2000 Chevy Malibu 3.1L v6 engine has cracked upper air intake manifold. I want to grind out crack and repair with JB metal weld. When I reinstall I will use some RTV Black and tighten bolt at crack only until snug and RTV starts to compress from under manifold. Has anyone tried this before or does anyone have any thoughts on this repair? Will it work?
I don’t have the experience or knowledge to tell you whether that will work or not. I do know that if it were me, I wouldn’t want to be messing around with it twice. So I would be combing the salvage yards for an intact manifold.
Here is a great website:
At this point I have not been able to price a new part. I have the $5 for the JB weld, but not the $$ for a manifold. Replacing the upper manifold really isn’t a bit deal…
How much experience do you have using JB weld?
None
No. JB Weld even states that it is not for use on manifolds. They get too hot.
http://jbweld.net/products/jbweld.php
bottom of the page on the right, in bold italics.
I think they’re mainly referring to exhaust manifolds although some of the older intakes used to be heated with exhaust gases. All of the more modern intakes I’ve had to mess with never would get that hot. YMMV.
One issue I would have with using epoxy to fix a crack that is under serious heat/cold cycling is that, if the ends of the crack are not drilled, it will continue to run. The patch may not last long if the stress isn’t relieved properly.
I was suggesting a used part - the car-part website is a big searchable network of salvage yards.
But if you don’t mind pulling the thing twice, then you have little to lose and I’d say give it a whirl.
Try using sealant all around and using bolts on just the opposite corners. It’s alright as long as there are no leaks.
I tried something similar years ago. Wasted a good week, and nearly stranded twice when the patch failed. I found a replacement manifold at a salvage yard for $25. Replaced it in an hour, and never had problems since.
I have no problem recommending a used part for this. This part is not a wear item, and should last beyond the life of the engine. Get a used one, and do it correctly. You’ll be happier.
Plus, the 3.1L V6 is a very common engine. Almost any salvage yard near you will have the parts to sell.
I echo BustedKnuckles here . . . I think just about every one of us tried to patch something or other like this . . . and ended-up fixing it properly after the patch failed. The advice is sound . . . and you really don’t want to get stranded out in the middle of nowhere on a dark and rainy night or ruin the engine because the part fails again. Find a replacement at a salvage yard . . . remove it yourself at the yard (this will show you how to get it off, what you’ll need to take with you to fix yours) and then take it home, give it a good cleaning, and replace it. Good luck! Rocketman
Be sure you explore why the ear of the upper manifold cracked off, don’t want it to happen again