Bongo Fury

My garage (not Bongo specialists) suggested changing the distributor cap and the rotor arm as part of a service. But what is a rotor arm? Anyone got any opinion about when these need doing? Hopefully I will have acquired enough Bongo wisdom in the not-too-distant future to be able to return the favour of sharing something of use to someone. In the meantime, many thanks once again for any info. Clara.

The rotor arm is inside the distributor cap and carries the HT current to the plugs, via the HT leads.
What engine have you got - 2.5 V6 or 2 litre 4 pot?

Hi Clara.

You obviously have a petrol Bongo?! (If not, the garage is really trying it on... )

The distributor is the device which sends (distributes...) the ignition spark to each spark plug in turn. The 'cap' is literally that - a cap which sits on top and has all the ignition leads coming from it and going to the spark plugs. The rotor arm sits inside the cap and rotates - when it is adjacent to each ignition lead terminal, a spark jumps from it to the terminal and hence to the ignition leads and spark plugs.

It all has to handle many 1,000s of volts, and the parts do erode with the sparks over time. The parts to suffer from this erosion are, indeed, the rotor arm and cap.

If they have never been replaced - fair chance - then they will be well overdue. If left, it will lead to misfiring and possibly even failure to start.

Sounds like a perfectly valid suggestion by the garage. If you are at all suspicious, then ask to keep the old ones for a second opinion.

Do you know if they suggested this after looking at the old one? It would be a bit of an presumptuous to just guess it needs doing - after all, you could have replaced the parts a year ago!

They could certainly do with replacing after, say, 10 years or 60k-odd miles.

Apole and cheffy34 both replaced theirs and commented on how pitted the old ones looked and how much better their V6 ran once new stuff was fitted. Is yours running better?

Hi, I recently replaced mine on a V6 petrol and yes it starts and runs much better as a result.

I would recommend the garage take a quick look, doesn't take long to take the cap off and see what state it's in beforehand.

They are quite pricey mind, and will take a few days to arrive as Mazda are unlikely to have any in stock in the UK. So I'd recommend they take a look first.

BTW the rotor arm surface is supposed to be pitted, the new one was the same, didn't realise that beforehand.

Woops - should read posts more carefully - thought you'd had them changed already

As Apole says etc.......

Bizarre, I don't know where the 'petrol eng' bit of the heading came from? It's a diesel engine. Thanks to everyone for your helpful advice. Both myself and the garage were just trying to get everything ready, so that when they took ol'Bongo in, everthing was there for what needed doing. But it doesn't quite work like that, I suppose. Cheers for all replies.

Hi Clara.

ONLY petrol engines have distributor caps!!

The garage presumably didn't know yours was a diesel and were just trying to plan ahead (I'm being charitable here!)

So, you DON'T need one!

(The nearest equivalent - tho' quite different - item in the diesel are the 'glow plugs' which pre-heat the combustion chamber before 'cold' starts. You'll know if one of them has failed as the Bongo will become more stubborn to start in colder weather, and may run roughly for a short while after starting. Subsequent 'warm' starts should be ok.)

Ooooooh, my head is starting to throb. Rewind Bo Selecta

Clara wrote:Bizarre, I don't know where the 'petrol eng' bit of the heading came from?

I put it there to help people with assisting you. ONLY petrol engines have distributor caps and rotor arms.
Petrol bit now removed

Oops - I'm guilty too in my first post...

Trouble at t'Mill wrote:Oops - I'm guilty too in my first post...

As Sherlock Holmes would say "Elementary Mr. TATM" - let's hope the garage hadn't seen the Bongo when they made their comments

Well I'll let you know how we get on! Fingers crossed, and hope to be in tip-top condition for the new season. Many thanks one and all. Clara