Replacing freeze plug that's under motor mount - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Hair · 04-17-2022, 03:23 PM

1989, 5.7, 1/2 ton, 2wd
The freeze out plug on driver side directly under the motor mount is leaking bad. I am going to replace it. My plan is to slide the horizontal motor mount bolt out, then raise the engine up on that side enough to unbolt the motor mounts from the A frame and the block to get them out of the way and then get in there and replace the freeze plug. I'm not sure if my plan will even work, maybe I cant get the motor mount out that way? Has anyone on here replaced this freeze plug with engine still in the truck before? Got any tips or perhaps a better way before I go at it?

Tx Firefighter · 04-18-2022, 06:38 AM

I'm sure this is the very last answer you're wanting to hear.

I always remove the engine entirely and replace them all. If that one plug has corroded enough to leak, the others can't be too far behind. It's just a matter of time until the next one gives way. I could never trust it if I just did one. Someday far from home it would bite me. I'm all about the reliability and having confidence in getting to where I'm going.

I'll be quiet now so others can come forward and answer your question directly. Good luck with whichever path you choose.

**Getter-Done** · 04-18-2022, 07:03 AM

I would pull the engine and replace all of them as Tx Firefighter has mentioned.

I have seen people put the rubber plugs over them

If I used those I would be wondering when it was going to pop out

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Hair · 04-18-2022, 09:33 AM

Yep, you guys are correct about them all rottening out. The ones in front went first, I fixed those - fairly easy to get to. About a year later, one on the back of the engine under the bell housing went bad. I slid the tranny back and replaced all of the ones on the back. So now, the only ones left are on the sides. It's been about two years and one of the ones under the motor mount has sprung a leak. The rear ones look easy to get to, but the ones under the motor mounts I think will be a booger.

**Getter-Done** · 04-18-2022, 12:13 PM

You may be lucky enough to raise and slide it forward.
I would be leery of it falling while trying to get them out and hammering them back in.
If you could block it up somehow while it is lifted up?

04-17-2022, 03:23 PM	#1
Hair Registered User Join Date: Mar 2008 Location: Tullahoma, TN Posts: 421	Replacing freeze plug that's under motor mount 1989, 5.7, 1/2 ton, 2wd The freeze out plug on driver side directly under the motor mount is leaking bad. I am going to replace it. My plan is to slide the horizontal motor mount bolt out, then raise the engine up on that side enough to unbolt the motor mounts from the A frame and the block to get them out of the way and then get in there and replace the freeze plug. I'm not sure if my plan will even work, maybe I cant get the motor mount out that way? Has anyone on here replaced this freeze plug with engine still in the truck before? Got any tips or perhaps a better way before I go at it?

04-18-2022, 06:38 AM	#2
Tx Firefighter Watch out for your cornhole ! Join Date: Jun 2003 Location: Azle, Texas Posts: 14,162	Re: Replacing freeze plug that's under motor mount I'm sure this is the very last answer you're wanting to hear. I always remove the engine entirely and replace them all. If that one plug has corroded enough to leak, the others can't be too far behind. It's just a matter of time until the next one gives way. I could never trust it if I just did one. Someday far from home it would bite me. I'm all about the reliability and having confidence in getting to where I'm going. I'll be quiet now so others can come forward and answer your question directly. Good luck with whichever path you choose. __________________ I'm on the Instagram- @Gearhead_Kevin

04-18-2022, 07:03 AM	#3
Getter-Done Senior Member Join Date: Dec 2009 Location: TN. Posts: 9,874	Re: Replacing freeze plug that's under motor mount I would pull the engine and replace all of them as Tx Firefighter has mentioned. I have seen people put the rubber plugs over them If I used those I would be wondering when it was going to pop out __________________ ________________________________________________________________________________________ ____________________________________________ The early bird gets the worm, But the second mouse gets the cheese 85 Chevy K-20 63 Impala (my high school car) http://67-72chevytrucks.com/vboard/s...Crew Cab Build

04-18-2022, 09:33 AM	#4
Hair Registered User Join Date: Mar 2008 Location: Tullahoma, TN Posts: 421	Re: Replacing freeze plug that's under motor mount Yep, you guys are correct about them all rottening out. The ones in front went first, I fixed those - fairly easy to get to. About a year later, one on the back of the engine under the bell housing went bad. I slid the tranny back and replaced all of the ones on the back. So now, the only ones left are on the sides. It's been about two years and one of the ones under the motor mount has sprung a leak. The rear ones look easy to get to, but the ones under the motor mounts I think will be a booger.

04-18-2022, 12:13 PM	#5
Getter-Done Senior Member Join Date: Dec 2009 Location: TN. Posts: 9,874	Re: Replacing freeze plug that's under motor mount You may be lucky enough to raise and slide it forward. I would be leery of it falling while trying to get them out and hammering them back in. If you could block it up somehow while it is lifted up? __________________ ________________________________________________________________________________________ ____________________________________________ The early bird gets the worm, But the second mouse gets the cheese 85 Chevy K-20 63 Impala (my high school car) http://67-72chevytrucks.com/vboard/s...Crew Cab Build



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