failed mot emission

Richard53

Before you make any decisions, a simple compression test would tell you a lot.

atrixblue.-MFR-.

a leak down test 1st, see whether its rings or valve stems or somewhere intebween like Head gasket.

i'd probably hedge a bet here that:

A.your lambda sensor has been gone for a while

B.that due to faulty lambda sensor your cars been over fuelling.

C.due to the excess unburnt fuel in the combusion chamber it has bore washed the cylinder walls.

D.due to the fuel now passing your piston rings it has started to affect the crank bearings in the bore wash effect where your little rattle is comeing from.

E.now that you oil is contaminated with petrol and cleaning addetives its started to affect the top end stem seals or cleaned out the hydraulic lifters.

due to excess fuel in the exhaust emissions its probably started to decay the catalytic converter aswell.

you went and baught a used sensor so no guarentee its going to work or last very long.
lambda sensors for fords are relatively cheap from a motor fator brand new or if really strapped a universal on all you need to prove is how many wires it has and where the black wires are located and there will be a universal to do the job for about £11.00

if none of this has happened yet then this will be what will be the future demise if you dont repair it correctly now.

atrixblue.-MFR-.

Richard53 wrote: »

Before you make any decisions, a simple compression test would tell you a lot.

A compression test will tell wich cylinder is low on compression a leak down will tell you top end or bottom end.

Richard53

atrixblue.-MFR-. wrote: »

A compression test will tell wich cylinder is low on compression a leak down will tell you top end or bottom end.

Sure, but I would start any diagnostics of a problem like this by seeing what the compression was like - both absolute values and the cylinders relative to each other. That gives a good basis for further testing, like a leakdown test, or my favourite, the 'teaspoon of oil through the plug hole and see if it goes away' test.

Worst case, the OP is looking at a rebore to first oversize, plus possibly a top end overhaul. Then the value of the car comes into the equation. With luck, it's nothing worse than valve stem seals.

Or, a 'friendlier' MoT station.

forgotmyname

If its the oil control rings a compression test maybe inconclusive.

It may have good compression. Just the scraper rings stuck to the piston or lost the spring to keep them against the cylinder walls.

james007ago

quick question, if the lambda sensor is gone, will the eml come on? Because my eml hasn't come. Also the lambda sensor i bought from scrapyard came from a 1.6, will this fit my 1.4? How much is a compression test? can i DIY it?
thank you.

Richard53

If it's a pterol car, then a compression gauge is about £20 from Halfords. Very easy to use:

• all sparking plugs out
• screw compression gauge into No. 1 cylinder
• full throttle
• spin engine on starter until gauge gives a steady reading
• note reading and move on to the next cylinder.

If any of the cylinders reads 10% or more different from the others, you have a problem. I don't know the manufacturer's expected values for compression, but a quick Google should find them, probably in the region of 110 to 150 psi for a family car with no racing pretensions. A reading lower than this would indicate a problem. You can go a bit further by putting a teaspoon of engine oil into the spark plug hole and repeating the test. If the reading stays the same, the problem is likely to be valves, and if it goes up it's likely to be rings or bore wear. (The oil temporarily seals the piston/bore gap.)

That's a very rough way of checking it out. Atrixblue's suggestion of a leakdown test is much more useful, but that's not really a DIY proposition. I've never had a compression test done by a garage, but I can't see it being more than about half an hour's labour charge.

jay1181

A long time ago i used to have a skoda octavia that refreshed its oil nearly weekly (burnt oil like a trooper) we were quoted at the time £500 pounds to fix.

At that time i worked for a company delivering papers ect so i needed this car for work so i went ahead with the work. I wish i had just sold the car as after the valve seals ect were fixed it still burnt oil and was still very high on the emissions.

I purchased cataclean from ebay i think it was and after a good run on the motorway went back to the test station and it passed, but only just.

I used it for a few months while i looked for another car but in that time the oil burning got worse to the point it was going thru an oil change every 3 weeks I wasted all that money (which we didnt have at the time) thinking it would solve the problem but it didnt.

If i were you i would be putting it on gumtree/ viva street / flebay ect and get another car as it could be a money pit regarding v seals ect.

good luck

james007ago wrote: »

hi guys,
My focus 1.4 2002 failed its emission test today:o. it has an excessive reading both the lambda and HCs (apparently these can be sorted by getting a new lambda sensor). Tester also said that a dense blue smoke is coming out from the car and he started mentioning about piston rings worn?
I noticed actually this smoke whether car is cold or hot, stationary or moving, its the same. There is also rattle coming from the engine and this is the same time when the blue smoke comes.
After MOT, I went to an indie garage who said that he needs to remove head cover and replace stem seals. At the same time he will renew cambelt. He quoted me £420 for this job including parts and labor. Is this reasonable? More importantly, will this pass the retest? Do you think I should scrap my car?
By the way, I took my car in a council-run MOT station.
Any advice welcome!:beer: