Nissan Almera N16 (2002) 1.5 - Random Misfire Detected

dave66

Hi,

Hoping somebody might be able to point me (and mechanic) in the right direction.

I have a 2002 Nissan Almera 1.5l Petrol, recently it was "chugging" at low revs (1500) when driving, so reckoned it was best to have an overdue service done. The clutch also needed to be done, but postponed that for financial reasons.

Spark plugs, air & oil filters, oil change all done. Collected car and when driving away from garage notice chugging still present and then the engine warning light came on. Engine was ticking over nice a quiet just under 1000rpm (I'm guessing about 800-900rpm) but every now and then the revs would drop momentarily to about 500rpm.

Back to garage, when they read the error they got "Random Misfire Detected" I'm waiting for them to call me with the error code and which sensor reported it.

The mechanic reckoned, it could be one of the induction coils on a spark plug. Anyhow to cut a long story short, the mechanic has now tried:

1. Replaced induction coil on all cylinders/spark plugs
2. Removed rocker cover & checked timing belt (he reckons belt was previously replaced & tensioner well within limits <5mm extension)
3. Removed and cleaned Idle Control Valve/Motor (he reckons it was clean)
4. Checked all cables to/from ECU, no visual damage
5. Check all battery and body earth cables, now visual problems.
6. Even replaced clutch & exhaust (which had two holes)
7. Checked emissions from exhuast and well within (below) acceptable MOT/NCT limits.

The problem persists, symptoms are:

• When idling, with car in neutral, clutch not depressed. The car runs nice and quietly but can see rev counter needle dipping from 800/900rpm to 400/500rpm.
• When driving at below 1500-2000 rpm, car "chugs" but has not ever stalled.
• When cruising on motorway at 100-120km/hr and revs at about 3000rpm, car is much smoother but can occassionally see brief dip in rev counter.

Does anyone have any suggestions as to what else we could check, beyond frustrated at this stage.

galwaydude18

Coil pack. I had to replace two last week
And it doesnt have a timing belt it has a timing chain

dave66

galwaydude18 wrote: »

Coil pack. I had to replace two last week
And it doesnt have a timing belt it has a timing chain

Sorry that was an error, yes I realise it's a timing chain. Replaced all 4 coil packs, no change or improvement.

dieselbug

I know you say the tensioner is only protuding <5mm but...

I would make absolutely sure it's not the problem.

You really need to put a scope on this and check how the cam and crank signals are behaving. Given the symptoms you describe timing chain would be my first suspect.

I can post a known good cam crank pattern if needed.

Waterson

What is the fuel trim data like for the car when idling? For example a non cylinder specific misfire which your P0300 code will flag for, could be down to a lean running condition, i,e. unmetered air or restricted fuel system. Your mehani shoud be able to pull live trim data with a generic OBD 2 scanner. Whicle stretched timing chains are an issue on these engines, your emchanic is corect in that if tehre is less than 5mm defelection of the chain against the hydraulic tensioner, its probably ok, provided the timing chain was fitted correctly. Also a lack of cam/crank phase error codes would lead me away from this area.

dave66

Car going back into garage on Thursday. Going to look at trim data and also recheck MAF.

I just popped into mechanic to ask about MAF as possible problem. He had checked it and it was providing correct voltages, however with car idling we just unplugged the MAF, engine stuttered for a moment then returned to ticking over as it was with MAF connected, when revved it was "lumpy" around 1500-2000rpm. Reconnected MAF and engine behaved same as it did with MAF disconnected.

We're not 100% convinced it is MAF but it's looking at least slightly suspicious.

Waterson

With the MAF connected and live data output of the MAf sensor signal line, let the car idle then snap the throttle pedal to a wide open position very quickly. Check the voltage spike is within spec, i.e. around 3.8-4.5 V. At idle I would expect an output of around 1.5-2v.

dave66

Waterson wrote: »

With the MAF connected and live data output of the MAf sensor signal line, let the car idle then snap the throttle pedal to a wide open position very quickly. Check the voltage spike is within spec, i.e. around 3.8-4.5 V. At idle I would expect an output of around 1.5-2v.

