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VW Golf 1.4 16V AUS 2000 - Emissions failure, cats replaced - Fixed #

Posted by Paul Howd on September 8, 2015, 5:53 pm

Year of Manufacture *: X reg
Engine Size and Code *: AUS

When I first saw this there were a load of codes relation to the front oxygen sensor. I replaced this and the fault codes have not returned. Customer also reports that car drives much better. However the emissions did not pass the MOT.

I replaced the Cats (there are two) with after market type approved units and although the emissions are a little better they are still not better enough

Idle

HC 249
CO 0.229
CO2 15.56
NOX 0
O2 0.08
Lambda 0.988

Fast Idle

HC 56
CO 0.410
CO2 15.51
NOX 0
O2 0.03
Lambda 0.986

What is wrong?

I cant help feeling that the rather high HC at idle is a give away. When I go back to it I am going to check the camshaft timing. (I can see that somebody has replaced the timing belts at some point) But at the moment I am just frustrated with it.

Even more frustratingly there does not seem to be any mechanism via VAG-COM to monitor the primary O2 sensor behaviour!

Any other suggestions for when I go back?

TIA,

Paul

Re: VW Golf 1.4 16V-emissions fail. What is wrong?

Posted by Andy Broomhead on September 8, 2015, 8:55 pm, in reply to "VW Golf 1.4 16V-emissions fail. What is wrong?"
Edited by board administrator September 10, 2015, 9:35 am

Try lookin using the EOBD side of your VCDS, what version are you using to call is a vag com?

Re: VW Golf 1.4 16V-emissions fail. What is wrong?

Posted by aidan birley on September 8, 2015, 9:53 pm, in reply to "Re: VW Golf 1.4 16V-emissions fail. What is wrong?"
Aidan Birley

Hi

Is this a wide band sensor ?

Looks slightly to rich to me.

What are the fuel trims showing ?

What where emission readings with old cat ?

As Andy said, EOBD can be useful with Emission faults

Aidan

Re: VW Golf 1.4 16V-emissions fail. What is wrong?

Posted by Peter Mutlow on September 9, 2015, 6:19 am, in reply to "Re: VW Golf 1.4 16V-emissions fail. What is wrong?"
Peter Mutlow

Hi Paul,

From my balcony in the Philippines drinking ice cold beer, I would suggest you change the oil and check crankcase breathing if you have not already done so.

It is an old car... It may require more efficient catalytic converters. I.e the genuine article.

Regards

Pete M

Re: VW Golf 1.4 16V-emissions fail. What is wrong?

Posted by Paul Howd on September 9, 2015, 7:50 am, in reply to "Re: VW Golf 1.4 16V-emissions fail. What is wrong?"
Paul Howd

Oil change already done. It may be old but the mileage isn't particularly high.

When I get back tomorrow I will check and report trims, manifold vacuum and physically check the timg belt.

Thanks

paul

Re: VW Golf 1.4 16V-emissions fail. What is wrong?

Posted by Ian Whitmore on September 9, 2015, 7:56 am, in reply to "Re: VW Golf 1.4 16V-emissions fail. What is wrong?"
Edited by board administrator September 10, 2015, 9:34 am

Check the block group for misfire counters, to see if any of the cylinders have a misfire, may explain the high HC ?
Have you also done a compression test or cylinder leakage, some of these espically on lower mileages suffer with worn valve guides,

Re: VW Golf 1.4 16V-emissions fail. What is wrong?

Posted by Kevin Apps on September 9, 2015, 8:46 am, in reply to "Re: VW Golf 1.4 16V-emissions fail. What is wrong?"
Kevin Apps

Paul

Read the info on the sticker inside the fuel filler flap ! but i suspect the damage has already been done.

Or do a forum search using AUS.

Kev.

Re: VW Golf 1.4 16V-emissions fail. What is wrong?

Posted by Paul Howd on September 10, 2015, 8:08 am, in reply to "Re: VW Golf 1.4 16V-emissions fail. What is wrong?"
Paul Howd

Interesting if alarming!

