Removing Glow Plugs With Wax - PeachParts Mercedes-Benz Forum

jay_bob · #1 04-20-2017, 09:56 AM

Get the engine warmed up. Ok to run without the manifold to get it warm, use common sense and don't let anything get sucked in.

Try AeroKroil penetrant, nothing else compares.

I would get it warm, pull the manifold, and apply the penetrant in the evening (like Friday night). Then Saturday morning start it up again and let it get heated up. Then hit the plugs again with the AeroKroil.

Wait a few minutes then use a battery operated impact to free the plugs. I have read many threads on this and this seems to be the best tactic. Don't use a gorilla 3/4 inch air compressor impact, just a little 1/4 inch battery drill type with a socket adapter. The impact has several benefits. One is that the many small shocks are better at breaking the plug loose than the constant force provided when you turn the ratchet. Also applying force with a ratchet tends to be off center due to the physics involved, this ends up applying an uneven force to the plug and I suspect this is what really ends up snapping them off.

Also don't forget to pick up a tube of Anti-Seize for the new plugs. And be sure you have either the official reamer tool or use an appropriately sized drill bit smeared with grease. Use No Power Tools on the reamer!!

packerfan · #2 04-20-2017, 11:55 AM

Quote:

Originally Posted by jay_bob

Get the engine warmed up. Ok to run without the manifold to get it warm, use common sense and don't let anything get sucked in.

Try AeroKroil penetrant, nothing else compares.

I would get it warm, pull the manifold, and apply the penetrant in the evening (like Friday night). Then Saturday morning start it up again and let it get heated up. Then hit the plugs again with the AeroKroil.

Wait a few minutes then use a battery operated impact to free the plugs. I have read many threads on this and this seems to be the best tactic. Don't use a gorilla 3/4 inch air compressor impact, just a little 1/4 inch battery drill type with a socket adapter. The impact has several benefits. One is that the many small shocks are better at breaking the plug loose than the constant force provided when you turn the ratchet. Also applying force with a ratchet tends to be off center due to the physics involved, this ends up applying an uneven force to the plug and I suspect this is what really ends up snapping them off.

Also don't forget to pick up a tube of Anti-Seize for the new plugs. And be sure you have either the official reamer tool or use an appropriately sized drill bit smeared with grease. Use No Power Tools on the reamer!!

Excellent advice Jay-Bob,
I just bought this car with all service records from previous owner and came across one of the invoices from 2012 that stated #1 glow plug was replaced and the remaining 5 were seized and not replaced at owners request. I called the Mercedes service center that has maintained this car and the guy I talked to was very familiar with it, he said previous owner was very very meticulous with the car but opted not to spend the money to change the glow plugs because the car was stored winters. he also told me what they do is set a torque wrench to the correct value for glow plugs and attempt to remove the plugs and if they do not come out the head comes off and goes to a machine shop were they get cut out with an EDM machine, then the new plugs go in and the head goes back on and $4000 later you are good to go!!

packerfan · #3 04-23-2017, 10:33 PM

Quote:

Originally Posted by jay_bob

Get the engine warmed up. Ok to run without the manifold to get it warm, use common sense and don't let anything get sucked in.

Try AeroKroil penetrant, nothing else compares.

I would get it warm, pull the manifold, and apply the penetrant in the evening (like Friday night). Then Saturday morning start it up again and let it get heated up. Then hit the plugs again with the AeroKroil.

Wait a few minutes then use a battery operated impact to free the plugs. I have read many threads on this and this seems to be the best tactic. Don't use a gorilla 3/4 inch air compressor impact, just a little 1/4 inch battery drill type with a socket adapter. The impact has several benefits. One is that the many small shocks are better at breaking the plug loose than the constant force provided when you turn the ratchet. Also applying force with a ratchet tends to be off center due to the physics involved, this ends up applying an uneven force to the plug and I suspect this is what really ends up snapping them off.

