Problem With Oil Leaking Between The Trans And Engine?
 

Hello everyone! I have this small leak of oil coming from the trans and engine. I took it to the dealer and they said it was the "Rear main seal".
So they changed it under warranty. But a few days later I got the same F$&*#* leak again!!!:banghead: So I took it back today. Now they still haven't found the problem yet, they said its such a small leak that its not very noticeable, plus it is on the back of engine all the way on they top side. So what they have done is put this oil dye in the engine to see tomorrow with a black light as to where the oil is leaking from. Does anybody know what this could be? And if so what can be done? Thanks. Everyone on this site is 150 Times smarter then those so called techs that BMW has.

Which engine?

hopefully its not a headgasket.... could be a valve cover gasket and numerous other possibles

Dude, get away from Patrick. Between them and Knauz, they couldn't combine to produce one competent service department. If it wasn't the rear main seal, it might either be a cam seal or headgasket. A simple leak down test would easily allow them to rule the headgasket, or not.

make sure it's transmission fluid. if it's not then it's the valley pan gasket and coolant is leaking. it runs down the back and drips from the bell housing.

Sure its not the front seal?

he said it's originating higher up- not trans fluid. valley pan gasket leak?- not if it's oil lol.

Trans side= rear portion of the engine LOL.

Vinuneuro, you are right! Today I will know what the problem is, thats if they can find it. I already had it out with them yesterday. I told them my mechanic that I know could find the problem in 10 mins. I also told them if they can't do the job I will take it to my mechanic, pay him whatever, and then back charge them. They got so scared because they charged my warranty for the rear main seal leak, and that wasn't even the problem. These guys in my opinion SUCK!!!

But anyway, does anybody know where this oil might be coming from? Again its not Trans fluid, its not coolant fluid, I've had everything serviced, vally pan, valve covers, all hoses. What else is in the back of the engine upper part, leaking down and coming right around the trans and then leaking onto the lower strut bar right under the trans that butts up to the engine. Any info would help. I'm dealing with idiots... Thanks...

http://www.xoutpost.com/281996-post4.html

I'm curious..how many hours did it take to change the rear main seal?

8 hrs to be exact... Why does it take a lot less?

One other possibility is a leak from the oil breather lines at the rear of the engine . I got this problem a while ago fixed under extended warranty. Whatever the leak is they should be able to easily locate the source IMO.

I've changed that too. There is nothing that hasn't been changed on this X. IMO it is probably, something that hasn't been tightened enough and now its a very slow leak.

No, I'd expect to be a long process. Just wanted to see how long it takes with these things..

My bet is still on the cam seals..

How many miles on your car?

And has it always been sythetic oil changes, or did you go from castor to synthetic?

You are probably right. Is that a tough job? I have the warranty thank God, but my point is how long and where is it? Thanks...

I have an 01 X5, with 83000 miles...And yes I go from Castrol to Synthetic... Why?

They're at the very back of the cylinder head.

They're? So you mean theres more then one? Sorry but as you can see I have no idea about this subject. Thanks...

I thought front seal is between engine and tranny. Rear seal, tranny and drive train. If that is true, whats so funny?

Vin thought that you meant the front seal of the engine. You were talking front seal of the transmission. Quite logical IMO.

Bimmerdude:

I think you should relax. They may or may not have got the rear seal wrong. You don't know yet. Whatever it actually is, they are far more likely to be able to determine it than we can on this board. You have a warranty. What is all the drama?

The rear seal was the original diagnosis. It may have been leaking and been diagnosed correctly, but it may not have been the only leak. Also, it might still be leaking, depending on the condition of the crank where it contacts the seal, and the quality of the repair. Or, maybe it was never the problem. You are assuming the latter, but that is not necessarily a safe assumption.

If it is showing higher up, it could be thrown there, or it could be leaking there. If it has been leaking for a while, the area will all be oily and it won't be obvious where it is coming from. Using the dye sounds very logical to me, not sure why you wouldn't want to know for sure prior to randomly replacing seals and gaskets. Let them do it.

If many parts have been replaced, and there is a leak, it is more likely that it is a leak from prior workmanship than a part defect IMO. We can tell you what parts are likely to leak (oil breather, cam seals, etc) but not about the work that was done previously since we just don't know.

You say it is oil, but many posters here are questioning whether it really is, since other fluids can pick up oil as they drip down and often appear to be oil. We just want to be sure, and I don't know how you know for sure it is oil.

