The decline and fall of my glowplug? - PeachParts Mercedes-Benz Forum

#1 06-30-2003, 03:10 PM

Here's what happenned:

1.) As always, after a car wash, the glowplug light would not go out. I just waited a while and started the car.

2.) Then, all things were working properly for about a week.

3.) Then, when I turn the key and the glow plug light went on, a couple of times it was accompanied by a rapid ticking noise and a flickering of the tachometer needle. This happenned a few times, then went away on the next start.

4.) I was out of town for four days and returned. I had to move the car out of the garage, and when I went to start it, there was no glow plug light. I tried 3 times, still no light. It started with a few 2-3 second crank sessions.

5.) What's up? I smell my first big bill coming...

leathermang · #2 06-30-2003, 07:49 PM

Well, I don't know why someone that Does know about this has not answered yet... luck of the draw I guess..
It does not sound like the actual glowplug is what you are having problems with... this sounds like more of a relay or timing or sensing situation... but the point is that it has probably been explanined pretty good.... you probably ought to do a search and see what you can find while you wait for someone to speak up who instantly recognizes what your problem it.. We have a really good search engine....but this will put it back to the top ...

300SDog · #3 06-30-2003, 10:16 PM

Am in full agreement with Leatherman.... its gotta be one of millions of relays to be found on newer cars less than 20 yrs old.

Nobody will reply because post '83 electronic, engine management technology is sacred science beyond normal human comprehension..... and nobody sane would fiddle with existing electronic relay systems in their own backyard.

Is it glow plugs failing from wacky relay network- or just the dashboard light??

If it was me I'd soak the car at wash, causing this problem to occur.... then pull one glow plug and dangle it to see if it heats up.

psfred · #4 06-30-2003, 10:44 PM

Water in the wiring caused the tach flicker, I'd bet.

The lack of a glow plug light means you have iether a burned out dash bulb or several bad glow plugs. This can mean bad wire or connections, too, by the way, the sensor reads current draw.

Take the wires off the glowplugs and check the resistance to the block of each -- they should be 0.8 ohm or close. If one shows open or zero, replace them all, they aren't that expensive and are easy to replace. You can also pull the plug on the relay and test from there, too.

If they are all nominally good, check to see that the relay clicks when you turn on the key and that you have voltage (usually 11 V or so) at the glow plugs. Check them all, and if they all don't, it's relay time. If some do and some don't, the wires are bad (not very common).

If you have one GP out, the light either comes on and blinks after you start, or stays off until you start, then blinks. More than two, and it usually doesn't come on at all.

Peter

#5 07-01-2003, 11:05 AM

Washing a modern car at a modern car wash makes about as much sense to me as hosing down my computer. I wash my car with a wet towel in one hand and a dry one in the other. Takes about 12 minutes and I have a hand-dryed car at the end. If this is luddite, so be it....

P.E.Haiges · #6 07-01-2003, 08:06 PM

Orkrist,

And if one of the light bulbs in your car burns out, replace them all because PSFRED says you should. Get my point?

You might have a bad connection between the GP relay and the connectors. Pull them off and put back on about 10 times. This will clean off some of the corrosion on the connectors that might be causing your problem.

I don't see much of a repair cost coming. Most would be if you had to replace the GP relay.

P E H

psfred · #7 07-01-2003, 09:07 PM

PEH:

I replace my GPs in sets because I've found that if one is bad, the others look nasty, too, and it's not enough fun to replace them one at a time.

Besides, if you drive a Volvo, you learn to replace bulbs in sets, too, or that d....d lamp out warning light keeps coming on!

Peter

P.E.Haiges · #8 07-02-2003, 01:11 AM

Peter,

How about sending all those old GP you replace to me? I could recycle them and get thousands of miles of use out of them.

I also can't figure how it is easier to replace an entire set of GP compared to replacing one. Seems like if replacing one GP takes X minutes, replacing 5 GP would take 5X minutes.

Never owned a Volvo, Never will. Especially after I saw the stupid design of the Diesel engine they put in them.

P E H

300SDog · #9 07-02-2003, 09:28 AM

What's wrong with Volvos?

Lots of people drive Volvos..... you see them travelling under 60mph in the fast lane, backing into traffic on busy streets and blocking lanes in the wrong direction at parking lots.

Volvo has justifiably earned the reputation as very safe car - for people who dont like to drive.

Mordecai · #10 07-02-2003, 01:27 PM

Quote:

Originally posted by 240DieselDog
Lots of people drive Volvos..... you see them travelling under 60mph in the fast lane, backing into traffic on busy streets and blocking lanes in the wrong direction at parking lots.

The problem with Volvos is the folks that drive them always seem to be so serious. I think of them as the Metamucil for lunch bunch.

M.

psfred · #11 07-02-2003, 07:42 PM

PEH:

You have a use for burned out glow plugs? having glow plugs burn out one at a time over a couple months is a PITA, especially on the Volvo, they are hard to get at. By the way, before you trash that D24T, get you hands on a manual tranny 740 TD -- 0-60 in 8.4 sec, quite a ride!

Dieseldog:

Obviously, you've not driven a 740/760 turbo gasser. My brother-in-law was complaining about the lack of performance after I replaced the head a couple years ago (blown upper radiator nipple, just like on the Benz plastic rad), I thought is was pretty fast myself. Turned out the temp sensor for the FI was bad, I couldn't get a replacement in time to put it in for him before they went back to Fl.

With the multilink rear end I'd put them up with a W124 -- similar performance, similar ride, better seats.

Most people who buy them don't drive them very hard, though.....

Peter

P.E.Haiges · #12 07-02-2003, 10:22 PM

PSFRED,

I've been driving MB Diesels for 35 years and about 500,000 miles. In that time I had about less than 10 GP go bad. So if I replaced all the GP when one went bad, I would have bought about 45 GP instead of 10 for a difference of 35. At ~$10 each, it would have cost me about $350 more if I replaced all instead of the one that was bad. You may say $350 isn't much, but would you throw $350 out the window? With taxes, that's $500+ in new earned money.

Notice that this is an average of one bad GP every 3.5 years and every 50,000 miles. For something that is not a show stopper and easy to replace, I'm not going to replace a GP until it fails.

I'm not interested in how fast a car goes 0 to 60 MPH, I'm more interested in how fast it goes 0 to 500,000 miles.

As far as the used GP, I was talking about sending the 4 or 5 good ones you replace each time when only one was bad.

P E H

psfred · #13 07-02-2003, 10:58 PM

PEH:

Does a hole in the end count as bad? Hehe -- this was on the Volvo, Champion GPs, bad mistake, they burned out pretty quick. Bad relay that stayed on all the time didn't help, I'm sure.

I currently have 220,000 miles on my 740 TD, but I've been told they usually run 300,000 or so before the compression goes. Subject to aluminum head problems (and I'm afraid mine is gone, won't start at the moment, quit this winter at 4F).

Peter

coachgeo · #14 07-02-2003, 11:25 PM

I actually have a use for these pulled GP's that are not burned out.

I could distribute them to those experementing with Vegetable oil as a diesel replacement.

Please... if ya got any send them my way. I certainly would appreciate and so would the other experementing in this area.

Thanx
George

300SDog · #15 07-03-2003, 06:03 AM

Sorry Peter, no offense intended at jabbing Volvos as "very safe cars for people who dont like to drive".... but this is image they project, and the way many of them are driven.

In similar fashion, am constantly poking BMW owners with the comment "BMW builds better motorcycles than they do cars."

Btw, am in full agreement with you about changing all glow plugs together..... comparable to changing all the bypass fuel lines if one starts leaking - preventive maintenance.