juddering!!

[Alex86]

hi just got my bongo 2 weeks ago, soon after.... disaster!!!!! cooling system went!! now a lot of pennies later its fixed i'm happy again!! but on start up it judders a bit but after about 30 seconds it stops. (it was doing this before aswel) Is this normal??


Cheers Alex

[Mike Jill and Emily]

Hi Alex,

Can't help with this one other than to say mine does the same thing Do you get white smoke too that stops when the juddering does?

I am sure that someone knows where to point you (and me ) to on this one

Mike

[dandywarhol]

Get the glow plugs checked out.

[missfixit70]

How long are you leaving it after turning the key before starting? If you are leaving it until the light goes out, give it another 10 seconds, could be the glow plugs as dandy says. Are you using veg oil at all?

[Alex86]

HI all, i always start just after glow plug light goes out! Yes there is white smoke, what is that? i haven't used veg oil yet but i am considering trying it out i didn't realise how much diesel it uses! my partners car is a 1.9tdi beetle 130bhp goes like s**t of a shovel!! and uses half the diesel!! anyway i'm not complaining i've got a bongo!!!!!!!!

[Rhod]

I've a similar problem, but no solution yet! Most of the time it's ok, but sometimes if left standing for a week then the engine will fire up ok (leaving starting until glowplug relay has clicked off), but then after idling for a few minutes she'll start juddering, refuse to pull away & then die amid small clouds of whiteish blue smoke. After leaving it for a couple of minutes she'll start & run fine - although the starter needs to be churned a bit. I haven't changed the glowplugs yet, since the problem seemed to rectify itself. It also seems to coincide with low battery voltage - voltage monitor plugged into the cigarette lighter shows around 11.5V after a week, which is about 0.5V below the actual voltage measured at the battery. The main battery is only 65AH, so I intend changing this to see if that makes any difference, since it doesn't seem to be holding charge as well as I'd have expected (rear internal lighting runs directly from the Mazda kitchen unit, with isolating switch, so that can't account for a drain). Alternator output is fine & voltage shows at 14-15V when under way.

I don't know my way around diesels so it's a lot of "suck it & see". I can't quite work out why either a dying glow plug or a weak battery would start the engine ok initially, & then let it die, but the let it start up again perfectly afterwards. Any possible explainations from the gurus?

[dandywarhol]

I wouldn't wait til the relay has clicked off Rhod because it it will probably stay off and thats why is starts to chug in cold weather. If you wait 5 seconds max (even though the glowplug warning light goes off on the dash) the relay will stay on for as long as the temperature controlled timer wants it to sty on for.

Alternatively, fit a switch in series with the timer and turn the plugs off manually as I have done. That should extend the plug life somewhat.

[Rhod]

Dandy - If I'm following you then I think that you're suggesting that the glowplug ciruit is switching off while the engine is still idling & because the engine isn't up to temperature it's spluttering & dying?

I thought that the Bongos glowplug relay continually switched the plugs on & off until the engine was up to temperature (& that's why you hear the relay clicking in & out below about 40mph when cold)? I assumed that the relay circuit working in this way would keep things running at idle until the engine was up to temp. I was working on the assumption that the warning light is just a reminder that you need to wait for the plugs to warm up, but doesn't relate to the actual time they need to heat the system up?

A thought just occurs to me.... I can hear the glowplug relay clicking in on start-up & clicking on & off at low speed, but haven't been aware of it at idle (must try listening more carefully). If the relay was sticking intermittently after start-up then I'm guessing that that could result in the symptoms of the engine firing up ok, but then dying with syptoms of glow-plug failure, but starting ok again after a another couple of trys (when relay decides to work normally) Or is my logic & diagnostic mind as lacking as usual

I really don't know my way around diesel systems, but glowplug failure doesn't seem to quite explain the intermittent nature of my starting fault .

Rhod

[mikeonb4c]

I believe that model engine glo-plugs can oil up if the engine cools too much on prolonged tickover. When that happens and the throttle is opened, the quenching effect of cold fuel / air entering the chamber weakens the glow still further and the engine misfires due to erratic burning of the fuel charge. Similarly, a glo-plug model engine can be hard to start if the battery lacks enough power to make the coil glow brightly.

