Glow plug removal question
 

Hello,

I'm removing the glow plugs on my 1999 e300. I have all out and new ones in except the number 1. It is making a squeeking sound when I try to remove it, and is hard to turn. Any suggestions? I don't want to break this plug off. I have sprayed the plug with PB blaster and it is setting now. I was thinking of starting the engine and warming it up. Would that make the removal easier? Thanks for any help

I had this happen on all of my glow plugs on my 240D last month. I replaced all four on a cold engine. Using the PB Blaster will loosen them for you just let them sit for a half hour or so. All four of mine squeaked and were tight, sounds pretty normal to me.

Do searches for "210 glow plug" and "606 glow plug" before you break anything, but it looks like you may have already done the search.

Starting the engine and warming it up may indeed help loosen that plug. If you ensure that nothing will can sucked into the ports, you can run the engine without the intake in place. It may throw a code, but that shouldn't be a problem once you get it back together and reset the code. But before you install the other five plugs, be sure to ream the holes with the proper tool and use anti-seize compound on the threaded portion of the new plugs.

Working the plug gently back and forth may help you get it out. Be very careful to not put too much torque on it. The figure of 45NM comes to mind, but I'm not sure that this is correct.

I agree with what Matt said except it doesnt yet sound like it is broken?

Additonally, after warming up using a "Freeze" product immediately afterward might also help. Concept is to shrink the plug after the heat expands the cyl head.

Another member did failure analysis on old Beru plugs and found in the vise they all snapped between 80-90NMs. 45nm's sounds reasonable to me for removal torque.

There is a point where you may need to grab it with vise grips and worry it back and forth to free it up. Sounds like it is held by carbon buildup now.

Sorry about that. I was unclear in the original post.

plug removal
 

On my car ...
I aquired an older pointer type torque wrench.
Spray the area with pb blaster or Kroil ....let it soak. Then while backing out do not go over 45 foot lbs.....if you have a small 3/8 drive impact wrench you can use that to help loosen the plug between the manual wrenching. 85 foot lbs is the shear point on the plug If I recall.
Be real carefull. take your time......Back and forth motion may cause it to break off...
When there all out I used a brass Pipe cleaning brush to clean out the holes beyond the threads while using a shop vac to suck out the soot....You can determin the depth by looking at the lenhth of the plug..There is a reaming tool available however I had great success with a drill bit and the pipe brush....
Warming the engine seems to make it tighter...Of course you cant run the engine when the intake is on the bench...

606 GPs
 

I'd go to the store and get a 3lb block of "Dry Ice" ,break it into smaller pieces
and use those to cool the "HEAD" around the GP(Shrink It)
AFTER 1st applying Kroil or SiliKroil to the GP and letting it sit OverNight.

That would be backwards. You want to head to expand and then to freeze the GP so that it contracts and becomes smaller/loser.

The rapid thermal change from hot to cold may also help loosen any carbon keeping the GP from turning freely.

Were the Glow Plug holes reamed to clean out the carbon buildup before the new Glow Plugs were put in?
The Glow Plugs stick due to Carbon build up trapping the tip, the threads being seized or a both problems at the same time.

Rather than use PB, you might want to try using GM Rust Penetrant and Inhibitor, Heat Valve Lubricant. An old GM diesel mechanic turned me on to it, and it actually softens carbon deposits. It also eats paint, so be careful using it! Just spray it on and let it soak, just like any other penetrant. You can only buy it at a GM dealer- part # 1052627 for a 10.8 oz. can. It costs around $9.00 for a can- expensive, but it works. It also works for lubricating the wastegate shaft on a turbo.

All of mine squeaked like that as they came out - it is caused by carbon which is tightly packed around the tip. I'd try loosening it after warming the engine with the torque wrench and using PB and even the freeze stuff too on the plug. The hot head and cold plug might just be all it needs to loosen enough to come out without squeaking. I bet you will get it out without breaking. Once they turn they generally do come out. Once out it will be necessary to ream out the holes before putting new ones in.

On my car, five out of the six plugs squeaked when being removed. As other posters have said, it is the carbon holding the tip of the plug that causes that noise. Like you, I used PB blaster, and another product called Freeze-Off, that most auto supply stores carry. I would spray the plug with Freeze-Off, which lowers the temperature, and then spray it immediately with PB Blaster. As another poster mentioned, use a torque wrench and try to stay within the 45-50 N/M area when applying force. I also used a long 6 sided socket, and would "pull" meaning applying outward pressure while turning the plug. Take your time, use plenty of spray, and it will come out...Good luck.

When you install the new Glow Plugs use one of the Never-Seeze type products on the Glow Plug Threads.

Oops
 

While changing a glow plug on my 240D I broke the terminal off the wire that connect to the glow plug ! Any specs on what it is or can I just buy one at a regular auto store or even a home depot type of store. I guess thinking it is high current scares me.

My .02 - When I changed mine, this is probably the advice from others that helped me the most. Since I didn't know the glow plug history of my car, I allocated a good 2-3 days for the project. I used lots of PB blaster, lots of working the plugs back and forth, more PB blaster and lots of patience. A couple of plugs were right down scary to turn, I thought they were going to snap for sure, but they came out. A couple of the plugs went the distance (to the 3rd day), although they were fully unthreaded, the tip had lots of carbon and wouldn't let go. With time and patience, the PB blaster dissolved the carbon and the plugs slipped right out with minimum effort.
On the new plugs, I used an anti-seize compound not just on the thread, but halfway on the body of the plug (not the heating element). I'll find out in a couple of years if this helped any...