patch for radiator reservoir

[2MIZ129]

hey so i got this needle size hole in the plastic radiator reservoir and was wondering if i can patch it up with anything maybe some high temperature epoxy or anything?! i dont want to buy a new radiator

[bazar01]

You can patch it up as a temporary fix but keep a close watch on the coolant level everyday but still plan on getting a new radiator.

(Lots of stresses finding a used engine, pulling out the blown engine, installing the used engine, replacing all cooling hoses and plastic fittings, replacing radiator, no history on water pump and thermostat condition, etc.)
There's just so many things to address when replacing a blown engine.

A new radiator amd coolant hoses are still cheaper in the long run

[BlackBMWs]

Just a note, I has a slight leak on my radiator bleed screw that I was going to fix the next week that ended up costing me a motor when I got caught in dead stop traffic on a hot day on the freeway.

$120 turned to $900 in the end. JB weld will work for a temporary fix, but I'd still replace the radiator.

[740isport]

If it is just the expansion tank, it can be replaced! I bought a brand new one when I rebuilt the cooling system only to find out that the radiator came with one already! If your interested, I'd sell the expansion tank for $30 shipped!

[HotChickenStrips]

I just bought a new radiator for the same problem off ebay for 62 bucks shipped.

[BMW_Hatchback]

You can replace the plastic tank separately from the entire rad...

[740isport]

Originally Posted by BMW_Hatchback

You can replace the plastic tank separately from the entire rad...

+1

[bazar01]

If the reservoir is compromised, you will never know if the radiator itself is. Usually, the radiator is not too far behind when that plastic reservoir gives up.
My son replaced just the reservoir in his E46, then less than 1k miles after, radiator itself started leaking and he ended up replacing the whole radiator.

I am not saying this is the same case as yours but it is safer just to replace the whole thing rather than piece meal it. Overheating is so expensive to fix.

[740isport]

Originally Posted by bazar01

If the reservoir is compromised, you will never know if the radiator itself is. Usually, the radiator is not too far behind when that plastic reservoir gives up.
My son replaced just the reservoir in his E46, then less than 1k miles after, radiator itself started leaking and he ended up replacing the whole radiator.

I am not saying this is the same case as yours but it is safer just to replace the whole thing rather than piece meal it. Overheating is so expensive to fix.

OP stated he didn't want to replace the entire radiator. That's why I offered a solution! I just finished a cooling system rebuild and did everything myself. But I have also seen a reservoir get cracked while other work was being performed and successfully replaced!

[bazar01]

That's why I recommended that he can patch it up as a temp fix but he has to watch it very closely.
If he really does not want to replace the radiator, at least pressure test the cooling system to check the integrity of the radiator and other cooling components.

[740isport]

I wouldn't try a patch on the plastic reservoir myself. Easier and safer to replace the reservoir. Your various epoxies, including jbweld and others, don't attach well to that white plastic that the reservoir is made of. Plus if there is any oily residue on it, it won't adhere after it hardens. Just my $0.02