On the passenger side of the motor (I believe it's the timing chain cover) there is a sensor and under that sensor, there appears to be oil leaking. Does anyone know what this sensor is or have any sugestions? I looked in the FAQ and Daniel B posted something about an oil pressure sending unit, but I don't think that is the same thing. If anybody knows what this is and has a solution, please let me know. I'd rather get info here than at the dealer. Thanks in advance.

The sensor on the timing chain cover is the camshaft position sensor (I think that's what its called).

I had the same problem last week. It seems you are talking about the oil pressure sensor. I changed mine and the leak from there stopped. Jack up the car and let the engine run and see where the drip is coming from. If it is that, you'll have to drain all the oil, change the sensor and and add more oil. Now my leak is coming from somewhere else. i think my oil pan seal is bad.

The oil pressure sender is in the oil pan, facing backwards and level with the drain plug.

The camshaft position sensor is on the timing chain cover, and visible from the top side of the engine. I believe the crank sensor is also, but lower and maybe not accessible from the top.

Dave

I know what he is talking about. I noticed this as well on my 95. Is this sensor needing to be replaced if it is leaking from there? I know sounds like a dumb question. If oil leaks then fix it pretty much but this particular sensor is puzzling with oil leak spottage around it.

If it's just a little oil leakage I wouldn't sweat it. The Camshaft sensor sits high enough that the only leakage is from oil splashing off the timing chain, so it will never become significant. If it's the cam sensor it's very easy to remove and inspect the o-ring, in fact it's probably a standard o-ring size if the leak bothers you.

I would leave it alone unless it's making a mess. I have so much salt spray in my engine bay I'd be hard pressed to find an oil leak.

Dave

So, I pretty much just need to replace the O ring on it. Sounds good to me. Ill take a look at it this weekend. I have many things planned for the car this weekend might as well add this to it.

oil sending unit maybe???

Thanks for the help folks. To verify, I checked the manual and it's the cam position sensor. I called Nissan to ask about the O ring and they said it could either be Mitsu or Hitachi. I wonder how to make that determination??? Anyway, I may try to take a peak at it when i get some time.

If you have another car take the o ring out and bring it to a hardware store they should have one, it is a common size, had no trouble getting one.

SLVR99MAXSE, can you take a picture of the sensor and leak? I didn't think the camshaft sensor was a common leak.

Sounds like Camshaft position sensor, and yes this has been a very common problem, I haven't heard much about it on Maximas but I had the same problem and got the O ring replaced. Mechanic buddy of mine tells me that he sees this same or similar problem on a lot of cars he's dealt with.

EDIT: Here's a pic of my sensor and oil leak.

Yep, thats the one. Thanks for confirmation. Its weird because my oil leak looks exactly like that, lol.

mine is leaking under the car somewhere...its kinda splashed around, i changed my oil a week ago and noticed it, i use 10w30 synthetic, think it could be the same prob???

i checked the drain plug and its tight, the iol is never just one drop in the same place...its a splash....

If you have spots on that side, it is probably not from the CPS, only leaks when car is running. More likely spot is the oil pressure sensor, near the oil pan underneath the belts.

I changed the O-ring to the CPS and changed my oil pressure sensor. However, I still have an oil leak and cannot see where its coming from. Is seems like its in between and drips mainly when the car is running. Any ideas?

does anybody know the size of the o ring in the camshaft position sensor

i have the exactly problem can someone tell me how to fix it like what tools i need to use. how to take it apart and put it back on?

10mm wrench or ratchet/socket, and a new o-ring. It's one bolt to R&R.

I'm still diagnosing mine but I do have some oil on the side of the engine like in that pic. Only leaks when running and even then the oil level hasn't dropped during the two months I've owned it.

If it ends up being the TC cover I'd just as well add a quart of oil every six months. Heck, with as little as I drive it each 3,000 mile oil change would cover any leakage.

If it's just like the pic above, then it's just the CPS o-ring. $4 from Nissan, or a couple of cents at an auto parts store.

Ill be replacing my o ring this weekend. Would I have to drain the oil before I remove the old o ring?

nope

No, the oil level is far below. Just pop it out, replace the o-ring, throw it back in.

just replaced the o ring bought it from auto zone for $4 a pck. it took me less than 5 mins to change it just remove the bolt change the o ring put the bolt back on that's it. i will see if it still leak in the next few days.

I went to passport nissan to get an o-ring today and the parts guy said that he has NEVER sold the o-ring for the cps alone and that I should just replace the cps. Should I replace the whole thing or just go to an auto parts store and get the o-ring? If I replace just the o-ring, is there a certain size one that I need to get or are they all the same?

Just because he's never sold it, doesn't mean it doesn't work. No need to replace the CPS for just the o-ring.

There are a thousand different sizes of o-rings, not sure what size it is though. Pull the old o-ring, and compare is really all you can do (unless someone has noted the exact size).

I'd still get one from Nissan. If you go elsewhere to buy just that o-ring you'll have to buy like 25 or 50 at once. It might not cost much more than buying just one from Nissan but what would you do with the rest?

Like pmohr said, the parts guy is not very smart. Most dealer mechanics would replace the whole sensor instead of just the o-ring, just in case the sensor itself is damaged. If one of them actually found a bad o-ring, they wouldn't necessarily think to get the o-ring alone. The fact that you're the first person to come by just shows that you're smarter than anyone else with a leaky CmPS to come by his counter.

JUST CHANGED THE OIL PRESSURE SWITCH. LEAKING IS GONE. BUT I HAVE ANOTHER PROBLEM WHEN THE CAR IN GEAR THERE IS SHAKING. SHAKING IS ONLY WHEN IN GEARS NOT PARKING OR NEUTRAL. WHAT CAN THIS BE CAUSED BY???

This has nothing to do with this thread, post in the Newbie thread.

Mine looks almost identical to that photo! I'm wet all the way down though! More wet the further down I look (maybe about 20 inches). The bottom of the trans is wet too, but I assume it's from something else. Strange, I have yet to actually drop on the cement.