Noob to noob advice - replacing glow plugs (1983 300d)

[Cinnamonandgravy]

First time I had to replace my glow plugs... 'Be a badass' I thought, 'dont need to remove no hard lines' I thought. I've got a ton of fancy wrenches with extensions and adapters and crap - probably fairly easy.

The job, I've read, takes ~approx 1 hour. Took me 4 hours.

So my noob advice: Remove the hard lines! (Esp if you're going to ream each chamber... Mine needed it badly)

2 or 3 glow plugs are kinda easy with the hard lines still in... The rest range from '@%^#$%^#%^' to 'I want to kill myself'. Save your hamstrings / lower back!

Lesson learned.

Ps if you let your injector fuel lines really deteriorate they'll often break off on the injector nozzle when you try to pull them off. Not fun either. You either have to gently wiggle them off with pliers or something, or just rip them apart around the nozzle (all without damaging the nozzle).

Vodka time

[vstech]

Originally Posted by Cinnamonandgravy

First time I had to replace my glow plugs... 'Be a badass' I thought, 'dont need to remove no hard lines' I thought. I've got a ton of fancy wrenches with extensions and adapters and crap - probably fairly easy.

The job, I've read, takes ~approx 1 hour. Took me 4 hours.

So my noob advice: Remove the hard lines! (Esp if you're going to ream each chamber... Mine needed it badly)

2 or 3 glow plugs are kinda easy with the hard lines still in... The rest range from '@%^#$%^#%^' to 'I want to kill myself'. Save your hamstrings / lower back!

Lesson learned.

Ps if you let your injector fuel lines really deteriorate they'll often break off on the injector nozzle when you try to pull them off. Not fun either. You either have to gently wiggle them off with pliers or something, or just rip them apart around the nozzle (all without damaging the nozzle).

Vodka time

what are you talking about? hard lines deteriorate? do you live in a corrosive environment? florida/beach, or MASSIVELY salted road area?

[Diesel911]

Originally Posted by Cinnamonandgravy

First time I had to replace my glow plugs... 'Be a badass' I thought, 'dont need to remove no hard lines' I thought. I've got a ton of fancy wrenches with extensions and adapters and crap - probably fairly easy.

The job, I've read, takes ~approx 1 hour. Took me 4 hours.

So my noob advice: Remove the hard lines! (Esp if you're going to ream each chamber... Mine needed it badly)

2 or 3 glow plugs are kinda easy with the hard lines still in... The rest range from '@%^#$%^#%^' to 'I want to kill myself'. Save your hamstrings / lower back!

Lesson learned.

Ps if you let your injector fuel lines really deteriorate they'll often break off on the injector nozzle when you try to pull them off. Not fun either. You either have to gently wiggle them off with pliers or something, or just rip them apart around the nozzle (all without damaging the nozzle).

Vodka time

When People are new to Diesels and they remove the Fuel Injection Hard Line they often do not realize the Air needs to be bled out of them and have ended up deadening the Battery trying to crank the Air out. So you did not have to deal with that.

You need to know this anyway if you ever run completely out of Fuel. To bleed the Air out of the Fuel Injection Hard Lines you screw the Fuel Injection Line Nuts at the Injectors down and crank the Engine till Fuel comes out of them. Tighten the Line Nuts at the Injector and attempt to start.

Repeat the above if it does not start in a reasonable time.
You can use the Hand Primer to get the Air out of the Fuel Supply System but that won't get the Air out of the Fuel Injection hard Lines.

Only Bosch or Beru Glow Plugs should be used. The tips on the Autolite Glow Plugs can swell up and you might not get them out easily.
Monark Glow Plug don't last long. I know because I tried both of the above.

When the Glow Plugs are there is a Tool to ream the Carbon out of the Holes' Glow Plug Reamer or there is alternative methods to clean the Carbon out of the Holes.

Cleaning the Carbon out helps the Plugs last longer and in colder areas People sometimes say cleaning the Carbon out helped them start easier.

Now on to the Valve Adjustment.
DIY Repair Links
http://www.peachparts.com/shopforum/forumdisplay.php?f=82
http://www.peachparts.com/Wikka/DoItYourSelf

[t walgamuth]

With the hard lines removed for me the total job on a 240 would be less than an hour I believe and for a five cylinder perhaps a little more than an hour.

[Cinnamonandgravy]

Originally Posted by vstech

what are you talking about? hard lines deteriorate? do you live in a corrosive environment? florida/beach, or MASSIVELY salted road area?

I probably misspoke; I meant the braided fuel lines which run from the primary fuel filter to all injectors. Mine were so old and steeped in diesel they disintegrated when I tried to pull them off.

You need to know this anyway if you ever run completely out of Fuel. To bleed the Air out of the Fuel Injection Hard Lines you screw the Fuel Injection Line Nuts at the Injectors down and crank the Engine till Fuel comes out of them. Tighten the Line Nuts at the Injector and attempt to start.

