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  #1  
Old 04-20-2010, 11:40 AM
1984 Federal 300D Turbo
 
Join Date: Sep 2009
Location: Portland, OR
Posts: 59
Trouble Starting... Starter Relay?

Alright, so I have a 1984 300D Turbo. It starts intermittently and I have already replaced the battery and alternator (they needed to be replaced anyways). Here are the symptoms:

When the car DOES start, everything seems to be fine. The starter engages, the engine cranks, etc. When the car DOESNT start the key goes in and turns fine, but the glow plug light doesn't come on. The car won't even begin to crank. It acts as though the battery is totally dead.

I've noticed that getting a jump start actually helps, which is weird because it's a brand new battery. Generally, the jump start has worked every time until this last one. Now the starter engages but sounds strange when cranking (it cranks really fast) and the car doesn't start.

What should be my next steps of things to diagnose? Here is the list I've come up with by reading the forums here:

-Neutral Safety Switch
-Draw on the battery
-Connections to starter
-Starter Relay
-Starter itself

Anything else it could possibly be? Also, how do I test the starter relay?

Thanks,
Brendan

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  #2  
Old 04-20-2010, 11:46 AM
vstech's Avatar
DD MOD, HVAC,MCP,Mac,GMAC
 
Join Date: Mar 2006
Location: Mount Holly, NC
Posts: 26,832
check your cables, and the battery itself. new does not equal good.
test it to be sure.
it could be many many things, but starter solenoid would be last on my list to check with the symptoms you list.
my list would be
1 battery connections
2 battery itself
3 connections to body/engine and ground strap.
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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!
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  #3  
Old 04-20-2010, 12:02 PM
1984 Federal 300D Turbo
 
Join Date: Sep 2009
Location: Portland, OR
Posts: 59
Sorry, forgot to mention that I've already tested the new battery so we can rule that out.
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  #4  
Old 04-20-2010, 12:02 PM
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Join Date: Jun 2004
Location: West of Ft. Worth. TX
Posts: 4,186
Ditto, especially the chassis-engine ground strap (there is only one). Mine was loose at the engine and caused very intermittent problems.
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84 300SD 350K+ miles ( Blue Belle )
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  #5  
Old 04-20-2010, 12:30 PM
1984 Federal 300D Turbo
 
Join Date: Sep 2009
Location: Portland, OR
Posts: 59
That's on the drivers side correct?
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  #6  
Old 04-20-2010, 03:57 PM
Diesel911's Avatar
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Location: Long Beach,CA
Posts: 50,968
Quote:
Originally Posted by Silver_300D View Post
That's on the drivers side correct?
If you are in the US; under the Car near where the Trans connects to the Engine.
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  #7  
Old 04-20-2010, 04:10 PM
Diesel911's Avatar
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Quote:
Originally Posted by Silver_300D View Post
Alright, so I have a 1984 300D Turbo. It starts intermittently and I have already replaced the battery and alternator (they needed to be replaced anyways). Here are the symptoms:

When the car DOES start, everything seems to be fine. The starter engages, the engine cranks, etc. When the car DOESNT start the key goes in and turns fine, but the glow plug light doesn't come on. The car won't even begin to crank. It acts as though the battery is totally dead.

I've noticed that getting a jump start actually helps, which is weird because it's a brand new battery. Generally, the jump start has worked every time until this last one. Now the starter engages but sounds strange when cranking (it cranks really fast) and the car doesn't start.

What should be my next steps of things to diagnose? Here is the list I've come up with by reading the forums here:

-Neutral Safety Switch
-Draw on the battery
-Connections to starter
-Starter Relay
-Starter itself

Anything else it could possibly be? Also, how do I test the starter relay?

Thanks,
Brendan
Bunch of thoughts:
Jumping the Battery from a running Car increases the available Voltage and the available Amperage. If there is some sort of electrical contact point as in your Starter Solenoid (has 2) or in the Neutral Safety Switch or even the Ignition Switch the higher Voltage and Amperage could burn through the oxide coating on the contacts exposing some fresh metal and allowing it to work temporally.

If the Starter is actually moving the Neutral Safety Switch must be working at least at that particular time.

