[BitMechanic]

My 2000 Jetta tdi with 180,000 miles has been averaging 41-43 mpg. The following maintenance has been done:
- Cleaned EGR valve, intake manifold, and intercooler.
- MAF clean and checked.
- Exhaust turbo rotor and variable vanes chemically cleaned with oven cleaner.
- Vacuum hoses replaced with silicon hoses.
- Fuel and air filter replaced within the last 1000 miles.


To identify potential causes of poor fuel economy, the compression was checked and found to be between 380 and 420 psi. Compression is not a problem, but I would like to do a leakdown test to make sure that rings and valves are not the problem. How can a I do a leakdown test?

John

 

[Fluid]

Is it an auto? If so that's not that bad. Check the nozzle balance and injection quanitity using a ross tech VCDS. Worn nozzles do often wear together though. You could try a can of diesel purge to clean the nozzles out. You could do the leak down test through the glow plug hole on a warm engine.