Engine woes

coach_potato

I have a 51 plate Vectra petrol 2.2 CDX estate. Ever since I've had it I've had issues with the EML staying on. It's been turned off a few times but will come back on again after a few days or maybe even a few weeks. I've had opcom/tech 2 on it and the code always comes back as PO420, this basically translates as a catalyst/lambda sensor fault. I have since replaced the front pipe with a good 2nd hand unit and the fault still persists.
I also have had an issue with the running of the engine. It has never let me down but does run rough on idle. I notice it more when starting from cold whilst on fast idle as it slowly comes off fast idle, it really is rough then and once warm you can feel it running a bit lumpy through the steering wheel. If I try to start it when it's warm it takes a few turns before it catches and then seems to start on 2 or 3 cylinders before running on the full quota.
I did think these two faults to be related but have been told since that it probably isn't.
The engine has done 61k and when I bought it last year off ebay it was onky in 47k, the engine had had a broken timing chain which had been replaced and the head itself looks new.
Ideas and comments welcome. 😃

coach_potato

Better mention that I have also fitted an EGR blanking plate and cheater.

Matt

Have you actually replaced the lambda sensors yet?

coach_potato

Matt said:
Have you actually replaced the lambda sensors yet?

Tbh no, well not new ones anyway. When I replaced the front pipe/cat with the 2nd hand unit it had lambda sensors fitted in so used those ones so although they aren't news they are new to the car. How much do new ones cost and where's best to get them from and are they both the same?

pottsey

coach potato said:
Tbh no, well not new ones anyway. When I replaced the front pipe/cat with the 2nd hand unit it had lambda sensors fitted in so used those ones so although they aren't news they are new to the car. How much do new ones cost and where's best to get them from and are they both the same?

looking at around 50ish odd for one and 40ish odd for the other ,have a word with derry see if he can get them cheaper through work

MikeS

lumpy idle usually indicates timing, egr valve

could try coolant temp sensor however I believe you have more than one fault

so front lambda & coolant temp sensor

coach_potato

pottsey said:
looking at around 50ish odd for one and 40ish odd for the other ,have a word with derry see if he can get them cheaper through work

Not as much as I thought tbh. Will do Jase.

coach_potato

MikeS said:
lumpy idle usually indicates timing, egr valve

could try coolant temp sensor however I believe you have more than one fault

so front lambda & coolant temp sensor

Saw something about coolant temp sensor can cause problems somewhere before. Where on the engine is this located?

MikeS

thermostat housing below egr valve

it wont cause lumpy idle but will cause it to cut out when warm, hesitancy

knackered front lambda will cause like a slight misfire around 2500 rpm, rough idle, p0420 codes, shite mpg

it does sound more like a chain problem, head gasket, cracked head

so check spark plug holes for coolant

coach_potato

MikeS said:
thermostat housing below egr valve

it wont cause lumpy idle but will cause it to cut out when warm, hesitancy

knackered front lambda will cause like a slight misfire around 2500 rpm, rough idle, p0420 codes, shite mpg

it does sound more like a chain problem, head gasket, cracked head

so check spark plug holes for coolant

The chain was replaced by the chap I had bought the car from but I think he only replaced the broken chain and not the whole timing set up. I also think he has replaced the head with a recon unit but at the very least replaced damaged valves but I am leaning towards him having had replaced the head. Running problems caused by lambda sensor sounds more like it although I've not noticed misfire at 2500rpm. Think I'll replace coolant sensor and both lambda sensors just to be sure and see what happens.

Thanks, will report back when done.

pottsey

coach potato said:
Not as much as I thought tbh. Will do Jase.

6th and 7th ones down on here
http://www.lambda-sensors.co.uk/vauxhall/vectra/ecotec/2001

Matt

pottsey said:
6th and 7th ones down on here
http://www.lambda-sensors.co.uk/vauxhall/vectra/ecotec/2001

Those are a good price! Quite a bit cheaper than AutoVaux
http://www.autovaux.co.uk/LoadPortal.aspx?cnum=85&tabid=5&vnum=136

coach_potato

MikeS said:
lumpy idle usually indicates timing, egr valve

could try coolant temp sensor however I believe you have more than one fault

so front lambda & coolant temp sensor

Just been to Vauxhalls to buy a coolant temp sensor but was unsure if I was buying the right one especially as I was told there were two sensors. One by the thermostat and another called a timing sensor. Any clarification please?

pottsey

You want the one near the thermostat jim .dont know what the timing sensor one is

coach_potato

pottsey said:
You want the one near the thermostat jim .dont know what the timing sensor one is

Thanks Jase.

Matt

This is the part you want:
https://z22se.co.uk/shop/service-parts/water-temperature-sensor

coach_potato

Matt said:
This is the part you want:
https://z22se.co.uk/shop/service-parts/water-temperature-sensor

Thank you Matt, didn't realise it was available on here, will order it Friday I think.