Troublesome Oil Leak Failed the NCT Test

A persistent problem that causes you car to fail the NCT not once but twice can be very annoying and troublesome oil leaks can be a common cause of failing the NCT.
Recently we've heard of people being advised to powerhouse the underside of the car before the test but we were concerned that this wasn't a long-term solution and could lead to bigger trouble further down the line.
Nell has exactly this problem with her Audi A6 that's caused it to fail the NCT on two separate occasions. Maybe a better mechanic is needed? We asked our resident expert Shane O'Donoghue for some advice...
Hi Motorcheck!
I drive a ‘99 audi A6 2.5tdi that failed the nct twice. The only major issue..leaking oil.
I put it through without doing anything the first time, it failed. My mechanic said without taking the engine apart and incurring major costs it could not be fixed simply.
It drips a couple of drops a day. I do a lot of mileage so need to put oil in every 6 weeks or so. So before the re-test my mechanic cleaned the whole engine down and completed a temp seal job where he looked like new! But he said it spluttered a little oil underneath after he tested it on road. I powerwashed underbody 30min before nct and it failed! Too late for another re-test to add insult to injury!
I know these cars are renound for oil leaks.. could I get some advice from someone who's been through this.
Thanks for your help!
PS. Also, driver door handle (outside) giving me trouble since today, door will only open after about 30 tries.

AnswerHi Nell,
This car's engine is quite prone to leaks so it really could be coming from any number of places. However, I'm a little surprised by your mechanic's attitude to it. If it's quick enough to be detected in an NCT then it really should be possible to at least trace where it's coming from. It may still be a big job to fix it of course. I'd take it to another mechanic.
If you don't mind getting your hands a little dirty and you're any way mechanically minded it shouldn't be too difficult to take off the inner door card and see if you can see what's wrong with the door handle for yourself. It may require a replacement part though.
Failing that, ask the mechanic to look at it for you, but beware that it could take a couple hours of his time that you will have to pay for.
Hope that helps.
Shane O'Donoghue -

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Mobile Mechanic - August 01, 2010 at 2:58 pm
The only way to fix an oil leak as such is to degrease and jet wash the area of the oil leak,road test and then re-check for leaks.If the leak is quite bad it will be noticeable after a 20-30 minute drive. It's best to have a mechanic that is familiar with the particular model spend some time to pinpoint the fault. TD's often leak around the turbo area as there are few different oil lines and seals that can perish over time. It's a good idea to have your car service done a few weeks prior to the NCT so any repairs can be carried out in due time.
Shane Teskey - August 04, 2010 at 9:26 pm
HI Kerin, Thanks for the contribution. Good advice there. Shane.
Auto Mechanic Dublin - May 03, 2011 at 12:31 pm
Myth Engine oil should be changed every 3,000 miles. Reality Despite what oil companies and quick-lube shops often claim, it's usually not necessary. Stick to the service intervals in your car's owner's manual. Under normal driving conditions, most vehicles are designed to go 7,500 miles or more between oil changes. Changing oil more often doesn't hurt the engine, but it can cost you a lot of extra money. Automakers often recommend 3,000-mile intervals for severe driving conditions, such as constant stop-and-go driving, frequent trailer-towing, mountainous terrain, or dusty conditions.