New Polo GTI Cold Start

[mattty]

Hi All,

Picked up my new white polo gti last week and lovin it. I have couple of questions and would appreciate your feedback:

1. Consistently noticed for the first min of a cold start that the note of exhaust is quite unusual. Quite sporty but couple of short intervals sounding like it is going to stall. Interesting the the fuel consumption start with 3L per hour while idling... slowly drops to 2.9, 2.8 to 2.0L. Then you will hear a rely switch 'click' and all of the sudden, the exhaust sound becomes a constant note (and fuel comsumption is 1.1L/Hour). There is not much drop in rpm, maybe from 1,000 to 900. Even if I rev to 1,000, exhaust still sound constant and fuel consumption does not go much over 1.1L.

Anyone experiencing this?

2. After 150km into the new car (2 days), the exhaust warning light came on. Took it into the dealer the following day and was diagnosed with 'Fuel too lean' error, possibly caused by one misfire. And apprently when the light is triggered, it stays on. They cleared the error, I explained that I was still on the first tank... dealer thought it may be dodgy fuel from their pump or across the road. I left and put in Shell 98 in to 'blend' what's left of the 1st tank.

After another 130km, light came up again. Went to dealer and they said with busy schedule, have to book the car for next Friday. They did not clear the second warning light, and said it could be faulty sensor.

The performance does not seem to be affected, still perky (yet to pass 4,500 rpm)... previously owned a seden and noticed with the hatch, that the back of the car get dirty easy with black powder (looks like brake pad stuff)

Apologies in advance for the long thread, but interested to see what everyone think..

cheers,

-Mattty

[Wand Weaver]

Hi All,

Picked up my new white polo gti last week and lovin it. I have couple of questions and would appreciate your feedback:

1. Consistently noticed for the first min of a cold start that the note of exhaust is quite unusual. Quite sporty but couple of short intervals sounding like it is going to stall. Interesting the the fuel consumption start with 3L per hour while idling... slowly drops to 2.9, 2.8 to 2.0L. Then you will hear a rely switch 'click' and all of the sudden, the exhaust sound becomes a constant note (and fuel comsumption is 1.1L/Hour). There is not much drop in rpm, maybe from 1,000 to 900. Even if I rev to 1,000, exhaust still sound constant and fuel consumption does not go much over 1.1L.

This is reasonably normal - the Polo really likes to slurp down the fuel before it's up to temperature. I've seen figures of 20+L/100KM on the trip computer before it gets up to temperature.

I've never seen the exhaust light go on before - that must be some seriously dodgy fuel they put in your Polo, or the sensor's broken. Either way, that's a warranty job. I note that even using this forum as a sample space, we're getting close to the reported 50% of cars delivered with faults or developing them soon after delivery.

[mattty]

The extended warrenty is something that I will seriously consider in couple years time... I am trying stay positive about it and not worry to much about potential long term effect from this...

[awestonvp]

(yet to pass 4,500 rpm
-Mattty

The day I picked up my white Polo GTI company car, my boss (Alfa 156 GTA 3.2) took it to 7500 rpm to see how it would go...went bloody well! He loves it too!

[FL00DY]

This is reasonably normal - the Polo really likes to slurp down the fuel before it's up to temperature. I've seen figures of 20+L/100KM on the trip computer before it gets up to temperature.

I've never seen the exhaust light go on before - that must be some seriously dodgy fuel they put in your Polo, or the sensor's broken. Either way, that's a warranty job. I note that even using this forum as a sample space, we're getting close to the reported 50% of cars delivered with faults or developing them soon after delivery.

Yeah it seems to be the newer GTI's that are having quality problems, this is a shame.

I don't get the click your talking about. In regards to breaking it in and limiting the revs, forget bout what it says in the book. Drive it the way you want, the faster you drive it now, the better it will perform later.

[Ben_GTI]

I think the sound it makes at start is a result of running cold and also i think the 20V has variable cams which are only active at idle to meet emission regs.

I'm pretty sure that this is the case, i just can't remember where i read it.

[Wand Weaver]

I don't get the click your talking about.

The only 'click' that can be considered normal in the Polo is the relay for the brake lights, which you can certainly hear clicking every time you hit the brakes.

I'm not going to get into a flame-war on run-in procedure, everyone has a different philosophy on the matter. I personally believe in a high load, low RPM approach to run-in, which I've seen work well on plenty of cars, including my own. With a car like the GTI that has a fair amount of torque under 3000RPM anyway, it's no chore.

[awestonvp]

High load low rpm sounds logical, to bed everything in without overstressing, but I guess I've heard so many different stories about running in that I've no idea which is best. Wish someone who could afford it would run 3 or 4 cars in different ways then strip them to see the result!
Performance guys say one thing, handbook says something else, dealer told me to "drive it like I stole it". Guess I just cross me fingers and hope! And change the oil every 10,000!

