Glow Plugs - PeachParts Mercedes-Benz Forum

dieselmania · #1 09-30-2012, 06:34 PM

Pelican has Bosch glow plugs #000-159-83-01-M14 for a little over $10 each, are these the right ones for my 87 with the 603 engine?

Also, is there an o ring where the air horn connects on the pass side near the egr or do I just need the gasket where the air horn connects to the manifold?

toomany MBZ · #2 09-30-2012, 06:53 PM

I believe those are the correct glow plugs.

See attachment.

Jeremy5848 · #3 09-30-2012, 07:28 PM

Quote:

Originally Posted by dieselmania

Pelican has Bosch glow plugs #000-159-83-01-M14 for a little over $10 each, are these the right ones for my 87 with the 603 engine?

Also, is there an o ring where the air horn connects on the pass side near the egr or do I just need the gasket where the air horn connects to the manifold?

I'm not sure of your terminology but the crossover pipe from the turbo to the intake manifold has an aluminum connector (that plugs into it and into the EGR mount) with two expensive o-rings on the turbo side and a metalized composite gasket on the manifold side.

Jeremy

layback40 · #4 09-30-2012, 08:03 PM

Hmmmm,
The first GP thread of the season!!
Many more to come.
Hope the Pelican has good stocks of them !!

dieselmania · #5 09-30-2012, 10:30 PM

Quote:

Originally Posted by Jeremy5848

I'm not sure of your terminology but the crossover pipe from the turbo to the intake manifold has an aluminum connector (that plugs into it and into the EGR mount) with two expensive o-rings on the turbo side and a metalized composite gasket on the manifold side.

Jeremy

Yes I think that's it, pelican calls it the air horn, while the FSM calls it a charge air pipe and looks like here it is the crossover pipe. Anyway I didn't see the orings on Pelican.

vstech · #6 09-30-2012, 11:01 PM

I've serviced hundreds of these cars, and have yet to need to replace that o-ring. I usually replace the manifold side gasket, but it's often in perfectly serviceable condition...

jay_bob · #7 09-30-2012, 11:32 PM

I just started doing this on mine yesterday. It's a pretty big job.

You will need a LONG 6 mm hex wrench. Some of the 12 manifold to head bolts are child's play, others are nearly impossible.

I would recommend a 6 mm with a solid (not a ball) end to break torque on the bolts, then you can switch to a ball end to ease the bolts out. The worst is the lower bolt on #6, it is up tight against the firewall. It was necessary to remove some of the secondary covers in this area below the wiper to allow enough access to get to the bolt.

---deleted, you don't need to break the hard lines to get the manifold off. ----

While you are in there, change all the injection hard line clips. It will cost around $70 for the parts. These are not there for cosmetic reasons, unsecured hard lines are bad and the vibrations will cause the lines to fail.

Take lots of pictures (or have a friend take pictures, it's a dirty job) so you can see how all the bolts and brackets go back together. It's a huge Chinese puzzle.

Once you get the manifold off, you can start on the glow plugs.
Note that you have 6 open holes staring at you. There are obvious negative consequences if something goes into those holes so take precautions to prevent that from happening.

While the manifold is off you also have the decision to make about cleaning the grunge from the inside. You can thank the wonderful EGR for dumping all that nasty sticky black crud in there. Many threads about what to do about it. I recommend cleaning it if at all possible. Search also for EGR delete so you can avoid this in the future.

Now take loose the 6 harness nuts from the back of the glow plugs, then using a 12 mm deep socket work those babies out carefully. Slow and gentle are the key words here. Give the end of the ratchet handle a gentle hand blow or 2 to break torque.

To ream or not to ream. That is the question. Your choice. Many threads on this subject.

Coat the threads with anti-seize before reinstalling. Do not overtorque these, the plug body is stainless, and you are going into aluminum! Use a 1/4" drive socket wrench with a short handle, to help yourself avoid over torquing.

Hook up the electrical connections, baby torque here, it just has to stay securely hooked up...very easy to overtorque and strip out the insides. Pay close attention to the angle of the connector, if it is clocked wrong it will short against the manifold.

Once you have all the plugs in place go over to your GP relay and unplug the 6-pin plug and grab your meter and check resistance between the 6 pins and ground. Each pin should give you approximately 1 ohm to ground (this is the heater in each plug). Between any 2 pins you should have 2 ohms (2 heaters in series - out 1st wire, thru 1st plug, thru the head, back thru 2nd plug, back up 2nd wire).

(I'm at the hold point waiting for hard line clips and the little gasket between the crossover pipe and the manifold, this is as far as I got in one day.)

Now put your manifold back together.

After getting everything back together, do a final check on your harness, make sure the terminals are not touching something they are not supposed to and another ohm check isn't a bad idea. Don't forget to plug it back in!

---deleted, referred to purging hard lines, not necessary----

Not trying to scare you off but just a reality check so you can be prepared. Before taking the manifold off you want to make sure you have the new hard line clips, the intake and cross over pipe gasket, and the o-ring for the supply end of the cross over pipe. And of course the glow plugs.

On my 240D/OM616 it took me 30 minutes start to finish and it was super easy. Not so much on the 603.

vstech · #8 10-01-2012, 07:19 AM

... hard to believe some mechanics have successfully changed the plugs WITHOUT removing the manifold...

