Fault finding a faulty 300tdi starter

[megz]

Hi guys

I’m having intermittent issues starting my defender. Ignition lights go on but nothing happens.

9 out of 10 times one little love tap on the starter motor solves the problem so I’m almost sure it is a sticky solenoid but wanted to throw it out there for others experience.

I’ve tried hooking up a multimeter but every time I do it starts fine so haven’t been able to rule out faulty electrics yet.

Anything else it could be? If it is the solenoid can the starter be pulled out and cleaned up or is it a replacement job?

Many thanks

Dave

[towe0609]

Might just be worth checking the wiring. I've had intermittent starting from a poor connection from the ignition wire at the starter. Its possible that the love taps are also (temporarily) resolving a connection issue on that circuit. It seems unlikely in this situation, but I've also experienced intermittent starting when the earth cable at the battery wasn't refitted properly by a 'storage guy'. I'm sure others with more experience will be along shortly with some other things to check before pulling the starter.

[350RRC]

Before you go too far, try swapping your cranking battery for another known good one and see what happens.

I've been caught twice with 'starter symptoms' with a supposedly good battery (showing 12.9 v +) and it turned out to be the battery.

DL

[BathurstTom]

Some common problems in a 300tdi in a Disco 1 (which may or may not translate to a Defender) are;
1. Solenoid - wear out and can be bought separately to the whole starter
2. Lose actuator wire from the ignition
3 Spyder alarm - I don't know if defenders have ever been fitted with these. Not all Disco 1's were. My '96 has one and is bypassed.
- The Definitive Alarm Spider Post - Land Rover Technical Archive - LR4x4 - The Land Rover Forum (https://forums.lr4x4.com/topic/86-the-definitive-alarm-spider-post/)
- https://www.gomog.com/allmorgan/LandRoverSecurityManual.pdf



I would suggest that you get somebody to turn the key while you have the actusator wire off and connected to a volt meter. If it is getting consistent feed that will rule that out. Probably pay to see if it is getting good (10-13) voltage while you're there.

[workingonit]

9 out of 10 times one little love tap on the starter motor solves the problem

Advice I've read is not to tap the starter body as there is a risk of loosening the magnets glued to the inside. Not sure if enough shock can transmit to the starter body if you are tapping the solenoid body.

Have several D1 Tdi300's. One vehicle had issues with the earth strap running from the bell housing to chassis - refresh the metal contacts. The second vehicle had an issue with the solenoid, not serviceable, which is annoying as my old Toyota solenoid is serviceable with the purchase of new contacts for a few dollars. The starter can be taken apart and the thrust components cleaned/lubed.

[trumpycam]

Had similar problem in my 81 RRC with 300tdi. Frustrated for nearly 12 mths, would be no problem for months then without warming would fail to start, but would start after a short time, seemed worse on hot days. Went through all possibilities relay starter etc.Problem ended up being the small wire to starter, ran a new one direct from relay to solinoid problem solved. Ended up costing a fair bit for a piece of wire and 2 connectors. Ended up with a lot of spare parts.

[rrturboD]

Starter solenoid is rebuildable....
Had a recent experience if intermittent starting, and sometimes staying on.
removed solenoid and polished sleeve and piston. All contacts etc were ok.
Now runs every time and shuts off when expected.

[megz]

Might just be worth checking the wiring. I've had intermittent starting from a poor connection from the ignition wire at the starter. Its possible that the love taps are also (temporarily) resolving a connection issue on that circuit. It seems unlikely in this situation, but I've also experienced intermittent starting when the earth cable at the battery wasn't refitted properly by a 'storage guy'. I'm sure others with more experience will be along shortly with some other things to check before pulling the starter.

Yeah I'll be checking the wiring next. Thanks for the heads-up.

[megz]

Before you go too far, try swapping your cranking battery for another known good one and see what happens.

I've been caught twice with 'starter symptoms' with a supposedly good battery (showing 12.9 v +) and it turned out to be the battery.

DL


Interesting. The battery always shows at least 12.3V but it is 5 years old so worth a look into.