Repeat the above if it does not start in a reasonable time.
You can use the Hand Primer to get the Air out of the Fuel Supply System but that won't get the Air out of the Fuel Injection hard Lines.

Only Bosch or Beru Glow Plugs should be used. The tips on the Autolite Glow Plugs can swell up and you might not get them out easily.
Monark Glow Plug don't last long. I know because I tried both of the above.

When the Glow Plugs are there is a Tool to ream the Carbon out of the Holes' Glow Plug Reamer or there is alternative methods to clean the Carbon out of the Holes.

Regarding bleeding the hard lines, that's exactly what I've read. I don't exactly trust my fuel gauge (not sure the reserve light functions) so I always refuel around the 1/4 mark. Good info to know though.

I used bosch glow plugs. Found a seller on amazon selling 6 for $50.

I bought a reaming tool from **************.com for ~$40... Didn't love the price but it worked well (lots of carbon in each chamber).

In addition to the glow plugs and braided injector fuel lines, I also replaced the 'cigar' fuel return line (moderate cracks near the fuel filter) and the breather line (not sure what it's called - tube from the air filter to the top of the valve cover, since mine was cracked and leaking oil).

And definitely need to adjust the valves!

[Skippy]

You guys must have big hands or something. I can do all five in 30 minutes using nothing but 8 and 12 mm combo wrenches.

[toomany MBZ]

It is easier to remove the hard lines, but I don't bother anymore.

Those "jumper" lines, as I call 'em, the braided rubber ones, do deteriorate over time.

When installing new ones, I dip the ends in oil or trans fluid.

[funola]

Originally Posted by Skippy

You guys must have big hands or something. I can do all five in 30 minutes using nothing but 8 and 12 mm combo wrenches.

You must have skinny hands with looong fingers.

[Diesel911]

Originally Posted by Cinnamonandgravy

I probably misspoke; I meant the braided fuel lines which run from the primary fuel filter to all injectors. Mine were so old and steeped in diesel they disintegrated when I tried to pull them off.



Regarding bleeding the hard lines, that's exactly what I've read. I don't exactly trust my fuel gauge (not sure the reserve light functions) so I always refuel around the 1/4 mark. Good info to know though.

I used bosch glow plugs. Found a seller on amazon selling 6 for $50.

I bought a reaming tool from **************.com for ~$40... Didn't love the price but it worked well (lots of carbon in each chamber).

In addition to the glow plugs and braided injector fuel lines, I also replaced the 'cigar' fuel return line (moderate cracks near the fuel filter) and the breather line (not sure what it's called - tube from the air filter to the top of the valve cover, since mine was cracked and leaking oil).

And definitely need to adjust the valves!

When you first turn the Key on the Reserve Light comes on as do the other Warning Lights to check the Bulbs. But, that does not tell you if the Fuel Level Sending Unit is working properly.

After the Car gets out of warranty People who own the older Mercedes seem to loose interest in having the Valves Adjusted.

The next owner of the Car likely believes they have Hydraulic Lifters like Most Cars do and may not even know the Valves need to be adjusted.

[Cinnamonandgravy]

Originally Posted by Diesel911

When you first turn the Key on the Reserve Light comes on as do the other Warning Lights to check the Bulbs. But, that does not tell you if the Fuel Level Sending Unit is working.

Well my reserve light doesn't work then - never ever seen that sucker illuminate.

My fuel gauge can also be a bit sporadic, esp around the 1/4 mark and below (when below the 1/4 mark, the gauge occasionally swings very slowly between the empty and 1/4 mark). Minor issue though, taking care of the bigger things first.

[Cinnamonandgravy]

Originally Posted by funola

You must have skinny hands with looong fingers.

I have big palms with short stubby fingers... Probably the worst combo for this job.

[toomany MBZ]

You may be able to get your fuel gauge back by removing the sending unit, cleaning it, then reinstall.

You'll need a new gasket tho.

[funola]

Originally Posted by toomany MBZ

You may be able to get your fuel gauge back by removing the sending unit, cleaning it, then reinstall.

You'll need a new gasket tho.

It's a fat o-ring. I have always re-used the old one and never had a problem with leaks.

[funola]

Originally Posted by Cinnamonandgravy

I have big palms with short stubby fingers... Probably the worst combo for this job.

Put plenty PB Blaster on the 8 mm nuts and the glow plug threads. Support (hold) the wire lugs while undoing the 8 mm nut or the electrode may spin ruining the glow plug and make it difficult to remove. Break loose all glow plugs with a long 12 mm box then use a gear wrench to spin them off.

[toomany MBZ]

Originally Posted by funola

It's a fat o-ring. I have always re-used the old one and never had a problem with leaks.

Cool deal.