I would imagine The symptoms would end up being similar to tight valve clearances on an old mechanically adjusted engine.

Compressions might be good, but HC would be very high and inlet manifold vacuum poor.

The engine actually starts and drives reasonably well.

But how would one check this possibility without stripping it down??

In the old days one might check and adjust valve clearances. However with Hydraulic ones I can certainly see how they might go "Tight"(By ending up at the end of their adjustment range) but cant really see how one might easily check this other than by inference??

(Manifold pressure etc)

In my OP I said that the relatively high HC might bee a clue, thinking about it the low O2 and NOX might also be one (The Cat is actually doing its best) but the incorrect manufold vac might be producing an overfueling situation that the cat cant cope with.

Ho Humm,

Will report back later

Re: VW Golf 1.4 16V AUS 2000 - Emissions failure, cats replaced #

Posted by Paul Howd on September 11, 2015, 8:28 pm, in reply to "VW Golf 1.4 16V AUS 2000 - Emissions failure, cats replaced #"
Paul Howd

Anybody have any idea what the correct fuel system pressure should be for this.

I have two sources of information for this and they seem to be in conflict (One is Autodata)

:/

Re: VW Golf 1.4 16V-emissions fail. What is wrong?

Posted by Jon Morgan on September 12, 2015, 7:39 am, in reply to "Re: VW Golf 1.4 16V-emissions fail. What is wrong?"

Quiz the owner if it has a thirst for oil.

These early 1.4's had a bad habit of suffering ring trouble & breather issues.

Some of these engines were replaced under warranty back in the day for oil consumption - complete engine, VW didn't bother trying to repair.

Oil burners are difficult to get through the emissions & will have demolished those 2 x new cats by next year.

As a rule cars used for pottering about were more likely to suffer this.

Re: VW Golf 1.4 16V AUS 2000 - Emissions failure, cats replaced #

Posted by Jon Morgan on September 12, 2015, 7:47 am, in reply to "Re: VW Golf 1.4 16V AUS 2000 - Emissions failure, cats replaced #"
Jon Morgan

2.5 Bar @ idle, Vac hose to FRP regulator connected

3.0 Bar @ idle, Vac hose to FRP regulator off

See post above reference breather & ring trouble on these low milers.

Re: VW Golf 1.4 16V AUS 2000 - Emissions failure, cats replaced #

Posted by Paul Howd on September 12, 2015, 9:03 am, in reply to "Re: VW Golf 1.4 16V AUS 2000 - Emissions failure, cats replaced #"
Paul Howd

I don't mean to doubt you figures but what is your source?

I have a load of figures that I collected the other day but I do not have the time to post them just now. I will do so over the weekend.

Hopefully, we might have a winner. but I still have one more thing to check.

Paul

Re: VW Golf 1.4 16V AUS 2000 - Emissions failure, cats replaced #

Posted by Jon Morgan on September 12, 2015, 9:31 am, in reply to "Re: VW Golf 1.4 16V AUS 2000 - Emissions failure, cats replaced #"

"I don't mean to doubt you figures but what is your source?"

VW Workshop Manual Paul - They built the thing, so I can only assume they know what the fuel pressure should be?

I was going to email you the document, but you have no email on your post for me to send it to you.

Quote from the manual reference the pump pressure...

"Checking fuel pressure regulator and holding pressure

Fuel pressure is controlled by the fuel pressure regulator in accordance with intake manifold pressure.

The specification for this test depends on the working pressure of the fuel pump. The working pressure is approx. 3.0 bar."

Re: VW Golf 1.4 16V AUS 2000 - Emissions failure, cats replaced #

Posted by Paul Howd on September 12, 2015, 9:56 am, in reply to "Re: VW Golf 1.4 16V AUS 2000 - Emissions failure, cats replaced #"
Paul Howd

Thank you for that.

paul.howd@btinternet.com

As I said, I think we may have a winner.

Will report later.

Re: VW Golf 1.4 16V AUS 2000 - Emissions failure, cats replaced #

Posted by Jon Morgan on September 25, 2015, 8:57 pm, in reply to "Re: VW Golf 1.4 16V AUS 2000 - Emissions failure, cats replaced #"
Jon Morgan

Hi Paul, did you get a fix in this one?