Also don't forget to pick up a tube of Anti-Seize for the new plugs. And be sure you have either the official reamer tool or use an appropriately sized drill bit smeared with grease. Use No Power Tools on the reamer!!

Aerokroil has been ordered and on it's way.
Thanks again for your help and wish me luck!

jake12tech · #4 04-23-2017, 10:56 PM

Quote:

Originally Posted by jay_bob

Get the engine warmed up. Ok to run without the manifold to get it warm, use common sense and don't let anything get sucked in.

Try AeroKroil penetrant, nothing else compares.

I would get it warm, pull the manifold, and apply the penetrant in the evening (like Friday night). Then Saturday morning start it up again and let it get heated up. Then hit the plugs again with the AeroKroil.

Wait a few minutes then use a battery operated impact to free the plugs. I have read many threads on this and this seems to be the best tactic. Don't use a gorilla 3/4 inch air compressor impact, just a little 1/4 inch battery drill type with a socket adapter. The impact has several benefits. One is that the many small shocks are better at breaking the plug loose than the constant force provided when you turn the ratchet. Also applying force with a ratchet tends to be off center due to the physics involved, this ends up applying an uneven force to the plug and I suspect this is what really ends up snapping them off.

Also don't forget to pick up a tube of Anti-Seize for the new plugs. And be sure you have either the official reamer tool or use an appropriately sized drill bit smeared with grease. Use No Power Tools on the reamer!!

Best advice is right here and the method I used to remove the glow plugs on my now sold '98 E300. If they still don't wanna come out, tighten it with a ratchet and back it off again. Rinse, wash, repeat!

packerfan · #5 04-30-2017, 08:37 PM

Quote:

Originally Posted by jay_bob

Get the engine warmed up. Ok to run without the manifold to get it warm, use common sense and don't let anything get sucked in.

Try AeroKroil penetrant, nothing else compares.

I would get it warm, pull the manifold, and apply the penetrant in the evening (like Friday night). Then Saturday morning start it up again and let it get heated up. Then hit the plugs again with the AeroKroil.

Wait a few minutes then use a battery operated impact to free the plugs. I have read many threads on this and this seems to be the best tactic. Don't use a gorilla 3/4 inch air compressor impact, just a little 1/4 inch battery drill type with a socket adapter. The impact has several benefits. One is that the many small shocks are better at breaking the plug loose than the constant force provided when you turn the ratchet. Also applying force with a ratchet tends to be off center due to the physics involved, this ends up applying an uneven force to the plug and I suspect this is what really ends up snapping them off.

Also don't forget to pick up a tube of Anti-Seize for the new plugs. And be sure you have either the official reamer tool or use an appropriately sized drill bit smeared with grease. Use No Power Tools on the reamer!!

jay_bob, I wanted to simulate removing a seized glow plug before attempting it on my car. I took a piece of aluminum, drilled a hole a little larger in diameter than the small end of the glow plug (the tip that glows) then drilled down with the tap drill staying above the bottom of the block for the glow plug to seat at the bottom and finally taped the top and removed all cutting oil.
Using an oxy acetylene torch adjusted with a yellow flame, I covered the glow plug with soot, then screwed it into the block as tight as possible without risk of breaking it (I do not have a torque wrench yet) then applied Aerokroil and let soak for three days. I put the block in a vise and hit it with a small 3/8" air operated "butterfly" impact wrench (80 ft/lbs. max.) turned way down. I turned the wrench up half way, I'm guessing 40ft/lbs. and the glow plug would not budge. I tried this several times letting the impact wrench hammer for at least ten seconds at a time. the next thing I did was to heat the block up with the torch getting it just hot enough where I could hold it in my hand without getting burned. I hit it with the impact wrench and the plug spun right out!
Your idea of keeping the engine warm is excellent advice.
I might try this test again with the block cold and turning up the impact wrench a little at a time just to find the breaking point of the glow plug then turn it back down somewhat when I attempt this on my car with the engine warm.