Jeremy5848 · #9 10-01-2012, 11:11 AM

Quote:

Originally Posted by vstech

... hard to believe some mechanics have successfully changed the plugs WITHOUT removing the manifold...

I've heard it is possible to remove glow plugs with the intake manifold in place, some a lot easier than others. Glow plug #1 is fairly easy, for example, and #6 perhaps the worst. It takes a good supply of 1/4 inch flexible extensions and you will learn some new words in the process.

Personally, I found OM603 intake manifold removal to be not that bad after the first learning experience. Once everything had been loosened up and replaced (with anti-seize) it came apart much easier on subsequent occasions. Ditto all of the hard line clamps and clips. Once they have been replaced with fresh ones they are less likely to break. You can remove the manifold with all of the lines undisturbed, you just have to remove the bolts that hold the clamps to the manifold.

I used biodiesel to clean the inside of the manifold and followed up with hot soapy water. Some folks send the manifold out to have it "hot tanked." As long as the solvent is safe for aluminum alloys that is OK. If the EGR valve is blocked or removed you'll have to do that job only once. Mother's Aluminum and Mag Wheel Cleaner (a white paste) works well for cleaning the outside of the manifold.

The two big green o-rings on the connector between the crossover pipe and the EGR mount generally do not wear out but they can be pinched and damaged if you're not careful with reassembly.

Jeremy

sixto · #10 10-01-2012, 12:18 PM

Do the injector lines have to come off separately from the manifold? IIRC I loosen the injector lines at both end and leave them attached to the manifold. No guessing how it goes back together.

I find there's reasonable access if you remove the cruise actuator even with the manifold in place.

Sixto
87 300D

jay_bob · #11 10-01-2012, 12:23 PM

That is one absolutely awesome looking engine, I hope I can get mine looking like that....
Anyway if you happen to have photos showing how the hard line clips are supposed to look, especially with the intake off, would you mind sharing?

PO used zip ties and whatever else to hold the lines, I want to do it right. The exploded view in EPC helps but some details are lacking.

Yes I see now that you don't have to pull the hard lines to remove the manifold. I think my problem is that the PO tied the hard lines off to the manifold so I thought it was needed.

So I will go back and revise post above.

Fulcrum525 · #12 10-01-2012, 12:35 PM

Quote:

Originally Posted by vstech

... hard to believe some mechanics have successfully changed the plugs WITHOUT removing the manifold...

With a twist socket and small hands it can be done. In fact I've replaced a number of glow plugs on my 603 and we have never taken anything out to do the job! (Having a 2nd person to hold open the throttle for clearance of the last two plugs helps.) For me its the 2nd and 3rd plug behind the IP that are the hardest to get to.

sixto · #13 10-01-2012, 02:36 PM

Let's see how far I can push Jeremy. These are pictures from a working engine, not a cat's heating pad:

Clamps for lines 1-3 on a bracket attached to the top side of the manifold. There are two 3-line clamps and a 2-line clamp into the bracket with a rubber pad between the lines and bracket. The 2-line clamp is in the shadow of the crossover pipe in this view -

Individual 2-line clamps for lines 4 through 6 into individual brackets on the top side of the manifold. I don't think it matters whether the lines go through the top or bottom hoop. There's a rubber pad between the line and bracket -

Standalone 3-line clamp where lines 1-3 come around the forward end of the intake manifold -

Standalone 2-line clamp for lines 4 and 5 over the IP and a 2-line clamp into a bracket (with rubber pad) also for lines 4 and 5 attached to the underside of the manifold -

2-line clamp into a bracket (with rubber pad) for line 6 attached to the underside of the manifold. It looks like there's a standalone 3 line clamp over the ALDA for lines 4-6. I don't know if that's standard. I might have used an extra clamp from the cars gone by.

Here's the shopping list -

A final note - despite all the clamps, lines 2 and 3 sometimes come in contact where they bend forward towards their injectors. I cut a split into a length of common vacuum tubing and slipped it over one of the lines to prevent contact. I don't know if this car has that band-aid or a previos 603. It certainly wasn't Jeremy's cat's heating pad.

Sixto
87 300D

Jeremy5848 · #14 10-01-2012, 02:39 PM

Quote:

Originally Posted by jay_bob

Anyway if you happen to have photos showing how the hard line clips are supposed to look, especially with the intake off, would you mind sharing?

Here are two pictures of hard lines off of the engine. Most/all of the clips are present. I'll look for more photos (no longer own that car). Also see the photos in post #9 of this thread:

http://www.peachparts.com/shopforum/diesel-discussion/258174-looking-mr-groundbar-w124.html

Jeremy

dieselmania · #15 10-01-2012, 11:48 PM

Wow thanks for all the detailed info! After 15 years GP#3 & 4 are failed. I had that intake off ten years ago but I don't remember why, could've been just to clean it, I remember I had it hot tanked at that time. The GPs were all ok at that time so I didn't mess with them.

This car is needing a lot of work and I am almost tempted to look for another one. The paint is the biggest issue, all the clear coat is flaking off. No dents or rust though. Also needs a rear window regulator, some upholstry work, IP re-seal, tires, and injector service. I put in a set of Bosch remans about 10 years ago and always had a slight miss at idle. They were not rebuilt by Bosch, I got them at a discount parts store for $50 ea. I am deciding whether to send them out to a local diesel shop or order Bosio tips and do it myself.