[dave_v2]

Hi all

I have a 53 plate 1.6TS 147 with 86k on the clock.. I've been having a few probs with the engine over the last couple of months or so.. Firstly, I know I need the variator changing as it's got the diesel sound at start up, I'm not too worried about this as I had this problem 50k ago and had the variator and cam kit done, I know it needs doing again some time soon..

The main problem is this: sometimes the engine looses power and sounds like its running on 3pots, very similar to a scooby but without the power.. It ticks over fine and only does this betweem 1 and 3 thousand revs, it doesn't do it all the time and temperature doesn't seem to make any difference. It can go days without doing this then suddenly it will do it all the time, the other day the dreaded 'motor control failure' message appeared and wouldn't go away... it only went after a short drive when the engine began to run ok...

I'm suspecting its an ignition problem rather than mechanical as its very intermittent, possible plugs, coil packs or sensor problem.. Lately the engine runs a little sluggish and rough when first starting up and setting off, reminds me of my first car 20 years ago!!!

Any Ideas before I just start replacing plugs, coil packs etc to see what works, anyone else got or had this kind of problem

Thanks in advance for any help or suggestions.

Dave

 

[filipharvey]

Sounds like MAF to me. Disconnect it and (once moving) if it is better when disconnected, that will confirm it.

I take it you've had the cambelt replaced in the last 50k miles? Should be done every 36k.

 

[dave_v2]

filipharvey

Thanks for the reply mate, if I disconnect the MAF sensor should I expect any warning lights or other problems, if it is the MAF can it be left disconnected until I buy a new one?

Just to mention I don't have the standard air filter / box fitted.. I fitted a cone filter about 18 months ago, this replaced the standard box and filter unit, I did origionaly suspect it might be something to do with this but as its been fitted for 18 months I dismissied it..!

Cheers

 

[AlfaAlfa]

scooby - water?

Since you describe this as firing on only 3 cyl and then I would suggest at least checking for water in the plug holes. Just take off the engine cover and the coils and see if there are any water in cyl 1 or/or 2 from left -facing the engine.

But you also describe a change in the way is reacts or behaves - and then I would be inclined to suggest MAF.

Both can make the engine failure light go on and off without resetting it by the external tools...

Any air filter introducing more dirt or oily air to the intake could kill off the MAF, and after a while also the throttle body. Although its a while back that you did the switch the dirt accumulates over time on the MAF.

There is quite a debate over "sport" filters from various sources, but looking at my MAF after using K&N for a while make me certain that the MAF and the whole intake did get noticeably more dirty using the K&N compared to standard and also compared to sports filter of the foam type with oil.

Rgds
Alfa^2

 

[Smaky]

I would suggest you get the cam belt done NOW, your 18K over the schedule limit, this coud be the engine telling you that the belt is spiting teeth and sliping, so far you've been lucky, but don't push it, if your near me Ill take a look for you.

 

[AlfaAlfa]

Belt skipping teeth would probably not be intermittent problem that comes and goes? Or rather !

But totally agree that belt and runner change is something to not skip or postpone.

Alfa^2

 

[filipharvey]

Thanks for the reply mate, if I disconnect the MAF sensor should I expect any warning lights or other problems, if it is the MAF can it be left disconnected until I buy a new one?

Yes, the engine management light will come on, but will go off again when reconnected (some models take 4 restarts for the light to go out - my V6 for example).
Yes, it can be left off, but don't leave it for too long - your engine still won't run correctly with it disconnected, as it is guessing airflow.

I would suggest you get the cam belt done NOW, your 18K over the schedule limit

...[the] belt and runner change is something to not skip or postpone.

To elaborate on my original post and reinforce the above; the belts pulleys and tensioners should be replaced every 36k miles and within 3 years.
If they haven't been done in that time/mileage, get them done yesterday!

 

[dave_v2]

Sorry I should have mentioned this in my first post..

Around 20k ago one of the cam shafts siezed up while doing 50 mph... £881 later I had the head reworked and the cam kit changed... I know I should have done the variator at the same time but it was lovely and quiet back then, and £881 was already a stretch as I was back in full time studies at the time ( got my gas ticket).. hind sight and all!!!

I removed the MAF as well the other day and have to say it looked really clean, I left it disconnected and went for a drive but the car kept cutting out so I plugged it back in.

I've seen people on youtube cleaning MAF sensors with carb spray, would this work on the ***** MAF?? I've yet to check plugs and leads etc, job for tomorrow all been well but its still running the same.. crap..

 

[Smaky]

A belt with missing teeth can skip back and forth so it can be intermittent, though a belt this old can also stretch so the timing is out of limits so the cam sensor would show in the diagnostics.

Cleaning the MAF rarely works, normally it's breaking the corrosion on the plug pins when they do that which is the cause of the fix.

 

[dave_v2]

Just an update really..

The last week with the mornings been much colder my problems have worsened, on a morning it ticks over very rough and runs like its on 3 cylinders or is missing badly, its ok when it gets nice and hot, starting to suspect the ignition side rather than the MAF..

 

[filipharvey]

What happens when it is running rough, and you disconnect the MAF (engine running)?

 

[mave]

Did you check the plug recesses for oil? Were the plugs changed when the head was off or at 60K?

 

[dave_v2]

When I first start it at around 7am it sounds very rough on idle, you can feel the car shaking a little as the engine strugles to idle smoothly, when pulling away it sounds like its not running on all cylinders, real lack of power and it misfires too, it gradually gets better with temperature and distance but still misses now and then, I use the car for my job at the mo, (service engineer) so am in and out of it all day long, funny thing is it can sudenly just start running rough and misfiring again even when I've been driving it for hours, its deffinetly much worse though now the cold mornings are here... I disconnected the MAF last weekend and drove around the block, it kept cutting out and sounded like a bag of spanners, I quickly connected it again fearing I'd do more damage...

 

[filipharvey]

Have you tried disconnecting the Lambda sensor? It is one of the connectors at the back of the engine, along the top. From memory, I can't remember which one though, but you should be able to trace it.

When mine went, it started with the occasional lurch, and then ended up sounding like yours. When I disconnected the Lambda sensor, all symptoms disappeared, proving that the sensor was at fault. This had been masked by a faulty MAF in the past.

 

[dave_v2]

Hi

Haven't checked for oil in the plug recess and as far as I know the plugs were not changed on the head rebuild, just at 60k.. cheers

 

[CroBaron]

I have new Lambda but still get rough idle when cold.

 

[dave_v2]

Just another update...

Had all the plugs out yesterday and had some oil in one of the plug recesses! plus, on number 1 cylinder (nearest the cam belt) both plugs were not in good shape, quite sooty in fact. I also noticed that one of the other plugs (small one) had a bit of ceramic missing!!! Anyway I cleaned all the plugs and wipped the oil away and have to say it's running a lot better, think I'm gonna change all the plugs at the weekend and see what difference that makes, they've only done 25k but 90% of my driving is city so guess that messes them up quicker.. I will replace with like for like plugs, all NGK.