MOT fail

[morrispaul]

That time of year again, just got back from MOT test and my trusty pick up ( 1.3 mpi petrol ) has failed on emissions. Always struggles every year but manages to pass, new cat last year and readings were more or less nothing, co readings today averaged 0.5 so way over the 0.2 pass level.passed the other tests...not been looking after it as well as I should as I do relay on on it to get me to work every day.....going shopping shortly for plugs, filters, oil and might take a look at "cat cleaners" ive used these before in my daughters saxo with no change in the readings, mot man suggested using in the pick up along with new plugs and filters so will give it another try....my garage is full with other hard to move projects so working outside on the drive in the cold and wet.....not looking forward to that ....

[Gaz]

Add a dizzy cap and rotor arm (if it has them) to your shopping list and take it out for a really good run before the MOT so it's up to temperature and blown clear.

 

My garage will never get a car in it so commiserations - I too have to work out in the cold and wet   

 

Gaz

Edited 13 February, 2016 by V6TDI

[RicardoM]

morrispaul

Forget about the generic "a dizzy cap and rotor arm" advice since your engine has not such thing.

Forget also about "cat cleaners" as that is a scam (this goes for any 'magic' liquid you pour in the fuel tank).

How about telling us relevant information about your car? Such as mileage, fuel consumption, oil consumption, rough idle?

[morrispaul]

No dizzy cap on the MPI gary......so.what did I buy ?....plugs, oil, oil filter, air filter and a bottle of cat clean...£53in total including £17.50 for the cat clean......nice to know iam not thd only one outside, heavy rain here in south bucks so going to have a lazy afternoon indoors and get out there tomorrow......

[morrispaul]

morrispaul

Forget about the generic "a dizzy cap and rotor arm" advice since your engine has not such thing.

Forget also about "cat cleaners" as that is a scam (this goes for any 'magic' liquid you pour in the fuel tank).

How about telling us relevant information about your car? Such as mileage, fuel consumption, oil consumption, rough idle?

hi ricardo....I dont hold much hope for the " cat clean " following the testers advice, ive know him for a few years and hes helped me out a few times......cars on 109000 miles, regularly get 47 mpg on a long run, uses no oil, smooth idle but not 100 % perfect...now confession time.....cars not been serviced for 5 years, approx 25000 miles.....sorry to all you skoda lovers, please dont be too harsh on me............new cat last year but still struggled to meet the requirements, a good 15 mins on the tester before it suddenly dropped to next to nothing......recently had a coil pack fail on me, drove the car home on 2 cylinders for approx 5 miles, not surd if this would have damaged the cat.....

[Tom_vRS]

Cataclean is a genuinely good product, especially when followed by an Italian tune up. I've personally seen it get 4 cars through emissions after failing.

Cheap cats are absolutely rubbish though.

[fordfan]

We've had success with Cat a Clean, plus getting the cat needs get really hot.

[RicardoM]

cars not been serviced for 5 years, approx 25000 miles.....

Surprise, surprise... there's your problem.

new cat last year but still struggled to meet the requirements

No cat can cure CO of a neglected or defective engine.

...a good 15 mins on the tester before it suddenly dropped to next to nothing......

I subscribe to previous advice about warming up the engine well on highway before MOT.

I would also check for exhaust leaks before oxygen sensor. A tiny hole could make the sensor think the air/fuel mixture is too lean and in turn the ECU would command the injectors to dump more fuel. The result? Rich mixture, high HC and CO.

recently had a coil pack fail on me, drove the car home on 2 cylinders for approx 5 miles, not surd if this would have damaged the cat.....

Nothing happens in such short time. Cats fail when the engine runs rich for long time.

[daverapid]

Don't forget the valve clearances when servicing...very important but often missed by modern mechanics/DIYers used to more modern engines.

[morrispaul]

Thanks for reply ricardo.......I take all the blame for the fail.i need to look after my skoda a bit more owned for just over 5 years, serviced it when I bought it and then just drove it.......have to say its been fantastic in the 5 years just needing petrol......I do like the robustness of the felicia......

