Glow plugs, such thing as "service interval or .....

[Simon Jones]

Several people have previously recommended waiting for the light to go out, switch ignition off and on then wait for the light to go out a second time before attempting to start. Given that the glowplugs remain powered for several minutes it would actually be better to wait for the light to go out and then wait a further 3 or 4 seconds before starting rather than powering off and on again.

Definitely worth investing in good quality parts and replacing them at sensible intervals. Several folk have ended up snapping the tops off the plugs as they have been seized up either due to being overtightened or being left untouched for too long.

[Northern Bongolow]

the difference between long plugs and short plugs is all above the thread height if you post a picture of yours (close up) and the surroundings i should be able to tell you long or short without the need to remove any.

[Velocette]

Several people have previously recommended waiting for the light to go out, switch ignition off and on then wait for the light to go out a second time before attempting to start. Given that the glowplugs remain powered for several minutes it would actually be better to wait for the light to go out and then wait a further 3 or 4 seconds before starting rather than powering off and on again.

Definitely worth investing in good quality parts and replacing them at sensible intervals. Several folk have ended up snapping the tops off the plugs as they have been seized up either due to being overtightened or being left untouched for too long.

I think if you don't start the engine they go off 10 to 15 seconds after the warning light. Otherwise you could easily flatten the battery by leaving the ignition on. Mine do anyway. I found this out by testing with a clamp meter. I agree they stay on when the engine is running dependant on revs and temperature.

[Simon Jones]

Ah, that's useful to know - thanks .

[Velocette]

I'm still non the wiser on my glow plugs condition as I could only measure the total current which was 29A falling to 19A which I think is about right but noone seems to have measured a known good set of plugs. Someone else did the same as me and got about 17A but I don't know if they had four good plugs either! I was hoping to get the individual current readings and weed out any duff ones but the clamp (more of a fork) was too bulky and long to go over anything but the main connection.

[BongoBongo123]

Good info, getting a decent photo seems a lot easier than removing them (even though they have to come out anyway) ! Then I can get them in ready. If they are the shorter ones £40.00 for 6 years of perfect starting does not sound like much money to me. I wonder if I can do that without taking the top middle panel off ? I have never even seen where glow plugs live but can only imagine that A) there is one for each cylinder (logic) B) a rail or wiring for power which may possibly obscure the top of the plug threads if not removed.

I think I will lift the seats and see what I can see first. I should get a chance this week. Thanks.

[brorabongo]

I have replaced glowplugs twice over the last 7 years and two bongos, first I used cheap plugs off ebay.....did not last, NGK next after being recommended on here, been fine since. Also, I've not had to removed the center panel to replace them.

[scanner]

first I used cheap plugs off ebay.....did not last,

So you're the one who started this rumour that Bongo glowplugs don't last.

Should have known...........

[rita]

Some Peeps on here have fitted a switch on the glow plug system in order (by their thinking)to prolong the life of the plugs.

[BongoBongo123]

Here are my plugs...sorry you have to click the links to see them...but picture will be clearer:

http://i44.photobucket.com/albums/f24/b ... 3dwhjj.jpg

http://i44.photobucket.com/albums/f24/b ... rdowis.jpg

http://i44.photobucket.com/albums/f24/b ... se9la6.jpg

http://i44.photobucket.com/albums/f24/b ... b5nmal.jpg

http://i44.photobucket.com/albums/f24/b ... m0lpbi.jpg

Hope that allows you to see if they are short ones.

[BongoBongo123]

Ok I will have a guess at this...based on what I see here :

Short (note space between thread and nut):

http://www.mazdabongo.com/catalog/popup_image/pID/220

Long (note space between thread and nut):

http://www.mazdabongo.com/catalog/popup_image/pID/222

I have the expensive long type.

If someone could confirm that would be great but on mine there seems to be more smooth metal above the thread that looks more like the longer ones to my eye. And I bet the long ones are not NGK either it does not say they are NGK (short ones are NGK)

http://www.mazdabongo.com/catalog/filte ... glow-plugs

Will these still be decent quality parts from mazdabongo.com ?

Also have them at Ians shop a little more dosh.. £67.00 (Ian are your long ones NGK branded?)

http://www.igmaynard.co.uk/bongo/merchandise5.htm

Thanks, though I need to confirm that I have the long uns' first. (looks that way)

[cmm303]

I'm sure I have seen a post some time ago by somebody who determined that the glow plugs don't simply stay on for x minutes after starting but cycle on and off, more on at lower revs (I think), more off at higher revs (I think). The poster went on to explain the thermal shock this cycling imposes on the gloiw plugs.

My conclusion would be that short stop/start journeys will shorten the life of glow plugs more than long journeys cruising from the start. So maybe comparing different diesels is less significant and vehicle usage is more of a consideration.

[g8dhe]

Surely once the engine is running then there won't be that much thermal shock as the glowplug will be kept hot by the burning fuel ?

[scanner]

I'm sure I have seen a post some time ago by somebody who determined that the glow plugs don't simply stay on for x minutes after starting but cycle on and off, more on at lower revs (I think), more off at higher revs (I think). The poster went on to explain the thermal shock this cycling imposes on the gloiw plugs.

My conclusion would be that short stop/start journeys will shorten the life of glow plugs more than long journeys cruising from the start. So maybe comparing different diesels is less significant and vehicle usage is more of a consideration.

Glow plugs are like 'planes it is the starts and stops (in the case of glow plugs the starts) that are the problem.

As they only get triggered at start up the more start ups the quicker they burn out.

[mikexgough]

I don't know where anyone gets the idea that such operation is peculiar to Bongos. That is just the same system that I have known on European diesels (Fiat, Citroen, Peugeot and Renault, amongst others), it is common in diesels with indirect injection.

Also if that is how the glowplug is designed to work, wouldn't you think they would be designed to cope with it?

Perhaps that is why people who use good quality (e.g. NGK) glowplugs don't appear to have as many problems as people who fit cheap glowplugs to save a few quid?

I am still not aware that glowplug life is a particular problem for Bongos.

+1 ......... and NGK are....... Japanese... #justsaying