z18xe misfire/temp/emissions prob

[jimmyred]

hello all. I have been having a problem with my vectra since this cold weather started. It is misfiring at low revs when accelerating. Mostly when cold and just started engine but sometimes at other times. The emissions light has been on too, and fuel economy not great. I have cleaned TB and redex'd it, also airbox mod. Performance greatly improved but not fixed misfire even tho i try and tell myself its better! I have also realised that the temp gauge NEVER moves off zero. I had just assumed gauge failure, but after reading around forums I realise this could mean thermostat or engine temp sensor. The heater works but not spectacular and slow to warm up. I had a look at thermostat housing and the wire going to it has a crumbled casing exposing bare wire. Clearly a trip to garage is on cards. But I'm skint and don't know a lot about cars, I'm learning cos I can't afford to pay for unnessasary work, so I want to have a rough idea before I go and what the going rate is. What I want to know is could the misfire be connected to a temperature fault? Presumably if the computer doesn't know the temp it will get fuel mix wrong causing over consumption and emissions, but could this be causing misfire too? I have pedal tested following codes: 0115: engine coolant temp malfunction. 0301:cylinder1 misfire detected 1481: fan secondary low with high fan? 1482:SCP?
1565: speed control command control switch out of range.

The last three were present when I took it to garage i bought it from, with on off spanner in car light, a while back. They told me one was cruise control(made sense cos its tempremental) and first that other two were cooling fan, then mechanic noticed heater fan was squeaking and decided must be that. I have lubricated squeaking heater fan, but light still came on. Spanner light not been on since emissions light appeared however, which is some comfort.
Any help or advice gratefully recieved before I return to garage, or perhaps a different one.

[jimmyred]

excuse no paragraphs, thought i put em in but did on phone

[Jezzy]

Try changing the spark plugs - that may especially help on cylinder 1.

[jimmyred]

cheers that is probably a good idea. It may shock you to learn I have never changed a spark plug, but it did occur to me that would be next thing to do. Basically can't afford garage till end of month so just faffing around with it using my extremely limited knowlege, internet,and haynes manual. If thats all it is i will be well pleased.

[Big Sig]

Z18xe? It will be the thermostat and most likely the plugs and/or coil pack.

[jimmyred]

ok well i will try plugs first see if that helps misfiring cylinder. Is thermostat urgent or can it wait until end of month? Doesn't sound expensive but perhaps bit ambitous for me to do myself. If it needs doing now i could prob scrape money up.

[ChrisBilly]

Here's DasArabs 'How2 Change Thermostat Z18XE' http://www.vectra-c.com/forum/showthread.php?t=122762
Replacing just the thermostat as in the How2 will cost around £14 for the stat and some instant gasket. Or you could replace the stat and housing but thats around £60 from the stealers and a waste as there's nothing wrong with the old housing.

[goafer]

Whilst doing thermostat just before christmas I also noticed Temp sending wire badly crushed & stripped although not bare quite yet! Is this common? I just patched up with electric tape as it appeared to be only housing damage. Also if it helps I also have no mechanical experiance but managed thermostat EASY & as long as you have socket ratchet here is what it cost me 6weeks ago ish..
Autofactors: QTH600K £10.20
x3 Hose clips £2.14
Halfords: Gasket sealant £5.49
E12 & T30 bits £8.50
Vauxhall: 5L Antifreeze £16.57
=£42.90
You could possible save abit more by getting 2x 1 litre Anti Freeze for time being, I believe £3 ish each from vx?? Dont hold me to that! + I only used 1 hose clip but hey safer than sorry

[jimmyred]

yes it looks like wire has been rubbing on edge of engine cover. I have been looking at the how2 and it doesn't look too hard. Everyone I know tells me you can't meddle with modern engines because of 'all the computer stuff'. But the way I see it the computer stuff is there to make things easier. Plenty of people meddling with their engines on here anyway! Cheers everyone for advice. Can I change just one spark plug, or is it best to do em all? And if so which end is cylinder one?

[Big Sig]

Never do one, change the set.