Two of my glow plugs test bad (with an ohmeter) and I have ordered the glow plug reamer. As soon as the reamer gets here, I want to do the job. However, I get conflicting advice with the search. One school of though says remove the hard (metal) fuel injector lines for easier access. Another school of though says drive the car hard and stop and unscrew a glow plug fast while everthing is still hot. Are these both equally accepted schools? Also, I read a couple of horror storries about having to drill glow plugs out of 603 heads. How likely is it that I will have trouble getting the glow plugs out? Should I soak them in penetrating oil the night prior?

TIA.

On the 617, it takes about 10 minutes to remove the hard fuel lines. This is certainly preferable to do rather than attempt to work underneath them. Access to the glow plugs is much faster and easier without those lines in place. If you are using the reamer, it makes no sense to leave the lines in.

You probably won't have any problems getting the plugs out of a 617. The struggles that you have read about in the archives concern the OM 606 engine.

You don't need to run the engine and stop it to remove the glow plugs. You'd burn yourself on the engine if you tried to do this. Just work on it cold. The plugs will come out. The use of a ratcheting box wrench will greatly shorten the time required. Some of the plugs are inaccessible with a socket (#3, #4, and #5). Without a ratcheting box wrench, you are forced to use a standard box wrench (or open end wrench) which takes forever.

Be careful with the small nuts that hold the wires in place. If you drop them, they will fall into no man's land. Retrieval from no man's land is not possible without a special retrieval tool (small retractable claw).

hurt to soak them prior.

for myself, i always take the hard lines off to do it. it makes the glows an easy task to do and removing the hard lines and replacing them prob only takes ten to fifteen minutes. more than that is saved i believe. also the chances of damaging a plug or wire is much less with them off. i do have fairly big hands. if yours are small you might find it less of a need.

good luck

tom w

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

One more question, do I need to replace any parts when I put the hard lines back on?

No, Just make sure no dirt/debris gets on the threads or in the lines.
Be sure you have a good battery or a charger or a second car to jump the battery. It takes some cranking for the fuel to fill the lines.

You will only need to replace parts if you cross thread the hard lines.

Be very careful and start the nuts by hand for one full turn.

If the nut won't go by hand, force the hard line to line up with the injector or the delivery valve thread (on the IP) so that you are positive that you have it started.

If you use a wrench and strip it (easy to do), then you will be replacing parts.

hand primer to fill your lines. look at your manual for how to use it. if it leaks it prob will still work but should be replaced as it can cause mysterious fuel issues.

tom w

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Just wanted to let you guys know that the job went flawlessly.

However, I have a couple of hints:

1. Disconnect the 13mm bolt that holds the glow plug wiring harness down before attempting to remove the first glow plug. This is the bolt that goes in the bracket that is almost above the glow plug closest to the radiator (#1?).

2. Have very small channel locks on hand BEFORE you start the job, in case the inside of the glow plug turns when you try to disconnect the electical connector. This way you can hold the inside of the glow plug and get that 8mm nut off.

3. Listen to Brian Carlton and buy a 12mm ratcheting box end wrench (I got mine for Sears).

4. (not really a hint) but it is #4, not #5 that is the hardest.

Thanks Again Guys!

EDIT/PS- I used a glow plug reamer (with grease) then turned the car over a few times with the glow plugs out to try to "puff" any remaining carbon out. I was glad I had the reamer on hand as all five plugs/prechambers had a noticable amount. When I "puffed" the carbon out I just unplugged the glow plug wiring harness to make sure than the harness didn't short to ground and blow the 80A fluse.

What he said......accurate decription of this job.

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Proud owner of ....
1971 280SE W108
1979 300SD W116
1983 300D W123
1975 Ironhead Sportster chopper
1987 GMC 3/4 ton 4X4 Diesel
1989 Honda Civic (Heavily modified)
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Section 609 MVAC Certified
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