Rear Main Engine seal STX550 2011

[spiezzy]

hi to all
I have just noticed a oil leak at the rear of the v6 V9x engine in my 2011 STX550 not sure where it is coming from and it was all over my bash plate but only could have a quick look I have cleaned the oil off in a attempt to see where it is coming from just wondering if anyone else has had the same problem I am hoping it is not a rear ending seal as I recon that would be quite expensive to repair there has always been a little oil around there but this looks a little worse even though i have not looked under there for a while any advise would be greatly appreciated
many thanks
cheers Pete

 

[Old.Tony]

I'd not panic straight away. We had oil appearing on the cross member, turned out to be a leak from the high pressure hose after the turbo (no catch can) - we had a small boost leak and PCV oil was making its way down the side of the engine. You might also have a cracked PCV hose (top of the engine) and we've had one report of a broken (cracked) PCV outlet - not sure if that was due to a mishap with a tool, but the PCV outlet hasn't been a widely reported problem so my hunch there is an "oops" moment.


We've had a couple of people reporting poorly seated oil filters causing the issue too and that's a concern, because you don't want to loose oil from there, the engine starts without lubrication when that happens, so check the filter.

 

[spiezzy]

hi Tony thank you for your reply and your valuable advice once again today I removed the bash plates and cleaned under the sump and back of engine I ran the vehicle at idle for around 20 min and was trying to see if i could locate the leak but could not see anything stopped the engine and for some reason i checked the oil and noticed it was over full on the dip stick and a far way over full don't know how i did that as it has warnings not to over fill with oil so I drained 1 litre of oil out in the manual it says to fill just on the bottom of the full notch so I made sure it was to that took it for a run under a bit of hard driving and when i returned i noticed there was still oil there but not nearly as much possibly residual oil just hope i haven't damaged any seals and it comes good
cheers Pete

 

[ericcs]

you might want to keep an eye on your oil level, in the event that starts showing it is over full again, so It could be leaking injectors, and the sump is filling with diesel. Just a symptom iv'e heard of!

 

[Old.Tony]

you might want to keep an eye on your oil level, in the event that starts showing it is over full again, so It could be leaking injectors, and the sump is filling with diesel. Just a symptom iv'e heard of!

Exactly this. Your oil will LOOK the same, even with diesel in it.


It's usually just a seal. No, I'm not going to make a crack about getting a penguin to fix it.

 

[Adhaul]

Guys, has anyone had the joy of removing the V9X engine it seems no matter which way you look at it you must split the trans from the engine to enable the sump to clear the front drive line any help would be appreciated

 

[spiezzy]

it would seem that you would have to remove transmission to remove engine yes
an up date on the rear seal I have my vehicle booked in to do the job as it seems it is the seal worn looks like the crank is ok and not moving just worn seal the mechanic has to remove transmission to replace a $150 seal the main cost is removing the transmission at $1300 but better to get it done now before it completely goes

 

[Adhaul]

Well what an experience that was - taking the engine V9X out - points for the uninitiated - the whole front of the vehicle needs to come off radiator/condenser etc: drop the front driveshaft/diff and remove the exhaust at the turbo end. Gearbox can stay on.
Now the oil leak mine was the breather box which is a two part heat welded "plastic box" hidden under the turbo and the manifolds - you need a lot of patience to get this little "M F>>>>" out. The fault is that due to the high heat the 'welded plastic' cracks and allows oil to escape out and over the bell housing, given that Nissan had this part in stock & on the shelf seems to indicate it is a known event however they denied all knowledge - just amazing how little they really know in these dealerships, I'm surprised that they can even change the oil - I'm sarcastic!! All I can say from the experience I learned a lot about the V9X - if the engine were to blow it'd probably be cheaper to just buy a new car .

 

[KevinE]

That sounds painful. Thanks for the update.

 

[spiezzy]

wow Adhaul your a braver man than me I ended up choking a bit of Liquid Intelligence in and seems to have stopped my leak for now have been monitoring it for about 3 weeks and it has almost slowed to nothing but this would be a temp fix I will wait till i get back from up north and see where its at and re book it to do the seal as I have a new one sitting there .
how long did the job take Adhaul and was it super hard to remove the engine and put back in and is all running good now ??
cheers Pete

 

[haylz23]

I have kind of the same issue at the moment. I have the egr blocked off and running a provent catchcan. I assumed it was the engine pressurising under load. I have taken the filter out the catchcan and left the drain hose open. I tow a gooseneck horse float and the rear main seals seems to seal while I’m driving normal then after towing the gooseneck I notice the rear main seal leaking again. Does anyone have any suggestions as in replacing the egr as that’s the only reason I put the catchcan in cause I had the dreaded check engine light on which was egr error. Remove the catchcan and put it back to factory.

 

[Rice]

This may be of some help to someone. I have a 2012 STX-550 with a blanked off EGR AND a catch-can. The catch-can developed a blockage in it which over pressurized the engine and consequently blew the rear engine seal. My mechanic (Nissan certified) told me that if the EGR is blanked off YOU DO NOT NEED A CATCH-CAN. He eliminated the catch-can and re-routed the pipes. The Navara now has heaps more power, fuel consumption is better and is not costing me a fortune in oil.
They removed the transmission (what idiot would want to remove the engine) They had the vehicle for 24 hours and it hasn't missed a beat since.

 

[haylz23]

This may be of some help to someone. I have a 2012 STX-550 with a blanked off EGR AND a catch-can. The catch-can developed a blockage in it which over pressurized the engine and consequently blew the rear engine seal. My mechanic (Nissan certified) told me that if the EGR is blanked off YOU DO NOT NEED A CATCH-CAN. He eliminated the catch-can and re-routed the pipes. The Navara now has heaps more power, fuel consumption is better and is not costing me a fortune in oil.
They removed the transmission (what idiot would want to remove the engine) They had the vehicle for 24 hours and it hasn't missed a beat since.

Cheers for the info.
I recently had a busted cold side intercooler pipe while driving. Car had no power and limped it home doing 60klm.

Once my cold side hose kit arrived. I decided while I was going, to remove the catch can and re route the pipes.

Took the provent catch can off and noticed the vent release cap was actually no longer attached, so essentially, catch can was not effective what so ever.

Also noticed the return hose was pinched severely by the intercooler hot pipe, essentially not allowing enough return air to the motor quick enough.

My dad managed to machine a u shaped metal hose that I attached the outlet and inlet hoses too.

I have done a few trips in the vehicle since. Power is way better down low. Previously when you tried to accelerate it would lag then accelerate hard.

Fuel economy is also far better around 7.5lts per 100. No rear main seal leak and temp is normal.

I will be towing the gooseneck over the weekend and very much hoping that this may fix my limp mode and rear main seal issue while towing.