[megz]

Some common problems in a 300tdi in a Disco 1 (which may or may not translate to a Defender) are;
1. Solenoid - wear out and can be bought separately to the whole starter
2. Lose actuator wire from the ignition
3 Spyder alarm - I don't know if defenders have ever been fitted with these. Not all Disco 1's were. My '96 has one and is bypassed.
- The Definitive Alarm Spider Post - Land Rover Technical Archive - LR4x4 - The Land Rover Forum (https://forums.lr4x4.com/topic/86-the-definitive-alarm-spider-post/)
- https://www.gomog.com/allmorgan/LandRoverSecurityManual.pdf



I would suggest that you get somebody to turn the key while you have the actusator wire off and connected to a volt meter. If it is getting consistent feed that will rule that out. Probably pay to see if it is getting good (10-13) voltage while you're there.


Thanks Tom. Solenoid is still seems likeliest and there's no alarms but I'll try the actuator/multimeter trick.

[megz]

Advice I've read is not to tap the starter body as there is a risk of loosening the magnets glued to the inside. Not sure if enough shock can transmit to the starter body if you are tapping the solenoid body.

Have several D1 Tdi300's. One vehicle had issues with the earth strap running from the bell housing to chassis - refresh the metal contacts. The second vehicle had an issue with the solenoid, not serviceable, which is annoying as my old Toyota solenoid is serviceable with the purchase of new contacts for a few dollars. The starter can be taken apart and the thrust components cleaned/lubed.

Unfortunately when the vehicle is not moving I've no option but to tap until I have more time to get in there properly. Good advice nonetheless.

Will check earth strap.

Pulling apart starter is further down the list but good to know it's an option.

Cheers

[megz]

Had similar problem in my 81 RRC with 300tdi. Frustrated for nearly 12 mths, would be no problem for months then without warming would fail to start, but would start after a short time, seemed worse on hot days. Went through all possibilities relay starter etc.Problem ended up being the small wire to starter, ran a new one direct from relay to solinoid problem solved. Ended up costing a fair bit for a piece of wire and 2 connectors. Ended up with a lot of spare parts.

Yes will definitely check the wire out. Also check the relay while i'm on it. Cheers

[workingonit]

Starter solenoid is rebuildable....
Had a recent experience if intermittent starting, and sometimes staying on.
removed solenoid and polished sleeve and piston. All contacts etc were ok.
Now runs every time and shuts off when expected.

Be interesting to know your brand. Mine are Bosch. I can pull the piston and clean the cylinder. But the contacts are enclosed inside a can that is crimped to non conductive plastic - you can't inspect or renew the contacts unless you risk destroying the enclosure. The old Toyota unit allowed you to access the contacts by undoing some small bolts that hold the can and its o-ring seal to the plastic body.

[rrturboD]

Think it was Bosch ... the piston had a scratch on it and the edges were slightly raised, hence the polishing. Contacts were a visual inspection, no heavy corrosion etc.

[johnp38]

Did I miss it or has nobody mentioned the brushes?

Almost always they wear down and not enough pressure on the armature and a tap lets them move and contact better.

[megz]

Did I miss it or has nobody mentioned the brushes?

Almost always they wear down and not enough pressure on the armature and a tap lets them move and contact better.

Could be that John. I'm going to pull the whole starter off and report back. Cheers

[d2dave]

I had a similar problem in my D1 300 tdi. Started off only on really hot days about once a year.

I would remove turbo hose and start it with a screw driver across solenoid.

As time went on (a few years) it started to become more frequent. So what I did was piggy backed the small wire to the starter solenoid.

I then ran the wire to near the battery with the end taped up. When it would not crank, I could then lift the bonnet and place wire on positive battery.

This also eliminated the starter motor/solenoid as being the problem.

Over time it got worse, to the point it was like yours, about one in ten it would not crank.

I just recently ran this wire to a starter button, which has solved my problem.

[megz]

​Hi all,

Thanks again for the comments and suggestions.

As a first measure I decided to pull off all the cables with the starter still in place and give everything a clean. The cables and nuts were spotless but I gave them a wire brushing anyway and put it all back together.

It has started without fail every time since (dozens of times).

I suspect the small white wire with the spade terminal might be the culprit. Maybe it wasn't sitting correctly or it has a bad solder and the act of pulling it off and on again was enough to settle it.

The love taps were probably just enough to make the connection too, hence why it would start most times after a tap.

Ot it could be nothing to do with the terminal and something else altogether!

Anyway, goes to show that the simplest approach is often the best to begin with.

Dave