took my disco 300tdi for its mot today, failed on two things. one head light beam too high, and the emissions which were- peak 1 9.99 m-1 peak 2 9.99 m-1 peak 3 9.99 m-1 peak 4 9.99 m-1 peak 5 9.70 m-1 peak 6 7.74 m-1
average 8.95 m-1 limit 3.00 max
serviced it 1 month ago so a new air filter was fitted, took it to a local garage who is a trained land rover mechanic. he suggested fitting new injectors should fix it but he also said very rarely it could be the injector pump. its going in Tuesday for new injectors, another £400 gone.
This is sometimes normal for an engine that isn't worked hard. The level is falling, which is what you would expect to see anyway. Some of the motors we get in for test respond well to a blast down a local back-road and back then re-test the smog emissions. Some need a tub of injector cleaner and the same blast, but I've yet to see one fail after that, maybe worth a try before shelling out £400?? Badger.
On Thu, 22 Sep 2005 20:20:55 +0100, "Paul" scribbled the following nonsense:
before I mot my diesel vehicles, I normally run couple of tanks of injector cleaner through, coupled with some hard driving, and making the engine work. On the way to the MOT I normally never use 5th, and rarely 4th.
Have used this method for years, and never failed test on smoke yet...
Like what other's have said, give it a good thrash before spending money. I've only been MOT testing for 6odd months but I've seen loads of gently driven diesels failing as spectacularly. A 10 minutes thrash near the red line soon cures them. Is there an oil temperature on the read out?
no temperature is shown, infact now i think about it he did not put a temperature probe in the dipstick. i did have to take it for a spin of around 3 miles before he did the test
I once had horrid readings in an MOT test so went to a local motor factors for some injector cleaner. I explained why I wanted some and they suggested fitting a new fuel filter and filling/priming it with 'some of this' dunno what it was, some kind of injector cleaner, IIRC silver bottle with blue or green lid, smelt and felt like diesel but twas a funny colour and also 'chemical' smelling. anyway I did that in the car park there and then, blasted it the 10 miles to the MOT place near home for a retest. He said something like 'clucking bell'. worked a treat anyway and was very very interested to see what I'd used on it, the other guys all came over to see too.
-- Mark.
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On our machine, if you ignore the prompt to measure the temp for 40 seconds it'll carry on without it. I know some people don't like using the dipstick probe thing as there are various storys circulating of the end being eaten by the engine.
I'd take it back, get it done properly or go somewhere else.
I've read in LRO that putting even small quantities of petrol in a diesel engine is a realy bad idea as it strips away the vital lubrication that the engine requires.
Funny you have come up with this post, but have just heard the same thing from our local MOT station, and then took to another test station and passed there without any problems, I beleive with readings of 2.50.
Just a thought ! Was it a new type testing station, and if so are they doing it correct !!!!
On or around Thu, 22 Sep 2005 19:43:23 +0000 (UTC), "Badger" enlightened us thusly:
and unless it's obviously got an injector fault or something, I'd be sceptical of replacing injectors. Presuming it's no EDC, the pump can be adjusted. if it IS EDC, then there could be an electronics fault leading to over-fuelling.
"trained land rover mechanic" isn't necessarily what you want, in any case. "diesel specialist" would be what I'd hunt. If you were in west wales, I could point you to one :-)
On or around Thu, 22 Sep 2005 21:22:22 +0100, "Paul" enlightened us thusly:
Norty boy, then, the tester: you're supposed to measure the oil temp which should be up to a specified level before commencing the rev-the-nuts-off-it stage.
Other tricks you can do:
move the maximum engine speed stop in a bit to lower the maximum revs by 500 or so. This makes a fair bit of difference and may be enough together with the other things like making sure the engines properly up to temperature and nailing it up the road just before the test.
You can't really do it wrong, it's all computer prompted. You can press the throttle down slower when the computer tells you, this will actually reduce the emissions considerably, but is about the only "fudge" you can do. As for the oil temp, there have indeed been issues with ends being eaten due to the flexibility of the probe, being inserted into a very turbulent area of an engine, in close proximity to a whirling crank and rods, where the original dipstick was solid or at least stiff enough to resist any flexing. If the vehicle has been driven there immediately prior to the test and is up to temp (i.e. it's gone at least 10-15 miles) and it's kept running right up to the emissions test, then there's nothing to be gained by checking the oil temp 'cos it ain't gonna get any hotter unless you work it hard! Within reason, the temp has nothing to do with the emissions, it's simply a check that you aren't "racing" an engine that hasn't got up to working temp for correct lubrication. What reduces the emissions, is getting the thing hot enough (piston crowns, injectors, valves etc) to effectively self-clean all the accumulated soft carbon that builds up when driving sedately. The MOT test works the engine hard enough to loosen this carbon, producing the smog that fails the test. Badger.
The machine does ask can the temp be measured? problem is, on some vehicles the probe is too big for the dipstick tube or it's inaccessable so as long as the temp gauge shows hot you should be ok I can't honestly remember the last time I measured the temp before testing one and I don't think getting it a few degrees warmer would bring the readings down that far
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