Need help/tips/advice on oil leak

[Airmaster]

I have finally narrowed my leak down to either a main rear seal or the like.

I have been leaking a good quantity of oil, I've drained some oil out (thought it might be overfilled), I've changed the PCV Valve (the old one was good and this one obviously hasn't stopped the leak), and I've double checked my drain plug for tightness and security (just in case, but it was good and tight already).

So I think it's the rear main seal and my question to everyone is how should I go about the replacement. My haynes manual suggests removing the transmission, is this the easiest way?

If I go ahead with the tranny removal what all should I purchase to replace while I am down there. I've heard I should change the "Throw Out" bearing, and replace the clutch set... beyond that I am not sure, so any help will be appreciated.

 

[Big Jim M]

Hmmm

I have finally narrowed my leak down to either a main rear seal or the like.

I have been leaking a good quantity of oil, I've drained some oil out (thought it might be overfilled), I've changed the PCV Valve (the old one was good and this one obviously hasn't stopped the leak), and I've double checked my drain plug for tightness and security (just in case, but it was good and tight already).

So I think it's the rear main seal and my question to everyone is how should I go about the replacement. My haynes manual suggests removing the transmission, is this the easiest way?

If I go ahead with the tranny removal what all should I purchase to replace while I am down there. I've heard I should change the "Throw Out" bearing, and replace the clutch set... beyond that I am not sure, so any help will be appreciated.

Are for sure and certain the leak isn't from a valve cover or a badly installed oil filter?
Big Jim

 

[Airmaster]

I thoroughly checked the engine while running it with a mechanic. We visually checked the valve covers, and I took a good close look at the oil filter. The leak begins to develop between the oil pan and the transmission. I'll upload my photos to show you.

Tomorrow I am going to drive to work with the oil cap off the engine to ensure that it is not a PCV related issue. I will also double check tightness and security of anything that could cause the leak.

 

[doyouquaxu]

it may sound dumb, but i had a loose oil filter and the leak only showed up in the same areas as yours. i got a few suggestions when my leak showed up, one was the oil pressure sending unit on the passenger side. this is a bad pic i have of it, but it's diagonally up from the green and white connector (with two wires going to it).

 

[Airmaster]

Leaking on the pre-cat

Coming from between the oil pan and the tranny

Second pic of the leak...

The amount of oil I lost in a matter of 10-15 minutes troubleshooting and looking for the cause of the leak

Another pic during the day while I was doing the troubleshooting...

Is it Rear Main Seal or is it Oil Pan Seal??? I've consistently overfilled the tank by accident, 5 qts instead of the 4.5 qts... don't know if that caused it or not...

 

[Airmaster]

it may sound dumb, but i had a loose oil filter and the leak only showed up in the same areas as yours. i got a few suggestions when my leak showed up, one was the oil pressure sending unit on the passenger side. this is a bad pic i have of it, but it's diagonally up from the green and white connector (with two wires going to it).

Damn, that may be something to look at, where is it in relation to the tranny. Is that the tranny on the left and the engine on the right. Is it on driver or passenger side.

 

[t0x1k]

I highly doubt a bad oil pan gasket would cause you to leak oil idling. I've been putting my pan gasket off for a while, only seeps oil right now.
My guess is as good as yours as main oil seal.

 

[Airmaster]

I highly doubt a bad oil pan gasket would cause you to leak oil idling. I've been putting my pan gasket off for a while, only seeps oil right now.
My guess is as good as yours as main oil seal.

Well I mean I revved it a little but most of the time it was idling, so yeah don't know if that much would leak from an oil pan...

 

[Rearanger]

My experience has been that rear mains weep, then slow leak, then a little more slow leak - not the amounts you're showing, especially for a 2006(miles?). I thought I had a premature rear main but when I took the starter off I could see it was coming from the oil filter. As suggested oil pressure switch also a possible as the leak rate looks more like a pressure leak, not a gasket\seal leak.