Jon.

Re: VW Golf 1.4 16V AUS 2000 - Emissions failure, cats replaced #

Posted by Paul Howd on October 11, 2015, 3:23 pm, in reply to "Re: VW Golf 1.4 16V AUS 2000 - Emissions failure, cats replaced #"
Paul Howd

No!

I am well past the point of this being economic (either for me or the owner) but I do want to know what is wrong.

Fortunately the owner is not in a hurry and is being really quite nice about it.

The fuel pressure issue was a bust (I thought that the pressure was too high, but a new regulator made no difference so either it is meant to be like that or both of my fuel pressure gauges are faulty in exactly the same way!)

I have managed to take a pre cat sample by removing the egr valve, it is not perfect (There was clearly some leakage resulting in higher O2 levels than might be present) but it is clear that the pre cat HC is way too high (500+)

I also did a compression test, 3 cylinders were 220PSI, one was 210PSI. I would not normally have regarded this as a big issue, but coupled with the high HC and earlier comments about valve damage as a result of not using the correct fuel, a nasty picture is beginning to form in my mind!

I would be grateful for any links referring to the valve issue, despite searching I have not been able to find anything on line.

Re: VW Golf 1.4 16V AUS 2000 - Emissions failure, cats replaced #

Posted by andy pethig on October 12, 2015, 4:38 pm, in reply to "Re: VW Golf 1.4 16V AUS 2000 - Emissions failure, cats replaced #"

have you tried venting the crank case to atmosphire ??

if the 02 sensor eq ratio on the scan tool matches the gas machine reading, lambda (as this car has a wide band o2 sensor, )

then the car is not running rich, 0.98 is ok .but the high HC readings sugest oil burning.

As a last resort you could employ a defeat device, it is after all a VW.

Fixed #

Posted by Paul Howd on November 30, 2015, 10:29 pm, in reply to "VW Golf 1.4 16V AUS 2000 - Emissions failure, cats replaced #"
Edited by board administrator December 2, 2015, 11:57 am

Well,

Fortunately I had a customer who was patient and in no particular hurry.

The problem seems resolved!

I finally bit the bullet and removed the camshaft carrier.

Although seemingly clean inside, many of the hydraulic lifters had in fact locked solid. I gave them all a squeeze in a vice to get them moving again and now reassembled emissions are now all spot on!

Basically what we were looking at was tight valve clearances.

Unfortunately the design of the AUS engine makes easily checking this difficult.

But, once you bite the bullet, it isn't really that hard.

I would suggest doing the lifter squeeze as a matter of routine with a cam belt change on this design of engine. It would only add an hour or so to the job (if that) and represents good preventative maintenance on older vehicles that might have had irregular oil changes in the past.

HTH helps somebody else in the future!

Regards,

Paul

Re: Fixed #

Posted by Derek Sumnell on December 1, 2015, 3:05 pm, in reply to "FIX! Whohooo!"
Edited by board administrator December 2, 2015, 11:58 am

Re: VW Golf 1.4 16V AUS 2000 - Emissions failure, cats replaced #

Posted by andrew pethig on December 1, 2015, 7:09 pm, in reply to "VW Golf 1.4 16V AUS 2000 - Emissions failure, cats replaced #"

so what did the customer spend in the end on a X reg car to get it through the emissions that amounted to .20 on the co at fast idle and 50 hc at idle ???

Re: FIX! Whohooo!

Posted by aidan birley on December 1, 2015, 7:12 pm, in reply to "Re: FIX! Whohooo!"
Aidan Birley

Hi

>>>>Surprised you did not drain the oil then run it dry to relieve pressure on the hydraulic tappets.<<,

A bit extreme, certainly not a method I would use.

The 'Correct way' to drain lifters without dismantling and without risk is simply rotate the engine until 1 or more valves FULLY open, leave engine for at least 2 hrs, rotate engine and repeat.

Simple, risk free and works !

Aidan

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