In this thread you may find some useful information relating to MOTs and how common issues can be resolved. So please take the time to read this thread before asking a question.
If it doesn't answer your question or you're still unsure? Then feel free to post in this thread, or PM me directly, and I will try to help. I am a licensed class IV and VII MOT tester so should be able to answer most of your questions, and if I am not about there are many other people on this forum who may be able to assist.
Useful Links
MOT Testers Manual
MOT Check List
Before your car goes in for an MOT here is a few things that may help:
1.Make sure you car/van is clean and presentable or the tester will be thinking if they can't keep it clean then they probably can't be bothered to look after it or maintain it resulting in them going over it with a tooth comb
2. Check all your lights and make sure they work. As this is a very common failure and it's simple to check yourself.
3. Make sure the screen wash is full of fluid (the amount of cars/vans that i have failed due to no screen wash is crazy ). It's not the testers place to top it up and pass your car/van. Also check your oil level make sure its where it should be
4. Check the tyres. It's very simple to do make sure they are at the correct pressure and not like a Damon Hill racing slick
5. Be on time or just before. There's nothing worse then someone turning up late its very annoying as the tester will have a big workload and MOT's are done in slots and you don't want to be annoying the tester if you put him behind.
6. Make sure your rear view mirror is clear from hanging air fresheners and fluffy dice. A Tomtom mounting bracket stuck to the windscreen is a no no (they're all failures ).
7. Take your old MOT cert makes life easier for the tester they like an easy life
8. If you had been advised on something last year have you rectified it? Or have you left it to get worse and not checked it since? Chances are if left and not been checked on it will get picked up on again this year and either be another advise or a failure
9. Check your car/van for management lights and fault lights. At the moment only ABS light on is a fail so get anything like that sorted before taking it for test as it will fail.
10. Makes sure everything opens, boot ,fuel cap ,bonnet and all the doors. If none of them will the tester will refuse to test it and its a waste of a journey for you.
11. If you are able to have a good look around at the brakes, suspension etc. If there's something you're not happy with chances are the tester won't be. The more effort you put in, the more likely your car/van will pass with flying colours
12. For a petrol vehicle make sure you get it nice and warm before you take it in for test. The cat does not work until it's upto a certain temp and can result in a failure on emissions, due to the vehicle not being hot enough. So make sure you get it nice and warm before.
13. For a diesel vehicle the same above applies but make sure its not smoking excessively when revved
While your vehicle is being tested:
1. You can watch the test from the viewing area. You may want to chat to the tester but the rules state he is not to talk while a test is in motion. So you are better to leave the tester to do his job if he wants to talk he will talk to you first.
2. Stapling £20 notes to the drives seatbelt and trying to bribe a tester wont work so don't attempt it as you will only get their back up they don't know you!!
If you follow all the above you cant go far wrong
Emissions
Spark ignition ( petrol )
High HC reading means excessive unburnt fuel could be cause by:
1. Spark plugs need replacing or faulty leads,cap,rotor arm check ignition system
2. Faulty CTS ( cold temp sensor )
3 Mechanical fault if present engine will not be running even
4. Lambda sensor
5. Defective air filter
High Lambda reading means the AFR ratio is not correct could be caused by:
1. The engine having a high HC level see above to rectify
2. A leak in the exhaust system even if a minor leak
3. A defective lambda sensor
4. A leak on a vac or intake pipe.
High CO reading can be cause by:
1. All of the above
2. Was the vehicle tested at correct temp was cat allowed to get to operating temp
3. Defective Cat
If you go through the above and in most cases the above will solve most issues if it does not then put a post up but please include the reading from the emissions printout for CO,HC,LAMBDA as this will aid to see what the engine is doing
AFR = Air Fuel Ratio: The ratio of fuel to air entering the engine or the "mixture".
CO= Carbon Monoxide: The result of incomplete combustion.
CTS = Coolant Temperature Sensor: Measures coolant temperature as a reference for the ECU. Faulty sensors can cause the ecu to enrichen the fuel mixture or difficult cold starts.
HC= Hydrocarbons: A byproduct of burnt or partially burnt fuel.
Lambda Sensor: Also known as the O2(Oxygen) sensor, is used to monitor AFR. The Lambda probe does this by measuring the oxygen content in the spent exhaust gases. This is then converted into a signal (voltage) and used by the ECU to interpret the AFR.[/quote]
Compression ignition ( diesel )
Excess level of smoke measured
Ways to help get it though are as follows
1. Give the vehicle a good rev till it clears diesels tend to get clogged up and this is normally enough if not follow number 2
2. A new fuel filter and air filter and add some anti smoke or fuel cleaner to the tank that will 9/10 times sort it
Corrosion is often failed in areas that it should not be so check that any corrosion/holes fall within 30cm of the prescribed area it was failed on all details can be found in the testers manual link at the top of this post if it does not fall within the 30cm's then it should of not been failed
I hope this post is of use to you
) First failure in my ownership...
