injector heat shields

Anyone know how to get a heat shield out (little round things with holes in the middle that sit under the injectors) when it is glued in place with carbon deposits? Is there some sort of fluid that would dissolve a carbon deposit that I could pour in the injector hole in the head maybe? A mechanic wanted to try and break it in two but I wouldn't let him because it might crack the head.

Any good penetrating oil should work. WD-40, LPS-2, etc are good but Kano Labs Kroil is the best.

On my MB I had to do this when I rebuilt my fuel injectors. I also took a long slender punch (a long shank screwdriver will work too) and give the heat shield many gentle taps with a mallet. The heat shield should break free.

On one particularly stubborn heat washer I had to find a long punch with just the right amount of taper at the end to it so I could tap the end of the punch though the hole of the heat washer and get the washer to stick to the punch. After a few tries I got the washer loose from the head and it came right up when I pulled the punch out of the head.

Don't worry about any penetrating oil that drips into the cylinder. Penetrating oils are very light and will burn off cleanly.

Brian, 97 Passat TDI

I had the same on number 4 injector a while ago: a large screwdriver will do the trick, helped by some WD-40(or similar). If you have tried all that and have an oilchange coming anyway, then try some coca-cola and let it sit overnight.

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70-FR-TX
'94 Golf tdi 1Z
Eibach lowering springs
Bilstein front&rear

Are you serious about the coca-cola? Isn't that the equivalent of putting sugar in your gas tank?

Coke contains sugar but it is also a weak acid due to the dissolved CO2 creating carbonic acid. This helps dissolve some of the crud slowly without destroying anything.

Do you know of any other weak acids that would react with a carbon build up (I'm pretty sure that that's what's sticking the heat shield down there, because I chipped a lot of it out of the hole where the injector was)?