M156 head gasket failure? Head bolts are done. Check the comments and description for DIY videos.

As I was opening up the intake manifold of my m156 powered w211 AMG to clean its guts from the oil and gunk, I found blue liquid on the back of my valves which scared me. It looked like coolant. The head bolts had been replaced long time ago.
M156 head bolt DIY:
• Head bolt DIY replacem...
How To Prevent Mercedes Keyless Entry From Dying
• How To Prevent Mercede...

[@roadwarrior144]

The fluid shown in the video could potentially be fuel. Its possible you may have a leaking fuel injector. How many miles on the car?

[@AccentOnCars]

It’s all good. Thank you for chiming in. It was just fuel. Injectors are new. It happened because I turned on the car and turned it off several seconds later.

[@jcdentonunatco]

That is the intake manifold gasket. Seems extremely unlikely it would be coolant. More likely oil or fuel. It’s not uncommon to get oil blowback inside the intake manifold

[@AccentOnCars]

Thanks man. Yes, it ended up being fuel. I have link to the part2 video in the comments. I have new IM gasket and injectors, and installed a catch can since then 🤝

[@greydog1104]

Has the coolant reservoir level gone down or got oil in there?

[@AccentOnCars]

Thanks man. False alarm, thanks goodness. kzbin.infoamq-nm99oR4?feature=share

[@phillm156]

😮that is scary. when you changed the headbolts, was it a 3 step torque process? Is there another way the coolant could have gotten into the intake?

[@AccentOnCars]

Watch part two, lol. kzbin.infoamq-nm99oR4?feature=share

[@joshwong99]

I have the same problem, but when i put a paper towel in the values it come out really green. Not sure if its coolant. But can coolant leak for the intake valves? Shouldn't it leak only from the exhaust values? Weird

[@AccentOnCars]

Let’s think about it. 1. Unless you have aftermarket coolant then Mercedes coolant is usually blue. 2. Depending on purity, gasoline can have green-ish color to it. 3. D you lose coolant? Open the coolant tank and check. Does your exhaust fumes smell sweet at first startup? It will if you burn coolant. 4. I am thinking in order for coolant to show up on the valves your cylinders must have coolant in them. 5. Does your oil appear to look like milkshake (milk and coffee) in color? Check using the dipstick.

[@joshwong99]

@AccentOnCars thanks for the info. So my oil is not milky and looks fine. Engine runs fine. The coolant test is good and doesn't have a leak of co2. So I'm lost

[@joshwong99]

@@AccentOnCars the coolant looks blueish green

[@AccentOnCars]

Happy to help! Keep monitoring it. If no changes then you are fine. Have you changed your injectors? That’s highly recommended if never changed. I have a diy video here. What repairs are you doing that you are seeing the valves?

[@joshwong99]

@@AccentOnCars I'm doing the intake manifold gasket and fuel injectors.

[@alanmotran426]

That’s fuel, u can see it from the color.

[@AccentOnCars]

Yes, ended up being fuel. Thanks goodness 😁

[@OGYELLOW]

Stick a paper towel and absorb some? Smell it. Taste is. Looks like dirty fuel

[@joshwong99]

I have same problem, but can't tell it is coolant or dirty fuel.

[@AccentOnCars]

Part 2: kzbin.infoQYX7-4f98tY?feature=share Head bolt DIY: kzbin.info/www/bejne/sHuyYqSEo82rrZY