V6 running problems

[gonzohop]

Hi all

I've had a peruse through previous threads and I'm getting an idea of what the problem could be (distributor cap, HT leads etc) but I thought I'd post up the symptoms just in case there's something I've missed.

I've had the old girl for a couple of years now and never missed a beat. A few months back occasionally she would splutter for a mile or two, shuddering, not pulling, sounding like she's only running on a few cylinders rather than all of them. Then, with a bit of heat in the engine she would be as right as rain and then for the rest of the day.

About 2 months ago I was going for a longish drive when I hit a flood (not tremendously deep). The Bongo just stopped there and then and wouldn't budge. About 10 minutes passed and finally she's started, albeit reluctantly, and then spluttered for a mile or so. After that as good as gold. The next morning she really, really struggled to start but eventually got going with the usual spluttering, shuddering for a mile or two before getting back to normal. The next day though she point-blank refused to start. Not even a sniff. I got the AA to recover her to my local garage. They replaced the plugs (but not the caps) and all seemed well. I couldn't really believe it was that simple to be honest.

Anyway, a couple of weeks passed before the symptoms returned. And now it's pretty regular - every morning. Will start, shudder, splutter, virtually no power, sounding like only 2 or 3 cylinders are working. Curiously though if I run her for about a mile, switch off and leave her for about an hour before trying to start her again and then she'll run perfectly...

My local garage seems to think it's the distributor cap and rotor arm so I've gone ahead and ordered those. Could it be anything else? HT leads, plug caps?

Thanks in advance.

Richard

[Simon Jones]

I've just replaced: HT leads (all 7), cap, rotor arm & plugs & have yet to notice any difference, but at least I have piece of mind that they should be good for a number of years to come.

Several suggestions:

1) Rotor arm & cap as you've suggested will probably be a good start. Remove the cap & have a good clean round with meths or white spirit. Be careful with the rotor arm as it has a special rough coating on the outer end which looks like corrosion, but comes like that from the factory. If you have got water in the cap, consider getting a new rubber gasket part number JE2618V57 (under £9 from Mazda).

2) On the crankshaft pulley there is a metal ring with 6 lugs which pass the crankshaft position sensor which does clever stuff with the ECU. This is very exposed at the front of the engine & may be worth unplugging the lead & giving it a squirt of WD40 to displace any moisture.

3) When the engine is warm, switch off & unplug each HT lead from the engine. Check for condensation at the top or bottom of the rubber parts. I recently washed off my engine & it took a while to get all the moisture off the leads an from around the spark plugs. Again, squirt of WD40 may help.

Good luck

[g8dhe]

Also worth checking that the Spark Plugs themselves are tight, we had very similar problems during the summer and it was noticed that a couple of the spark plugs were only finger tight. Do note that the spark plugs have a crushable washer under them so don't undo them for no reason.

[BongoBonkers]

Hi

All the stuff with the distributor cap and leads, etc is definitely the way to go BUT we had similar issues and unfortunately changed all of the above before finally discovering that the fault was nothing to do with that: We have a long-running saga on our V6 of oil / water collecting in the plug holes. This causes misfires. Have you checked yours?

If you are getting this problem, let me know and I'll tell you the gory details of what's happened on ours.

Good luck

[haydn callow]

Examin the plug leads and plug lead caps very carefully........mine had burnt through on one plug cap....not easy to see if you do a quick check.......

[gonzohop]

Appreciate all the very helpful advice. I've ordered a new distributor cap and rotor arm as well as replacement HT leads and plug caps. While I'm replacing them I'll give the plugs a good inspection and see if there's any other tell-tale signs which have been suggested.

Thanks again everyone - I'll pop back with an update once I've done the above.

Richard

[Simon Jones]

As I was under the van anyway tonight, I've taken a picture of the crank position sensor. While it is in an exposed position at the front of the engine, there should be a plastic undertray which should keep the majority of the muck and spray away from it.

[cheffy34]

Hi all

I've had a peruse through previous threads and I'm getting an idea of what the problem could be (distributor cap, HT leads etc) but I thought I'd post up the symptoms just in case there's something I've missed.

I've had the old girl for a couple of years now and never missed a beat. A few months back occasionally she would splutter for a mile or two, shuddering, not pulling, sounding like she's only running on a few cylinders rather than all of them. Then, with a bit of heat in the engine she would be as right as rain and then for the rest of the day.

