White Smoke & Lumpiness On Startup - Glowplugs Fine . . .

[mikexgough]

Hi Chris, a couple of points... Have a look at the connector to your engine fan temp sensor, if that is disconnected (or is dodgey) that disables the glowplug circuit. I can't remember if that also disables the orange glowplug dash light. When you start the bongo from cold, what revs are you seeing on tickover? Mine is around the 1000RPM mark, then drops to 800 (ish) after about 7-8 minutes of tickover in this weather.

Since the replacement engine temp sensor on mine...... cold start = 900/1000 rpm for around 2 mins max then down to the usual 750 rpm idle speed

[ChrisCT]

Hi mikexgough,
mine does exactly same only idle when hot is 850-900 RPM, starts perfect. Last night was -2*C no problem at all but have to remember to wait 15sec till I hear "clik", didn't see any smoke. Couple months ago I try to run engine without radiator cup and see what happen. Up to 2500 RPM water circulates nicely (almost 1 hour) above 2500 RPM water splash from radiator as pump runs faster no boiling and overheating, temp. needle stays on 1/3.
I go to Austria for skiing twice a year. It is nice after all day to jump in to warm car. In few days time I'm going to fit myself Webasto diesel heater, hope it will pays

[haydn callow]

Topped the header tank up this morning it was above the lower level mark so 1/4 of a litre took it slap bang in between empty and full, i have marked the level with a permanent marker and will monitor it over the next couple of weeks.

Best to put the level up to the FULL line when cold.......from what you say I assume you do not have a low coolant alarm or it would have warned you of the low level.

[M 80NGO]

Topped the header tank up this morning it was above the lower level mark so 1/4 of a litre took it slap bang in between empty and full, i have marked the level with a permanent marker and will monitor it over the next couple of weeks.

Best to put the level up to the FULL line when cold.......from what you say I assume you do not have a low coolant alarm or it would have warned you of the low level.

No i don't have a low coolant alarm and tbh i really don't want one, people become reliant on alarms, whistles n bells, i've managed 22 years of driving without a coolant level alarm so i'll continue with the old fashioned method of popping the bongo's bonnet once a week and doing a visual check, being a profesional HGV 1 driver i regulary check my gauges probably the same amount as i check my mirrors, my coolant wasn't low enough to set off an alarm any way and i've never run a vehicle with maximum of anything in it usually 1/2 to 3/4 works for me, Thanx for the heads up tho its much appreciated

[mikexgough]

Topped the header tank up this morning it was above the lower level mark so 1/4 of a litre took it slap bang in between empty and full, i have marked the level with a permanent marker and will monitor it over the next couple of weeks.

Best to put the level up to the FULL line when cold.......from what you say I assume you do not have a low coolant alarm or it would have warned you of the low level.

No i don't have a low coolant alarm and tbh i really don't want one, people become reliant on alarms, whistles n bells, i've managed 22 years of driving without a coolant level alarm so i'll continue with the old fashioned method of popping the bongo's bonnet once a week and doing a visual check, being a profesional HGV 1 driver i regulary check my gauges probably the same amount as i check my mirrors, my coolant wasn't low enough to set off an alarm any way and i've never run a vehicle with maximum of anything in it usually 1/2 to 3/4 works for me, Thanx for the heads up tho its much appreciated

Some Bongo owners....fill to the full line and end up with a steady level at just under full to 3/4 full between the high and low parameters........

[The Great Pretender]

Topped the header tank up this morning it was above the lower level mark so 1/4 of a litre took it slap bang in between empty and full, i have marked the level with a permanent marker and will monitor it over the next couple of weeks.

Best to put the level up to the FULL line when cold.......from what you say I assume you do not have a low coolant alarm or it would have warned you of the low level.

No i don't have a low coolant alarm and tbh i really don't want one, people become reliant on alarms, whistles n bells, i've managed 22 years of driving without a coolant level alarm so i'll continue with the old fashioned method of popping the bongo's bonnet once a week and doing a visual check, being a profesional HGV 1 driver i regulary check my gauges probably the same amount as i check my mirrors, my coolant wasn't low enough to set off an alarm any way and i've never run a vehicle with maximum of anything in it usually 1/2 to 3/4 works for me, Thanx for the heads up tho its much appreciated

Sorry cant agree with you totally on this, yes over reliance on whistles n bells accepted. As I like experimenting I am now on my second coolant alarm, still home made and a float system in the degassing tank. I still check the tank a couple of times a week and also look on the ground when moving off from a parking space.
However a loss of coolant when on the move could destroy the head or more without warning. Whistles n bells may not be foolproof but offer a good chance of saving the engine.

[haydn callow]

Topped the header tank up this morning it was above the lower level mark so 1/4 of a litre took it slap bang in between empty and full, i have marked the level with a permanent marker and will monitor it over the next couple of weeks.