In the below problems the Engine would not turn when the Starter is going:
The Starter Solenoid is not moving the Starter Gear Far enough to engage the Ring Gear. The only noise you might here is that Starter spinning.
If there is a loud metal to metal sound the Starter Gear is trying to engage the Ring Gear but the Ring Gear Teeth could be buggerd up and not allowing the Gear to engage the Ring Gear.
(When the Starter Gear engages a good part of the Ring Gear you might get an normal start.)
When this happen on other Cars I was able to get in there with a File or later a Grinder and grind off the burrs/ mashed over metal and that restored it; but I have not done this on a Mercedes.

The Overrunning Clutch on the Starter Gear is no good. The Starter Gear would move out and engage the Ring Gear but the Gear itself would not turn as it is not attached to the Starter Shaft due to the mechanism inside of the Overrunning Clutch being no good.
This might also make a little noise but not as loud as the paragraph above.
above.

The lack of a Glow Plug light when you turn the key to the #1 position could indicate a bad Bulb or and Ignition Switch problem.
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Last edited by Diesel911; 04-20-2010 at 04:26 PM.
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  #8  
Old 04-20-2010, 11:38 PM
Registered User
 
Join Date: May 2007
Location: Out in the Boonies of Hot, Dry, Dusty, Windy Nevada
Posts: 9,649
Iam thinking you have a ground problem. as said above, check the ground strap body to engine. remove it, clean and tighten it back down.

there is a little black plastic junction box on the passenger inner fender next to the battery. open the lid, there are 3 screws with wires to and from the battery/starter etc...
short across 2 and the engine should turn over. I have used this when my NSS was causing me troubles.

How are the shifter bushings? is they are sloppy from wear will not let the shifter lever make contact in the NSS.
Charlie
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there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

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  #9  
Old 05-11-2010, 11:48 AM
1984 Federal 300D Turbo
 
Join Date: Sep 2009
Location: Portland, OR
Posts: 59
Alright, an update. The car has been sitting for a little bit (couple weeks). I went back out to try and start it. The starter is trying to engage but is making a strange sound. It almost sounds like it's cranking really fast. Anyways, I tried putting the car in neutral and it didn't make any difference.

I'm pretty sure the starter is shot. I'm assuming the reason it's cranking so fast is that the starter gear isn't engaging the ring gear (like Diesel911 predicted). If it were the neutral safety switch or a ground problem, then the starter would be getting any power.

Does this sound correct? Let me know if I've overlooked anything. I don't want to buy a new starter unless I know it's the problem.
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  #10  
Old 05-11-2010, 11:56 AM
vstech's Avatar
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Location: Mount Holly, NC
Posts: 26,832
that sound is the motor engaging, but no bendix applying.
so the motor is just spinning.
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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!
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  #11  
Old 05-11-2010, 12:06 PM
1984 Federal 300D Turbo
 
Join Date: Sep 2009
Location: Portland, OR
Posts: 59
Yeah, makes sense. I'll probably just buy a new starter instead of trying to repair it.
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  #12  
Old 05-11-2010, 12:22 PM
vstech's Avatar
DD MOD, HVAC,MCP,Mac,GMAC
 
Join Date: Mar 2006
Location: Mount Holly, NC
Posts: 26,832
no, it sounds like you could pull your starter, and clean it up and regrease it, and you'd be fine.
pull the solenoid out, and reverse the contact bolts, and you'll be ahead of the game.
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  #13  
Old 05-11-2010, 01:51 PM
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Location: Middle TN
Posts: 4,154
Start by measuring battery voltage across the posts. It should be 12.6 if fully charged. No sense guessing. How much does it drop when key is turned to start? Now measure the voltage at the small terminal at the starter. It should be 0 until the key is turned to start. Then it should be full battery voltage, solenoid should trip and the starter should crank the engine at normal full speed.

My SD has a junction block on the passenger's side engine compartment. Make sure those terminals are clean if your car has similar set up.
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  #14  
Old 05-11-2010, 02:25 PM
compress ignite's Avatar
Drone aspiring to Serfdom
 
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X2 for vstech's suggestions

No Reason to spend all that money on a "New" (Reman) Starter
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  #15  
Old 05-20-2010, 04:01 PM
1984 Federal 300D Turbo
 
Join Date: Sep 2009
Location: Portland, OR
Posts: 59
Alright, another update. I checked the voltage of the battery and it read 12.4, probably a little low from me trying to crank it so many times. I replaced the starter and now the starter wont even crank. I double checked the wiring to it. I checked the battery and main grounds. I tried jumping the neutral safety switch and still nothing. What else could it be? Starter relay? If so, is there a way to test it? Any help would be greatly appreciated. I'm going crazy trying everything with no success.

Thanks,
Brendan

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