I bought my 2004 x350 with about 42000 miles on it. The original owner gave me all the maintenance records since new. He had had it cared for by the dealer. At 40000 he had quite a bit done to it when the fuel pump quit.

When I bought it seemed really peppy. After nearly two years of ownership it did not seem to be as powerful but it ran well. Then a couple of weeks ago I got a Restricted Performance notice and the Check Engine light came on.

A gas station mechanic read the codes and they said one bank of cylinders was getting a weak fuel mixture. He reset everything and it still ran ok so I drove it a couple of days. Then it happened again.

So I drove it to a Independent European Car shop an hour away from my house. He ran a smoke test and fixed a couple of vacuum leaks. I paid him and took it home. The next day the same message and light were back!

I returned the car and left it two days. He had some trouble finding the problem, but finally found that the fuel filter, installed at the dealers at 40000 miles, was installed backwards[I]! He theorizes that a slightly restricted fuel flow was compensated for by the computer until the vacuum leaks made this impossible.

I have the car back and it seems to me that it is more powerful than ever. Hope I'm done with this issue.

Tom

 

Good story! I am sure that's not one that hits the books too often, so having some sort of record on it listed here will definitely help someone else out in the future. Is there any way that you can get the specifics on the filter, the back, the MPH before and after, and if, By some some Hammer of Thor chance, you have any dyno tests at the rear wheels. Anything, I'm sure would be helpful! Thanks again!

R,
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