Oil leakage near oilfilter (?)

[MvM]

Last Saturday I noticed white oil fumes after a 20 mile drive and smelled burned oil. Came from the right side, near the right rear wheel. I immediately checked the oil level which was above the first marker and put a little extra oil in the car. Drove home taking it easy. At home I looked under the car and saw oil on the oilfilter, rear suspension arms and heat-shield. AFAI could see, no oil on the oilpan or engine-block. From the top of the engine bay nothing could be seen, everything there was neat and dry.
At no time were there any warning lights. Oil-pressure has always been ok (about 2 bar at idle going to 6 at speed), temperature has always been a fine needle in the middle situation. Car has 41K miles on it.
Sunday-night I put the car up and wiped everything, then started the car again. I could see oil dripping down from the oilfilter but I am unsure if it came from the filter itself or somewhere higher up.
Since the car was due for an oil-change I did that, replacing the oilfilter in the process. After the change I drove the car for 20 miles. Oil-filter was still clean after that, suspension arms too.
I put an (old) newspaper under the car and this morning there was (black) oil on the paper. Being unsure if this was from oil that had dripped on the floor I took the car to work (40 miles). I just checked again and I don't see any oil on the parking lot now. I've put some paper under the car so I can check again when I leave this evening.
Could it have been the oil-filter itself or it's rubber seal? And if not, what would be the first play to look?

 

[kpond]

MvM,

I've seen this symptom before, althogh not on an NSX. What you have described sounds like an oil filter that has been over tightened. Often what peolpe do upon suspecting the oil filter is to tighten it more - unknowingly making the problem even worse.

What happens on an over tightened oil filter is that the metal edge of the filter starts to make contact with the mating surface on the car. As the entire assembly becomes warmer, this metal to metal contact doesn't allow the filter to expand and instead it tends to lift the rubber sealing gasket. When this happens, oil will leak around the intended seal and will easily work its way out from this metal to metal contact around the perimeter.

As you suspect, I think you've resolved the problem now with an oilf filter change and proper torquing of the filter. I think the oil you saw at first was just residual oil dripping down - just as you suspected. Keep an eye on it for the next couple of drives but I'd be pretty convinced that you've got the "problem" resolved.

Thanks for sharing - likely your experience can help others.

 

[Lud]

I'd say the filter or drain bolt are always good suspects. Since you've done and oil change, I'd say verify you still have a problem before worrying about it.

You said the car was dripping dirty (black) oil right after you changed the oil, but that was old oil that had already leaked somewhere else and was just dripping down once it got hot enough. Obviously the new oil wouldn't be black that quickly.

 

[MvM]

Thanks for all the replies.

Actually, Kpond, you might have a point there. I had a LOT of trouble getting the oil-filter loose. In fact, I just purchased the oil-wrench(oil filter socket) from Dali and expected it to be easily. However, I winded up extending the wrench I used with a piece of pipe for some extra leverage. Mind you, lying under the car with all those suspension parts in the way don't make for a very good position to put in some strength. Thing is, I don't remember putting it on that tight when I did my last oil change.
I tightened the oil filter this time with one turn (360 degress) as described in the manual (page 8-5).
Can it be that because of the heat generated the filter-fit becomes tighter after being on the car for a few months. I had tracked the car several times but always checked the oil and never had any trouble before.

Anyway, I still have to drive another 80 miles today and will, of course, check again when home. Will keep you posted on my results. I really do hope of course it is something simple as this since gasket-repairs on a NSX don't come cheap.

 

[4AU4LIFE]

It is a little time consuming but I have found that taking the right rear wheel off makes changing the filter SO much easier.

------------------
ALL NSX
92 RED/BLACK 5-SPEED

 

[Markbert]

FWIW, I have HEARD from a friend with an RSXS that Mobile1 filters sometimes leak in the manner you describe. I have used nothing but OEM Honda filters and have had absolutely no trouble whatsoever. I'd just do an oil change with a new filter/crush washer and see if that fixes your problem.

P.S. the oil filter wrench is a WONDERFUL tool. I just back the car up on some custom made (shallow approach angle) ramps and its a breeze.

 

[MvM]

Guys,
Thanks for all the replies.
Drove another 120 miles last night and some of it at over 110mph (only moments of course). Oil pressure/temperature reads fine as usual. Parked the car in a dry spot.
This morning, not a drop of oil anywhere. Feel much much better now

Will of course check in the coming weeks if the problem will reappear. As oilfilters are concerned, I always use Honda OEM.