About 2 months ago I was going for a longish drive when I hit a flood (not tremendously deep). The Bongo just stopped there and then and wouldn't budge. About 10 minutes passed and finally she's started, albeit reluctantly, and then spluttered for a mile or so. After that as good as gold. The next morning she really, really struggled to start but eventually got going with the usual spluttering, shuddering for a mile or two before getting back to normal. The next day though she point-blank refused to start. Not even a sniff. I got the AA to recover her to my local garage. They replaced the plugs (but not the caps) and all seemed well. I couldn't really believe it was that simple to be honest.

Anyway, a couple of weeks passed before the symptoms returned. And now it's pretty regular - every morning. Will start, shudder, splutter, virtually no power, sounding like only 2 or 3 cylinders are working. Curiously though if I run her for about a mile, switch off and leave her for about an hour before trying to start her again and then she'll run perfectly...

My local garage seems to think it's the distributor cap and rotor arm so I've gone ahead and ordered those. Could it be anything else? HT leads, plug caps?

Thanks in advance.

Richard

Don't forget the cap O ring that makes a massive difference to water and damp ingress especially when you drive through allot of puddles at speed, condensation gathers in the bottom of the cap and kills cylinders 3 and five if i remember right

Dar

[cheffy34]

Hi

All the stuff with the distributor cap and leads, etc is definitely the way to go BUT we had similar issues and unfortunately changed all of the above before finally discovering that the fault was nothing to do with that: We have a long-running saga on our V6 of oil / water collecting in the plug holes. This causes misfires. Have you checked yours?

If you are getting this problem, let me know and I'll tell you the gory details of what's happened on ours.

Good luck

Plugs 1 and 2 on mine done it for years prob still does just haven't had a butchers for a while and it doesn't do the mileage it was doing 2 year ago, wet weather driving causes water to gather in front plugs as a rule no2 espec i found, i used to get oil in plug 1 every few thou mile so i ended up nipping the rocker cover down a 1/2 turn or so, the road i used to travel on for work always used to have alot of standing water in wet weather and no matter how carefull i drove i got damp probs, nothing a new O ring and a butchered 2 ltr icecream container didn't sort oh yeh and some gaffa tape plagued me for donkeys

fair weather camper vans dont get the thrashing my puppy mpv tinny used to get on a daily basis, now my wife just drives it to tesco's and through my garage door it is affectionately known as the pheonix in my family cause it has risen from the ashes a few times now

Dar

Ps TOP TIP

carry a small 1/4 ratchet etc with 8mm socket or a stubby posi drive screwdriver and some wd40 in your toolbag so you can do some roadside de damping

[gonzohop]

Thanks for all the great advice. Just waiting on parts now...

[gonzohop]

Ok, all sorted now - was the cap and rotor arm - particularly the arm - the contact was all but worn away. She's running beautifully again.

I'm going to replace all the HT leads and caps too next week, just for my peace of mind more than anything.

Thanks for your help everyone - have a great Xmas and New Year.

Richard

[Glenda]

Richard I found your thread whilst searching for sluggish V6. Mıne has had all the same symptoms
for a good few months now. I have dropped it in at Allan's (Allansvehicles)and he is looking at it for me.
I will report back on diagnosis as it seems to be a common V6 problem.

Checks Fuel Filter, HT Leads, Distribution Cap, Rotor Arm and possibly crankshaft position sensor.

Stuart

[Simon Jones]

Anyone tried checking / adjusting the timing? I followed the instructions in the engine manual, but the yellow paint on the pulley is quite faint & I could't get a reliable mark.

[mikeWalsall]

I don't have an V6 manual ... but I do have a good induction strobe, and did wonder if knocking the ignition back (retarding) a couple of degrees would be kinder to the engine with running LPG .. ??

A bit like they did a few years back when dis continuing four star petrol and introducing un leaded.. and the RAC .. AA .. etc: 'modding' cars on ASDA / Sainsburys car parks ..!!

[teenmal]

Anyone tried checking / adjusting the timing? I followed the instructions in the engine manual, but the yellow paint on the pulley is quite faint & I could't get a reliable mark.

Hi,clean the surfaces then tippex or chalk on new marks.