82 300d wont no start questions
 

Hello all. I replaced 4 of the 5 glowplugs but still have a very hard time starting the car in cold weather. Would the one " not changed " glow plug make a difference? The relay looks fine but I have a replacement that I will try tomorrow. The battery was new last year but is worn from having to crank, sometimes for minutes, before it will start. I have had the car plugged in for the past 4 hrs and am trying to jump it with my 7.3 diesel but it just cranks fast for a few seconds and then slows down. It seems to me it has to be the relay but I thought I would check here for other suggestions. Also, how long does it take the heater to warm up the engine enough to start it in cold weather? I wonder if I need a new block heater as well? Thanks. Oh yeah, it is my wife's car and she said that lately she has noticed it bogging down ( not enough power ) going up hills ( wot ) when the engine is cold. Maybe fuel filter? I need to learn more about this car. I also need a garage.

A few things:

1. Posting where you are and how cold it actually is, wouldn't hurt, in evaluating no-start problems (some areas are experiencing extreme temps). Also it would be helpful to know if the car starts okay down to a certain temperature.

2. You say the relay "looks okay". Is the glow light coming on on the dashboard? How many glow cycles do you do, before you try to start it?

3. I am guessing you didn't change the rearmost glowplug, as it is the most difficult. That alone should not produce a no-start problem.

4. Have the valves been adjusted recently? Correct valve adjustment is critical on these cars, for cold weather starts.

5. When you plug in the block heater, you should be able to hear a sizzling or crackling sound with 10 seconds as it starts to work. If you can't hear that, the heater probably needs to be replaced.

6. What oil is in the crankcase? If you are in an area experiencing severe cold, synthetic oil allows the motor to turn over much faster.

Have you checked out the glow plug electrics? Are the plugs getting 12 volts with the key in the glow position? Yes, one bad plug can stop the engine from starting in cold weather.
You can check the function of the block heater with a non-contact thermometer. You should be able to detect a warm block compared to the surrounding metal. Also, the temperature gauge should show warmth if the block heater has been on for more than a couple of hourse when you turn the key on.

I am in Northwest Michigan. It has been pretty cold lately ( 0 - 30ish ) but the symptoms started last winter and have gotten worse. I replaced all the glow plugs this fall ( with the exception of the rear most;) ) In the summer the starts were just okay and the car would vibrate a lot at idle. Before I changed the glowplugs, I did notice that the light was acting strange, sometimes on, sometimes no. Since I changed them, I comes on every cycle, for about 8 seconds. I picked up the car last year on trade and haven't had much time to get to know her. With 225000 and no known history, I would bet the valves need to be adjusted. I will listen for the crackle of the heater or maybe just feel the block when I go out next to try and start it. I have been using a 15/40 oil ( same as my truck ) either valvoline or rotella.


Thanks for the help. I got the car at 212000 last year and picked up a doner that I have used only for the alternator and calipers so far, I think:confused:. I love the car. I drove it down state for thanksgiving and got about 25mpg while doing 80ish. It has it quirks, but I just need to spend more time learning about it. I will post back after some more tests.

List of things I would do.

Valve adjustment
Fuel filters and primer pump(if old style)
Replace ALL glow plugs with Bosch plugs
Check battery cables
Have battery tested
Replace oil with synthetic
Replace starter motor

Your going to find out that the car has not seen normal maintenance for 20+ years and the no start problem is a combination of other neglected items. My no start problem was a combination of a weak starter, glow plugs and battery cables.

Not sure exactly why one bad glow plug will create a no start condition in cold weather but I've had it happen 3 times.
Waiting for the 8 seconds until the light goes out is inadequate in cold weather. The plugs keep glowing after the light is out. You should wait at least 20 seconds.

After 6 hrs of being plugged in, and while being " jumped " by a healthy 7.3, still nothing. I could let the glow plugs cycle for 10 or 20 or many cycles and it makes no differance. I think I need a relay and a battery for starts. There is about a foot of snow around the car that I would like to plow. In the morning, I think I will just pull it to a new spot until I can swap the relay. Would a good relay/plugs allow a cold start even if the block heater didn't work? To what temp? I am sure there are other varibales involved but I am done for the night. Thank you again for the help.:beerchug:

Have you confirmed that the relay is or isn't working? I wouldn't swap it out without some diagnostics. It could be simply a bad strip fuse.

I agree that it might be a bad strip fuse. Diesel Giant has a good write up on testing the glow plug system. Also, are you saying it cranks but will not start or is it not cranking? When you are jumping it are you only connecting to the battery or are you connecting the negative cable to the block?

You say in your SIG that you plan to put this car onto WVO... just to verify, you hadn't started running any vegoil through yet, right? If you have it changes some of the conversation.