[dodgeGTI]

Jut on your first point... that's seems fairly normal, mine does exactly the same thing. Until the car is warm its going to suck a bit more juice to get it there then the idle will be noticably lower. Isn't that just an automatic choke?? :confused:

[SoVeReIgN]

Simple answer : runs very rich on startup and revs are higher than usual. Slowly leans mixture out to normal and at the same time the revs slowly drop down. (Might notice from a dead cold start it'l be idling @ ~1500rpm)

[MINTpolo]

As Ben_GTI said, noisy cold start idle is caused by the valve timing advancing aloong way (The only time it happens) to suck some of the unburned exhaust gasses back into the combustion chamber. This is pureley for emissions purposes. It goes for about 45 sec as you would know and then clicks off as the timing returns to normal.

First post btw, so i should say hello! new member with a 6 month and 8000km old white polo GTI with the oettinger chip.

cheers

[shaneth]

Welcome Mintpolo where are you from. How are you enjoying your polo. You should start your own thread with some pics so we can all welcome you properly. :wink:

[MINTpolo]

Hi there, well, i dont really have any decent pics, just imagin a bone stock (bar the chip :) )white GTI, not even with tint, u get the idea.......bloody fantastic that is!

From Brisbane southside btw.

[mattty]

thanks for all the information, I am looking forward to next friday when the dealer fixes the warning lamp. Will let everyone know how that goes... cheers. Mattty.

[Spec83]

Point 1 - I think the high initial idle is caused by the secondary air pump running is it not while the car warms up??? You can hear it click off after idle for about 45 sec (owned a rotor for a little period so used to warming up before i drive anywhere lol)...

Point 2 - the black dust is soot from the exhaust - these cars run very rich from the factory (stock the AFR up around 14.5:1 isn't it??)... ideal is about 12:1... One reason why just a chip gives a large power increase...

[Kai]

I get the weird click!
I get the weird idle!

[MINTpolo]

From VWvortex 1.8T faq:

"What is VCT?
VCT or Variable Cam Timing. Synonymous with Variable Valve Timing
The AWW, AWP, and AWV engine codes have VVT, while the AWD and APH do not.
The VCT in later 1.8T's is simply for emissions purposes. It has only two states - normal and massive overlap. The overlap is used to draw exhaust gasses back into the cylinders at startup."

[Ben_GTI]

OMG I was right!!!

[mattty]

Thought I will provide an update on the issue with my exhaust warning light. Took it to service yesterday and they were unable to pin point what was causing the light to come on with the error of fuel too lean.

The car had no other errors other than this particular error which came on for the second time.

Service staff asked about the fuel that I filled and I explained that its on shell 98 (full refill) that was purchased couple of days ago. Basically they cleared the code, test drove the car and were unable to see the error coming up during that time.

Well... 24 hours after picking up the car, the light appear again after 100kms. So it looks like its back to the service centre again. I note on both occasions after they clear the code, the car felt realllllly sluggish for the first 20kms or so after leaving the dealership. As if the boost was lowered... and then it returns to normal. (maybe remapping somehting?)

Knowing the I have put in the proper fuel, either the oxygen sensor is faulty... or something else is causing wrong mixture of air/fuel (MAF?).. which means my car has been running lean or too rich in its first 750kms (assumption made here is faulty sensor causes rich mixture as a way to compensate the lean fuel reading).

Any ideas?

[Ben_GTI]

Speak of cold starts; How warm should the engine be before you accelerate to 180km/h or nail it onto the freeway?

I usually let it idle for 5 mins before moving off and then travel very calmly below 40km/h for a while before I start looking above 1500rpm on the tacho.

What are peoples opinions?

[h100vw]

I wait until the water temp needle has started to move on my Audi, then it's open season on revs!!
If you guys have oil temp on the MFA, I reckon once that hits 50 degrees, off you go.
Gavin

[Wand Weaver]

Speak of cold starts; How warm should the engine be before you accelerate to 180km/h or nail it onto the freeway?

I usually let it idle for 5 mins before moving off and then travel very calmly below 40km/h for a while before I start looking above 1500rpm on the tacho.

What are peoples opinions?

I personally don't idle my car in the driveway or stationary at all. I've always had the mentality that (especially in an enclosed environment), it's a good way to end up with heat soak problems with your engine.

What I do is drive lightly (generally shifting before, or just as I hit boost at 1900RPM), and only opening it up (I don't really drive that hard regardless) any further once the temperature gauge is sitting at its final position (approx 90 degrees). I've seen plenty of people (including a neighbour with an Audi A4) open it up as soon as they back out of the driveway - I don't do that. I'll accelerate briskly, but I won't rev the engine hard until it's up to temperature.

While I do this with all cars, I suspect it might be more important to treat turbo cars (including turbo diesels) well for the sake of mechanical longevity.

[shaneth]

What I do is drive lightly (generally shifting before, or just as I hit boost at 1900RPM), and only opening it up (I don't really drive that hard regardless) any further once the temperature gauge is sitting at its final position (approx 90 degrees). I've seen plenty of people (including a neighbour with an Audi A4) open it up as soon as they back out of the driveway - I don't do that. I'll accelerate briskly, but I won't rev the engine hard until it's up to temperature.



I wait until the water temp needle has started to move on my Audi, then it's open season on revs!!

Yep im with these two and have been in all my cars, Once the needle hits the normal operating temp then its open season. :D

[Ben_GTI]

cool thanks fellas.