Volvo penta 2003 small oil leak, source?

[redbeard1]

Hello all,

We recently added 50 hours to our engine in 10 days. While checking the engine bilge, I noticed about two tablespoons of oil (the engine bilge was cleaned before our 10 day trip).

I'm assuming healthy engine leaks NO oil, is this true?

Two tablespoons of oil in 50 hours is such a small amount that I'm not sure we will be able to observe the leak. Besides cleaning our engine and checking for oil residue, does anyone have ideas where such a small leak could come from?

We recently replaced the water seal on our water pump">raw water pump. It was in poor shape. Next on our list is a rebuild of the entire pump. Could a poor oil seal in the raw water pump be the cause?

Thanks for any ideas.

[deblen]

I have a 1984 VP 2003 with 2000 hrs on it.
No major oil leaks. I consider 2 tsp of oil after 50hrs running on an engine that age as a minor inconvenience personally.
Place an oil absorbent pad under it & watch for any change.
http://www.homedepot.com/p/Oilinator...UNIT/205188710

It may disappear when you replace the oil seal during raw water pump rebuild.

When you have time,use a bright light to check for signs of oil on front of engine. Start at the top & work down. You may have to loosen alternator to see behind it.

Cheers/ Len

[redbeard1]

Thanks for the link, Len. Ever since we threw out our old pad a few weeks ago, I'd been wondering where to buy an inexpensive pad.

Looking at the leak again, I think I need to downgrade the amount of oil to 1 teaspoon instead of 2 tablespoons.

I will clean engine of old stains and see if any typical areas get greasy again. We will also start getting the parts for the raw water pump rebuild.



The engine is over 25 years old. I think we will take a similar attitude. After all, we change our oil every 100 hours. A teaspoon or two out of 4 quarts does not sound too bad.

[DougR]

It seems logical that if the leak appeared after working on the raw water pump there is a good possibility that something on or around the pump was disturbed, causing the oil leak. This could be the oil seal in the pump itself, or the larger O ring where the pump mounts into the front timing case.

There are also several other places in/on the front timing case that could cause an oil leak. These are:
- oil filter
- oil filler cap
- front crankshaft seal
- oil pressure relief valve (on the bottom of the front case)
- cam shaft protrusion thru the front case (hand crank location)
- oil pressure sender on the top of the front case
- O ring behind the oil pump
- throttle connection cover gasket & O rings on throttle shafts
- front cover gasket

Yipes, there are lots of possibilities! As you said clean it up and keep a sharp watch.

DougR

[redbeard1]

Thanks Doug,

I traced the leak to an adjustment screw. The screw (in yellow circle) has something to do with the throttle, but I'm pretty sure it is not the idle adjustment screw.

Either way, the leak is less than a drop per hour of run time. If I can't find a replacement, I'll learn to live with the leak.

On an unrelated note, you seem to know these Penta's very well. We were speculating today on the best way to remove the metal tube that holds the oil dip stick in place. I think it may screw out, but could find no clues in the parts diagram. Any ideas?

[DougR]

Screw #6 is the adjustment screw for max. fuel at full throttle. It is factory set and shouldn't be adjusted willy nilly, but you should be able to reseal it.

Hold the screw stationary with a screw driver while loosening and removing the lock nut. Then back the screw out a couple of turns, keeping count of the number of turns. Clean up the exposed threads and give them a coating of something like a non-hardening permatex, then turn the screw back in to its original position. Clean up the threads on the lock nut and put some sealer on the nut threads and the underside of the nut and thread it back on the screw. Hold the screw in position and tighten the lock nut.

Screw#18 is the high idle rpm adjustment, which is also factory set. The idle speed adjustment screw is #39, which you can use to set your idle speed. Loosen the locknut a bit and turn #39 to move the idle speed up or down, then retighten the lock nut.

Normally dip stick tubes like on the 2000 series are just pressed into the block.

DougR

[redbeard1]

Thanks again Doug,

Repair does not seem to difficult as long as we're very careful in minding turns. Still, given the small amount of leaking, maybe we will save this repair to end of season.