Cleaning very dirty engine in 300D
 

Engine is having trouble starting cold and the glow plug light is not lighting. I have tested the plugs with a multimeter, some seem ok, some questionable, but I am unconvinced of the accuracy of these results; the internal resistance of the multimeter itself is at least .6 ohms, and that jumps a lot, so I don't trust it. But I'm rambling..

I want to pull the plugs so I can apply voltage to them and test visually, but when I put my hand anywhere near my engine, I'm covered in grease from head to toe. I want to degrease the engine and glow plugs a bit before I try to get the plugs out. I've read to take precautions like cover transmission vent and electronics, make sure engine isn't hot when washing, and check vac lines afterwards, but is it ok to spray degreaser/water directly on the plugs and wires around them?

I recommend putting kerosene in a hand pump spray bottle and soak it. Keep doing it for a few days, then rinse off with a garden hose. All that engine degreasing products are made of is basically kerosene in a can anyway, and anything fuel resistant is kerosene resistant anyway, since kerosene is #1 diesel fuel.

I use the de grease mode at the car wash and have never covered anything and never had a problem. I wouldnt spray cold water on the IP after driving hard on the freeway or spray water directely on the alternator but its not like the problem assocated with hosing down a gasser.

Pardon my ignorance, but what does IP stand for. Ignition ___ ?

Injector pump

Just an fyi I tested all the glow plugs on my SD when I first got it, they all tested fine. But when hooking them up to a battery only two actually glowed red.

All five were replaced and it started a lot better.

To clean your engine start with Gunk and a couple of brush's. You will need a few large ones and a few about the size of a tooth brush. Keep working it and re spraying the Gunk.

After you get 95% of the crud go back with Simple Green over everything. Get some Q tips and start working on the details.:D

Yes I am nuts but you can eat off my engine.

Step two is sealing the oil leaks that made the mess.

What Hatty said:D You are going to need some brushes long handle and scrub to do a good job (don't borrow the wifes:( ) go to the dollar store and buy a bag of them. Caution with power washers - this has only happened once but I must have drenched something causing my parking light to come on. I had to disconnect the bulbs until everything dried out.

I've heard that this happens, that's why I want to test them visually. On a side note, is there any reason I can't use a pair of jumper cables on the car's battery to test each plug?

From the posts I've read, it seems the safest option is to take the time to scrub manually instead of spraying off with the hose. I can see this taking a really long time/lots of brushes. I may just do the plugs and surrounding area for now.

I've done that and it seems to work well. Just stand away from the battery and hold the GP in the negative jumper cable by the the threaded part. Just touch the positive cable to the contact and verify the GP turns bright yellow within about 5 seconds. Don't touch.:eek:

If I'm not back sometime next week, you can assume I've electrocuted myself and decided to let someone else handle my car issues from now on. :cool:

It's not that bad. The hardest part is taking them out and getting your hands dirty. I do mine without removing the fuel injection lines, but it's a tight fit. Some folks find it easier to remove the fuel lines. Try not to drop the wrench and/or nuts behind the injection pump, its a PITA to get them out.

I would definitely clean the engine first, I hate working on dirty engines.

testing glow plugs
 

I use an old Marquette avr tester to test glowplugs. you can find these things cheap at garage sales and junk stores. I just hook it in series with the glow plug and the positive battery post. set meter to amps and I find the glow plugs spike to about 20 amps and slowly drop off. The good thing about testing this way is you can prove the things work. Heating elements take more current when they are cold and quickly build resisitance when they heat up. The last time I had a starting problem it happened intermittently. turns out the #5 glow plug would only fail sometimes. The ammeter was the tool that isolated the problem. Cheap autolight glow plugs

But testing with the meter doesn't always seem to work. I had glow plugs that tested fine yet failed to actually get very hot when hooked to a battery.

WARNING if you do this hold the glow plug with a pair of pliers. If not you will burn yourself pretty bad.

So far I am 2/2 I have two MB diesels and both needed a complete set of glow plugs.

"To clean your engine start with Gunk and a couple of brush's. You will need a few large ones and a few about the size of a tooth brush. Keep working it and re spraying the Gunk."

I started with a puddy knife to get the big stuff off:rolleyes:

Well I guess it depends on how dirty your engine is!:D I just had lots of dirt on mine no oil leaks really...