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[Big_Al]

Hi guys ,
            finally traced the oil leak that has been bugging me for weeks. Cam cover was the presumed culprit so changed both gaskets as per maintenance guide. Still leaking. Then thought it was 2-4-6 cam cover , done gasket again  twice , then replaced cover  & gasket. . .  still got oil leak . Have now ruled out a cam cover leak 

To cut a long story short, stripped down again as far as inlet bridge removed & a lot of oil laying in the V around the oil cooler plate.

Car is on ramps at the moment & when running ,oil leak is down back of the engine block.But cam covers are bone dry all round & plug wells dry. On flat ground oil runs to the front of engine showing mainly on top of the sump under the pulleys.

Have mopped up & dried all the oil in the V & turned the engine over with starter as best as possible in this stripped down situation . Oil light goes out so pressure is up ok.  cant see anything definate as to a leak apart from a slight trace showing around the rear pipe union.

Re dried it off & turned engine over for a while . after leaving for a few minutes a slight trace of oil shows around the base of this rear pipe union. This is the large nut that is attached to the actual oil cooler plate. oil it seems is seeping out slightly around this joint . . . not the copper washer sides of the pipe union.. but the actual nut to plate joint

Cannot get a spanner on either this big nut or the union bolt (22mm)  to see if not properly torqued up without taking the coolant bridge off & draining coolant.

does this big nut thread into the plate ?   should there be a copper or fibre washer under it ?

Any one had an oil leak from this area & what is best option to stop it please.

No oil in coolant  . .  no coolant in oil .  oil cooler was replaced by previous owner not long ago .

Any help greatly would be appriciated

TIA   Al

[The Red Baron]

Oh dear Al, not good news after all the bloomin hassel youve already had with it.
ive not stripped one out so cant help you on that im afraid.

[amba]

Hi Al.

Oil cooler is not such a big deal to remove,but if its leaking oil it sounds like a failure in either the banjo bolt going from the oil pipe into the cooler or a pipe.

I assume you havent got oil in the water ? as that would seem to rule out the oil cooler actually failing.If you need to seal the oil cooler plate you would have coolant leaking as the plate seals the "bath of coolant" in the center of the V that allows the oil passing through the little radiator to be cooled...hence oil cooler  .

The 2 oil pipes feeding oil into the radiator have a metal washer on either side of the banjo bolt so I suppose one of them could have failed .Best bet is to get under the car on the N/S just above the oil filter and attempt to undo the 2 oil feed pipes that go up behind the back of the engine.You will need a 19mm crows foot wrench as access is quite tight.Easier with the oil filter out the way and also undo and tie the crank sensor out of the way,then you should be able to get on the 2 19mm pipe nuts.

If these can be undone you can then be sure the other end by the cooler will not have tension on them .Its then a matter of undoing the 2 banjo bolts and removing them from the oil cooler and probably replacing the sealing washers ..4 in number.They are a GM part so might not be available till mid week depending how good you local crew are ?.Suppose the banjo bolts might just be loose and need tightening up but don,t go mad as they are hollow and could shear off then you would need a new oil cooler at £120.

Seems strange its leaking oil there but that would be my advise....Best of luck with it.

[amba]

Just to add..the actual oil cooler is secured to the plate by the large 30mm copper nut.The banjo bolt then threads into the oil cooler with a small metal washer on either side of the oil feed pipe and that is then torqued....think 30nm.... into the cooler to make an oil tight seal.

Thats about the only way oil could seep out if either a washer is missing/damaged or the banjo bolt is loose...think the bolts are 22mm so almost worth just getting a 22mm socket on first and seeing if they are loose.

Coolant bridge shouldn,t need disturbing unless you are planning on taking the entire cooler radiator out which seems pointless as you don,t have a coolant leak.

[Big_Al]

Hi Al.

Oil cooler is not such a big deal to remove,but if its leaking oil it sounds like a failure in either the banjo bolt going from the oil pipe into the cooler or a pipe.

I assume you havent got oil in the water ? as that would seem to rule out the oil cooler actually failing.If you need to seal the oil cooler plate you would have coolant leaking as the plate seals the "bath of coolant" in the center of the V that allows the oil passing through the little radiator to be cooled...hence oil cooler  .

The 2 oil pipes feeding oil into the radiator have a metal washer on either side of the banjo bolt so I suppose one of them could have failed .Best bet is to get under the car on the N/S just above the oil filter and attempt to undo the 2 oil feed pipes that go up behind the back of the engine.You will need a 19mm crows foot wrench as access is quite tight.Easier with the oil filter out the way and also undo and tie the crank sensor out of the way,then you should be able to get on the 2 19mm pipe nuts.

If these can be undone you can then be sure the other end by the cooler will not have tension on them .Its then a matter of undoing the 2 banjo bolts and removing them from the oil cooler and probably replacing the sealing washers ..4 in number.They are a GM part so might not be available till mid week depending how good you local crew are ?.Suppose the banjo bolts might just be loose and need tightening up but don,t go mad as they are hollow and could shear off then you would need a new oil cooler at £120.

Seems strange its leaking oil there but that would be my advise....Best of luck with it.

Hi  Andrew , OK  i'm getting the picture now.  I was thinking oil would escape from the perimeter of the plate but now understand that if leaking there it would be coolant not oil

So  it looks like after turning the engine on the starter for a while oil seems to be seeping (only a  very slight seep though bearing in mind only been turning engine on starter)   at the rear banjo bolt .

