possible oil leak

[JCL]

Originally Posted by we350z

Is the only way to check by removing the engine acoustical cover?

Nobody can tell you, it isn't even a picture of your vehicle if I understand your post correctly.

With respect, the only way to check, as you put it, is to properly diagnose where the oil is leaking from. Your choices (in no particular order) are the oil pan, the oil drain plug, the oil separator, the valley pan gasket, one or both cylinder head gaskets, one or both valve cover gaskets, one of the lines leading to the oil separator, or potentially a vehicle that was parked in the same spot before the X5 (just testing). I am sure there are more possibilities.

Asking us to diagnose the cause of your possible oil leak based on one drop of oil on your garage floor is a real stretch. Any oil at the bottom of the engine inside the belly pan could have come from anywhere, including a previous fill that spilled.

There is no substitute for a proper diagnosis and failure analysis. While the temptation is to come to the web for answers, it has limits. My father, a very old-school mechanic, taught me that the lowest form of mechanic was a 'parts replacer', someone that simply replaced parts in an attempt to find the problem. I recommend that if you can't find the leak yourself, you rely on a trusted mechanic. Spend your efforts finding a mechanic to trust if you can't find the leak.

Standard protocol would be to clean the wet area of the vehicle, clean the floor, put out dry paper overnight, and see where it is dripping based on the evidence in the morning. Follow it up to find the source. That's it, no rocket science.

Good luck.

[we350z]

Yeah thats not a pic of my vehicle, just the same area for reference purposes. I'll try to take a pic later tonight - but the problem is that I already cleaned the area (like you suggested) and the leak hasn't re-occured. Granted the passenger front half axle is out of the car and I prob won't be driving it within the next couple of days if this only happens or is excaerbated by the engine running.

I'm not too concerned about it yet but if there is a problem I would like to take care of it sooner than later or perhaps even make the decision sell the vehicle because it has been pretty much nothing but problems.

I don't really expect anyone to diagnose it, just want to get some initial thoughts on what it could be and where to look. I know it could be a lot of things. I guess I figured oil leaking down in this area might only typically be one particular common issue.

No doubt the only way to know for sure is to do due dilligance and check all the possible items until the leak is found. I would also agree that replacing a part might not also solve the problem, root cause should be identified and addressed or else the leak may re-occur.

Maybe you can help me undersand how the valley pan leaking, which is coolant to my knowledge would be black in color? I'm pretty sure the substance is engine oil.

I did have a problem with the torque radial seal leaking but that was replaced and the TIB was done by a BMW dealership to tighten and locktite the transmission bolts. That fluid was different looking anyway.

Originally Posted by JCL

Nobody can tell you, it isn't even a picture of your vehicle if I understand your post correctly.

With respect, the only way to check, as you put it, is to properly diagnose where the oil is leaking from. Your choices (in no particular order) are the oil pan, the oil drain plug, the oil separator, the valley pan gasket, one or both cylinder head gaskets, one or both valve cover gaskets, one of the lines leading to the oil separator, or potentially a vehicle that was parked in the same spot before the X5 (just testing). I am sure there are more possibilities.

Asking us to diagnose the cause of your possible oil leak based on one drop of oil on your garage floor is a real stretch. Any oil at the bottom of the engine inside the belly pan could have come from anywhere, including a previous fill that spilled.

There is no substitute for a proper diagnosis and failure analysis. While the temptation is to come to the web for answers, it has limits. My father, a very old-school mechanic, taught me that the lowest form of mechanic was a 'parts replacer', someone that simply replaced parts in an attempt to find the problem. I recommend that if you can't find the leak yourself, you rely on a trusted mechanic. Spend your efforts finding a mechanic to trust if you can't find the leak.

Standard protocol would be to clean the wet area of the vehicle, clean the floor, put out dry paper overnight, and see where it is dripping based on the evidence in the morning. Follow it up to find the source. That's it, no rocket science.

