Technical My stilo

[Deckchair5]

O2 No 1 pre cat is the one that is most relevant for tuning and it's output is taken most notice of for fuelling.
O2 No 2 post cat is largely there to check the operation of the cat and double check the pre cat O2 sensor

I think O2 No 2 is reading correctly as in the top trace it follows No 1 when you are accelerating and decelerating so it's functioning and it's copying what No.1 is saying at those times quite correctly

 

[Seraph]

well in that case...********.

the coils are brand new, so I'll be thoroughly annoyed if they're boned...
the head's been pressure tested since being re-fitted.

the plugs are all in good condition, and the air filter is an induction kit, which appears to be in working order - besides it was there before all this shat.

 

[Seraph]

ok, so i've been undferneath my car, and I can find nothing to suggest there's a leak in my exhaust.

the problem is getting worse again, which suggests that something in the day to day running of the car is progressively getting my car clogged up or something.

it's starting to do my head it.:bang::bang::bang:

 

[Rich]

Who did all this engine repair work?

Just re-read it again, and saw that your timing belt went the first time round, then the tensioner went?

My thinking is around the big-end bearings line and the engine not being able to manage it's power correctly as a result. Do you hear any knocking from the engine during idle?
Does the oil pressure light ever come on whilst driving?

 

[Seraph]

Who did all this engine repair work?

Just re-read it again, and saw that your timing belt went the first time round, then the tensioner went?

My thinking is around the big-end bearings line and the engine not being able to manage it's power correctly as a result. Do you hear any knocking from the engine during idle?
Does the oil pressure light ever come on whilst driving?

oil pressure light doesn't come on while driving, only on the first cold start of the day, and i really mean that, i can let the car sit for 8hrs in one day and come back and no oil warning.

there's no knocking sound, but there is a really really loud raspy electronic sound coming from the engine bay when it starts up cold, that does go away after a few minutes though.

the idling is just as bad, but it's stalling more frequently the last 2 days.
and to add insult to injury, the engine cut out the other day just as I was parking and I curbed one of my wheels. first time.

the engine work was done by a mate of mine, he's a really experienced mechanic, and he's always been really good. the issue withthe timing belt to be honest I think he stuffed up a bit, but I've no real idea. Aparently the tensioner loosened off and i the timing belt went.
i couldn't say really, cos like i say, I'm not a mechanic

 

[Rich]

Ok, how long ago was oil / filter change?

If you rev it above idle, does everything sound/respond ok?

 

[Seraph]

Ok, how long ago was oil / filter change?

If you rev it above idle, does everything sound/respond ok?

it was in for a full service when the repair work was last done... I have actually only assumed that the garage had done an oil/filter change, but I had a fresh bottle of 10w40 in my footwell, which was near empty...

i can hold revs and it's fine, like i say which the gears are engaged, there's no problems. 2nd's not as punchy as it used to be, but other than that, seems to run smooth...
until we disengage the gears and then we have the idling troubles.

annoyingly too the mpg seems to be ok too for cold weather... about 29.6mpg which is about what I was getting before.

 

[Rich]

Ok, so the engine runs perfectly when not idling. Thats a good thing .

When you did your diagnostics on the engine, did the coolant temperature rise properly from cold?

 

[Seraph]

Ok, so the engine runs perfectly when not idling. Thats a good thing .

When you did your diagnostics on the engine, did the coolant temperature rise properly from cold?

yes, perfectly.

what's thie brake switch thing, could that have anything to do with it? and how do I find it and beat it to death?

 

[stilosporting]

brake switch? you referring to the brake light switch? are your lights sticking on?

 

[Seraph]

brake switch? you referring to the brake light switch? are your lights sticking on?

no, something else, about the engine cutting out when you brake.

 

[Rich]

Wouldn't make a difference.

 

[Seraph]

Wouldn't make a difference.

glad to hear it.
what else then?
i've got some vouchers for halfords, so i'm gonna get some 5w40 oil and a spark plug wrench...

 

[Seraph]

does the 1.6 have a MAF sensor?

 

[Deckchair5]

You're running rich Seraph. Your Post Cat O2 is flat lined full rich. You think it sounds rich and your mpg isn't great. Go with your gut feelings

Try it at steady 40mph on the flat 5th gear. Select inst consumption -Should be hovering 50mpg or more

Av mpg should be an easy 35mpg around town near 40mph on a run.

Disconnect the pre cat O2 sensor and try a run. See if it improves tickover as it will run on base settings (it'll fire up a warning but it'll be sorted after 3 clear starts again after reconnecting)

Your O2 sensors look very unhappy with what’s coming down the exhaust in your traces.

Changing oil wont do anything to help but new plugs are always good. They’re pretty cheap on the 1.6



1.6 has a MAP sensor (that's what you're readiing in your inlet manifold pressure trace) and that wont affect your tickover. You could disconnect that too on a different run to eliminate it if you like

Connect it all back up and give us another trace of varying revs and at tickover -both O2 sensors on top and rpm and car speed on bottom

 

[Seraph]

You're running rich Seraph. Your Post Cat O2 is flat lined full rich. You think it sounds rich and your mpg isn't great. Go with your gut feelings

Try it at steady 40mph on the flat 5th gear. Select inst consumption -Should be hovering 50mpg or more

Av mpg should be an easy 35mpg around town near 40mph on a run.

Disconnect the pre cat O2 sensor and try a run. See if it improves tickover as it will run on base settings (it'll fire up a warning but it'll be sorted after 3 clear starts again after reconnecting)

Your O2 sensors look very unhappy with what’s coming down the exhaust in your traces.

Changing oil wont do anything to help but new plugs are always good. They’re pretty cheap on the 1.6



1.6 has a MAP sensor (that's what you're readiing in your inlet manifold pressure trace) and that wont affect your tickover. You could disconnect that too on a different run to eliminate it if you like

Connect it all back up and give us another trace of varying revs and at tickover -both O2 sensors on top and rpm and car speed on bottom

saw you lurking and wondered when you'd post...

i don't know how to disconnect the precat sensor...other than "pre-cat, i don't know where it is.

as for new plugs, i'm tempted to believe that even if i've had new plugs, (which was before the timing belt went.) i reckon they could be as good as shagged now.

 

[Deckchair5]

Ha! Must admit though I'm getting stumped without seeing the engine running. Put some new plugs in though if you're in any doubt

Here's the precat sensor wiring connector, real easy on the 1.6 as it's right on top.


Pre cat No 1 O2 sensor connector


post cat no 2 O2 sensor connector


MAP sensor

 

[Seraph]

now, you'll laugh...

that first picture... errrr where the hell is that referring to...?

or wait, is the thing to the bottomr right the coolant reservoir?

 

[Seraph]

another point i have is that if I rev it really high out of gear, why does it not stall when i take my foot off?

it only stalls when it's coming out of gear...

 

[stilosporting]

when revving out of gear it comes down slowly? when diping clutch it comes down quickly?