NCT revving engine during emissions test

adocholiday

I recall reading a few posts on various forums about NCT testers raising the revs on some cars to a very high level during the emissions check, causing severe engine damage in some cases. Just wondering if anyone knows whether or not this is still part of the test?

I have a 2002 1.9l petrol chain driven engine. There are 107k miles on the clock and given its age I'm worried about them wrecking the engine during the test. I read the 2012 NCT test guidelines manual and it says that the tester should slowly bring the engine to 2.5k revs and hold it there for 30 seconds. If the emissions reading is still out of the good range then bring it back to 2.5k revs and hold it for 3 minutes and retest the emissions.

Now while driving on the motorway my car stays at about 3.5k revs at 120kmph, so I don't see why revving it to 2.5k for 30 seconds would do any damage; but I suppose when it is not under load revving it will affect the car differently.

Just wondering if anyone knows exactly what the testers do in this test?

biko

NCT testers rev the engine as part of test yeah. It is to measure the emissions at idle and at operating revs.
However they don't go into red.
Can you point out a source where a tester will have revved the engine and cause engine damage?

I had an emissions issue once and the tester did rev the car a long time. This was simply to get it to pass the emission. Sadly he could not and I had to get rid of car.

adocholiday

biko wrote: »

NCT testers rev the engine as part of test yeah. It is to measure the emissions at idle and at operating revs.
However they don't go into red.
Can you point out a source where a tester will have revved the engine and cause engine damage?

Well there is this one for example just from a quick google: http://www.askaboutmoney.com/threads/engine-blown-in-n-c-t-test.166522/

That one is a diesel one though so it is a different scenario. I'm just worried about the potential for engine damage that's all I'm not here to criticise the NCT testers

biko

Aye I understand. However, a healthy engine should be able for the strain.

vandriver

The problem is with timing belts snapping.You don't have one.

Special Circumstances

Some vague load of waffle in that link.

I had a vague problem with my car . A vague amount of money was charged for a vague remedy.

Omg I had exactly the same problem. You should do this thing that my uncles labradooodle told me about.

9935452

One of the lads at work had trouble with a mass air flow sensor after nct, i think, could be wrong. He blamed the lads at the nct. he said the car was screaming at the nct, reckoned it was at the redline. 2.2 diesel accord 08.
Audi i have wont rev over 3000rom when it isnt moving so overrevving shouldnt be a problem.

But if the car is healthy there shouldnt be a problem.

Special Circumstances

Anyone who genuinely says "JM&J all the revving tid gonna blow up shtop the tesht shtop the tesht" is most likely a chronic "speed kills, must merge at end of slip road at least 40kph below the main flow and in a gear that gives no prospect of acceleration" type.

arthur daly

They rev the car to clear out the engine to lower the emissions,the amount car cars that fail emissions test from built up carbon is huge,where using a lower gear and reving more clears this on the way to test.
I think it sounds worse than it actually is with the acoustics in a big open building.
As said proper maintenance shold ensure a good engine.

arthur daly

They rev the car to clear out the engine to lower the emissions,the amount car cars that fail emissions test from built up carbon is huge,where using a lower gear and reving more clears this on the way to test.
I think it sounds worse than it actually is with the acoustics in a big open building.
As said proper maintenance shold ensure a good engine.

Flick of the switch

I recommend bringing your phone with you and video record the test through the observation window in the waiting room. I have done this.

C4Kid

This happened with my last car. I thought it would fly through the emissions, it didn't and required some amount of revving just to scrape by.

To be fair I appreciate that they will at least spend time to try to pass it rather then just letting fail.

I always take my car for a good burn before the test, usually 4th gear on the motorway or something to get the revs up and clear it.

It's called an Italian tuneup and works everytime, as long as there's no major problem you are aware of that's causing poor emissions. At least I'm in command and I can choose how hard to push the car and it avoids letting it up to the tester because it probably won't require any hard revving after a good clear out.

myshirt

I had a car in for Pre NCT, and all good. The afternoon after the test, timing chain had jumped a tooth. Bad luck? Just pure coincidence? Maybe.

In any event, you sign a disclaimer.

Toyota. They revved the absolute bollix out of it, from near cold. Had it warmed, but with delays it had cooled.

9935452

myshirt wrote: »

I had a car in for Pre NCT, and all good. The afternoon after the test, timing chain had jumped a tooth. Bad luck? Just pure coincidence? Maybe.

In any event, you sign a disclaimer.

Toyota. They revved the absolute bollix out of it, from near cold. Had it warmed, but with delays it had cooled.

Id be worried why the timing chain jumped a tooth. You could have a tension-er failure or a stretched timing chain

corkgsxr

In a healthy engine it's no hassles.