Good luck.

[supersteve]

Originally Posted by we350z

So replacing unit is a bitch, but replacing the lines is not? Or is both a pain? Whats more likely? You had to replace only the lines? Is the only way to check by removing the engine acoustical cover?

thx

The lines run along the top of the engine (under the cover). The separator sits between the engine and the fire wall. The lines are easy to check, but difficult to change.

[we350z]

OK cool. So take just the plastic acoustical cover off and inspect the lines? I suppose it will be pretty obvious if they are leaking.

As for the valve covers... would it be obvious if they were leaking too? Anyone have any pics to reference?

thx

Originally Posted by supersteve

The lines run along the top of the engine (under the cover). The separator sits between the engine and the fire wall. The lines are easy to check, but difficult to change.

[supersteve]

Originally Posted by we350z

OK cool. So take just the plastic acoustical cover off and inspect the lines? I suppose it will be pretty obvious if they are leaking.

As for the valve covers... would it be obvious if they were leaking too? Anyone have any pics to reference?

thx

If the lines on top of the engine are bad, they will be more like putty than rubber. If those lines are bad it's also a good idea to replace the line that goes form the oil sep back into the engine. That is the hard one because it's behind the engine. You'll want to do it when the engine is stone cold (first thing in the morning).

It's not really that bad. I did it without taking the firewall out (didn't realize it came off at the time) so it was tight; but, I got it done.

[we350z]

Good to know. Now all I need to know is how to check the valve covers. If it's neither of those then i guess it may likely be the valley pan.

Originally Posted by supersteve

If the lines on top of the engine are bad, they will be more like putty than rubber. If those lines are bad it's also a good idea to replace the line that goes form the oil sep back into the engine. That is the hard one because it's behind the engine. You'll want to do it when the engine is stone cold (first thing in the morning).

It's not really that bad. I did it without taking the firewall out (didn't realize it came off at the time) so it was tight; but, I got it done.

[supersteve]

To check the valve covers you just need to look at the seam where they meet the head. You could also look in the spark plug wells. I don't think it is either. If the valve cover gaskets where leaking, chances are you would smell oil burning after driving. If the spark plug wells where leaking you would most likely foul out the plug.

As far as I know the valley pan will only leak anti freeze. There are no oil galleys there.

I really suspect it is the oil return line that goes down the back of the engine from the oil sep to the oil pan. IIRC looking through the front passenger side wheel well with the wheels turned to the left gives a pretty good view with a bright light. Again, it's tight but if the engine is wet on that passenger side rear corner you have found the leak.

[GXL]

My 2001 4.4i is leaking just like the picture, how do I know for sure if the lines or the valve cover need to be replaced?

I really don't like oil leaks, so I want to take care of that as quickly as possible.

Thanks in advance,

GXL

[GXL]

I didn't realize there was a second page until I posted, so please disregard.

I think I can find the leak with the informacion provided in this thread.

Thanks to those who replied.

Regards,

GXL

[we350z]

Cool. I think the valve covers are fine then. I have the entire half axle off the front passenger side so needless to say i can see in there pretty well lol. I'll take a pic. I think some of the cv joint moly grease got sprayed in there somehow when the cv boot burst - perhaps thats all that was leaking. But I am going to check out the oil seperator send/return lines nonetheless.

Originally Posted by supersteve

To check the valve covers you just need to look at the seam where they meet the head. You could also look in the spark plug wells. I don't think it is either. If the valve cover gaskets where leaking, chances are you would smell oil burning after driving. If the spark plug wells where leaking you would most likely foul out the plug.

As far as I know the valley pan will only leak anti freeze. There are no oil galleys there.

I really suspect it is the oil return line that goes down the back of the engine from the oil sep to the oil pan. IIRC looking through the front passenger side wheel well with the wheels turned to the left gives a pretty good view with a bright light. Again, it's tight but if the engine is wet on that passenger side rear corner you have found the leak.