I have a TDI-150 VW/Mercruiser
marine engine aboard. It has run well apart from my recent problems with bad fuel (lots of
water in the fuel when I started it). I had a lot of issues that were
solved, but my big problem with the engine is the lack of support and lack of knowledge. While
Mercury is a big company, very few of their hundreds of
service points have any expertise at all with the engine and even fewer will actually
work on the engine.
The engine is a common
diesel in
Europe (Jetta, Passat, etc.) while the 5-Cylinder TDI was never put into cars in the
USA. There are lots of
manuals and lots of expertise in the car world. I ended up using a VW car shop in
Newport, RI this year since the only Mercruiser
service point who would
work on the engine wouldn't make house calls and their marina's
depth was too shallow for me to be towed in.
The
parts situation is absolutely ludicrous. I needed a new fuel injection
pump, and the official source was $5700 and several weeks wait; since the
pump is 100% identical to the car pump I opted to go for a $400 replacement from VW. Likewise the little
electric fuel pump that costs $70 in stores was being
sold for $570 (same part number, except it is hidden by white
paint on the marine engine).
What is good is that the engine uses a Bosch ECU with only slightly modified EEPROM code. So for the
price of a
cheap CAN-BUS cable and some free
software you can examine all the data from the engine - something that can't be done on most other diesels. I used Ross-Tech
software and the engine code for the VW Marine engines is on their list of supported engines.
All in all the engine is rock-solid but keep in mind that car mechanics and car supply stores are going to be much better in terms of knowledge, availability and
price than Mercruiser.