Threads Inside Bolt Hole Stripped While Changing Water Pump

Hello, all. Just finished replacing the water pump and a few other things on my 2000 2.7L. In the process of bolting in the new pump, one of the 10mm bolt holes got stripped out. The bolt just spins and doesn't get snug. In my ignorance, I wrapped the bolt in plumbers tape, put it in, and figured one loose bolt wouldn't make a difference. Of course, I was WRONG! Coolant is slowly leaking from that area while the truck is running and I don't think there is much pressure in the system as it starts smoking after a minute or two. The exhaust manifold and fan clutch were also replaced, for reference.

Is there anything I can do? My first thought is epoxy; knowing I'll probably never get to remove that bolt again. I'm closing in on 225k miles so that may not be an issue. Open to suggestions. Thanks in advance.

 

There isn’t much meat there to helicoil or install an insert, unless you are extremely careful... Jb weld, or LPS steel stick unless you feel like replacing the chain cover....

 

Actually, looking at that casting there is plenty enough meat to go deeper. Get a tap drill for that thread size and a bottom tap. Leave the pump on, drill the stripped hole deeper, run the tap in there with some grease on it to collect the chips. Get a longer bolt. Even if you popped through thread sealant on the bolt will seal the oil

 

Tap it to 1/4 20 standard thread. That's the next size up.

 

Not having a 4 Cylinder and thinking M10x1.25 was what OP was calling 10 mm bolt I am thinking how can 1/4 20 be the next size
M6x1.0 interesting .

 

Good to hear! This is the bolt/hole in question.

 

Like this?

 

In my personal experience those tap drill combos are very prone to snapping if you're not completely straight in your approach. You'll want somethimg like this

https://www.lowes.com/pd/IRWIN-HANS...kFnxeXEUbW8-4H0Zw_jWOIltVZ1RtC9gaAg_rEALw_wcB

 

Excellent. Thanks!

Should I use a tap wrench or can I use a standard cordless drill (given it fits in the space)?

 

A tap wrench gets you a lot more control.

 

With a bottom tap, I'd use a tap wrench. The lack of a taper means you can make threads almost the entire depth of your cut but when they bottom out they like to snap lol

 

If the water pump is still on it, it will help align the tap.

 

I bet you wont even need to dril it. Just run the tap in.

 

Yes, still on. Hoping I can remove just the radiator and fan shroud to make enough room to do this.

 

I've drilled out and added a Heli Coil on my BMW aluminum block in order to use the same fastener. Either way, go slow and not too deep.......

 

Well, the tap and new bolt worked well (which is awesome, never done that before), but there's still a leak around the water pump (I think) and the truck is getting hot. Hard to pinpoint the leak but once it stops raining I'll try harder. I'm pretty certain I installed everything correctly, gasket included.

This is the water pump and fan clutch I ordered. The fan clutch was not a perfect fit (had to use a couple of washers to space the fan away from the pulleys and belts) so perhaps this is a bad part?

Also, I didn't change the thermostat because I changed it maybe 2 years ago. Was that a mistake?

 

Did you use any silicone on the gasket? I always put a thin coat on the gasket.

 

Why was the water pump changed ??

Poor quality parts??

The new water pump spins like it should??

The water pump housing may be warped?? Might be what caused the bolt to strip so easy.

If your leak is between the pump and timing cover .

Is it leaking enough the coolant level will drop to the level of the leak in a few minutes ??

Is your thermostat opening??

How long is the engine running till it gets to hot ?? It is getting hot not oil cooking off the new manifold??

 

1) Water pump was changed because of overheating and because I'm not sure how old the existing one was. I've had the truck for about 6 years and this is my first attempt at changing it.

2) Possibly. Ordered from RockAuto. Don't have a lot of experience with auto parts so it's hard to say.

3) The fan and belts are spinning like they should. Before installing the water pump I gave it a quick inspection and it seemed fine. The old one also seemed fine, to be honest.

4) Gosh, I hope not.

5) To be determined. I'm going to clean and dry the area around the leak and try to pinpoint. Very cloudy and rainy at the moment so that'll have to wait.

6) Slow leak. And I'm not certain the coolant reservoir is being tapped. The leaking coolant is green and the only fluid in the reservoir is (temporarily) water.

7) Not sure if the thermostat is opening. How can I tell? In any case, I'm going to replace that today. Easy to access and cheap, why not.

8) Engine is only running for maybe 30-60 seconds before I start seeing small amounts of smoke. I took the temperature gauge about 5 minutes to creep past half way, although I've only let it run that long once.

Once the rain stops I'll clean the engine up a bit and get some pictures and video. Thank you all for you input so far!

 

I just read this post:

This exact thing happened when I let the truck run for 5 minutes. Upper hose was very hot. I touched it in hopes that I could feel fluid but it was just hot and empty.