope....For boost, tee into the hose that connects to the wastegate accuator.....Pyro, remove passenger side inner fender, with the truck RUNNING, drill a pilot hole in the manifold towards the back on the flatest area you can find....Then drill to 7/16....Then CAREFULLY tap with 1/4 NPT pipe tap....Do NOT bottom tap out, about half way should be good. Use lotsa never-sieze, this will be your best friend if you ever have to replace your probe ! Note....Make SURE your probe is 1/4 NPT before drilling, I have never seen one thats not but it is possible ! Hope this helps... :cool:

[britannic]

Thanks very much for the info! Question: If the truck is running, won't the break through metal flakes from drilling the hole cause problems with the turbo? Shouldn't the U pipe to the turbo be disconnected so that the flakes can be removed first?

[SoCalDMAX]

LOL :D

That's why he said to have the truck running. The exhaust will blow the chips out of the pipe towards you. Better to wear safety glasses as well. It works great! The longeest part of the whole procedure is gatheriing up the tools and removing the fender liner.

Good luck! Steve

[Toddster]

With the truck running the "chips" will blow right at you, wich reminds me, WEAR GOGGLES ! I personally have never heard of anyone having turbo problems following this proceedure....If you don't feel comfy, remove the manifold, drill, tap, and replace....Not difficult but much more time consuming...

[3-Fan]

With the engine running, the exhaust will blow the chips out, not suck them in. Maybe right before you break through, pull the bit out and put a little grease on the end to "grab" the flakes.

(on edit) echo, echo, echo.....

[ 01-24-2003: Message edited by: 3-Fan ]</p>

[TooMuchMuscle]

For anyone interested, call your local dealer and the good dealers will remove the manifold then give it to you and when you are done drilling and tapping return the manifold and have them re-install it for you. This is what I did. I dont want to replace the turbo if something goes wrong. Costs of labor are around 100 dollars

[hoot]

Remember you are all exhaust side. With the truck idling, even if a small chip went through the turbo it's highly unlikely it would cause any harm at all. It'll just go out the exhaust pipe.

At idle the turbo doesn't spin real fast.

[britannic]

Hey Hoot, thanks for letting us share the excellent pictures, you should illustrate the Duramax workshop manual that Toddster will write - and Toddster, very helpful instructions - thanks!

[Toddster]

LOL ! You're very welcome, glad I (and others) could help....Hey Hoot, Britannic may be onto something here kid ! $$$$$ ;)

[Maverick]

I drilled mine with it on the truck and running. 50,000 miles later, no problems.

[Buck]

I would do it like Kennedy says. Remove the pass. side manifold (a good penetrating oil won't hurt) drill and tap, deburr inside if needed and replace. Gaskets are reusable ;) That's the way I'm going to do it when my gauges get here.