Thanks for that. I'll pass it along to mechanic.

Bloody fault is driving me nuts.

dieselbug

Could we have an update on this please.

Did you get sorted on Thursday?

dave66

dieselbug wrote: »

Could we have an update on this please.

Did you get sorted on Thursday?

Sorry for delay in replying.

I didn't make it to the garage on time on Thursday (M50 mad traffic day) so they didn't get a chance to take another look. They did tell me that they had already checked timing chain both visually & by scoping Cam/Crank sensors so they are certain it's not the timing chain.

I've noticed that when the car starts from cold, that the idle is better. I'm wondering if the it's because when car starts it runs rich and then when it reaches operating temps it's then running too lean.

Car due back into garage on Wednesday.

Volvoair

dave66 wrote: »

Hi,

Hoping somebody might be able to point me (and mechanic) in the right direction.

I have a 2002 Nissan Almera 1.5l Petrol, recently it was "chugging" at low revs (1500) when driving, so reckoned it was best to have an overdue service done. The clutch also needed to be done, but postponed that for financial reasons.

Spark plugs, air & oil filters, oil change all done. Collected car and when driving away from garage notice chugging still present and then the engine warning light came on. Engine was ticking over nice a quiet just under 1000rpm (I'm guessing about 800-900rpm) but every now and then the revs would drop momentarily to about 500rpm.

Back to garage, when they read the error they got "Random Misfire Detected" I'm waiting for them to call me with the error code and which sensor reported it.

The mechanic reckoned, it could be one of the induction coils on a spark plug. Anyhow to cut a long story short, the mechanic has now tried:

1. Replaced induction coil on all cylinders/spark plugs
2. Removed rocker cover & checked timing belt (he reckons belt was previously replaced & tensioner well within limits <5mm extension)
3. Removed and cleaned Idle Control Valve/Motor (he reckons it was clean)
4. Checked all cables to/from ECU, no visual damage
5. Check all battery and body earth cables, now visual problems.
6. Even replaced clutch & exhaust (which had two holes)
7. Checked emissions from exhuast and well within (below) acceptable MOT/NCT limits.

The problem persists, symptoms are:

• When idling, with car in neutral, clutch not depressed. The car runs nice and quietly but can see rev counter needle dipping from 800/900rpm to 400/500rpm.
• When driving at below 1500-2000 rpm, car "chugs" but has not ever stalled.
• When cruising on motorway at 100-120km/hr and revs at about 3000rpm, car is much smoother but can occassionally see brief dip in rev counter.

Does anyone have any suggestions as to what else we could check, beyond frustrated at this stage.

lotta money wasted on an 02 almera.......get rid of it .

dave66

Volvoair wrote: »

lotta money wasted on an 02 almera.......get rid of it .

Only wasted if we can't resolve the issue, the car is worth more to us than it's worth. I suspect that's not unusual.

dieselbug

dave66 wrote: »

Sorry for delay in replying.

I didn't make it to the garage on time on Thursday (M50 mad traffic day) so they didn't get a chance to take another look. They did tell me that they had already checked timing chain both visually & by scoping Cam/Crank sensors so they are certain it's not the timing chain.

I've noticed that when the car starts from cold, that the idle is better. I'm wondering if the it's because when car starts it runs rich and then when it reaches operating temps it's then running too lean.

Car due back into garage on Wednesday.

Post how you get on with things on Wednesday.

With the chain ruled out other possibilities worth checking would be fuel pressure and supply.

I always check pressure with the engine under load.
It may be within spec in the garage at idle but may not be able to sustain it when stressed.

O2 sensor and ignition can all be well tested with the scope.

Freeze frame data would be useful to see what the engine conditions are at the point when the code is set.

Good luck.

jobseek

Hi,Sorry for pulling up an old thread,but we have the exact same problem here with an 02 almera,dave66,what was the outcome with your car

Just see account closed!

dieselbug

jobseek wrote: »

Hi,Sorry for pulling up an old thread,but we have the exact same problem here with an 02 almera,dave66,what was the outcome with your car

Just see account closed!

Dave 66 closed his account but I can tell you he had a new timing chain fitted and it solved the problem.