Any problem that happens would happen soon anyway.


You don't have to worry about revs.


I'll be drag racing on the bike soon. You sit for 5-10 seconds holding 8k revs. After launch you don't change up till 16k

Don't be afraid of revs

walus

I saw or rather heard them doing it when I went for NCT too. There were a couple of cars under test so I could not tell which car was screaming but for as long as I go there never saw anything like this. Every a couple of second they would redline the engine.

myshirt

9935452 wrote: »

Id be worried why the timing chain jumped a tooth. You could have a tension-er failure or a stretched timing chain

That was over 4 years ago. May have been their fault, and may not have been. Just annoying the way it had happened.

biko

In this video you'd think it's revving hard, but it's just at 3k revs

https://www.youtube.com/watch?v=1gjVYLuHVA0

Special Circumstances

Two THOUSAND EIGHT HUNDRED?
Oh sweet divine jesus have mercy on us all, get the emergency holy water capsule, lord god and that's crazy revving altogether.

CiniO

adocholiday wrote: »

I recall reading a few posts on various forums about NCT testers raising the revs on some cars to a very high level during the emissions check, causing severe engine damage in some cases. Just wondering if anyone knows whether or not this is still part of the test?

I have a 2002 1.9l petrol chain driven engine. There are 107k miles on the clock and given its age I'm worried about them wrecking the engine during the test. I read the 2012 NCT test guidelines manual and it says that the tester should slowly bring the engine to 2.5k revs and hold it there for 30 seconds. If the emissions reading is still out of the good range then bring it back to 2.5k revs and hold it for 3 minutes and retest the emissions.

Now while driving on the motorway my car stays at about 3.5k revs at 120kmph, so I don't see why revving it to 2.5k for 30 seconds would do any damage; but I suppose when it is not under load revving it will affect the car differently.

Just wondering if anyone knows exactly what the testers do in this test?

They rev petrol engines to about 2.5k or bit above.
It's diesels which are revved higher, sometimes to red line.
Absolutely nothing wrong with it.
If car is not able to withstand 30 seconds revving at red line, then it means it fecked already.

During my everyday driving I rev my 1.2 petrol engine which is 14 years old and with over 140k miles, to well above 6500rpm, sometimes above 7000rpm and have no problems with it whatsoever.

I rev my diesel to red line (4500rpm) fairly regularly as well, and I know this makes more good than bad for the engine.

Jesus.

How the phuck could revving a car to 2.5k cause any damage?

Jesus.

CiniO wrote: »

During my everyday driving I rev my 1.2 petrol engine which is 14 years old and with over 140k miles, to well above 6500rpm, sometimes above 7000rpm

Why?!!

Cheensbo

Jesus. wrote: »

Why?!!

Why not? Its what it was designed to do...

Jesus.

Cheensbo wrote: »

Why not? Its what it was designed to do...

Yes but why?!!!

Cheensbo

Jesus. wrote: »

Yes but why?!!!

Ah that old chestnut..

CiniO

Jesus. wrote: »

Why?!!

Two reasons - unrelated...

1. To achieve best performance
2. Because I like to do so

Jesus.

Sounds good enough to me Cinio!

I now know why folk on here much prefer petrol cars to diesels. Its cos you can rev the sh1t out of them

BTW Cinio, I resurrected a thread of yours from a long while back a few weeks ago but the Mods closed it before you had a chance to see my question. It related to you doing an experiment where you drank one pint of strong lager and then tested your breath on a device and then you drank another pint and tested again. As far as I can remember, your conclusions were that after the first pint you were below the limit but after the 2nd you had crept above it.

Do you remember that post you made?

Bongalongherb

Happy easter Jesus. I hope your text emission's are not over the top

CiniO

Jesus. wrote: »

Sounds good enough to me Cinio!

I now know why folk on here much prefer petrol cars to diesels. Its cos you can rev the sh1t out of them

I definitely prefer petrol, but unfortunately I drive diesel mostly, just because it's cheaper. Pity...

BTW Cinio, I resurrected a thread of yours from a long while back a few weeks ago but the Mods closed it before you had a chance to see my question. It related to you doing an experiment where you drank one pint of strong lager and then tested your breath on a device and then you drank another pint and tested again. As far as I can remember, your conclusions were that after the first pint you were below the limit but after the 2nd you had crept above it.

Do you remember that post you made?

I don't really remember. Any link to the thread?

Aint Eazy Being Cheezy

http://www.boards.ie/vbulletin/showpost.php?p=90232384&postcount=26

Possibly?

Bongalongherb

Emm... But what has this to do with 'NCT revving engine during emissions test' ?

