300 TDI Intermittent No Start

Dfunder90

Active member
I have a 1996 D110 300 TDI that’s new to me since May. The vehicle is from Spain. I’m having issues with intermittent non starting. I initially thought it was a dead battery, but the battery was replaced prior to shipping to the US and tested excellent at the auto parts store. The starter was also replaced in Europe. I’ve had starter failure in my D90 300 TDI and the click on turn over was much louder when it wouldn’t start. Most of the time the car won’t start when I attempt to crank it. There is a click (but not very loud) after turning the key and the engine doesn’t turn over. After multiple tries the engine sometimes turns over and the car will start. I’ve checked connections on the battery, connections on the starter and the battery voltage.
Any thoughts and help would be greatly appreciated. I have a video but don’t think that I can upload here.
Thanks in advance.
 

Napalm00

Technical Excellence Contributor
I'm pretty sure that year actually has the starter relay. Haven't checked the wiring diagram.
 

javelinadave

Administrator
Staff member
That or a really intermittent engine ground, battery ground or a bad positive cable.
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Dfunder90

Active member
Outstanding! I will check all of these out! I guess that relay is something that can be ordered if bad? My father in law understands electrics much better than I and will be helping me work through the wiring diagram. When turning over the key to position 2, the flow plug, battery and oil lights come on and the battery voltage gauge.
 

javelinadave

Administrator
Staff member
When turning over the key to position 2, the flow plug, battery and oil lights come on and the battery voltage gauge.
Those are all low currant draw items compared to the starter. You can test the poor grounding theory by hooking up one end of a jumper cable to the engine block and the other to the negative post on your battery. Is it starts right up then you have your question answered.

2 things you can't have enough of in life are cowbell and grounds
 

Dfunder90

Active member
Seems like this was the issue! Ground was very dirty; covered in greasy mud. I took it off, cleaned the connections and surrounding area up nicely and after several test starts the truck starts up nice. I will give it a few days of consistent starting to call it a success. Really appreciate all the knowledge and help from you guys!
 

Dfunder90

Active member
Bit of a snag. I just went out to give a test start and back to intermittent starting, though not nearly as bad as before. It has a new starter. I've checked the connections which look clean and tight. I guess will have to check everything again and may have a dud starter?
 

JimC

Super Moderator
Staff member
When you say you cleaned the starter connections, did you do them all, even the small lead? I had a crummy no-start problem that was actually corrosion and a loose connector at that location. fixed it three times before I got it good and solid.
 

jymmiejamz

Founding Member
Callsign: KN4JHI
The easiest way to see if it’s a ground issue, without using a volt meter, is to take a normal jumper cable and go from the negative battery terminal to the block.

FWIW, I had corrosion at the starter positive cable on my D90 preventing it from starting.
 

Dfunder90

Active member
I didn't do the little slide on connector to the alternator. I have some electric cleaner that I will spray on there tomorrow and make sure everything is tight again. I have a new starter on order and will try to switch the starter to another one later this week if cleaning up all the connections doesn't help. It's hard to nail down the exact cause, because it is now much more intermittent which makes me think there is a bad ground or connection somewhere. The wiring diagram has an immobilizer noted. I don't have a key fob, so from what I can tell that would mean the immobilizer has been bypassed at some point?
 

expanse

Well-known member
Before you swap parts out, take a few minutes and bypass the trucks wiring and manually trigger the starter. this will give you a good insight into where the issue(s) lie. I use a basic switch (or probe) and connect it between the starter trigger post and battery. pull the fuel solenoid wire off and trigger it for a few seconds.

my bet is the grounds look the part but are junk. you could skip the above and just slap a new fat ground wire between bell housing stud and the frame and see if your issues go away.
 

Dfunder90

Active member
Did you check the relay ?
Switched out for relay for the relay beside it and still same issue. Cleaned and lightly sanded the ground to bell housing stud connection to get as much dirt and grease off as possible. Sprayed it with electrical connection cleaner too. Battery and connections to battery are brand new. It’s only had trouble starting one session out of the last 10 times that I’ve started it. When it wouldn’t start on that one session I had to turn it over about 5 times before it would crank. Give the same click sound when fails but doesn’t turn over.
 

1of40

Well-known member
As you described, when it starts and doesn’t start and sometimes starts and clicks and sometimes clicks and then clicks sometimes and the battery is new when you ship it I think it’s done.
 
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