I would suspect the head gasket, or valve cover gaskets. You can't test for either, you have to find out where it is leaking. There is also the possibility that there is enough oil around the rear of the engine that you are seeing residual drips, and not a continuing leak. I don't know how long it has gone on for but that is a possibility.

My final advice is to let the mechanic do the search. If you don't trust them at all, then simply take your vehicle away, that is your choice. You do risk creating liability in that case, however, if one mechanic left something undone and another shop finds it. Who pays? Likely you unless/until they accept responsibility.

Good luck

Jeff

It could still be the rear main seal. I had a Toyota Tacoma that took multiple trips back to the steeler to get fixed correctly. The mechs changed the rear main twice before they called in tech service. I guess it didn't hurt that I was also suggesting the lemon law may apply if they didn't get it right.

What happened was the mechs where driving the seal in too far crushing the seal. Tech service told them to leave about a 1/16" of a shoulder on the seal to ensure it wasn't bottoming out. Leak fixed.

It could also be the oil separator or one of it's several oil lines. On the 4.4 there is a rats nest of hoses on the back of the engine.

Good luck.

Thx.

Yes :)

Thanks to everyone, again I have changed the oil sep, and breather hoses. I just spoke to dealer. They said that it is coming from three possibilities.

1) Could be a galley plug.
2) Oil check valve.
3) Maybe when the engine block was made, air bubbles may have happened and with time the oil could leak and cause a crack.

What do you guy's think about this? I'm covered with all of these items but still can't seem to picture the galley plug. Either way, I will know on Monday to see what it truly is.

Galley plug..it's a freeze plug. It's a hole that's used during the manufacturing process. Then blocked off at the end with this plug. Very unlikely.

Bad block? Again, very unlikely. Doubt it would only surface after 80k miles.

This really shouldn't be taking this long..get your vehicle to another dealer/tech.

Could be (1) or (2), but a porous block casting, while possible, doesn't seem likely to me. I have seen it, but it isn't common. Whatever it is, I would give them a chance to fix it. That is what your warranty is for.

I wouldn't call (1) a freeze plug, which is generally a plug in the casting that has antifreeze behind it, not oil. A core plug is part of the casting process, and in theory when the coolant freezes it can push out the core plug, but coolant plugs aren't the same as oil galley plugs.

You are absolutely right. I should've known that. One of the downsides of only having assembly production experience and not casting/forging.

Aren't almost all the core plugs, freeze plugs though?

EDIT- *sigh* answer found on wiki: "Most of the plugs to be found on an engine are actually to plug the holes where sand cores have been held. Freeze plug is a misnomer for core plug or expansion plug.."

http://en.wikipedia.org/wiki/Freeze_plug

Thanks everyone for all your info. JCL, I'm going to take your advice and let them do what they do. So far I really can't complain they have been pretty quick and honest with me. My car really has had some small oil leaks at every place you can think of. I'll just give it some time. They did tell me they would have this ready by tue. or wed. of next week. I will post the results... Thanks again...

Ot
 

Vin: It is the difference between a manufacturing environment, and a service repair shop environment ;) Don't sweat it.

Core plugs, as you noted, are a result of the casting process. If they cover an oil galley, they are called galley plugs. If they cover the water jacket, they are often, and somewhat inaccurately, called freeze plugs or frost plugs. They can push out when the coolant freezes. However, they aren't all really designed to protect the block as is sometimes assumed, they simply push out in reaction to the frozen coolant. The block can still crack.

This went off track when the galley plug was referred to as a freeze plug. Freeze plugs won't cause an oil leak, they will cause a coolant leak. Galley plugs can be the source of an oil leak. Also, galley plugs don't have to be push-in plugs like core plugs, they can be screwed in. The plugs are sometimes removed to install oil lines, ie for a turbo lube system or gauge.

All of the above is based on general mechanical repair knowledge, not on specific knowledge of the BMW engine. Purists are welcome to correct me.

Jeff

That makes perfect sense. Thanks for the clarification. :thumbup:

OK UPDATE!!!!!

This is what is going on with my car. First off JCL you were right. My problem is the crank-shaft seal? and a check valve O ring. The problem is minor and will be done today. I told them to keep it another night just to drive it around and make sure that there is no more leaks. All covered under warranty. I believe this happened as JCL said, when I had my oil sep. crack that one below zero night. It must have done a lot of damage to almost all my seals. I had to replace the following. Oil sep., all breather hoses, valve covers gaskets, rear main seal, and finally the above items. Talk about a problem!!!! But good news is everything has been covered under warranty, thank GOD!!!! I have one question. When do my spark plugs need to be changed??? Since I've done all this work to my car, might as well get that done also. Thanks...