From what you are saying, it sounds like it isn't even trying to start. Is that about it (doesn't try to fire at all)?

You have to look at the following:
- is it getting fuel?
- are the valves correctly adjusted?
- is the starter turning it fast enough?
- are the glowplugs heating?

You should be getting some puffs of whitish/greyish smoke out the tailpipe when you are cranking, and some odor of diesel. If you are, then at least you know fuel is present. If you aren't, try working the primer pump (and if you have a helper, ask them to pump it while you're cranking). If it feels like you're just pumping air (you should feel resistance when you pump, and hear a pfffft from the pressure release valve, after about 10 pumps if fuel is present) -- then you have a fuel gelling/freezing issue upstream. I had this happen this winter on my 300d, which usually starts like a champ in the cold.

If you are pumping air -- and assuming you have the newer-style black primer pump and not the old-style, white screw-in to lock type -- get hold of some Powerservice Diesel 911, dump some in and see if it helps. Change the fuel filters after you've let the 911 work. If the car still has the old style pump, change it. It may well be sucking in air.

Make sure all the clamps on the fuel lines are tight, including the very bottom one at the inlet to the lift pump (under the small filter).

Just to repeat what others said, check you have 12v on both sides of the strip fuse in the glow relay and at glowplugs. Make sure your battery posts and terminals are clean.

You ask if it will start without a block heater, that's a factor but not the critical one -- the valve adjustment is the biggest factor.

If you do doubt the block heater is working, put an incandescent trouble lamp or similar under the hood overnight. That generates a surprising amount of heat. You can also try a small fan space heater for a shorter time, maybe an hour, but if so don't leave it unattended.

I have some doubts that your block heater is working. After being plugged in for a few hours, you shouldn't even need glow plugs to start. Do a quick continuity check on it, if it's open, you know it's bad.

I also highly doubt your glow plugs are working. My '83 doesn't have one and starts fine on one glow cycle in single digit temperatures with a battery that isn't the best (four years old including one full year sitting in storage going nearly dead).

From the description it sounds like the battery is also weak. Charge and load test. Then check for voltage at the glow plugs.

And adjust your valves. I'm starting to think a valve adjustment should go on the list of things to do right away when you get one of these cars, kind of like changing the oil and checking the brakes. Speaking of changing the oil, 5W40 synthetic flows a lot better than 15W40 in cold temperatures. It's what I use.

Thanks for the replies. No veg oil yet. I am not sure where the primer is. The block heater is definitely not working but I am pretty sure the glow plugs are. I noticed that when I cycle the glowplugs it puts a load on my truck ( used for jumpstarting ). Are there any write ups on valve adjustment and heater replacement? Thanks again

Hunter went through the trouble to organize the DIY Links.
DIY Repair Links
http://www.peachparts.com/shopforum/forumdisplay.php?f=82
http://www.peachparts.com/Wikka/DoItYourSelf

first, I love the thread title:
Which of course means that it is starting.

Before we go any further, what has been done since yesterday?
Do you know when the last fuel filter change was? Were both replaced?
When was the last oil change?

To locate the primer pump, locate the hard fuel lines from the tank under the master cylinder. Note that these two lines are feed and return. The return line comes down from the top of the main filter. The other is the feed. This should have a hose attached that goes to a pre-filter with another hose to the lift pump.
If the lift pump has a white poker chip looking piece, that is the old style. If it looks like a black cap, this is the new pump.

I have the old style that you unscrew the white cap and then pull it out and use it as a pump. Do this to see what is going on with your fuel system. Also do this after changing your filters to prime the system.

If you are replacing filters, consider filling your main filter with injector cleaner or similar, then prime the system. Note the bolt on top of the main filter (22mm) has a crush washer. Replace it if you can, but not necessary. make sure it is clean and then make the bolt "good and tight".

another thing you can do is place a 250W halogen work lamp onto the hard injector lines with a drop cloth or similar over the engine to act as a blanket/insulator. Once the fuel lines are nice and warm the cylinder head may also be warm. This may take 2-4 hours.

In the coldest temps, the above heating trick has always gotten my benz to start. Note, your battery must be fully charged. All of this is a waste without a 100% fully charged battery. Test the voltage if you have to.

Best of luck.

Thanks for the help. I appreciate it.
Ha, ha. I hadn't noticed the title. Might have been a bit tipsy when I posted. Other then determining that the car draws power when the glow plugs are being cycled and that the engine block heater is not working, I haven't had much time to do anything else. I will try the light and blankett idea. I will also change the filters. Last oil change was not long ago. I am sure a new battery will be needed. I am also sure that if I could get it to start, and run it until it is all warmed up, I could shut it off and start it right back up while still warm. I should have some time this week to get things sorted out. I'll post as I make progress. Thanks again.

