At my wits end!

[Nikki]

HI all, 

I really need some help from a hive mind. It’s possibly a bit of a long one. 

I sent my pathfinder to the garage to have a pre MOT and full service about 10 weeks ago. The mechanic flagged up a few issues to get done before the MOT but all was good. The next day whilst driving up a hill the car hit around 42-43 mph and stopped accelerating for about 2 seconds, blew a load of soot out the back and drove lovely again. A little later at about 62-3 mph it did the same thing but the engine management light came on. The light stayed on but was gone when I started the engine the next morning. I phoned my mechanic who had no idea what was going on, but we remembered the car had a hissy fit for 2-3 days the year before when it had the service and some work done so decided to see how it was after a few days. Well it’s kept having the same issue. Not all the time but every couple of days it would have an issue at 42-3 or 62-3mph, not be able to accelerate, kick out a load of soot and then drive fine. The engine management light didn’t come on again. 

The car has been in for work every other week since having bits for the MOT done and trying to sort this issue. We thought it might be the DPF (there isn’t one), the computer said electrical issue but then decided it wasn’t an electrical issue. Then it said the EGR valve so that’s been replaced. Now since the EGR valve has been replaced it drives beautifully. The MPG had gone from 19-22mpg to 26-30.5mpg and I was over the moon. I drove around 10 miles to work, parked, turned engine off and went to train a dog for an hour. When I got back to the car the engine management light came on as soon as it was turned on and it drove like a slug again. I took it back to the garage the next day, had it put on the computer and the only thing that showed up was an o2 sensor which the mechanic said he wasn’t worried about. He got rid of the errors and the light was turned off. Again I drove home and the car was driving like a dream. Turned it off, went to sleep, got in it the next morning and the light was on again and it was driving like its 2 tonnes heavier. Saturday I had another job done and they cleared the computer and exactly the same thing. Drove beautifully until it was turned off and back on again and it drives awful, light on and its limited. 

Now the other new issue since last Wednesday is that it is no longer just not accelerating at 42-3 or 62-3 in fact it’s stopped all that. Now at 52-3mph it stops accelerating and starts losing power. I can’t accelerate at all…which isn’t fun on a 60mph stretch of road and when you need to turn right it crawls across the road as a large van is approaching at 60mph. As soon as the car is turned off and back on again it drives fine. Engine light is still on, I assume it’s still limited. 

My mechanic doesn’t know what to do next. I’ve spent over £2k on various things for the car in the last 8 weeks including all this and am now almost out of money. 

The car just failed its MOT on emissions. It failed last year but after the service went through no problem so I hoped having the service first I would sort that but obviously not. 

I’m at my wits end and have no idea what to do with the car and I need it for my business. Does anyone have any ideas what is going on with it that I can throw at my mechanic please? 

[Trevor]

You don't say what year the car is but for my money I would recommend that the turbo variable vanes are cleaned using a specialist cleaning solution.
Once this is done then it needs a proper hard run, not short-shifting on the gears but holding the revs up before shifting which will give the engine chance to clear its lungs.

Basically the carbon build up in the engine (EGR was testament to this occurring) and the turbo sounds clogged up also.

Listed below are links to cleaning products on ebay

https://www.ebay.co.uk/itm/331754313002?itmmeta=01J3JT0ARSVRG19F0E89P969TC&hash=item4d3e19152a:g:h5EAAOSw4Ehag~qM&itmprp=enc%3AAQAJAAAA0LTnITF3WGt3YJY4GI1hUKC%2BXP8ZHDRtSSnJ0dz0Rze3oyI4yeaUUtHVxMrZSc8hqxwfqLisgsWyg85fXSsypUG5TEPjryqdAfyY7W0poyavbKcZLCIPwk1KgAFZO6qaGbOFjvn1RJum1QmKPRgTz5T3wr1RkbfI2niLRxM5%2FHUmI3a19zKlItfpQ8dEqr7WSsZtiOO12fmwelgmXZ%2BWxQSEopwQ2bGvgZJsvk%2BEomby%2BYQQ9uGCpQNFJh2sOFE%2FRgKXXEAEicjKF7Fru2L8AsE%3D|tkp%3ABk9SR8CsgdqcZA

https://www.ebay.co.uk/itm/323958600044?itmmeta=01J3JT0ARVD0SDHSEBS2XS4RF5&hash=item4b6d6ff16c:g:basAAMXQfvlSg4~P&itmprp=enc%3AAQAJAAAA8MH81HR74rsuLLW6RBEnYbAOqZYRUJYaoT%2Bm13iI9d2GPBy%2BYMVauztqaiv2BhPDSQiUmH0mc8p9%2BlYvVgxiOqgQxqzxbULCTfwUvJO2BKw62hwA9eHFvDJaQPDJNL41sKqqH%2BtHdNHn994uhyIpMHCRj%2FsMAhrUEAFcWY%2FGnPf7AajOJv26HNE8JABGeaYZ1IyMJbV2HR%2B0aKL31GMCxHH3f64fVwTk8nlZRGNPeYmAFgEZrm4ne3oEDEiXKmrFLXhk3NLlGLDqex6gCZzr0e5xoFWhPsjRLqfMB2FvJfhJJbMRIwliczhp4cFCUmWn3A%3D%3D|tkp%3ABk9SR8KsgdqcZA