From your description the level when you checked it was a little below ....half way between Low & Full.......that would have activated a Low coolant alarm.......coolant can be lost in seconds when driving and unless you are in a position to notice this, the first you will know will be the gauge going to "H" and we know what that means........also it can drip away over night....unless you check every morning !!!!!! Just my thoughts

[mikexgough]

No i don't have a low coolant alarm and tbh i really don't want one, people become reliant on alarms, whistles n bells, i've managed 22 years of driving without a coolant level alarm so i'll continue with the old fashioned method of popping the bongo's bonnet once a week and doing a visual check, being a profesional HGV 1 driver i regulary check my gauges probably the same amount as i check my mirrors, my coolant wasn't low enough to set off an alarm any way and i've never run a vehicle with maximum of anything in it usually 1/2 to 3/4 works for me, Thanx for the heads up tho its much appreciated

Have you a Mason Alarm at all?.... or even modified the standard gauge?.... anyone of these options will give you more of a heads up should your motor start to get hot..... although to be fair it can put the fear of god in you.....as it does take a fair swing of the needle (3/4) across the gauge for the fans to kick in....

[haydn callow]

The instructions for making your gauge work are available to download from the homepage of the web shop below.......all you need is these instructions and a 100ohm resistor........available for a couple of pence.
Gotta be worth doing !!

[mister munkey]

Short term Heads Up.

After expert assistance from Miss Fixit at last weeks N Lincs bash, the source of the non functional fast idle has been sourced & sorted. All the hoses from the vacuum pump to the relays were frayed at both ends - hence no sucking up to kick in the relays.

Now sorted, albeit in a rather Heath Robinson fashion.

Fast idle now kicks in from cold & also works when the A/C needs it to.

Not affected the smokieness on startup however. Still fires up crisply & is fine as long as the throttle isn't touched for the first two minutes. Any blips otherwise cause a belch of stinky smog.

Still not got to the source, have yet to get the current draw to the plugs checked but have also been pointed to it posssibly being a failing front pump seal.

Any thoughts?

[munroman]

Short term Heads Up.

After expert assistance from Miss Fixit at last weeks N Lincs bash, the source of the non functional fast idle has been sourced & sorted. All the hoses from the vacuum pump to the relays were frayed at both ends - hence no sucking up to kick in the relays.

Now sorted, albeit in a rather Heath Robinson fashion.

Fast idle now kicks in from cold & also works when the A/C needs it to.

Not affected the smokieness on startup however. Still fires up crisply & is fine as long as the throttle isn't touched for the first two minutes. Any blips otherwise cause a belch of stinky smog.

Still not got to the source, have yet to get the current draw to the plugs checked but have also been pointed to it posssibly being a failing front pump seal.

Any thoughts?

When you blip the throttle you add more diesel, this cools the pre combustion chamber, hence the unburnt diesel.

The 2 minute time might indicate that the glowplugs aren't getting hot enough, and its only when the head has had some heat from combustion that the incoming diesel is getting vapourised enough to burn cleanly.

Did you ever check the earths, both at the battery and between the engine and chassis, you had commented that a new battery made your headlights brighter and I did think that maybe there is a bad earth somewhere about!

[AlliDelta]

Our Bongo suffers from white smoke on a cold startup too. Just recently the weather has got bleedin cold and when the Megane got stuck (-10) I de-snowed the Bongo and figured the 4WD would get me to work, it did, but starting was a bit touch and go. It took about 6 attempts at heating the plugs, and lots of cranking. I thought I was scuppered and decided hmm maybe more gas, and floored it on cranking, and it began firing. a couple more attempts and I got running. A lot of white smoke and lumpiness but I just set the revvs high at around 1800 rpm for 20 seconds or so and the white smoke went away and after 2 mins the smoothness returns. I reckon some new NGK plugs at the mot in february will be in order.

I thought it may be a small leak on the head gasket allowing water into one of the cylinders and this got sealed up at temperature. But the water level is rock solid.

Just need to find out if something is causing bad fuel consumption. Never done an actual test on it as I'm too tight to fill the tank! But the forum could do with a ready reckoner to help diagnose common faults. Maybe there is one and I'm too inept to find it!!

On a plus point the 4WD is awesome in the snow.

[BongoMTBer]

Mine was the same since I have owned it. Worse in cold weather but always started first time then after a few seconds went to lumpy mode with unburned diesel leaving the exhaust unless I gave it a toe full for a few seconds. I would have sorted it earlier nut I thought it may have been caused by my other fuelling issue.

I did all the standard checks on the glow plugs and could not find a fault.

Anyhow, changed them this morning ‘just in case’ with some off ebay and started from a overnight cold soak of about -5C and it didn't miss a beat... happy days. Obviously the old plugs were not up to scratch despite appearing to be from resistance and voltage checks.

Now, I think that when the plugs carry on being heated after the engine is running during warm up, they do so at a reduced current. Any reduction in effectiveness in the plugs will be felt worse when in this mode, especially at the current temperatures.

Not sure how long they will last as they were cheap: http://cgi.ebay.co.uk/MAZDA-BONGO-FRIEN ... 255f093a11

My advice: bite the bullet and buy some new plugs.

BTW, it would appear that I should have bought the longer plugs. However, you can fit the short ones where you should have long ones. You just need to gently bend the 3 inter-connecting return pipes on the injector manifold down a few mm so that the bus bar sits above them without touching.

[g8dhe]

The glow plugs are either ON or OFF via the relay, there is no reduced power mode on the Bongo that I can see from the diagrams;

The ECU does sense that power has actually been applied to the plugs, but that's all as far as I am aware.

[BongoMTBer]

Ah, so I see. The relay does click in and out below certain revs when cold though? I am guessing that is ECU controlled, but as you say, there is no provision for reducing the current.

Anyway, new plugs sorted mine