jamieh

Morning all,

Just the other day I started the car as usual:-

Ignition - wait for plug light to go out - turn engine - it starts (with a little relutance) and sounds like a box of rattling nials and the glow plug light comes back on for about 15/20 secs, then the car runs perfectly.

Persumably one of my Glowplug have failed. Will I do any damage running the car like this?

I have spoken to two Indys (good guys, know the car and engine) both have had 2 experiences with stuck plugs, and when this happens a head removal is required $$$$$$$$.

The car has 155,000 miles and had the plugs changed last @ about 80,000 miles.

Should i just bit the bullet and have all the plugs changed or just try to located the faulty plug and have that replaced.

Can anyone tell me how to check for a faulty plug?
I've been lead to beleive this can be done with a MultiMeter.

EdzBenz

I've changed the glow plugs on my 606. It takes time and patience as you do not want to rush this job. Rushing the job is what will cause cracked plugs and then the head needs to be removed.
There is a DIY link on www.peachparts.com that will show you how to change your glow plugs.
Forum members argue whether or not to change all of the plugs at once, or to just replace the faulty plug. I decided to replace all of my plugs because I didn't want to have to do this project for a while. The more "thrifty" members will only replace the one bad plug. I just don't have the time to waste on taking my engine apart. Plus buying a new intake manifold gasket each time isn't cheap.
I would definitely reccomend changing all of the plugs if you're not doing the work yourself.
There is an art to getting stuck plugs out of the engine without breaking them. Making sure the engine is warm, liquid wrench or another loosening fluid will help. Also, turning a stuck plug clockwise just a tiny bit before turning it counter clockwise can sometimes help it extract.
I don't know how to use a multimeter so I can't answer that question.

TMAllison

I would not replace all the plugs personally, not because of thrift, rather beacuse there is a greater chance of snapping one off. Why tempt fate replacing something that works?

Testing is simple. Go to dieselgiant.com and follow the tutorial there for testing GP's on the W123. Our relay is different but the testing principals are the same.

A good scanner will also tell you wants wrong. Code P1_365, 367 & 369 refer to cyls 1&2, 3&4 and 5&6. P380 means the relay is bad or someone turned the key before they were hot.

EdzBenz

Also, make sure you, or your mechanic, use the special glow plug reaming tool before installing the new plug.

jamieh

thanks for all the responces, its much appriciated.

I'll let you know how I get on.

jamieh

A couple of months ago I instructed my Indy to attempt to remove the bad Glowplug, knowing that they can break off (my Indy has plenty of experience with this engine).

Unfortunately it broke off after 1.5 hour of trying to remove, the element is still inside engine and offering sufficient seal to run engine.

So got the car back with just 5 plugs working.

Which, when it was cold would blow smoke out the exhaust for 15/20 secs then run fine.

And as the Air Temp increased (summer coming) it got easier and easier.

And for a few weeks now it just starts with no problem, You wouldn't know a plug is gone.

But a few days ago the Glow plug dash light stopped coming on for the 20 or so seconds after the engine started. (It still comes on to heat the remaining 5 plugs and then off before you turn the engine over).

Weird I can’t work out how if the plug for all intents and purposes is disconnected that the indicator is now not coming on to indicate a problem.

opinions welcome

NB:- Before the winter comes in I intend to advise my Indy to attempt removal of the remnants of the stuck plug and if that fails I’ll have the head taken off.

TMAllison

The wiring connected to the bad GP has probably come loose.

jamieh

Hi TMAllison,

If the wiring came loose would that not casue a fault in the system and cause the GlowPulg dash Indicate to light after starting. I was talking to my mechanic (I needed my fuel shut of value replaced) and said that when he tried to remove the plug perviously it snapped when turning but didn't break free so it may still be connected or have a bad connection.

Anyway not too worried about it, I'll probable need the head taken off to resolved so I'll wait till end of year for that.

Thanks for you feedback.

TMAllison

Before pulling the head, go to Peachparts.com and do an advanced search Kartek's posts on GP removal. Search NotFarNow also.

Both have taken the following procedure a bit further. http://sites.google.com/site/alanmcr...-mercedesom606

jamieh

I'll be sure to review the removal procedure before committing to the head removal

Thanks T Allison