I do wonder if your Bongo is showing similar symptoms. A 65Ah battery is really a bit small for a Bongo and I could imagine, if it were not in tiptop condition, it might not heat the plugs that well. The fact that Bongo plugs are kept on by the system during running suggests that they need to be kept glowing nicely until the engine is warm enough to ensure the fuel/air charge entering is kept warm enough by engine heat. And of course, the plugs themselves could be out of condition.

The above may be a load of tosh (no doubt someone will say if so) but I mention it just in case. I have a 95Ah in mine and others have 105Ah.

Mike

[Rhod]

Useful info there Mike. My Bongo was originally a winterpack model & when the battery was changed on import the existing 65AH batteries were apparently replaced with a single 65AH! I definitely think that the battery condition isn't helping things - the glowplug light usually comes on briefly after starting if the van has been standing for a bit, which I think was established as a symptom of a poorly battery. Not convinced that the battery isn't being drained by something though, but can't think what. Must get the ammeter out...

[francophile1947]

Useful info there Mike. My Bongo was originally a winterpack model & when the battery was changed on import the existing 65AH batteries were apparently replaced with a single 65AH! I definitely think that the battery condition isn't helping things - the glowplug light usually comes on briefly after starting if the van has been standing for a bit, which I think was established as a symptom of a poorly battery. Not convinced that the battery isn't being drained by something though, but can't think what. Must get the ammeter out...

65AH is rubbish for a Bongo
Regarding battery drain, check if your fluorescent tube light is dull. If it is, get a new tube - I kept getting flat batteries and a duff tube was the cause.

[Rhod]

flourescent light is powered by the leisure battery in the mazda kitchen & has an isolating switch in the circuit, so don't think that this can be causing a drain.

[mikeonb4c]

Not convinced that the battery isn't being drained by something though, but can't think what. Must get the ammeter out...

If worried, one of those isolating terminals for the battery would provide insurance against that. Only a few quid of ebay when I bought mine and - apart fro mlifting the bonnet to do it - v quick and simple. If its being left for days its worth the little extra effort as insurance I reckon.

[dandywarhol]

Dandy - If I'm following you then I think that you're suggesting that the glowplug ciruit is switching off while the engine is still idling & because the engine isn't up to temperature it's spluttering & dying?

I thought that the Bongos glowplug relay continually switched the plugs on & off until the engine was up to temperature (& that's why you hear the relay clicking in & out below about 40mph when cold)? I assumed that the relay circuit working in this way would keep things running at idle until the engine was up to temp. I was working on the assumption that the warning light is just a reminder that you need to wait for the plugs to warm up, but doesn't relate to the actual time they need to heat the system up?

A thought just occurs to me.... I can hear the glowplug relay clicking in on start-up & clicking on & off at low speed, but haven't been aware of it at idle (must try listening more carefully). If the relay was sticking intermittently after start-up then I'm guessing that that could result in the symptoms of the engine firing up ok, but then dying with syptoms of glow-plug failure, but starting ok again after a another couple of trys (when relay decides to work normally) Or is my logic & diagnostic mind as lacking as usual

I really don't know my way around diesel systems, but glowplug failure doesn't seem to quite explain the intermittent nature of my starting fault .

Rhod

I might have misinterpreted your post Rhod. I thought you were saying you waited til the glowplug light went out AND the relay clicked before you started the engine. If that is the case then the timer will have "timed out" thinking the engine hasn't been started and to save draining the battery. The residual heat will start the engine but it'll chug until warmed up.

My Bongo also has a 65 A/h battery which I agree is too small and I'll upgrade when it dies but it's been doing the job for 2 years now winter and summer.............

[bigdaddycain]

Try this rhod, (my method of starting the bongo) wait 5-7 seconds after glowplug light extinguishes, start the bongo with no throttle,hold her at just a tad under 1200rpm for ten seconds or so,then release the throttle.... You may notice that if you rev past 1200rpm you can hear the glowplug relay "cut out", this is something you don't want,after a long period of non use. I generally let mine warm for a minute or so before i pull away, i have a routine that comes second nature to me now,i also don't rev past 2000 rpm till fully warm.