 

[--weezl--]

you gotta narrow it down by classifying it 2 ways, first, quantity of oil leaking mild, or severe... second is it a running or engine off leak (a third/fourth possibility would be after running leak and all the time leak)

lets go with the time first, if it's an engine off leak, it's somewhere the oil will pool, and leak through, this is often your oil pan gaskets, your drain plug, lower engine things... your running leaks are anywhere the oil doesn't get to when it's pooling, like your valve covers, rear main seal, head gaskets... these are the most common, as there are MANY more places that it can leak from in this category...

the after running leaks, are often caused by leaking while it is running, but being burnt off on the exhaust, or not leaking while running because of swelling of parts from heat, this can be things like valve cover gaskets, typically these are the same as the running leaks, with a few exceptions here and there...

the last one is all the time leaks, these are more or less the same as parked leaks, with the exception of the oil pan gasket, they tend not to leak ANY, while the engine is running, because the level IN the pan while it's running is much lower than the gasket.

the next is quantity, if it's a mild leak, chances are it's a low pressure area, like oil pan gasket, or valve cover gasket, places that aren't directly in the flow of the oil pump...

if it's a high volume leak, you should be looking near the oil pump, which is directly connected to the oil filter, and pressure sending unit, like doyouquaxu posted...

the amount of oil you are loosing in that picture leads me to believe it's high pressure... is the passenger side wetter than the drivers? it's REALLY hard to see where everything comes from when everything's wet like that...

check your oil filter and pressure sending unit for leaks, if that doesn't solve it, take it to a mechanic who can do a dye test... basically they will have you shampoo your engine to get all of the old oil off of it, to give the cleanest test possible, then add a fluorescent dye to your oil, and run the engine, they will look for where the dye shows up first, with a UV light, and pinpoint the leak... i've got a sneaking suspicion that your leak is NOT the rear main OR oil pan

a similar test can be done, if you just shampoo the engine (or pressure wash it with a mild degreaser) and run the engine while it's on a hoist, or over a pit, try to keep the engine as level as possible, so you don't have the oil running towards the back...

remember, the transmission will get covered in oil with virtually ANY major leak, because that's the way that inertia takes it, and the way the wind blows

 

[--weezl--]

take a look at these pics...

in the foreground of this one, you can see the rear bushings for the lower control arm, they are dry, no oil on them

take a look at this one, you can see the passenger side rear lower control arm bushing, and the parts it mount to, they are wet with oil (can see it above also, but not as clearly)

 

[ufgators68]

Just went through a bunch of oil leaks on my 4.0, caused by a bad pcv. One of the leaks was the upper oil pan gasket and it looked a lot like what's going on in those pictures.

 

[Airmaster]

Well, I left the engine oil cap off today and it still leaked, I just arrived home, but I am going to do what you guys have suggested this far, I'm going down there and checking the pressure line and oil filter.

In reference to weezl, it seems to be a running leak, it only leaks while running and then once I am stopped it'll keep leaking until the residual is gone, then it stops leaking after a few minutes.

I'll be back with more info

 

[Airmaster]

Okay I went out and looked it over with everyone's advice. The leak is coming from the driver's side (or from the main seal which would be center I guess), not the passenger's side. I've snugged the filter up a bit more as it could take about a 1/2 of a turn more, and I've got plenty of pictures...

Showing more oil on the driver side vs the passenger side of the oil pan


Driver Side--wet

Passenger Side--dry

More Views of the oil scattered around the driver side of the oil pan...

View directly under the pan/tranny meet up...

The Oil Pressure sensor line thingy that u guys suggested to take a peak at... didn't see any oil anywhere on the passenger side, and definitely no valve cover leaks...

Finally, the oil filter. I just don't understand if it were the oil filter that it would have a chance to get by the little mini funnel that Ford built in to the filter area. It doesn't drip from the filter's self funnel it drips right beneath the tranny and oil pan area...

It looks like the oil pan is slightly covered in oil all the way to the front on the passenger side, but it may be from oil making its way over there.

The oil on the supports that weezl was speaking of seemed to be also caused by the oil making it's way over to it when I'm driving.

Tomorrow after work I am going to degrease the bottom of my engine and make sure it's cleaned up good.

Then I'll start it up and continue to look for leaks. I'll see if snugging the oil filter may have helped, I'm kind of doubtful but I would love it to be that, haha. Even if it were the filter I do not know why all of a sudden I'd start having this leak, why didnt it start leaking immediately after my oil change???


More updates to come tomorrow, thanks for the tips so far!

 

[cush]

take your oil filter off and make sure you didnt double gasket it. cause sometimes the rubber O ring will stick to the block and you wont notice and just throw another filter on then it'll leak. i doubt this is your problem but it doesnt hurt to check. especially if you havent replaced that filter yet.