Mazda 2 a bit sick

[mustang3434]

Think i might of posted in the wrong area...

Hi all...not often I have a problem but I do now and its a tricky one....
I have an issue with my 2009 Mazda TS2 Diesel the one with the Citroën/Ford/Mazda engine..its done 110000miles and the only ever issue ive had was a dodgy fuel rail other than that i love the car.
Right my issue.
Cold morning turn on the ignition the glowplug light illuminates for about half a second even at -6C takes ages to start then it starts pours with blue smoke for 10 secs and clears and runs rough for another 20 secs then smooths out and then its fine and fine when warm.
What has been done..
All glowplugs are ok and work but 6 months old.
Turn the ignition on there is a feed to the glowplugs for a second then no feed. Start the car and there is a constant feed of 12V to the glowplugs all the time even after running the car for 5 mins and its warm. The relay has been changed and the fuses are ok. Then the engine management light came on. An auto electrician checked the ecu no problems checked the glowplugs he said everything was fine which my mechanic who found the issue still doesn't agree with... he cleared the fault codes but didn't tell me what they were but I will ask but he did say the engine is running rich and recons its a timing issue not glowplugs.. valve guides are ok
New battery too but still have the same issue...
Has anyone else had this problem?? I could really do with some help please!!!

[paintman]

Blue smoke is engine oil.

Unburnt diesel is white - smells & makes your eyes sting
Black smoke is incomplete burning of diesel - too much diesel too little air.

ETAYou say 'valve guides are OK'. How have you established this?

Edited by paintman on Saturday 5th March 22:10

[Demelitia]

Does the car know it’s -6 with a flat cold engine, or a warm one when it’s warm. I.e. does the coolant temp sensor work correctly?

[Polly Grigora]

mustang3434 said:

Turn the ignition on there is a feed to the glowplugs for a second then no feed. Start the car and there is a constant feed of 12V to the glowplugs all the time even after running the car for 5 mins and its warm

You could do worse than checking the glow plugs one by one

There is little chance of starting the engine from cold if the glow plugs aren't coming on and staying on, one second on is a fault

You comment that the plugs remain powered for 5 minutes, do you mean the supply to the plugs switches off after 5 minutes?

If the power to the plugs is constant they will burn out

The cause of the fault is anybodys guess but there is no point in replacing any plugs if faulty until the problem is solved

By any chance is there a heavy resistor in series with the plugs that is used to sense their current draw and send that information to the ECU or plugs control unit?

[mustang3434]

Thanks for the replies...No paintman not 100% confirmed but was told by my mechanic its not that but even I know blue smoke is oil...was a 2 stroke nutter when I was younger....

Demelitia I asked the auto electrician this and he said no its not that...even though I think it has something to do with it...ie if its telling the engine its warm when it's really cold might explain why the glowplugs are not coming on before the engine cranked but runs great when warm..?

Polly Grigora you have basically repeated what my mechanic has said...he is going to test each glow plug 1 by 1 and see if they are ok...as for 5 mins that when we turned the engine off as there was power still to the glowplugs and that's still after the relay was changed for a new one...I dont think there is a heavy resistor in series...im wondering if the wiring loom to the plugs could be at fault...maybe grounding to earth?

[mustang3434]

Another thing worth mentioning...I had a snapped glow plug which is when this all started to happen luckily the glowplug was removed and replaced...the very first time the car started it fired up instantly no smoke no problems ran perfect. Parked it up and the next day it started running rough as before which is when my mechanic started testing and found the issues mentioned.

[chrisch77]

mustang3434 said:

Another thing worth mentioning...I had a snapped glow plug which is when this all started to happen luckily the glowplug was removed and replaced...the very first time the car started it fired up instantly no smoke no problems ran perfect. Parked it up and the next day it started running rough as before which is when my mechanic started testing and found the issues mentioned.

Are you sure all of the glowplug was successfully removed from the engine and bits didn’t drop into the cylinder? One of the common occurrences with 1.6 HDI engine is that when a cam belt failure occurs and piston meets valves it can spin the lobe(s) on the camshaft which is made up of press fitted components. If there is (valve) timing issue suspected then I would be suspicious of debris in the cylinder has come between the piston and valve and caused a lobe to move.

However, notwithstanding this, if you have blue smoke on startup that is a pretty clear sign of oil dropping into the cylinder from the top end (or inlet system) when the engine is stationary, so a separate issue and mechanically significant. Valve stem leakage or knackered turbo?

[Polly Grigora]

Have come across wrong voltage glow plug being fitted

[mustang3434]

Strange thing is before the glow plug snapped there was no problems and all the remaining glow plug was removed and we put an endescope through the injector port and the cylinder was clear albeit very sooty...

[mustang3434]

When the air intake was removed the interior was very sooty around the valves probably causing the valve not to seat correctly my guess?? Its been running for almost a year with a snapped plug through summer...

[mustang3434]

Interesting polly...I got the GP from euro car parts only changed the single one that had snapped..my mechanic is going to check each one and check them the old school way with a battery....im wondering if one two or all have failed if that is why the information the ecu is sending is causing the mixed signals...dont you just love cars lol

[Smint]

Yes, i would be checking the glow plugs actually glow individually.

It can be interesting to bridge an ammeter between the plug and its connector whilst in situ to see just how much each plug is drawing, i used to keep a really old Lucas ammeter for jobs like this, sometimes saves removing them unnecessarily.
Last time i checked glow plugs (can't even remember which car) each plug drew roughly 15 amps, wouldn't like to say if that's still a typical value.

[mustang3434]

I think that's where we are going to start... Will keep you posted

[mustang3434]

Ok picked the car up today to take it back to my mechanic..Still with the same problems..the auto electrician said there was a fault code with the MAF sensor but he's cleared it and its not come back on...he thinks the timing belt is one tooth out...and to top it all as I was driving to my mechanic they have cracked my windscreen...brilliant...
Now...spoke to mechanic and he is going to check the glow plugs individually and test the circuits again and check the timing...I asked him to check the coolant temp sensor as this is my thinking and what one of you mentioned...engine cold ambient temp here +6 turn the ignition on glowplug light on then off in a blink...let's say the CTS is saying the engine is hot well it wouldn't need to heat the glowplugs up right?? Now turn the engine over and struggles to start and eventually fires up and runs rough then as the engine warms up it runs perfect...I wonder if the temp sensor is telling the ecu which has been tested and is ok that the engine is hot even when it's not...does that make sense...for the price of one we are going to change it to be sure...again will keep you posted I really appreciate your comments 😀