Watch Jesus. He can be in one building, and then vanish a few minutes later.

unkel

If you don't regularly red line your car, you as a person are an NCT failure :pac:

Bongalongherb

Not once have I saw an NCT tester wearing a face-mask, considering the amount of hours and motors they test on a daily basis with revving and emissions ?.

Old 99D and I just drive it to the NCT with no revving and it always leaves with a gold stamp of award regarding emissions 0.03. little green banger of a mitsubishi colt. The Japanese sure know how to make them.

Special Circumstances

unkel wrote: »

If you don't regularly red line your car, you as a person are an NCT failure :pac:

Ah even bringing it above 75% of the rev range would do. Or not. I don't care as long as people can match the speed of the traffic flow they are joining rather than just concentrating on changing up as soon as they can without bogging the car altogether!
Mpg! Shpeed kills! Til blow up if you go beyond 2k! Etc etc.

Completing overtakes in less than a mile / 40s would be great to see too..

dr.fuzzenstein

Jesus. wrote: »

Yes but why?!!!

Because it's there.

arthur daly

Just to point out revving a engine stationary is a lot worse that revving a engine underload.
Constantly revving a car to the red line especially a old engine will end up with it going bang why do people think every single boy racer type car burns oil?
Iv seen lads buy the best of cars although they serviced them regularly with quality parts then drive the living sh1t out of them after which they all ended up burhing oil.
Try find a glanza civic Integra that aren't burning oil.
Take motor sports regardless of bikes cars etc etc they all carry spare engines and regular have to change them because they drive the crap out of them

kona

arthur daly wrote: »

Just to point out revving a engine stationary is a lot worse that revving a engine underload.
Constantly revving a car to the red line especially a old engine will end up with it going bang why do people think every single boy racer type car burns oil?
Iv seen lads buy the best of cars although they serviced them regularly with quality parts then drive the living sh1t out of them after which they all ended up burhing oil.
Try find a glanza civic Integra that aren't burning oil.
Take motor sports regardless of bikes cars etc etc they all carry spare engines and regular have to change them because they drive the crap out of them

Obviously! But the power is up the far end of the rev range. If you wernt ment to do it it would be limited.

Also vtec burns oil for the Craic anyways.

Special Circumstances

And driving wears tyres.
And braking wears brakes - doesn't stop the "shift up before 2k" merchants doing it every time they see an on-coming car.

Nobody sits holding their car on the limiter for an hour at a time. Well nobody that expects the engine to last as long as an engine used in typical road use.
But an engine that can't briefly ( in the grand scheme of things) rev to the limit? Fit for scrap.

CiniO

arthur daly wrote: »

Just to point out revving a engine stationary is a lot worse that revving a engine underload.

Because?

Constantly revving a car to the red line especially a old engine will end up with it going bang why do people think every single boy racer type car burns oil?
Iv seen lads buy the best of cars although they serviced them regularly with quality parts then drive the living sh1t out of them after which they all ended up burhing oil.
Try find a glanza civic Integra that aren't burning oil.

Most higher performance engines burn oil. That's just what they are.
And obviously using engine in it's higher rev range, will cause it to use more oil. But what's wrong with that?

Take motor sports regardless of bikes cars etc etc they all carry spare engines and regular have to change them because they drive the crap out of them

Where do they carry it? In the boot and swap between special stages?

As I said above - engines are designed to be used within all rev range.
Take any random car user manual, as read what red zone means. In most manual it's described as rev range which you shouldn't be using for prelonged periods of times.
So if your red range is from 7000rpm, then it's no harm to go up to 7500 during acceleration and change up the gear, but it might be a harm to drive at 7500 for few minutes. That's exactly how it works.

Imagine driving on motorway at 200km/h. I had a car which was at 6000rpm on 5th at 200km/h (that was Mazda 6 2.0). 2 hour journey at around 200km/h means 2 hours driving at 6000rpm. All good with the engine and I did that good few times. There's probably plenty of people who do it regularly.

alias no.9

arthur daly wrote: »

Just to point out revving a engine stationary is a lot worse that revving a engine underload.
Constantly revving a car to the red line especially a old engine will end up with it going bang why do people think every single boy racer type car burns oil?
Iv seen lads buy the best of cars although they serviced them regularly with quality parts then drive the living sh1t out of them after which they all ended up burhing oil.
Try find a glanza civic Integra that aren't burning oil.
Take motor sports regardless of bikes cars etc etc they all carry spare engines and regular have to change them because they drive the crap out of them

Care to back that up? I get that you will hit the red line quicker and with 'less gas' than when your engine is under load but specifically, if an engine red lines at 7000RPM, why would revving it to 6000RPM under no load for 30 seconds be worse than revving it to 6000RPM under load for 30 seconds?

godskitchen

So much ****e being written in this thread.

