astra h squealing+ oxygen sensor problem

[martand]

hi again guys! im afraid i need some help again, our lasses astra has developed a problem, the engine revs up and down on tickover and makes an awful squealing noise. ive got a fault code po138 o2 sensor signal fault, and the fuel system is in constant open loop . now and again it can be overcome by a few revs but smokes pretty bad . the engine is a 1.6 z16xep any ideas guys thanks!

[oldford]

P0138 is not the fault you are looking for. This is the sensor after the cat, which has no influence on fueling or ignition.
Carefully check the inlet and exhaust manifolds for leaks. Check all hoses around the inlet manifold for leaks.
Can you read live data in EOBD? Then post Long Term Fuel Trim and Oxygen sensor signals at idle and 3000 rpm.

[hackerabcd]

with engine running is it hard to remove the oil cap ? if so you will have to replace the rocker cover

[Albanais]

with engine running is it hard to remove the oil cap ? if so you will have to replace the rocker cover
Take a brake pads cleaning spray and spray all over the inlet manifold pipes, if the revs will rise up you have already resolve your problem

:deal:

[dafdiagnos]

as with the posts above, it sounds like a leak on the inlet side which will throw out the lambda & fueling

[martand]

thanks for your intrest guys! i will find time in the morning to plug on to the car and get the readings, i see what you mean by intake problems causing it to hunt for fuel .

[martand]

i used auto enginuity to take these readings here goes! got fault code p0130-04 o2 sensor range performance bank 1 sensor 1. at start up cold both o2 sensors reading 99.06 fuel system in closed loop. at 3000 rpm o2 sensor 1 at constant 1.24 v sensor 2 at 0.76v fuel trim sensor 1 was 0.00 fuel trim sensor 2 was 99.06 at idle fuel trim sensor 1 was 99.06 sensor 2 was 0.08 the squealing has stopped so the car is being used , but ive got a crecorder on it.

[oldford]

The fuel trims you describe are the short term fuel trims.
99% here isn't 99%, but it's a special case where the value is 0xff and means NOT USED.
The interesting value is the LONG term fuel trim (Pid 7).
See: OBD-II PIDs - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/OBD-II_PIDs)

[martand]

sorry! yes you did ask for long term results i will leave the recorder on for a couple of days then let you know then thanks!

[martand]

the readings from the data recorder are long term fuel trim bank 1 minimum 0 max 6.25

[oldford]

That's well within limits.
Is the car in closed loop or open loop? Because this in total contradiction with black smoke coming from the exhaust.
What signal do you get from the oxygen sensors?
Are there fault codes present at the time?

[kev50]

Make sure the exhaust isnt blocked and the cranhshaft pulley hasnt slipped altering the timing both very common problems.

[martand]

the fault code present is po130 -04 oxygen sensor range performance bank 1 the fuel system is in closed loop, and oxygen sensor 1 reads 1.24 volt sensor 2 reads 0.76 at 3000 rpm . the black smoke stopped when the squealing did

[oldford]

Oxygen sensor 1 is far out. Should not be more than 0.95 Volt. Either some short circuit on Oxygen sensor signal or sensor defect OR the engine is realy that rich.
What's the map sensor reading at engine off, engine idle and engine at 3000 rpm.
Whats the Oxygen sensor 1 signal with engine cold and NOT running (just before starting it the first time).

With this fault code the Closed loop control is disabled. So you need to fix this before anything else.

[martand]

i have replaced the oxygen sensor and all is fine now! thanks for all the tips guys!

[shanez26]

Hi i have been reading these post and my Astra has the same problems described did yours also loose oil? Could the oxygen sensor problem cause the engine to lose oil? and it is still ok after you had the sensor replaced.

Any replies would be great

Thanks

[oldford]

Oxygen sensor normally does not cause the engine to loose oil. At least not directly.
A defective oxygen sensor can cause a very rich mixture, which then washes away the oil on the cylinders. That causes a high wear and that will lead to oil usage.

Is the engine malfunction indicator on?

[shanez26]

Oxygen sensor normally does not cause the engine to loose oil. At least not directly.
A defective oxygen sensor can cause a very rich mixture, which then washes away the oil on the cylinders. That causes a high wear and that will lead to oil usage.

Is the engine malfunction indicator on?


No the engine malfunction light does not come on. The only light that comes on is a picture of an oil can with a zig zag line under it this came on after about 260 miles after i toppped the oil up, so basically after 260 miles the oil dropped enough to make the low oil light come on.

[oldford]

Any oil on the engine or under the car? Then it's leaking.
Blue smoke behind the car? Then it's burning oil.
A lot of black spots on the rear of the car? That's oil coming out of the exhaust.

[shanez26]

Any oil on the engine or under the car? Then it's leaking.
Blue smoke behind the car? Then it's burning oil.
A lot of black spots on the rear of the car? That's oil coming out of the exhaust.


It is the smoke option but you notice it more just after starting the car can't really notice it alot when driving on the motorway as this is where most of the miles were done. If it is burning oil because it is running rich would it burn it so it was noticeable all the time or would you notice it when stationary? And it only does the Fluctuating revs when the car is at normal operation temp not when cold?

Thanks for your replies

[dafdiagnos]

how much oil did you have to add to top it back up? is it a loud squealing noise that stays same no matter what revs like an inlet leak, or does it speed up/ increase with revs like bore wash or oil control ring failure

[shanez26]

how much oil did you have to add to top it back up? is it a loud squealing noise that stays same no matter what revs like an inlet leak, or does it speed up/ increase with revs like bore wash or oil control ring failure


It is exactly like the description at the beginning of this discussion it only does it af about 1500 revs anything above or below that it stops.

[shanez26]

how much oil did you have to add to top it back up? is it a loud squealing noise that stays same no matter what revs like an inlet leak, or does it speed up/ increase with revs like bore wash or oil control ring failure

Hi again. I replaced the oxygen sensor but it has made no difference still the whistling noise at 1500 revs ish and only when engine is hot. And the rev fluctuation is still there too.

Any help appreciated.

[dafdiagnos]

i'd check for inlet leaks spraying brake cleaner as posted @ inlet manifold & pipes @ throttle body. if no increase in revs then no leaks on inlet side. i think if lambda sensor fault, eml would have illuminated. it could well be injector fault but hard to say without seeing car. is coolant temp sensor reading accurately?

[shanez26]

Hi again just an update. I have had the coil pack replaced as that went yesterday (GRRRRR) oxygen sensor done but still making noise and idleing up and down when hot. Its at garage now and they have said that the squeaking noise is the timing belt pulley or something has lost grease so needs replacing ie a belt kit. Hopefully this will sort it.

[martand]

ive got problem again now ! engine temp 104 fan not kicking in revs up and down rocker gasket leaking . i think the squeeling is the ac compressor autodata gives it as a common fault and can be sorted with software upgrade