Can you help me identify this bolt / plug?

[JeTexas]

I've got a bolt that seems to be a plug of some sort in the direct center of my 99 c2 motor just behind the bumper. I guess that would be the front, center of the motor?

It's slowly leaking oil, so I'm trying to figure out what it is, where the oil is coming from and what seals/rings I need to replace it.

Thanks in advance for any help.

[JeTexas]

Actually, now that I'm sitting here looking at the photo instead of lying under the car, maybe something is leaking from above the bolt. What would leak in the center of the motor? Would that be where water pump seepage showed up?

Edited July 1, 2008 by JeTexas

[Tool Pants]

If it looks like this it is the oil pressure relief valve.

[JeTexas]

If it looks like this it is the oil pressure relief valve.

Thank you Tool Pants. What does it mean if I get a drip? Was my oil level too high? Has the valve gone bad? Is it just normal?

It only happens when the car is hot.

[Loren]

The first question is - is that really where the oil is coming from?

I suggest you clean it off and then look again after a drive and make sure that is the source.

[JeTexas]

The first question is - is that really where the oil is coming from?

I suggest you clean it off and then look again after a drive and make sure that is the source.

I was sure it was until I looked at that photo and saw all the grunge up there above it. When I finish driving, I'll have clean looking oil around the neck of the bolt and drip hanging from the head of the bolt.

I'll do more cleaning to make sure. It definitely only happens after I drive because I cleaned the bottom of the car up and wiped that bolt down when I did my coolant hoses last weekend and it sat all weekend clean with no drip. I would have never noticed the fresh oil on it if I hadn't just wiped everything (on the bottom of the car) down.

[Tool Pants]

Tighten the nut up. Clean the area with brake cleaner. Then take another look. That valve is not a known source of leaks.

[magcuda]

after you get it cleaned up, spray some baby powder up there. where the leak comes from will leave a trail in the powder.

[pjalexandre]

Unless someone bent it trying to jack the car up using that spot instead of the one directly behind it. Looks bent...could be the angle.

That valve is not a known source of leaks.

[CJ_Boxster]

FYI the piston at the top of the spring has been updated so while you have it out you might want to pick up the new one, i dont know what the benefits would be but an "improved" design couldnt hurt?

[JeTexas]

Just an update. I cleaned it all up again and put a wrench on that bolt. It took about another quarter turn without much effort. I've driven the car several times since then and have yet to see anymore oil.

I don't know why I was too timid just to make sure it was wrenched down in the first place, but I'm still so unfamiliar with some of the systems in this car that I'm scared to inadvertently break anything.

Thanks for your help.