Every problem gets worse than the last.

[Richey]

Not yet. I've had some other work related projects taking up all of my time. I did manage to get the 3D template printed and some bushings that make the bolts snug and center the template. I ordered some metal bushings to go into the template so the drill bit does not chew through the plastic bushing on that stud. I'm thinking I'll get a chance to try it again maybe mid next week or next weekend.

Any update on this?

[ROB III]

@Richey
I'm sorry to see the issue you are having, but thank you and ALL who have contributed and commented. For me, this was an excellent tutorial on how to address this type of issue that is unfortunately more common than any of us want. Tom, as you pointed out, there are numerous ways to approach this based on the internet, but the point to point feedback specifically for the 944 is greatly appreciated.
CARPOKES value as a teacher is proven once again.

[Richey]

I had some time this evening and to work on this a little more. None of the various bits I had would drill through the easy outs, cobalt, hardens steel, etc. I finally found a tungsten carbide drill bit that cut right through it.

I printed a few of the Car Pokes jigs and bushings to make everything tight and centered. I started with a smaller bit and ordered a steel bushing from McMasters then then had to modify and print a second jig for the larger bushing that was bigger than the original file.

I even made a jig that was 11mm deep to get it cleaned out for the Helicoil I ordered. The hole was measured at 12mm deep so the plan was to run the last 1mm by hand. Well I did that and found out that there is about 2mm of aluminum behind that hole because I punched right through it into the water passage behind it.

So I think the plan for the Helicoil is out at this point and I'm going to have to switch to a Timesert in its place. I'm thinking I can seal the Timesert with Red Locktite then use Blue Locktite on the stud. I really don't want to make the stud permanently installed.

[Tom]

I had some time this evening and to work on this a little more. None of the various bits I had would drill through the easy outs, cobalt, hardens steel, etc. I finally found a tungsten carbide drill bit that cut right through it.

I printed a few of the Car Pokes jigs and bushings to make everything tight and centered. I started with a smaller bit and ordered a steel bushing from McMasters then then had to modify and print a second jig for the larger bushing that was bigger than the original file.

I even made a jig that was 11mm deep to get it cleaned out for the Helicoil I ordered. The hole was measured at 12mm deep so the plan was to run the last 1mm by hand. Well I did that and found out that there is about 2mm of aluminum behind that hole because I punched right through it into the water passage behind it.

So I think the plan for the Helicoil is out at this point and I'm going to have to switch to a Timesert in its place. I'm thinking I can seal the Timesert with Red Locktite then use Blue Locktite on the stud. I really don't want to make the stud permanently installed.

Which stud is it? If memory serves, one of them is open to the water passage in back from the factory. I can look on my spare block if you think that's a possibility.

[Richey]

It's the top one. Looking at the small piece that's about 1mm or so that fell out the back it's got threads on it. I don't know that a Helicoil would seal up correctly.

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[Tom]

It's the top one. Looking at the small piece that's about 1mm or so that fell out the back it's got threads on it. I don't know that a Helicoil would seal up correctly.


Screenshot 2026-04-18 at 10.35.36 PM.png

For what it's worth, that hole goes all the way through from the factory on my 2.7L (104mm) block. For reference, a standard M6 nut is only 5mm thick. Not entirely sure I follow what or if something broke, but if you can get a 9mm helicoil in there, it would be stronger than the original threads. Loctite or even teflon on the threads should seal it 'enough' -- the threads will be tight and the pump gasket should keep everything sealed regardless (it would seem to me anyway).

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[Richey]

In the end I decided to seal it up with some blue thread locker. The idea is that the thread locker would act like a sealant and also prevent me from being in this same place next winter when I plan to pull the engine for a complete rebuild.

So one last thing on this part of the project. Water Pump Outlet for the Expansion Tank Hose comes with the outlet, gasket, two bolts, two washers and these two pins. I have no idea what the pins are used for or where they go. Any idea what I'm supposed to do with them?

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[O875]

They were installed on a new pump I got for my 1990 944 (3litre) but weren't on the old one. Maybe they're simply an aid to holding the pump on while its fixings are tightened?

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[Richey]

I figured it must be for another year or maybe the 16v cars. I didn't have the pins on mine so I didn't use them.

[Tom]

I never researched why this roll pins are sometimes included, but the last two times I've changed water pumps, they came installed in the pump and I had to pound them out and throw them away.

So I take it you installed a heli-coil and blue loctite and all is well with the new stud?