Hello all,

I recently undertook the dreaded glow plug change on the w210 turbo diesel. As you can guess by the thread title, things did not go so well. A brief run though is five of them came out with no issue at all, but the sixth was stuck and is now spinning freely in the engine head. I took it to the local mechanic in Colorado Springs, Salim's auto shop. Gus and his crew came to the conclusion that the best route for this would be a new cylinder head. They are renowned for doing good work, and I trust the opinion that they offer in regards to what needs to be done.

So now we are both searching for cylinder heads for a 1998 E300 Turbo Diesel. My question for all of you is:
- Does anyone have a cylinder head for a '98 they would sell?
- What else should I have replaced while the cylinder head is off? (the car has 200k miles on it, and besides a rough cold start in the mornings that was contributed to faulty glow plugs, the engine seems fine)

Thanks a lot for your help/advice/hopefully parts I will keep the thread updated as things are completed and resolved on this car.

Cheers,

John

I sure would look at saving that cylinder head and a lot of cash if it was my car. Seems to me like that glow plug could be removed with the head removed and then use a Timesert/helicoil? If you think you're going to lose the head anyway, you could also try to drill the glow plug out depending on which one it is and how accessible it might be. I drilled one of mine out in place and all has been well for eight years.

__________________
Len
'59 220S Cabriolet-SOLD and living happily in Malta
'83 240D 351,500 miles original owner-SOLD
'88 560SL 41,000 miles - totaled and parted out
https://sites.google.com/site/mercedesstuff/home
'99 E300 turbo 227,500 miles
'03 SLK320 40,000 miles - gave to my daughter
'14 Smart electric coupe 28,500 miles
'14 Smart electric cabriolet 28,500 miles
'15 Smart electric coupe 28,000 miles

I would not be so quick to give up on the head either.

I would try another machine shop. They can be drilled out successfully especially if the machine shop has the right equipment. It's a little dicey doing it with a hand drill but with a drill press it ought to be a piece of cake.

I would have them check the condition of the valve train, it would be worthwhile to have the valves redone while you have the head off.

__________________
The OM 642/722.9 powered family
Still going strong
2014 ML350 Bluetec (wife's DD)
2013 E350 Bluetec (my DD)

both my kids cars went to junkyard in 2023
2008 ML320 CDI (Older son’s DD) fatal transmission failure, water soaked/fried rear SAM, numerous other issues, just too far gone to save (165k miles)
2008 E320 Bluetec (Younger son's DD) injector failed open and diluted oil with diesel, spun main bearings (240k miles)

1998 E300DT sold to TimFreeh
1987 300TD sold to vstech

Advising that a spinning glow plug is grounds for replacing the head makes me question their renown. If the head has to come off, might as well fix it. Have the valve guides checked. While everything's apart, consider whether you want to keep EGR active. State inspection requirements might trump your conscience. If you decide to disable EGR, this takes some research rather than just a capping a vacuum line, have the manifold and related airways cleaned.

Corona's Auto Parts in Hartford, CT has a head off a 99 E300. Check car-part.com .

Sixto
87 300D

"Spinning freely in the head" .....could you provide a little more information. Is the glow plug broken in half, leaving the heating element in the head, or are the threads free of the head, but the plug will not come out? When I did mine, two were free of the threads, but still stuck in the head, being held by built up carbon. Used plenty of PB Blaster and Freeze Off, and after two days both came out in one piece.

__________________
96 E300d

I haven't had a chance to talk with Gus, the mechanic, since his recommendation. He was going to run some prices and give me a quote, probably Thursday. As far as what the glow plug is doing, the threads did not come out at all. The plug sits as if it were still set in the head, and is just spinning freely clockwise and counter-clockwise when force from a socket is applied.

I did find it a little strange that the shop did not even mention the possibility of drilling out the glow plug, and jumped immediately to a new cylinder head. Either way, the car does have 200k miles so I would like to try to fix a few things inside such as having the valves redone as recommended by most of you.

I did get in touch with the individual in CT about the cylinder head (thank you sixto) and I would be able to have it shipped to Colorado Springs for ~600. I'll keep you all updated as things happen, and thanks again for all of your help.