[morrispaul]

Dragged myself outside in full water proofs, fitted filters, changed oil took plugs back as wrong ones !!.....changed plugs job done....

no nasties in oil, blacker than black still a bit creamy...good considering in been thrashing about for about 25k....plugs were good as well, running a tiny bit hot parhaps but dont think its anything to worry about, I filled up this morning on the way to the mot station, its recommended to add the " cataclean"to 15 ltrs of fuel.might have z 400 mile trip tomorrow to collect some classic car parts for another project, I'll take the cleaner with me and add it mid journey, mostly motorways so will get a good run with the cleaner in.....

if I get back in day light I'll check the valve clearences.....

[RicardoM]

paul
There is a current topic here dealing with a neglected Felicia having the same type of engine. Read it. Passing MOT could be soon the last of your worries... Luckily you've bought the bag of goodies for your car (for another 5 years?)

Just curious, what does the "cat cleaner" promise to solve, how, and how fast?

 

Since you stay at warm today, here are some videos to watch.

 

 

 

 

 

[morrispaul]

Good videos ricardo, thanks for going to the trouble of finding and posting.

"Cataclean" promises to......clean engine, restore performance, improve MPG and protect the cat.

I need to add it to15 litres of fuel.i think iam right in saying my pick up has a 42 litre tank so about 1/3 tank.or about half on the gauge as the second half never lasts as long as the first......or is that just me ?

400 ish mile round trip tomorrow is now happening so a good chance to try this stuff out, I have a infrared temperature device as used in the video, if I can find a battery I will do a before and after test on the cat....dont fully understand why the cat should be hotter on the end furthest from the engine though....

[Breezy_Pete]

I really don't know the set-up in these cars, but if it has a cat, it must have at least one lambda sensor, I think. It would be useful to see what that is doing. I wonder if, for example, you may find it reading continually rich, due perhaps to a misleading sensor output from a failing engine coolant temperature sensor, making the ECU think that the engine hasn't yet warmed up?

Edited 13 February, 2016 by Wino

[RicardoM]

The fuel gauge linearity: yeah, not so good, although VDO (the German manufacturer of instrument cluster) went to town with it by putting one integrated circuit (4 operational amplifiers) to correct the non-linear shape of the fuel tank. So it's not just your gauge.

 

The videos: while I don't endorse any method or product in those videos, I am amazed to what lengths people are capable to go ignoring basic physics and chemistry. All in the name of comodity. Put that magic liquid in there and poof! we don't need any repair. Metal wear is reversed, bad gaskets get magically repaired, cats perform as in day one, bla bla.

 

About Cataclean: when I read "Liquid Science" I instantly know the product fills in the Marketing Bull$hit category. Other times you read "3D nanoparticles", "ultra", "FX", etc. All are very secret and SF. Oh, and very expensive. To my knowledge the effects are marginal at best, subjective or pure coincidental. You will NEVER see a product advertising saying "The value of X parameter will decrease/increase from value Y to value Z". All is relative, like "up to 100% efficiency". If you don't get the promised result, the customer is to blame because he didn't follow the instructions. Or he didn't buy enough. Yeah... I stop my rant here. But your cat is fine. Probably it meows too.

 

As for the downstream temperature being higher, here is why. Basically catalysts are a lame, yet expensive excuse for the inefficiency of combustion in internal combustion engines. Among other things, as long as we use liquid fuel, the combustion will be far from complete, resulting unburnt hydrocarbons and pollution. Those hydrocarbons get 'burned' in the cat (instead in the engine, mind you) in the presence of the catalysts deposited on internal mesh and the other harming noxes are broke down or combined in less harmful gasses. The catalytic reaction generates heat, so you can say a cat is an "oven" in simple terms. The real thing that gets burned in the cat is our money on fuel...

[RicardoM]

I really don't know the set-up in these cars, but if it has a cat, it must have at least one lambda sensor, I think. It would be useful to see what that is doing. I wonder if, for example, you may find it reading continually rich, due perhaps to a misleading sensor output from a failing engine coolant temperature sensor, making the ECU think that the engine hasn't yet warmed up?

That is just one possible scenario of malfunction. When you say "the set-up in these cars", what cars are you referring to?

