MOT Failure on Emissions

[Ganglandboss]

I put my S1 Elise in for an MOT today and it failed on emissions. The garage have suggested the catalytic converter could be the problem. When I bought the car, there was no cat fitted so I bought one brand new. It has been on the car for about 10,000 miles.

This is the printout I received from the garage.



As you can see, there are no recorded readings. The story from the garage is the car began overheating so they had to abandon the test. The emissions tester did not record a reading but they observed a reading on the screen, which is written in biro. The first reading is the fast idle and the second is the natural idle.

They spotted fluid coming from the coolant expansion tank and it turns out there is a very small hairline crack down the front. When the coolant gets hot, it leaks very slightly. I drove home 5 miles in stop-start traffic, getting out to check now and again, and there was no sign of overheating.

The thing that looks fishy is the oil temperature shows as 18 degrees C, but the MOT manual says the test should be done with the engine warm. Could a cold engine cause the readings to be high?

[Ganglandboss]

Special K said:

I would get in touch with an Elise friendly MOT station. PM me if you need any help finding one locally

Thanks for that. I would like to get to the bottom of the problem really - it breezed through its last MOT on the emissions test. I have made no changes to the engine, exhaust or induction since then so I would like to get it sorted. I will send you a PM shortly anyway for future reference. Someone on the Elise forum PM'ed me with a name - perhaps it's the same one!

[Ganglandboss]

StevelKinevil said:

Looks like the tester saw a potential problem and decided to cut it short in case there was costly damage or an exploding header tank.

Get it fixed and take it back. Should be a free retest within 10 days surely?

They are my thoughts but the bloke at the garage when I collected it was suggesting the cat was knackered. The part is ordered and will be on the car next Friday, ready for a retest next Saturday. I would understand if they said they abandoned the test because of the risk of damage but I'm confused why they did the emissions test at all if the engine wasn't warm.

[Ganglandboss]

AndrewW-G said:

StevelKinevil said:

AndrewW-G said:

I'd suggest fixing the tank, cancelling the cat and giving the car an Italian tune up on the way to next weeks retest. . . . . . . from your posts, the car failed as they were unable to test, no emissions figures = dont waste your money on a new cat until it has been fully tested and you know 100% that it does need a new one

At the risk of further confusion, Andrew, i think the part that is mentioned on order is the header tank and not the cat. That is the way i read it.

cheers

In that case, OP fit the new tank and thrash the st out of the car on the way to next weeks MOT to get it nice and warmed up

Steve's right - I have ordered the expansion tank. I have to work away for the next fortnight, coming home at weekends so it is going to be tricky getting anything done. I am going to order it today and have it sent to my parents so I cam pick it up next Friday, chuck it in that night, Italian tune-up Saturday morning and into the test centre. I'm not confident it will work but I don't have anything to lose. I won't have time to change the cat or lambda sensor within the 10 day retest period so if this doesn't work, I will have to shell out for a second test. I need to sort the expansion tank out irrespective of the emissions problem so it won't inconvenience me or put me out of pocket. I am borrowing a CO sniffer today so am going to see what effect running it up to temperature has, obviously this is only for guidance.

One thing they said when I picked it up re. the lambda sensor. I asked if that could cause a high reading and he said it could, but generally the readings are erratic if that is the problem. On the printout, I gather the reading should be between 0.95 an 1.09 - what units are these?

[Ganglandboss]

LooneyTunes said:

OP: Not sure if you meant to do this, but you've blanked out the VIN but left the reg!

I'm not too fussy about people knowing my reg number - some people even have their reg as their user name on here and anyone can see it when I'm driving. I'd have thought quite a bit of harm can be done if somebody knows both numbers.

[Ganglandboss]

I've just spoken to the garage - the tester wasn't there but the bloke I spoke to was with him as it was being done and knew a lot more than the bloke I spoke to when I picked it up. Apparently the car was brought up to temperature; he said they don't dip the temperature probe in the oil if they can get a reading in the car and the 18 degrees on the printout is the ambient garage temperature. He said he had a look in the tail pipe where he saw bits of broken up ceramic material so it looks like I will be taking it out this weekend for a look.

[Ganglandboss]

StevelKinevil said:

Bugger. They should have told you about the ceramic bits to start with as this would have cleared matters up instead of just suggesting it could be the cat.

There is a world of difference between yesterday's "With those readings, you're probably looking at a faulty cat" and today's "There are bits of lumpy st in the tail-pipe - that screams catalytic converter to me!".

[Ganglandboss]

vrooom said:

Maybe that mot tester "ooh, fancy lotus, let mug him for money..."

Funnily enough, they didn't even ask me if I wanted them to look at it. They failed it a while back when I was wrongly advised it would pass without a cat (there wasn't one on it when I bought it, which I only discovered when I had to take the undertray off) and for excessive play in the n/s/f lower ball-joint. When I went to collect it, they had a quote ready for the ball joint but he just sucked his teeth and said I'd have to go to a specialist to sort the emissions problem.