Vauxhall Astra design twinport mk v(5) 2005 1.6 failed MOT

Vauxhall Astra design twinport mk v(5) 2005 1.6 failed MOT

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kevintesta

Original Poster:

7 posts

141 months

Thursday 7th February 2013
quotequote all
Hello all,

My Vauxhall Astra design twinport mk v(5) 2005 1.6 failed its MOT today on emmisions see below.

I have ordered a new CAT and 02 sensor. Have a few questions for you

Is it possible its something else?

Any one know of any guides for changing CATS or have any advice for my car?

Thank you

http://postimage.org/image/shio5k08b/

Edited by kevintesta on Thursday 7th February 15:58

Crafty_

13,482 posts

207 months

Sunday 10th February 2013
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Cat is just part of the exhaust, so no different to changing one of those really.

If the car is running correctly (a ratio of 14.7/1, or stoichiometric) the lambda reading will be 1, above that the engine is lean, below it its rich.

The ECU will control fuelling by working out how much air goes in to the engine and then checking the lambda reading and then adjust fuelling as required.
So, if the ECU measures the amount of air entering the engine incorrectly it could put too much fuel in, causing rich running.
Air entering the engine is (usually) measured by the MAF sensor on modern engines.. if this has gone faulty (which they do) it could give an incorrect reading.
Also, if the MAF correctly measures the amount of air but some of that air leaks out before it actually gets to the combustion chambers we have the same scenario.

SO in theory your MAF sensor could be the culprit.
You might have an air leak

At the same time if the air measurement is correct, but the lambda sensor isn't working properly it could tell the ECU to add too much fuel.

Without seeing the car its difficult to say. I think I'd try and fix the rich running before replacing the cat, it might not be needed.
I would put the lambda sensor in, seeing as you have it. Drive it about a bit then get the emissions checked and go from there.

kevintesta

Original Poster:

7 posts

141 months

Thursday 14th February 2013
quotequote all
Hello Here is a update,

I am having problems with my car these are symptoms -
vauxhall astra design twinport mk v(5) 2005 1.6 has done 70K miles


Failed on MOT all emissions (See link)
http://postimage.org/image/shio5k08b/
- Running very lean
- ECU putting tons of fuel in because of lean running so its eating tons of fuel
- White intermittent smoke from exhaust only seen myself once

Garage number one says (After MOT fail on emissions) -

The o2 sensor gone and needs a new CAT. (£550)

Garage number two says (After emissions fail and white smoke)

- Needs new engine (Piston rings gone) (£1500)


What I have done

- New sparks
- New air-filter
- Various chemical cleans (RedX, Injector Cleaner, Cataclean)
- Only one error code now cleared and not returned (Running lean)
-Linked to laptop no obvious problems

Possible problem
- the o2 sensor might not be functioning correctly seems to take some times a few seconds to cycle further testing will be done on weekend although this does not explain white smoke.

Points to note

- Car idle perfect
- Car drives fine
- Using lots of fuel
-No signs of blow headgasket

When the car was running I put my hand under exaust fumes and it was so hot it burnt
when the car was blowing white smoke I put my hand in same place and it was just warm air, I could also feel flicks of liquid got a white piece of paper and the liquid was clear like water.


Any suggestions as to what could be causing white smoke.

Originally thought maybe the cat is dead but this would not cause smoke.
Then thought maybe its unburned fuel but this would be black smoke.

Crafty_

13,482 posts

207 months

Friday 15th February 2013
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You are correct that fuel would show as black or grey smoke. White smoke is usually moisture of some sort, a failed cat wouldn't cause white smoke (not that I've ever known anyway).

If you are concerned about the piston ring diagnosis get a compression test done. Sounds untrusting but I'd not do this at that garage. I don't think its a problem (but keep in mind I haven't seen the car).

I would be tempted to change the lambda sensor and then see what the emissions look like. Cats do wear out, so they might be right but all bets are off until we know the lambda sensor is good.



kevintesta

Original Poster:

7 posts

141 months

Friday 15th February 2013
quotequote all
All I want todo at the moment is get it though the dam MOT!

