Blue Devil...bad results

I poured some blue devil into my car to seal a blown head. Now I see white chunks in the radiator and it overheats much faster. Is there any way to undo this or get the car back to how it was before I poured in blue devil?


I poured some blue devil into my car to seal a blown head

The car was broken before you poured the Blue Devil in, and it’s still broken now. It didn’t help, but it didn’t hurt either. Additives like these are a last-ditch temporary patch to get a little more life out of a damaged engine. Sometimes it works, sometimes it doesn’t. Flushing it out won’t help anything.

It’s time to repair the engine or get rid of the car.

Agreed. Fix it right or get rid of it. The miracle in a can simply doesn’t always work.

why is it worse than before though? did blue devil clog everything up?

“It’s time to repair the engine or get rid of the car.”

Yes indeed.

Why is it worse? It might have plugged up some of the radiator (which I’d replace if you choose to repair the car). Or the blown gasket got worse, which is typical.

There really is no quick fix for a blown head-gasket. There are several products on the market that claim a quick fix…but they don’t really work.

I first thought this was about Diablo Azul (Blue Devil) tequila which would probably have been just as ineffective as the stop leak.

ANY TIME you pour in a stop leak ( radiator, engine, transm.) you can NOT predict which passage ways it will end up plugging…the leak ? or the small intended flow passages ?
and THAT, I think , is your resulting issue…it’s plugging too much.

Fix it properly (remove head, check for warping, machine shop and so forth) and then fix the problems which the Blue Devil caused . . . probably clogged your radiator, maybe water passages in the engine. Gotta get that stuff out, its’ job is to clog, not you have to un-clog whatever it touched. Sorry, but it’s gonna be a pain, but now’s the time to do it properly. Good luck! Rocketman

Would flushing the radiator work? How should I go about unclogging everything it clogged up during that process. Because when I went to look under the cap it had all these white puff balls and then the car overheated much quicker than before. Maybe the thermo is clogged too?


I can’t help with your problem , just for my own information I’d like to know if you followed the manufactures instructions exactly ? I don’t know but have read that many stop-leak problems are caused by not exactly following the instructions .

Not just the radiator but I think they are saying the water passages in the engine may be restricted now. That means engine disassembly to clean the passages out. Then might as well fix the head gasket and throw a new radiator in while everything is apart.

You cannot return it to the state it was in before you poured in the additive. It’s worse now. There’s no reversing the process. Even if you COULD return it to the state it was in, it would still need major work anyway. It was broken the way it was.

Your only options now are to repair it, which as an absolute minimum will mean a new headgasket and radiator + misc (such as the T-stat and coolant), or perhaps a new/rebuilt/boneyard engine and radiator, or sell it for scrap. Note that the gump you’re seeing in the radiator is also in the heater core and probably the valve that opens & closes the line to the heater core. Hopefully those can be successfully flushed out.

A friend of mine used Blue Devil on a 5.4L Ford engine that had a blown head gasket. Lots of steam out the exhaust, couldn’t keep coolant in it, turned the blue liquid in the sniffer yellow, added pressure to the system with the tester on it. In short it flunked all the tests. His son got two more years out of it before it developed transmission problems at just over 250K miles. They junked it. I’m not saying it will work in every case, but he bet the (blue) devil on that one and won. Maybe new head gaskets would have lasted longer, but it was an old truck to start with, and not worth that kind of money to fix.

No flushing radiator. It’s the same as using the stop leak. You never know. Always read the instructions thoroughly or bad results are 100% going to happen. At best it’s 50 %. You got the not best.

Scottie Kilmer would be disappointed, since he SWEARS by those kinds of products