I thought it was showing coming from the base of the large nut & the cooler plate , but how you have explained it , that would be coolant & not oil 

So it must be coming from above that at the actual banjo oil pipe union . Problem there is that being the rear one it sits directly under the coolant bridge & getting any sort of spanner on it with the coolant bridge in place is impossible.

my next move for tomorrow  i think  will be :  totally clean & clear all oil away from around the cooler plate. re assemble the top of the engine , run it up for 15 -20 mins  to allow oil to start leaking . allow engine to cool & strip plenum, injectors, & inlet bridge again.
theory is as that area was cleaned of oil ,  I should be able to see  where it is leaking .

last point  . . .  it must be the banjo union  as oil is laying in that area , if it was a pipe leaking further down the back of the engine , surely gravity would take the oil downwards along the pipe & no oil would lay up in the V by the cooler plate?

Heres hoping .   got my fingers , toes, legs & arms  all crossed for tomorrow

regards, Al

[The Red Baron]

dont forget if you take the coolant bridge off you will need new washers aswell. x4.   

[albitz]

Get new banjo bolt/copper washers for the bolt and dowty washers for the coolant bridge Al.The take the coolant bridge off, undo the banjo bolt and replace with new bolt and washers.This may be easier if you slacken the pipe down at the oil filter end first,but imo it should be ok to just do the top end on its own. Probably worth doing both banjo bolts ? washers while your there I suppose
Also worth checking the big nuts are correctly torqued while your in there.

[The Red Baron]

^^true, better safe than sorry. 

[Big_Al]

Hi Al.

Oil cooler is not such a big deal to remove,but if its leaking oil it sounds like a failure in either the banjo bolt going from the oil pipe into the cooler or a pipe.

I assume you havent got oil in the water ? as that would seem to rule out the oil cooler actually failing.If you need to seal the oil cooler plate you would have coolant leaking as the plate seals the "bath of coolant" in the center of the V that allows the oil passing through the little radiator to be cooled...hence oil cooler  .

The 2 oil pipes feeding oil into the radiator have a metal washer on either side of the banjo bolt so I suppose one of them could have failed .Best bet is to get under the car on the N/S just above the oil filter and attempt to undo the 2 oil feed pipes that go up behind the back of the engine.You will need a 19mm crows foot wrench as access is quite tight.Easier with the oil filter out the way and also undo and tie the crank sensor out of the way,then you should be able to get on the 2 19mm pipe nuts.

If these can be undone you can then be sure the other end by the cooler will not have tension on them .Its then a matter of undoing the 2 banjo bolts and removing them from the oil cooler and probably replacing the sealing washers ..4 in number.They are a GM part so might not be available till mid week depending how good you local crew are ?.Suppose the banjo bolts might just be loose and need tightening up but don,t go mad as they are hollow and could shear off then you would need a new oil cooler at £120.

Seems strange its leaking oil there but that would be my advise....Best of luck with it.

Hi  Andrew , OK  i'm getting the picture now.  I was thinking oil would escape from the perimeter of the plate but now understand that if leaking there it would be coolant not oil

So  it looks like after turning the engine on the starter for a while oil seems to be seeping (only a  very slight seep though bearing in mind only been turning engine on starter)   at the rear banjo bolt .

I thought it was showing coming from the base of the large nut & the cooler plate , but how you have explained it , that would be coolant & not oil 

So it must be coming from above that at the actual banjo oil pipe union . Problem there is that being the rear one it sits directly under the coolant bridge & getting any sort of spanner on it with the coolant bridge in place is impossible.

my next move for tomorrow  i think  will be :  totally clean & clear all oil away from around the cooler plate. re assemble the top of the engine , run it up for 15 -20 mins  to allow oil to start leaking . allow engine to cool & strip plenum, injectors, & inlet bridge again.
theory is as that area was cleaned of oil ,  I should be able to see  where it is leaking .

last point  . . .  it must be the banjo union  as oil is laying in that area , if it was a pipe leaking further down the back of the engine , surely gravity would take the oil downwards along the pipe & no oil would lay up in the V by the cooler plate?

Heres hoping .   got my fingers , toes, legs & arms  all crossed for tomorrow

regards, Al

what your opinion on this guys ,  could oil be leaking from anywhere else & laying in the V around the cooler plate ? Cam covers are absolutely dry  so not those.

[ozzycat]

 hi mate
i had the same problem with mine i cured it by replacing both banjo bolts and new copper washers not had a problem since

[Big_Al]

hi mate
i had the same problem with mine i cured it by replacing both banjo bolts and new copper washers not had a problem since

Ummm ! looking promising then 

[Darth Loo-knee]

I did mention this too you before. I have seen a number of banjo bolts leaking that I have replaced the alloy o rings to solve the problem.
There are not to many thinkings in the V that can leak oil water there are a few places

[albitz]

If you need any tools Al - torque wrench/spanners/crows foot spanners etc. let me know.

[Big_Al]

I did mention this too you before. I have seen a number of banjo bolts leaking that I have replaced the alloy o rings to solve the problem.
There are not to many thinkings in the V that can leak oil water there are a few places

You did Daz,  I checked out all the other suggestions you mentioned but overlooked that one  . . 

Typical of my luck at the moment . . .  the only one of your suggestions I could not remember   . . seems like the problem  :

[Big_Al]

If you need any tools Al - torque wrench/spanners/crows foot spanners etc. let me know.

Thanks Albs . .    but Bruv  has got more tools than a Snap On salesman     

He buys 'em    . .   I borrow them !

Nice offer though . .   Oof at it's best again