It's no wonder people get carbon build up in their engines, it seems people are scared to rev the thing!

Your doing far more damage to your car by not putting it through the Rev range.

If your engine gets damaged from an nct test it's on its way anyway.

As for burning oil because the cars are revving higher... Rubbish. Plenty of info on forums of new vw and audis burning oil from new.

kona

1.4 golf owners must live on the redline so

John T Carroll

arthur daly wrote: »

They rev the car to clear out the engine to lower the emissions,the amount car cars that fail emissions test from built up carbon is huge,where using a lower gear and reving more clears this on the way to test.
I think it sounds worse than it actually is with the acoustics in a big open building.
As said proper maintenance shold ensure a good engine.

They only rev the diesel engines to the "governd limit" see extract from NCT "manual". Petrol engines are not governed and are only revved excessively if the tester cannot get the emissions down, I have watched every NCT of my (petrol) cars and as they always meet the emissions easily, and have never been revved excessively. All the modern VW diesels will not rev beyond 2500 RPM while stationery so presumably the NCT testers accept this.

Vehicles registered on or after 1st January 1980
[FONT=Sun Sans,Sun Sans][FONT=Sun Sans,Sun Sans]1. Check visually that the emission control system is complete and properly connected and that there are no leaks in the exhaust system. [/FONT]

[/FONT][FONT=Sun Sans,Sun Sans]
[FONT=Sun Sans,Sun Sans]2. With the engine at normal operating temperature, raise the engine speed slowly to 2,500 rpm or half the engine manufacturer’s recommended governed speed whichever is less and hold for 20 seconds in order to purge the exhaust system. If the engine emits any unusual noises the test should be abandoned. Slowly raise the engine speed to its maximum rpm and note if the governor operates within the vehicle manufacturer’s recommended rpm setting. If not the test should be discontinued. [/FONT]


[/FONT]Do not hold the engine at maximum rpm for any length of time.

Jesus.

....

arthur daly

Opinions are like ar53holes everyone has one sadly the abount of misinformation here is unnatural.
Not to mention the manner of cino and the aggressive comments which leads people to go elsewhere to better run sites with more informed people..

Cheensbo

arthur daly wrote: »

Opinions are like ar53holes everyone has one sadly the abount of misinformation here is unnatural.
Not to mention the manner of cino and the aggressive comments which leads people to go elsewhere to better run sites with more informed people..

Went looking for misinformation, and by gum you're right, but guess who's posting it :eek:

arthur daly wrote: »

Just to point out revving a engine stationary is a lot worse that revving a engine underload.
Constantly revving a car to the red line especially a old engine will end up with it going bang why do people think every single boy racer type car burns oil?
Iv seen lads buy the best of cars although they serviced them regularly with quality parts then drive the living sh1t out of them after which they all ended up burhing oil.
Try find a glanza civic Integra that aren't burning oil.
Take motor sports regardless of bikes cars etc etc they all carry spare engines and regular have to change them because they drive the crap out of them

And tell me, what exactly does this excessive revving do, what part of high revving directly causes the increased oil consumption?? -

I can provide an answer as to why it doesn't make fcuk all of a difference, especially in an older engine, but please, do tell.

MAJJ

kona wrote: »

1.4 golf owners must live on the redline so

Laughed outloud at that, have one and it's kinda true if you're in a hurry needs the pedal

dr.fuzzenstein

kona wrote: »

1.4 golf owners must live on the redline so

Same for 1.4 Focus.

CiniO

arthur daly wrote: »

Not to mention the manner of cino and the aggressive comments which leads people to go elsewhere to better run sites with more informed people..

You stated a fact, which I asked you to explain, and you instead of explaining go into criticising my manner (without even being able to write my 5 letters nickname correctly, mentioning that everyone here is misinformed and people go elsewhere.
So far it looks like you are the misinformed one.

dr.fuzzenstein

arthur daly wrote: »

Opinions are like ar53holes everyone has one sadly the abount of misinformation here is unnatural.
Not to mention the manner of cino and the aggressive comments which leads people to go elsewhere to better run sites with more informed people..

He's one of the informed guys here, I'd trust what he says.
He's got a robust style of reply, but we're all big and ugly enough to take it.

arthur daly

CiniO wrote: »

You stated a fact, which I asked you to explain, and you instead of explaining go into criticising my manner (without even being able to write my 5 letters nickname correctly, mentioning that everyone here is misinformed and people go elsewhere.
So far it looks like you are the misinformed one.

I refuse to even lower myself to explain myself to you with your attitude,I actually can't believe you think I should.

But I guess you couldn't come up with anything to disprove what I said so you decided to go off topic on what I said,slowly read over what I said then your answer.