270R Sigma Breakdown

[tjuniper]

Recently built a 270R with a Sigma 1.6 engine. Completed a 1000 miles but had a breakdown during the week. I'm ok with a spanner and instructions but this type of challenge is a little beyond me (currently). Symptoms - thought I could hear a slight rattling from the engine bay as I pulled away from a junction and then within a few hundred yards the car died. Lights went out, engine died and had smoke from the engine bay (alternator area). After recovery, have had a good look and can't find anything obviously wrong (no unattached wires, nothing loose, no obvious signs of burning etc.). Car won't start and just makes a fast clicking noise when trying to start. Only changes made recently include oil and oil filter change. A small amount of oil on the oil filter/cooler which is probably a result of not being able to tighten it enough (pig to get the old one off) but not at all clear how/if this might be related.

Battery has good power.

Any thoughts or suggestions very welcome.

[Jonathan Kay]

Do you have a multimeter? It's going to save a lot of time.

Jonathan

PS: Where are you?

[nigelpugh]

Sounds like something electrical Tom.

I would be looking for a short from the main high current +12VE out of the alternator to the starter motor.

When I built my Superlight Twenty back in March this year I was surprised that the cable at the back of the alternator does not seem to be protected by the rubber cap.

I modded mine to make sure it was not so exposed.

Other things to look for are battery and chassis earths, at the engine mount.

As you had recently done and oil and filter change, it could be that you disturbed the +ve cable from the alternator to the starter motor, but it might have been loose from the build and moving it during the oil change caused this issue.

Hope that helps.

Nigel.

[Ian Mackenzie]

Is the fast clicking when you are trying to turn the engine over, if so its the starter solenoid, is is due to a big drop in voltage from the starter, so much that it can't hold the solenoid open, then from there it then oscillates.

Reasons are - flat battery, or fault in starter....the re seems to be some relationship here between the alternator and battery.

i'd charge the battery and then it should start, then check the battery voltage with the engine off and with it running and post the results here.

cheers Ian

[DJ.]

As you had smoke, there will probably be a melted wire somewhere, and hopefully a fuse blown. Have a look at the fuses, if one has gone it will help indicate which circuit has shorted.

[tjuniper]

Thanks all - Sunday afternoon investigations will commence very soon voltmeter in hand. 

Jonathan - I'm based in Chelmsford Essex.

[Stridey]

I had a couple of sudden electric failures which I tracked, like Nigel, to the wires coming out of the alternator shorting.  I  wired in a cover plug that clips in. I can't understand why thus wasn't standard (maybe it is) as its prone to water down there.

my symptoms were. 'Pop' and an electrical smell, but no fuses blown. 

Hope it's that simple.

y

you can see it here under the clip it was designed for.

[tjuniper]

All wiring fine, no earthing issues and all fuses ok. Battery also v healthy.

Found this though.../sites/default/files/images/users/35777/small_image.jpeg

 

Some residue on the alternator. Assume this is from an issue with the alternator rather than just some residue from the belt????

[tjuniper]

[Stridey]

Could that be from a water leak /overflow above the alternator? I know when my thermostat housing cracked(xflow) it splattered water all down the passenger side of block and alternator.

[Jonathan Kay]

From where you've got to already here's what I'd do next. But you're quite likely to flatten the battery while sorting this out. Do you have a way of charging it eg mains charger, power pack, jumping to another battery?

1. Measure battery voltage at rest.
2. Check function of every circuit, except starting and charging, including brake lights.
3. Does ignition warning light come on?
4. Try to start: Any cranking? Still getting the clicking? What's the lowest battery voltage seen when you try?

There are multiple causes of clicking, as above plus tired wiring + duff relay etc. But with the answers to these it shouldn't be too hard to take the next steps in finding which it is.

Jonathan

[Garry7]

Still under warranty? Get CC to fix it before you spend good money on DIY.

[tjuniper]

Thanks all. Confirmed as an alternator failure. As mentioned above, the car is almost new so have agreed with Caterham that this is an item covered by warranty. That may change when they get their hands on it but so far I have a repair plan, couple of other small issues and a 1000m service booked with Caterham in a week or so time.

[Jonathan Kay]

Are you going to change the alternator before that service?

Still need to explain the clicking. Could be the battery not having enough oomph from the lack of charging by a duff alternator. After that's replaced I'd check the battery voltage at rest, during cranking and at 3,000 rpm as part of the acceptance of the work under warranty.

Jonathan

[revilla]

Jonathan,

The fast clicking will be due to poor battery performance.

What happens is that the battery is able to energise the starter solenoid, but as soon as the solenoid reaches the end of its travel the main starter motor winding is connected which causes the battery voltage to drop off rapidly to the point where the solenoid drops out again. Which disconnects the starter, allowing the battery voltage to rise again and energises the starter again .. ad infinitum. Well, ad ... battery flat.

In essence it is just a big low frequency electric bell or buzzer. Whereas in the traditional bell circuit, at full travel it disconnects the power, in this case it just shorts it out through the starter with much the same effect.

Andrew

[Jim 123]

Tom, not directly related,but in your original post you mentioned a little amount of oil that you noticed on the oil filter/oil cooler after a change, and you had some challenge to get the old filter off.

The trace of oil you noted could just be from the filter sealing ring if you lubricated it before refitting. But if you think the filter is not fully home, I'd not leave it for too long before sorting it.

I also wanted to suggest that for removal/refit of the Sigma oil filter it is pretty easy if you use a filter removal cup tool.  Many choices on Ebay.

[tjuniper]

Thanks Jim. A friend at work has loaned me an oil filter tool of the type you are suggesting so I'll have a go at making a better seal on that sometime this week. I did lubricate the seal before putting on but I'm obviously not quite strong enough without the correct kit - more gym work required.

Jonathan - to be honest I am trying to avoid having to change the alternator and hoping that the Caterham boys wll do this as they see the burnout on the alternator casing. It looks a pretty involved job and given this was all pre-assembled on the engine when I got the car I don't think it is related to anything I have done as part of the cars assembly. Clearly a warranty issue in my mind. Will take another look at the starter battery over the long weekend.

 

[tjuniper]

Car currently with Caterham - fuel pump and starter motor replaced so far (under warranty). Small issues of flash not working, fuel gauge not accurately reading all resolved but further investigation underway associated with a small misfire I have and what I originally thought was an alternator failure.

[tjuniper]

Thanks all for your help. I got the car back from Caterham today - issue was with the starter motor that they believe remained engaged as I was driving, causing a major failure as it burnt out. Drive back from Crawley to Chelmsford was a joy - loads of country roads and some great little villages and country pubs. Other small items all resolved and just the cost of the service. All other items covered under warranty with no quibbles.

Hoping the weather stays good for some late summer blast now I have my baby back.

[Grubbster]

issue was with the starter motor that they believe remained engaged as I was driving, causing a major failure as it burnt out.

Blimey I think this is what I suggested on Facebook (if that was you posting there). In the past there have been a few incidents of the ignition switch being wired incorrectly (my first car was such an example, I realised before driving it) that caused the starter to remain engaged during use!