Gremlins in a Zafira Engine
Discussion
Hi All,
So I've got the strangest problem I'm trying to sort out for my dad with his Zafira A. He's got a 2004 Zafira A with a z16xe engine. The problem is that quite often it seems to be idling erratically. It will sit around the 500-600RPM mark quite happily one minute and the next it will bounce all round the place, 300-1000RPM. Never seems to stall though and from what he tells me it does it more when the cars hot (I've seen it do it both hot and cold). Also when it's idling erratically it feels like it's down on power pulling away, but only when it's misbehaving. When its idling ok it pulls just fine.
The whole thing seemed to start when the car threw out a front lambda sensor error. Since then we've changed Front Lambda, Rear Lambda, had an exhaust section changed that had a hole, flushed the engine of oil and coolant and replaced with manufacturer spec fluids. Changed the oil filter, fuel filter, spark plugs and the coil pack was changed a few months ago. They weren't manufacturer parts but were recommended Bosch and NGK parts.
In addition I've stripped the throttle body off the car and completely cleaned it out, including the little hole that gets bunged up. I've also checked all the air hoses for leaks and (I know its bad) checked for rev changes with some spray round the engine when running. Nothing comes up bad. The throttle body was pretty dirty but its spotless now and it still idles erratically when it feels like it.
Couple of extra bits, it doesn't have a mass airflow sensor it's only got a MAP sensor and it doesn't have an EGR valve, its blanked off. On the "check everything" list the oil was free from mayo before the change so hopefully lowers the chance of something like a head gasket or head crack. This thing has got me completely stumped, any ideas?
It's got just shy of 100,000 miles on it but its been driven pretty sensibly since he got it at around 20,000. The best part is the mechanic that MOT's both our cars is stumped too. His latest suggestion is run it on Premium Petrol, but can't see it being a fuel problem with a brand new fuel filter?
Any help appreciated.
So I've got the strangest problem I'm trying to sort out for my dad with his Zafira A. He's got a 2004 Zafira A with a z16xe engine. The problem is that quite often it seems to be idling erratically. It will sit around the 500-600RPM mark quite happily one minute and the next it will bounce all round the place, 300-1000RPM. Never seems to stall though and from what he tells me it does it more when the cars hot (I've seen it do it both hot and cold). Also when it's idling erratically it feels like it's down on power pulling away, but only when it's misbehaving. When its idling ok it pulls just fine.
The whole thing seemed to start when the car threw out a front lambda sensor error. Since then we've changed Front Lambda, Rear Lambda, had an exhaust section changed that had a hole, flushed the engine of oil and coolant and replaced with manufacturer spec fluids. Changed the oil filter, fuel filter, spark plugs and the coil pack was changed a few months ago. They weren't manufacturer parts but were recommended Bosch and NGK parts.
In addition I've stripped the throttle body off the car and completely cleaned it out, including the little hole that gets bunged up. I've also checked all the air hoses for leaks and (I know its bad) checked for rev changes with some spray round the engine when running. Nothing comes up bad. The throttle body was pretty dirty but its spotless now and it still idles erratically when it feels like it.
Couple of extra bits, it doesn't have a mass airflow sensor it's only got a MAP sensor and it doesn't have an EGR valve, its blanked off. On the "check everything" list the oil was free from mayo before the change so hopefully lowers the chance of something like a head gasket or head crack. This thing has got me completely stumped, any ideas?
It's got just shy of 100,000 miles on it but its been driven pretty sensibly since he got it at around 20,000. The best part is the mechanic that MOT's both our cars is stumped too. His latest suggestion is run it on Premium Petrol, but can't see it being a fuel problem with a brand new fuel filter?
Any help appreciated.
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