Some one has suggested their is a gasket leak but no signs of this apart from the white smoke

- Sparks good condition
- No milky stuff in oil
- Idle and drives fine

Yanayaya

912 posts

191 months

Friday 15th February 2013
quotequote all
Over fueling can also cause white smoke in some cases so don't be too hasty in taking the advice that your head gasket it borked.
Typically over fueling would cause black smoke however on my car it actually caused white smoke simply because there was so much fuel getting dump which turned out to be my fuel pressure regulator being faulty (I also failed emissions last year).

It may be worth running some CataClean through the car as well (whilst I notice you have said you have a new o2 sensor and cat this chemical cleans all sorts inside the engine as well). In terms of your O2 sensor what did you buy it from Vauxhall? I have seen times where 3rd party "cheaper" lambdas produce wonky results, ensure for your own piece of mind that you have proper parts.

I'm not sure about the Astra MK5 but with my engine the Coolant Temperature Sensor can cause strange fuelling issues despite not registering a fault. For your car they around £15 to buy and it may be worth replacing it.

To summarise, my advice would be:

1) Get a garage to check the voltage cycle on your O2 sensor to make sure its changing correctly.
2) Ensure your O2 sensor came from Vauxhall and if not, replace (It will be BOSCH that Vauxhall give you).
3) Replace your CTS (Coolant Temperature Sensor) as a matter of course just to be sure.
4) Have your fuel pressure checked at a garage, if she is running lean/rich it may be worth checking to find out what it's at.
5) If you haven't already it may be worth putting new plugs in and checking the gap just for piece of mind. I had running issues which also came down to fuel which turned out to be plugs, they looked ok but they weren't.
6) Run some CataClean and go for a long drive.

Worst Case Scenario:

1) Carry out a compression test and find out whats going on inside your engine.


References for you:

1) Place to buy Vauxhall parts. http://www.autovaux.co.uk/LoadPortal.aspx?tabid=4
2) CTS Information: http://vauxhall.workshop-manuals.com/astra-h/index...

Edited by Yanayaya on Friday 15th February 09:01

kevintesta

Original Poster:

7 posts

141 months

Friday 15th February 2013
quotequote all
New update -


I have some picture to follow.

While the car was idleing about an hour on and off. I noticed a large puddle on the floor by exhaust after smelling it, it just seems to be water but as I understand it no fluid should be coming from exhaust. This was accompanied by small amount of white smoke. 



Checked the coolant and doesn't seem to be going down going to buy a test kit from eBay to check the gasket.


idle only results

http://postimage.org/image/3xs5cmb4n/

http://postimage.org/image/tknojkaxn/

http://postimage.org/image/qkbfgrp0b/

kevintesta

Original Poster:

7 posts

141 months

Saturday 16th February 2013
quotequote all
Ok so this will most likely be the final update, after doing the following with no results

Compression test shows OK, No fluid loss.
White smoke still coming out of exhaust.
EGR valve cleaned.
New air filter
New spark plugs
Full diagnostic checks on various software no signs of any fault.

While doing the Compression test we did notice that one of the spark plugs looked almost new, only been in about four days but they others where already showing wear this one plug looked like it was new.


I have decided its time to take it to a garage. I just want to ask what do I ask for, I fear that they will just plug in the ECU code reader see no codes and charge £35 then do some other tests and charge me. And what can I expect a full diagnostic to cost.

On another note don’t spouse any one knows how to find a a good garage, any review sites for this. Looking for one in Portsmouth.

Crafty_

13,482 posts

207 months

Saturday 16th February 2013
quotequote all
I'd change the lambda sensor, you can do it yourself, 22mm spanner normally, get under the car you'll see it sticking out of the exhaust at right angles, there is just an electrical plug on the end.

Not sure about a garage, its a bit off my patch. Ask in the South Coast section maybe.

kevintesta

Original Poster:

7 posts

141 months

Saturday 16th February 2013
quotequote all
diagnostic software showed no fault with o2 sensor frown

Crafty_

13,482 posts

207 months

Saturday 16th February 2013
quotequote all
oops, sorry, missed that bit.

Ask in the osuth coast bit for a garage.

callyman

3,159 posts

219 months

Sunday 24th February 2013
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This guy in is Andover, you wont find a better VX mechanic.
Sheldon North
WWW.SNVX.CO.UK