View Full Version : Volvo Penta 2002 1987 leaking diesel from front of engine

07-08-2009, 04:40 PM

My sailboat came equipped with a Volvo Penta 2002 (1987). I have owned the boat for 4 years without any problems except for a diesel leak coming from the front of the engine but I have no idea exactly where the diesel is coming from.

It isn't a big leak, perhaps a few drops a day, but it is continuous. Doesn't matter if the engine is running or not. Doesn't matter if the boat is on the water or on the hard during winter. I always end up with a puddle of fuel in front of the engine.

I left two absorbent pads under the engine last fall. I placed one directly under the engine and the other right in front. Pad under the motor was bone dry but the one in front was soaked after a few weeks.

Engine does not seem affected but it seems the leak is becoming a bit worse as time passes so I need to figure out where this is coming from.

Any suggestions??



07-09-2009, 06:23 AM

If by front of the engine you mean where the fuel lift pump sits, i.e. the end of the engine away from the propellor, then it could be the Volvo mechanical lift pump shaft seal - not the diaphragm, but the little o-ring which seals the shaft. If you have a diesel header tank that keeps the fuel lift pump under slight positive pressure then this could be it. You will find a trace of diesel at the base of the lift pump.

It will be worse when the shaft is operating.


07-09-2009, 08:20 AM
"Hi Keith,

Thanks for the info. When I'm looking at the front of the engine, where should be looking at to find the mechanical lift pump shaft seal?

Do you think this is something that will require a mechanic or can a handy guy replace the pump seal himself?



07-10-2009, 02:56 AM
"Thinking more about that diesel leak, I am wondering if diesel will get to that shaft seal, unless it is leaking past the diaphragm. It is more likely engine oil that will drip out, but that will be very black and easy to distinguish from diesel. The pump is easy to remove. Just take off the feed line and exit line, remove two screws holding it to the crankcase, and pull it out. The diaphragm can then be taken out of the housing and a service replacement inserted. If this has not been looked at for a long time there could be a leak. If you can't get Volvo parts, which are rediculously expensive, use Deutz bits which are cheap but may need replumbing of the lines. A Deutz pump head fits right on the Volvo base.

The work is not difficult. Just make sure you don't drop the screws into the crankcase when you take out the pump.

To find the leak, clean and dry the engine thoroughly and then dust it lightly with powdered white chalk, especially around the diesel pump and pipe unions. The next day you will see from the 'moist' chalk where the leaks are."