Help! Engine light coming on and misfire - Southampton

[Mr K]

Hi Folks,
I wonder if any of you can help. My QP V (2007 MY F1) has started showing the engine warning light and misfiring. I've done 2 trips today with 1.5 hour rest in between. During the first, the car was fine for about 40 miles, then it repeatedly misfired. Then it was parked up for 90 mins. After that if was fine for 30-40 miles, then it started again.

I'm thinking Lambda sensors - the car has only done 38,000 in nearly 14 years and they're supposed to last a lot more miles - not sure they expire due to age, but they are recommended to be changed every 4 years. I don't think they've ever been changed. Maybe someone can advise. Would it be typical of Lambda sensor failure that the problem goes away after letting the car cool and it returns once thoroughly warmed up?

I'm in Southampton and am planning to call Emblem or maybe The Maserati Shed in the morning. It needs to have proper diagnostics obviously, but any pointers would be appreciated in the mean time.

 

[Wanderer]

Have u connected an ODB dongle to it to see the codes?

 

[Oneball]

I’d be looking at the coil packs. But a code reader will tell you without all the faffing. It’s OBD2 compliant so a cheapo one from Machine Mary will give you the basics.

 

[Mr K]

Have u connected an ODB dongle to it to see the codes?

No, I don't have have one.

 

[Lozzer]

I’d be looking at the coil packs. But a code reader will tell you without all the faffing. It’s OBD2 compliant so a cheapo one from Machine Mary will give you the basics.

Agree, they break down when they get warm.

 

[Oneball]

I meant Machine Mart!

Machine Mary is probably a wipe clean doll.

 

[Zep]

If you are in Southampton I would suggest you pop into Sports Italia in Eastleigh. I am sure they would read your codes for you.

 

[Zep]

And yes, it is almost certainly coil packs.

 

[Zep]

But I should also add that someone else had this exact problem recently and the coils were fine. The spark plugs on the other hand were old and knackered.

 

[Mr K]

Thanks Zep, will give Matt / Sports Italia a call first thing. Unlikely to be plugs, had them replaced by a forum sponsor specialist within the last 8k miles.

 

[Silvercat]

Almost certainly one or more of the Ignitor coils. I had the same problem on my 2009 QP 4.7S. So bought myself a OBD2 reader to identify which cylinder was affected, removed the ignitor coil (took me all of 40 minutes to do the change out) and hey presto it sorted it. The ignitor coils are around £105 each. But if one starts failing then the chances are the others will progressively fail to within a few thousand miles. Because the coils are buried so deep in to the engine, they are subject to very high temps which breaks down the electronics. Sadly unavoidable.

 

[Zep]

Thanks Zep, will give Matt / Sports Italia a call first thing. Unlikely to be plugs, had them replaced by a forum sponsor specialist within the last 8k miles.

Coils it is then. They will sort you out.

 

[Mr K]

Update: Popped over to Sports Italia and Conaero kindly helped try to figure out what’s going on. After a reboot (battery disconnect) the computers said they’d seen previous misfires on cylinders 1&3. He cleared these and they stayed away after some raucous revs. After about 2.5 hours of driving today, no further engine warning lights or “Take to dealer” messages. Could be down to lower temperatures today; we’ll see what happens tomorrow with 3.5 hour on motorways and dual carriageways!

 

[conaero]

Glad to help a fellow forum member in distress.

it’s odd to see two coil pack/plug errors on one bank and feel it will be something further down the line affecting them.

 

[Silvercat]

Update: Popped over to Sports Italia and Conaero kindly helped try to figure out what’s going on. After a reboot (battery disconnect) the computers said they’d seen previous misfires on cylinders 1&3. He cleared these and they stayed away after some raucous revs. After about 2.5 hours of driving today, no further engine warning lights or “Take to dealer” messages. Could be down to lower temperatures today; we’ll see what happens tomorrow with 3.5 hour on motorways and dual carriageways!

Fingers crossed but when I had my ignitor coil problem on my QP it started off intermittently until it failed completely and one cylinder wasnt firing at all. Also the other dead giveaway is the spark plug in the offending cylinder is also usually wet with fuel around the sparking area. Unlikely to be the fuel injector.

 

[rs48635]

good news Mr K happy you visited both this forum and the owner
Get yourself a code reader anyway. Nobody has gloves anymore so space to store the device for peace of mind.

 

[Mr K]

Glad to help a fellow forum member in distress.

it’s odd to see two coil pack/plug errors on one bank and feel it will be something further down the line affecting them.

Many thanks for your help Matt. Would you believe it I did 320 miles after you reset it, over 2 days, without it missing a single beat!

I think it's most likely to be something to do with me "carefully" pressure-washing around the engine bay (scuttle area and bonnet opening edge, never directly on the engine), and getting the electrics wet with overspray. What I don't understand is how that would manifest itself only after 30 miles, twice on the same day, the second time after cooling down for 1.5 hours and then driving a further 35 miles. Maybe we have physicist members who can come up with a hypothesis. Another possibility is old fuel. I had about half a tank of months-old fuel and filled with fresh before setting out. Not convinced, as why would it only record misfires on cyls 1 & 3?

I'll move the coil packs as discussed and get a compatible OBD reader so I can diagnose it if it happens again.

Anyway, it was b****y great to drive it again, I've hardly used it this year thanks to lockdown and working from home. I've probably run, walked and cycled more miles this year. I'd almost forgotten how good it feels and sounds, even at legal speeds.

 

[Adel68]

Hi Mr K,
I have the same problem misfire on cyl 1 and 3.
I have already change coil ignition and spark plug.
what should i do please?
Maserati Qp 2007 4.2

 

[Zep]

Have you checked to make sure you have the right cylinders? They are numbered unusually on the F136.



Also check the connections to the injectors, if you have a automotive stethoscope you should be able to hear them fire.

 

[Mr K]

Hi Mr K,
I have the same problem misfire on cyl 1 and 3.
I have already change coil ignition and spark plug.
what should i do please?
Maserati Qp 2007 4.2

So many possible causes, and so little information!

Do a battery reset, then clear the codes; see if it comes back. If it does, swap coils & plugs around, see if it follows the parts.

One of the many causes of these codes can be bad fuel according to an expert on the other forum. Fuel is >=5% ethanol (in Europe), which attracts water, and old fuel will have a few drops of water. Plus it goes off generally over time. There's been a lot of old fuel in cars due to the pandemic. A friend's car failed its annual MoT (UK safety & emissions) test due to old fuel. Obviously the thing to eliminate next. It's not too hard to remove the tank to completely drain it when it's almost empty.