Toyota Prado: Carbon build up

Problem with the carbon build up and turbo lag in an engine that’s done 200,000 km.

Three months ago whilst driving on a freeway I couldn’t get to top speed, the turbo didn’t want to kick in. It was sluggish and when it did boost there was a cloud of black smoke out the exhaust. On investigation it was found that the EGR valve was almost blocked with carbon. The management system was not registering any problem, then or since. The EGR was replaced and the addition of a carbon catch canister. Problem continued irregularly with the car not accelerating because the turbo was not boosting and black smoke continues under acceleration.

I have spent $2500 at this stage and the problem continues, though I have had some small improvement by going on a long drive and adding a fuel injector and carbon cleaner to two tanks of diesel. There is no loss of power when it is working and the black smoke didn’t exist before this current problem. I don’t know what to do next and I’m not getting much useful advice from anywhere. Every time I see someone it costs more money! I did find the following when asking about 2007/8 Prado Problems on the Internet.

Toyota has recalled diesel Prado’s in Europe and the Kiwis are replacing the seals every 45,000 km. It would be worth having the oil pickup in diesel engines inspected before purchase, which can be done by inserting a probe through the oil drain plug. If it has a build-up of carbon on the pickup the engine is suspect, if there is no carbon the engine is most likely in the clear.