Linhnb

Hi,
I've just done an oil&filter change yesterday. My oil pan seems like it has leak some where. But i cannot find out whether it is my oil pan or the hose near the drain plug (see picture)









I also have a video about it

wingnut2006

Most common leak is the oil cooler gasket. Check and see if the area under/around the oil cooler is dry. If not, then probably the oil cooler gasket.

Linhnb

the oil cooler is the stuff that the oil filter attached to, isn't it ?
I will check it tomorrow.

DeusExMaxima

iTrader: (1)

The best thing to do is clean your engine and then run it for a short time to see where the oil is coming from. Very commonly, the valve covers leak and drip down the engine and appear to make it look like the leak is coming from lower down. As the others have said, it could be the oil cooler or the lines running to the cooler. Just clean the engine and see where the fresh oil is coming from and it should narrow everything down for you.

NIKV69

Make sure it isn't the oil pressure sending unit if that what that is right above the leak. Those tend to leak more than the oil cooer and pan.

Linhnb

I am new to this car-fixing business. could you tell me what is the "oil pressure sending unit"?
Thanks

I got many exams these day. So I will buy a Break clean spray and clean around oil pan this weekend.

This is the new video shows around the oil cooler and the oil filter today. I put my phone inside to see the back of the oil cooler. it was all wet. and the area around it.

NIKV69

It is a sensor that sends oil pressure to the ECM (cars computer and brain) its screwed into the block and has an electric connector you can see it in your last photo before the vid directly above the clamp on rubber hose going to oil cooler.

wingnut2006

Linhub: Best to clean with product such as Super Clean degreaser and water. Brake cleaner is very hard on aluminum (engine is aluminum) and rubber. If you use brake cleaner be sure and wash off with water. Based on your video I would say that you have a leaking oil cooler gasket. There are many video's on the net showing how to remove and replace. Cost of the gasket is only a couple of dollars.

Linhnb

hi. I've spent all day with this oil leak inspection.
here are what i have found:
1. It seems like the oil pressure switch is not the source of oil leak. As in the picture below, i sprayed powder over it and after some miles driving around, i don't see oil there.



oil pressure switch inspection.

2. I cannot see it clearly but I think the Oil cooler gasket is not bad too. as shown in the picture above, the other side of the oil cooler do not show many oil. Of course i cannot see any oil dropping from that.

3. I see other evidence of oil from above the oil cooler. I don't know what it is yet. but I think it is the source, because I think liquid cannot flow upward.



this small leak really bother me since this is my first car. an used car but i like it a lot.
Hope that i could fix this thing.

Linhnb

Hi, i think i am gonna follow your instruction since I think the leak could be from upper side.
I see no leak from the valve cover that is out side, I am gonna check the valve cover on the inner side. I would be very appreciate If any one give me some youtube links or any further instruction.

Linhnb

Okay, the front valve cover is okay.
but after i put my phone back to take picture of the rear valve cover, I think I've found the source of the leaking. In the picture is the part of the rear valve cover that near the timing chain cover. You can see it is wet.



the rear valve cover leaks.

I think the reason I don't see it before is the old oil cannot go through the leak spot. But the new fully synthetic mobil 1 oil does.
since the local shop quote $228 for the valve cover gasket replacement, and I've just change the oil a week ago, then I wonder if I could leave it as-is and wait about 5000 miles and change back to the conventional oil or bite the bullet to change the gasket?
I still have 1/2 quart new oil left then I can put it in the engine when I see it low.

Is there any more damage the oil leak may cause ?

wingnut2006

Do not know how many miles is on your vehicle but it is never a good idea to switch from conventional oil to synthetic on a high mileage vehicle. You probably had the leak before you changed the oil. However, the synthetic just accelerate the leak. Yes, changing back to conventional oil may slow down the leak but will not stop it. $228.00 is really a good price to change the valve cover gasket. However, if it was my vehicle I would change the valve cover not just the gasket. Yes, it is more expensive but the spark plug tubes are probably leaking also and the plug tubes gaskets are not replaceable by themselves.

Linhnb

yeah, I am on 78k miles. since I need to solve one problem at a time at the most reasonable cost and this is the first time I touch an auto engine, then I'll do the cheaper part first. If I see some damage in the Valve Cover, I have no choice but to replace it. But for now, the manual said wait till 105k to replace the spark plugs, so I decided to wait for that time to take down the manifold again, and will do the replacement if necessary.

Have just order the intake manifold gasket set from fel-pro and valve cover gasket from ebay. will do it next week when those parts come.

This morning I've just do the Tranny Drain&Fill. It take me 5 quarts (although I just take out like 4.8-4.9 quarts - as shown in picture below). But I thought the tranny fluid was low then I added a little more.

The nissan CVT fluid color is tint green.


the amount of fluid I took out: I think it is around 4.8-4.9 quarts.

BTW, the FSM of 2007 maxima do not tell how much force you should torque the drain bolt, then I use the instruction of Rogue 2008 which is 25 ft-lb. (TM-187
http://www.nicoclub.com/FSM/Rogue/2008/TM.pdf )

and last thing is that I also cannot find the rubber ring of the transmission drain plug, so I still use the old one, which is not recommended by the FSM. Is anyone know the part number of that O-ring ? thanks

Linhnb

I have done the Rear Rocket Cover Gasket replacement last weekend.
This is the first time I do it. The process of taking off the manifold is really PITA.
The rocket cover has a curve between two bolt-hole, I think if the rocket cover leaks again, i will have to replace it.
Now the rocket cover is clear and dry, but the car still has oil leak.

Today I bring the car to Firestone to do the 4 wheels alignment. They say it is because of the Oil pressure switch.
I have just bought the switch from ebay. Let's wait and see

Linhnb

Changed the switch but broke the connector.
I still leave the connector on the switch it looks fine.
Good news is that Oil seems stop dropping today.

I broke the hose that connect 2 valve cover, and I use a clamp in order to hold the hose (as in picture)
Could anyone tell me what does this hose do and do I really need to replace it?

peetah

Breather hose is what that's called. It connects the two valve covers and is part of the PCV system - it gets brittle because of the oil. I used a similar sized rubber hose from Pep Boys to fix it.