Best of luck.
What ever is going on, I am confident it is simple.

I got it started the other day using a battery charger that had a " jump start " option. I would guess the battery is bad because it does not have much power even after being charged. The car will run ok once it is warmed up and will fire up throughout the day as long as it doesn't sit to long. We had a odd day of 54 degrees out and it fired up then okay, with out any jump or charge. Back down in the teens now and I am sure it won't start.

update
 

I replaced the battery and it still won't start. When I cycle the glowplugs the volts on the battery drop from 12.96 to 11.80 or so. After the cycle, the relay clicks and the volts go back to 12.96. I can cycle them as 5 times and still no start. It doesn't seem to be cranking as fast as it used to. Any good tests for the starter? Any other suggestions? It is about 20 deg. out and the heater block does not work.
Thanks

Are you trying to start the engine after the relay kicks off or before the relay kicks off? It should be started while the relay is still on so the plugs are glowing when starting.

Have you confirmed fuel and compression and air?

Before the relay clicks off. Changed the fuel filter, when it cranks, it blows a bit of smoke, it just dons't seem to be cranking fast enough. Maybe all the attempts with the old battery have worn down the starter. Could something be stealing the power? Yesterday, when I tried to fire it up, it was cranking faster but I figured there might be a little air in the lines from the filter change. I charged the battery, but just doesn't seem to crank as fast.

Video linked here would quickly reveal if it's turning fast enough.

Did you mean to post a link? If so, I can not see it. Oh, I think you mean for me to post a video. Not an option at the moment.

lots to check...
 

ADJUST THE VALVES!
Ensure that battery cable terminals are CLEAN AND TIGHT.
Ensure the ground contacts are clean and tight.
Same with starter connections.
Possible worn, slow starter.
ALL these things add up.
Synthetic can also help.
After a couple of hours, with the block heater on, you can hear the "sizzle" of the heater in the block.

Good luck!
We have all been where you are, today.
spo:cool:

Yes, I meant for you to post a video. People with experience should be able to tell you in a few seconds if it's turning fast enough.

Thanks. I have yet to find a write up on a valve adjustment. I don't have any repair manuals so I will keep searching.
Thanks again

The first part of the winter my new to me 300D was a bear to start. I had one GP out and a battery that would only crank for 30 seconds. The new gp would allow it to start at 18°F but not at 8°F.

Installed a new 1000/850cca battery and have it smoke at 4°F the coldest that I have had since.

Since then I also ditched the summer oil going to Rotella 5w40.

It is funny starting at that temp. You do the glows as much as you want then start cranking but don't stop cranking till it is started. Sounds really weird, It picks up speed gradually if it were a gas engine you could hear it fire a bit then let off not so with the diesel.

Valve adjustment pictorial

Mercedes Diesel Valve Adjustment Procedure

Your starter may very well be bad thus killing the battery but I would first insure all glow plugs are working and Bosch brand, valve adjustment and the oil isn't thick. Fully charge the battery, glow the system 3 times....and crank if it won't fire.....get the starter replaced....also confirm that the battery cables are solid and not corroded.

Here is also the Diesel Giant GP check.

Mercedes Diesel Glow Plug Repair

Charlie

One more cold weather startup trick I have used--on my Ford 7.3 IDI (never the Mercedes), is to use a hot air gun ( or the wife's hair dryer) and blow hot air into the air intake for a few minutes. This warms the intake, and the warm air itself is easier to ignite than the cold air.

Thanks for all the help. I will report back after following your leads.

You need a multimeter to check for voltage at the glow plugs (free w/ coupon at HF). If you have low compression (worn rings or mis-adjusted valves), it can be impossible to start at very cold temperatures. It took us 30 min w/ "blow-dryer in intake", plus starter fluid to get one guys diesel truck started one winter at Lake Tahoe. Once running, open the oil filler plug (keep a rag to catch oil flings) and see if a lot of "blow by". That indicates bad rings (very expensive). One of my cars shows some puffing at the PCV exit, w/ oil filler closed, but still starts immediately on the coldest days, so some blow-by is acceptable. To change glow plugs easy, get a set of ratcheting box wrenches (Sears ~$35).

Its alive! It is a little warmer today, mid 30's or so. I ran a blow dryer into the intake for a while had my truck jumpered to the new battery and after probably 5 minutes of cranking, it finally came to life. I still don't know the problem, but will go down the list you all have recommended. Anybody know what the part # would be for the special wrench and spacer I need for the valve adjustment? I also found a d2 leak under the car as well as a small coolant leak. Sure wish I had a garage. In the picture, you can see all the soot that came out of the exhaust. It has always done that but not quite the amount you see in the pic. Is that normal?

Thanks