polo 6n2 1.0mpi engine problem

fergus1001

the engine is running rough as if it is on 3 cylinders and i have already done the following

coil pack
spark leads
spark plugs
cleaned throttle body

and i will be doing the egr valve once i find it does anyone know whats wrong or is my engine just fudged

Nissan doctor

If all the ignition system(coil, plugs, leads etc) is new then next thing to test is the injectors, after that, timing and then leakdown/compression test to check for internal damage.

fergus1001

Nissan doctor wrote: »

If all the ignition system(coil, plugs, leads etc) is new then next thing to test is the injectors, after that, timing and then leakdown/compression test to check for internal damage.

I forgot to mention that I got it hooked up to a vag com and it was giving a missfire under load on cylinder 3 so if it was timing that was out or fuel pump or filter it would be a multiple cylinder misfire so I'll be looking at injectors If it's the cylinder that's gone itself I'm lookin at replacing the engine

Plug

Assuming all cylinders are of fairly equal compression. Get an oscilloscope, check the firing voltage of all the plugs. Compare readings, if one has high voltage well that means its not getting enough fuel(lean) if the voltage goes too low well then you know your on a rich mix in that cylinder. Do a compression/leak down first though before you start putting in injectors left right and centre.

fergus1001

would anyone recomend a injector cleaner addative to the fuel mix and see ?

couldntthink

Do a compression test. I've seen this a couple of times on these engines. It's a problem with the valve seats. Don't bother buying additives. Biggest waste of money ever. Bottles of fairy potions won't fix your car.

fergus1001

how much are we talkin to get the valve seats fixed new head or what ?

i also asked in the local garage about a compression test and they dont have the equipment

Nissan doctor

fergus1001 wrote: »

how much are we talkin to get the valve seats fixed new head or what ?

i also asked in the local garage about a compression test and they dont have the equipment

IMO bring it to a decent garage and have the problem properly diagnosed before you start panicking about repairing cylinder heads...

fergus1001

Nissan doctor wrote: »

fergus1001 wrote: »

how much are we talkin to get the valve seats fixed new head or what ?

i also asked in the local garage about a compression test and they dont have the equipment

IMO bring it to a decent garage and have the problem properly diagnosed before you start panicking about repairing cylinder heads...

Thanks it's worrying though I'm a student and I'm not awash with money Grrrrrrrrr

Thanks for the inputs lads If it was a diesel engine I'd sort it myself but I wouldn't be familiar with a petrol engine especially the new ones

fergus1001

sorry to bring this up again but i have also put in a new injector rail into the damn thing and i cleaned off the spark plug that was in it and it was hopping in and out of three and four cylinders really wreaking my brains now at this point the engine ir running rich also as in i can smell the petrol when i start the engine that kind of sweet smell but not in a good way ha

(i checked the injector rail no leaks)

crosshair1

How many times do you need to be directed towards a compression or leak down test...

couldntthink

fergus1001 wrote: »

sorry to bring this up again but i have also put in a new injector rail into the damn thing and i cleaned off the spark plug that was in it and it was hopping in and out of three and four cylinders really wreaking my brains now at this point the engine ir running rich also as in i can smell the petrol when i start the engine that kind of sweet smell but not in a good way ha

(i checked the injector rail no leaks)

There's no point trying to help people like this.

Nissan doctor

fergus1001 wrote: »

sorry to bring this up again but i have also put in a new injector rail into the damn thing and i cleaned off the spark plug that was in it and it was hopping in and out of three and four cylinders really wreaking my brains now at this point the engine ir running rich also as in i can smell the petrol when i start the engine that kind of sweet smell but not in a good way ha

(i checked the injector rail no leaks)

With respect, you said you hadn't got much money to spend on it....its going to cost you more just throwing random parts at it in the hope you get lucky then it will to have it properly diagnosed.

fergus1001

sorry for dragging this one back up but in the end it turned out to be a broken valve and is running like clockwork now

Nissan doctor

fergus1001 wrote: »

sorry for dragging this one back up but in the end it turned out to be a broken valve and is running like clockwork now

Good to hear, how much did it cost you to repair?

fergus1001

Nissan doctor wrote: »

Good to hear, how much did it cost you to repair?

cost 400 that included a timing belt water pump kit head gasget and valve