Oil tank overflows

[cashflyer]

Had the oil changed last week and after leaving the quick-lube we noticed that oil was dripping... no, it was running out of the rear fender well. Checked the level and found that the mechanic overfilled the system by about 1 quart.

Took car home and drained enough out of the reservoir to bring the level down in the correct range on the dip stick.

The car seems to still be leaking oil from the tank, though at a reduced rate. I cannot find where the overflow vent is at, and the oil is NOT coming out of the fill neck, or from the filter, or from the sending unit gasket. Those were the items I could readily check.

My question is: Where is the overflow vent? Is this oil that is still dripping going to stop when the vent clears? (is there a vent?)
OR has some major damage now occurred due to the overfill, and that damage allowing the oil to continue leaking?


Thanks.

[cashflyer]

Checked with engine warm, and at idle.

[svandamme]

shouldn't leak in the fender well , i don't see how that's possible with a good tank and properly attached hoses

to over fill it to the level of the breather hose would be way more than a quart , that would mean filling it to the filler !!

did the mechanic put in a new oil filter?
did he screw it on properly? and did he put some oil on the seal prior to installing the filter???

the oil filter is in the engine bay , but if that one would leak ,it would drip inside the fender, not in the engine bay...

[emcon5]

And your car is a...............?

[cashflyer]

Originally posted by emcon5
And your car is a...............?

'78 911sc

[cashflyer]

If it were leaking from the neck, from around the oil filter, or from the breather hose, I would have expected oil to be in the engine bay. But there is not.

The oil is dripping from the inner fender area just behind the rear tire, puddling on the floor just below where the oil tank is located.

[svandamme]

the base of the filter is not in the engine bay , it can't drip in the engine bay
but if you are sure.. then that leaves your oil level sender

or the 2 hoses to and from your engine...

or a completely rusted , damaged tank , since there are no other areas where it can leak if it's in good condition

EDIT ... the drainplug, but that would be very obvious to spot..

[Steve87-911]

Originally posted by tcar
Never, never go to a quick lube w/ a p-car! ... but you know that now.

I was just about to say that myself.

[cashflyer]

Originally posted by svandamme
the base of the filter is not in the engine bay , it can't drip in the engine bay

I figured that the thick neoprene rubber gasket that keeps road grime and water from crossing from the fender well into the engine bay would also keep the oil in the engine bay if the filter were leaking. It of no concern, though. A quick check around the base of the filter reveals no errant oil.

I'll degrease the tank and check around the 'S' hose. The threaded hose to the oil t'stat does not seem to be a problem.


Is there any chance that the extra oil would have caused a seam to split on the tank? I think I've seen the 3.0 system referred to as an "open" system, so I assumed there was a vent of some sort to prevent this.

[svandamme]

forgot about that gasket ... it's kind of dodgy on mine..

tank can't split due to excess oil , if at all , it would come out the breather hose...

[cashflyer]

I gave up looking for the leak. I just drained another half-quart of oil, and that seems to have fixed it. The oil quantity gauge now reads just above the low level mark, but the dipstick reads just below the full mark.

Whatever. It has oil and it does not leak - that's all I wanted.


I appreciate everyones input on this.

[JBO]

Just below the full mark is Ok but not ideal from what I have read, and everyone seems to say it is best to keep it between the low and high marks on the dipstick when hot (right in the middle), which is what I have always done. Sounds like you were still overfilled, but removing the extra half quart did the trick.

[Walt Fricke]

My two cents:

The oil tank is held to the chassis by a couple of "ears" welded or brazed to it. Eventually these can create a crack in the tank. They are pretty far up the tank (and you can't really see them), so oil level would affect when oil sloshes up that far under cornering.

When I removed my tank, which had this irritating minor oiliness in this area, and found a crack, I was able to braze it shut easily enough. Seems to be a permanent fix (15 years down the road by now maybe).

Walt Fricke

[Joe Bob]

Originally posted by cashflyer


Whatever. It has oil and it does not leak - that's all I wanted.


I appreciate everyones input on this.

DUDE......

You still NEED TO PROPERLY CHECK THE OIL LEVEL.....

[911pcars]

Check the air filter housing. That's where excess oil tank oil goes. The excess drips out onto the ground as well.

Sherwood