[RicardoM]

[Breezy_Pete]

That is just one possible scenario of malfunction. When you say "the set-up in these cars", what cars are you referring to?

Felicias. 

My car knowledge started with Polo and Golf from 1989-1991 era, before cats in this country. Then brief and unsatisfying acquaintance with a 1995 Vauxhall. Then a ten year jump to 2005 Fabia, and now 2003 Polo. So my knowledge of Skodas has biiiig gaps, backwards and forwards from 2005!

[bigjohn]

....recently had a coil pack fail on me, drove the car home on 2 cylinders for approx 5 miles, not surd if this would have damaged the cat.....

 

This could finish the cat off, 5 miles of unburnt fuel. Had a similar problem with my Skoda Octavia - fortunately a replacement CAT now pretty cheap

 

Cata-clean works but can't raise the dead

 

No servicing for 5 years - Houston.........

[RicardoM]

This could finish the cat off, 5 miles of unburnt fuel. Had a similar problem with my Skoda Octavia - fortunately a replacement CAT now pretty cheap

Was this your own conclusion after testing yourself the cat? If yes, how did you test it was bad?

Or you have been told by a mechanic it's the cat and (quite convenient) he had a replacement one?

[RicardoM]

Felicias.

Oh, OK. Well, it is very basic. See below.

[bigjohn]

Was this your own conclusion after testing yourself the cat? If yes, how did you test it was bad?

Or you have been told by a mechanic it's the cat and (quite convenient) he had a replacement one?

 

When my wasted spark coil pack failed I drove about 7 miles on two cylinders - was amazed how well it ran!

 

Failed it's next MOT on emissions, changed the CAT (it was old anyway) and it's passed many MOT's since 

 

If this ever happens to me again - I'll call the breakdown company

 

http://www.bmcatalysts.co.uk/downloads/TechnicalDownload.pdf

Edited 14 February, 2016 by bigjohn

[StevesTruck]

Don't just buy stuff and swap parts in hope.

Find one of your old plugs and compare it to a chart like this

http://www.aa1car.com/library/reading_spark_plugs.jpg

I'd bet they're sooted up from the car over fueling (how's your economy?). if it's overfueling, a good starting point is your lambda circuit. Are the wires damaged? Has the sensor got a good strong earth?

If it were a vw, I'd say charge the coolant temperature sender as a matter of course. You can check these with a multimeter if you can find what the resistance values should be for hot and cold.

Do these use the air flow meter full time, or just on warm up?

[morrispaul]

Wow, lots of replies.my thanks to all of you.......just got back from a 350 mile drive to collect some car parts for another project.mostly motorway or fast A road, stuck to 50/60 on the way up with no problems, coming home I pulled over when the fuel gauge was just under half and added the "cataclean"...then a swift drive home on the M11, M25, M40.more or less 70 all the way , at this time of year on the motorway the temp gauge usually sits on 70 degrees untill I hit slow moving traffic or come to a stand still, then it will rise to 90/95.today though after adding the "cataclean" and driving for 30 ish miles the gauge began to rise slowly and resting at about 85 degrees.......got me wondering is that the effect of the "cataclean", the new plugs, oil and filters or because its a bit warmer today.........

checked oil and water when home and not used any, still bang on the top marks, its never used any oil but on the odd occasions I have put a drop of anti freeze in the coolant tank, parhaps a couple of times a year just to keep it on the top mark..

old plugs looked excellent when removed yesterday after 25000 ish miles, if anything parhaps a bit lean....will pop down to the mot man tomorrow and book a re-test for next Saturday.....

[RicardoM]

It is not normal for coolant temperature to stay at 70 C when driving on highway, regardless outside temperature. Engines runs most efficient at 85-90 C. Colder engine means higher fuel consumption, lower power, higher emissions. Most probably the thermostat is faulty. It is very easy to verify that. From cold start let the engine idle or revv it a little (< 2,000 rpm). Feel the thick upper radiator hose. Up to about 80 C, the hose should be cold, except maybe 1-2 inches near thermostat.

 

When doing the MOT, be sure the coolant temperature is at 90 C.