Volvo 4.3 V6 sump gasket leak recurring problem

[PooleAndy]

Does anyone else have experience with recurring oil leaks from the oil sump of VP's 4.3 GXi-F engine?
The oil seems to be weeping from the front end of the sump, near the crankshaft (an area of the sump with fewer pull-down bolts!). The sump and block have been checked for scoring and distortion with no evidence to suggest a problem.
New sump gaskets and crankshaft seals have been installed and it's run for hours on the bench, again with no problems. But after a few hours of normal running the problem reappears. The engine has been out of the boat 3 times now (soon to be 4!) in an attempt to keep the oil where it matters.
The marina where the boat is kept have provided a sterling service, including engaging the input from the Poole area VP main dealer, but so far all attempts have failed.
Accepting that the issue needs to be fixed, again, can anyone on the Forum recommend a VP specialist in the Weymouth to Portsmouth region. who may have the knowledge and/or magic sealant to fix this problem?

Thanks in anticipation.

 

[dpb]

Mike Wills in Poole.
Sealant is needed where the sump goes around the crankshft seal. Are you sure it is not the crank seal leaking?

 

[PooleAndy]

Hi Mike Wills, thanks for replying so swiftly.

It does seem to be consistently leaking from the crankshaft area although I have a feeling that a sealant was tried previously. That said, a few fixes have been attempted and now they're all merging into one so I can't be certain!
As soon as the weather improves, probably next week now, I've got a meeting lined up with the guys who attempted the last fix and I'll try to find out what, if anything, was used.

 

[QBhoy]

Hi. Likely that you may be right in assuming it’s from the sump perhaps, but there are a few other known culprits for a source of an oil leak…all of which can find their way down to appear that it’s from the sump. Do you have an engine driven water pump ? Assume you might, if she’s a Volvo Penta version of the 4.3. Things like that can be the source. Is the boat a sea water boat and has there been a chance of corrosion inflicted anywhere, from sea water in the bilge previously perhaps ?
Might be already thought of…but I know that even the slightest spillage from filling with oil at the filler cap on the rocker cover, can result in oil finding its way down low on the engine and causing concern.
You’ll no doubt have the right grade of oil in her and the right amount of around 5 litres, but any chance that she isn’t getting up to temperature, running cold and causing a sustained high oil pressure situation?
The timing chain cover might be another suspect otherwise.
Another thought might be around the sole of these engines having an oil drain fitting to a hose that you can pull out the hull drain or bung plug. These can sometimes leak. As can any other fitting like oil pressure sensors etc etc.

 

[PooleAndy]

Hi QBhoy, thanks for getting back.

Most of the points you've raised have been investigated. You're assumptions about it being a sea water boat with engine driven pump are correct. The pump did indeed fail but was replaced about 4 years ago. And we also suffered from a different oil leak about 2 years ago which turned out to be a crack in the chain case cover (if you know the engine you'll know it's a plastic cover!). The engine was removed at this time and the sump removed to fix the chain case. A few other minor issues were sorted at the same time and the bilges given a thorough clean out so that we could check the corrective measures. It seemed ok, at least enough to refloat and go for a trial spin. A few 10s of running hours later and a small amount of oil reappeared in the bilges and we went around the loop again.

As mentioned previously, I've got a meeting lined up with the guys who performed the last surgery, we're just waiting for a decent weather window. Fingers crossed for next week!

 

[PooleAndy]

I just thought I'd close out this thread for anyone else who may have a passing interest (fingers crossed!).
After a forensic examination by the fine chaps at Mike Wills Marine, it turns out that a broken sump stud was causing the sump pan to not pull down squarely to the block. As the chain case cover position is affected by the sump pan location, this was also tightening up in a slightly offset position, damaging it's locating pegs and causing the crankshaft to rub on one side of the seal. So in reality probably multiple small oil leaks.

A bit of work to remove the broken piece of stud, and a box full of new fixings, gaskets and covers, and it now runs as good as new! We also took advantage of the situation and upgraded the cam chain to a duplex item, replaced the anti-vibration damper that was showing signs of wear and tear and fixed a damaged oil pressure sensor that was indicating a continuous 100% on the VP diagnostic tool.

We'll keep our fingers crossed for a trouble free '23.