Top of engine oil leak

My car has always leaked a little bit of oil but it seems to have gotten worse and I'm frankly getting jealous of these Bring A Trailer posts with a pristinely clean engine underside so I'm on a mission.

I cleaned the bottom of the car well and then took it for a few drives as well as did a 20 minute session on a small track nearby - so it got a reasonable workout. I did not clean the top of the engine, as will be important in a minute.

Bottom of the oil pan looks like it did before I cleaned it. Already have visible drops hanging off the bolts.

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Got it on jackstands and couldn't pinpoint where the oil was coming from. There was some wetness a little higher on the engine with no obvious source. Higher up, most of the oil was on something that looked like a wing-nut coming from the middle of the back side of the block.

Looked up top and found two pools of oil on top of the engine and some wet areas. What could be the source of oil up here?


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There is oil pooling around the plugs at the top on both sides of the block. The first is on the side by the water pump pipe. Second by the oil filter. I felt around under the oil filter wondering if there was a leak there but the oil filter flange was dry.

I also notice that there is some oil deposit on one carb and the hose next to it Image Unavailable, Please Login


If I run my finger under the valve cover, there's a little bit of oil residue there. Is that hose supposed to look wet? The one on the opposite bank looks similarly "wet".

Any next places to look or tips would be appreciated.
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Thanks for that list. Gave me places to focus my poking:

* Oil line attached to the oil filter housing
Nothing there. It was pretty dry - just some dust

* Oil filter housing
Could you let me know which # item you were referring to? 22?
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* Oil filter flange
Assuming you mean the intersection of the oil filter (20) and the oil filter base (19). Checked. Dry

* Cam Cover gaskets
Bank 1-4 gasket. Dry by cylinders 1-2. Tacky by 3-4. Light coating by vent
Bank 5-8 left side dry. Right side dry

* Cam cover oil cross vent (that thing you call a hose next to the carburetor)
Bank 1-4 vent on the cam cover looks soaked with oil. The surrounding area is tacky with oil. Not soaking but could be the source of an oil mist
Bank 5-8 vent on the cam cover - light misting of oil below the hose. Not damp. Not wet. I notice when I squeeze the top of the hose, some oil glistens.

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• Oil temp and pressure sensor

The sender (32 above) is dry. The low pressure light switch (37) is lightly coated with oil. No drops on the bottom side

There may be multiple leaks going on. There is a good amount of oil on the bottom of the distributor on bank 1-4. I could feel it with my fingers. Picture shows the location using the the mirror. I vaguely recall being able to see a drop in that area from the underside of the car. Not sure how oil can travel from there to the V by the oil filter.

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Unless there is an area I find another leak, my best guess for the oil in the V is now the cam cover oil cross vent. If that is it, two questions for you
1) Is the most likely cause the tightness of the clamps or is there something else possibly at play?
2) I'd like to clean the area well so it's clear what is still leaking and what is fixed. What's the best way to clean those hoses to get the oil off? Simple Green?

 

It's possible that cover was opened up when I had a repair in that area. Recalling it was a gasket between the oil pan and the transmission pan. That was done by my F-mechanic. Is there a connection between the jointing compound and the oil on the studs?

I do notice that the area immediately above it has oil on it so it's possible it's traveling down the block.

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Once I know the top of the engine is tight, it will be easier to figure out if there's a leak on the bottom side too.

 

Found oil in an interesting place. It’s right below the oil pressure light switch on the top side of the oil filter flange. If so, that rules out the gasket between the flange and the block. Not positive I cleaned that area before the drive I just took. Will clean the area and then take another drive and see if it reappears. Image Unavailable, Please Login

I really hope this is a real leak and not just carelessness during my last oil change from my mechanic. I guess that’s a possibility too but that would be surprising.

 

Ok. Found it. It was the oil pressure switch which lights the oil pressure warning light. I see from this thread that other's have had the issue.

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Cleaned up the area, took a 20 minute drive. Already had all that oil standing in the V

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Big ole drop hanging off the bottom of the oil switch

Ok, so replacement process

Saw a couple on line and is shared with the 288 GTO. This reminds me of changing my ignition switch - which is shared with the F40 and had a price to match. Still, $35 or $6 or whatever the part match thread says is cheap either way.

Can you get to it just by removing the oil filter? Remove the entire airbox?
Drain the oil or is that area relatively dry because gravity?
Do you need a special tool to remove it? I see one mentioned in this GT4 thread