[bluewater3]

Hi, this is my first post as I am a new member. I have a 2005 Jetta Tdi that is going into limp mode. It is throwing code 16683. I have spent a lot of time reading about all of the possible causes. So far things look pretty good under the hood with the exception of the hose going to the EGR. It seems this could be a possible leak point. Has anyone replaced this hose and solved a limp mode problem?

 

[chittychittybangbang]

It is possible. FYI, don't just look at the hoses because they can split and not be visible under the braiding. You have to inspect the hoses and at best, pressure or vacuum test them. The ends tend to split so if you don't inspect the whole hose, it's not an inspection.

 

[bluewater3]

Thanks. I have spent a few hours with the local diesel mechanic that I use for my truck (7.3 F250) and all of my other equipment. I have a couple of Bobcats and a mini excavator as I am in the landscape/excavation business. His experience is with bigger diesels, but he spent some time with the Bentley manual as well as a couple of posts from this site. He used a Minivac to check for vacuum leaks and didn't find any. I just bought the car from a local dealer and used his local mechanic to do some work on the car since they have a guy that works on small diesels. The car threw a code that suggested an n75 replacement. (I don't remember the code). They ordered the part and when I got the car back and started looking under the hood I discovered they had replaced the n18 instead. I won't take the car back to them and I have ordered an n239 and an n75. I am sorta throwing parts at the problem at this point, but this is probably better than taking it to the dealership and paying their prices for parts and installation. I have also replaced the MAF early on. The code the car is throwing is 16683. I will get the new parts within a few days and see what happens.

 

[Canadian]

If you are talking about the large boost air intake hose, that is a common problem on these engines. It looks like it does not connect securely to the EGR because there is a little clip at the bottom of the hose that wears off. You can either replace the hose (around $100) or find a doggie collar, some people have even had other ideas to save costs, look here: http://forums.tdiclub.com/showthread.php?t=308844

My car never threw me a bad code, but when I fixed this it regained it's power and boost.

 

[bluewater3]

Parts came in for my TDI. I replaced the N239 and the N75 as well as the cabin filter. It only took a few minuters thanks to posts and info on this site. I drove the car up my very steep driveway (which had been a problem due to lack of low rpm power) and I was amazed at the difference. The CEL went off by itself and the car pulled up the drive with little effort. I did use my code reader to clear the code before I drove the car. I drove the car for a couple of hours as I had to travel to another town to run some errands. I have tons of low rpm power now. Car didn't go into limp mode and I am confident it is fixed. I filled the tank and checked my mileage. It got 38.5mpg which is consistent with past checks. It did get 40mpg on a long trip one time. I can now quickly shift into forth and fifth gear at low rpm's and reap the mileage benefits of doing so. I have no doubt that mileage will increase since the engine is not working so hard to get and stay up to speed. This is a really fun car to drive now. Cabin air filter was really stopped up. Air is blowing stronger out of the vents now.