It sounds to me like the glow plug body has snapped off the threads and is spinning around. I would try to extract it and use an easy-out to remove the threaded barrel from the head. Its probably just carbon deposits preventing the GP from being pulled out. Perhaps a bit of compression (with the piston helping) will pop that thing out; just don't stand in the way.

__________________

'98 E300 DT
'87 190D 2.5 turbo RIP
'92 S500 Sold
'03 3.2TL-S A-Spec

Sure sounds to me like a boat payment is coming due.

__________________
Len
'59 220S Cabriolet-SOLD and living happily in Malta
'83 240D 351,500 miles original owner-SOLD
'88 560SL 41,000 miles - totaled and parted out
https://sites.google.com/site/mercedesstuff/home
'99 E300 turbo 227,500 miles
'03 SLK320 40,000 miles - gave to my daughter
'14 Smart electric coupe 28,500 miles
'14 Smart electric cabriolet 28,500 miles
'15 Smart electric coupe 28,000 miles

Had the same "broken, spinning" plug plus one I tried to drill and screwed up on our '98. Pulled the head, machine shop fixed both and did a valve job. Good for another 200,000 + and cheaper than replacing the head. (FYI, machine shop welded the "spinning plug", heated the head in a shop oven, and the stuck plug turned out easily. Head was really hot..not just warm!)

...and just as Pimpernell mentioned...using lots of PB Blaster and taking lots of time is the way to go. It took me 3 days to get two out of a friend's '99, working with the engine hot and turning maybe 1/8 rotation back and forth for the first two days. Learned my lesson on our car!

Too late here but for those who encounter a stuck but not yet broken plug... take your time, soak it, heat it, walk away when the urge to apply more force strikes you... Repeat for a few days if needed. Once I got them past the threads they were still stuck. I started the engine (make sure there's nothing loose to get sucked into the intake ports!!) and the compression blew both plugs out immediately.

I fastened a 1/4" drill to the glow plug and spun it in reveres.
The thread was just clear of the bore. It sounded like hell and got hot but after a couple of minutes out she came. I grabbed the plug and fried my fingers. Note to self. Never grab antthing that is smoking.
After removing blow all the dust out of the pre com chamber. I used a 1/8" copper tube fastened to my air gunand inserted right into the chamber. Air in dust out. I was hoping this would blow the dust out instead of into the engine ,seemed to work.

__________________
1984 300SD turbo 126
"My true love"

God made me an atheist and who am I to question His wisdom

Thanks for the advice all, I'm having the head removed Monday and will be taking it to a machine shop. There they are going to try and remove it, hopefully getting that done and costing a lot less than the price of a new head. Also, is there anything else I should have the machine shop do to the head while it's in there?

Hopefully I'll have my car back before Christmas, and I'm never trying to take the glow plugs out again!!

While the shop has the head, have them check the condition of the valve train (valve guides and seals). It is very easy (and incrementally expensive) to go ahead and have those refreshed while the head is off.

Once you get your car back together, use anti-seize paste on the GP threads, and plan to change them proactively every 50 k miles, and you should not have a problem in the future.

__________________
The OM 642/722.9 powered family
Still going strong
2014 ML350 Bluetec (wife's DD)
2013 E350 Bluetec (my DD)

both my kids cars went to junkyard in 2023
2008 ML320 CDI (Older son’s DD) fatal transmission failure, water soaked/fried rear SAM, numerous other issues, just too far gone to save (165k miles)
2008 E320 Bluetec (Younger son's DD) injector failed open and diluted oil with diesel, spun main bearings (240k miles)

1998 E300DT sold to TimFreeh
1987 300TD sold to vstech

Agreed, check the valve seats, especially #6.

__________________
-Evan


Benz Fleet:
1968 UNIMOG 404.114
1998 E300
2008 E63


Non-Benz Fleet:
1992 Aerostar
1993 MR2
2000 F250

An update to the situation: I returned from the holiday break to hopefully find my car working. The head hasn't come off, and the mechanic is trying to spin it free. Unfortunately for me, I don't have time to wait for it to come out, and the shop doesn't want to take the head off due to a lack of knowledge on the subject. It looks like it is off to the dealership for me, at least Mercedes tows it there for free :/.