Oil Leaks - where;s the most common places

[ivan129]

Where are the most common places on a 1UZFE that leak oil?
My engine swap leaks oil and of course drips from the lowest point on the engine making it difficult to spot where its coming from.

 

[gloverman]

I have seen leaks from the tappet cover gaskets , Spark plug seals ( these are the ones in the centre of the tappet covers), the oil filler cap, the cam seals, the front crank seal , the rear crank seal , the blanking plugs at the back of the cams in the cylinder head , the oil filter housing , the oil pressure switch , the oil filter itself , around the main sump pan, around the lower steel sump pan , the sump plug , the dip stick oring, from behind the engine front cover ( oil pump) and even seen oil leaks from the head gaskets. As this is pretty much every gasket and oil seal on the motor I would suggest you get some degreaser and a water blaster and give it a clean and see where the oil leaks out.

Ive also had one leaking oil (and water) from a hole in the centre of the valley and another from the hole in the side of the block but I think its pretty safe to say your leak isnt from there.

Cheers

 

[XR8tt]

Did you leave any out ??? LOl...
Yea mainly cam covers and front / rear main seals...

 

[ivan129]

Tracking down that oil leak

Thanks.. the problem is the engine is too clean (just had a rebuild) and the oil hasn't blackened up yet (guess I change it too frequently) so its hard to see where the stuff's coming from. I did spot one drop tonight from what looks like the RHS valve cover but the larger leak is on the LHS I think. Been toying with the idea of buying an LCD endoscope so I can get an eye up from the underside of the engine. Into those ackward to see spots. Thanks again.

I have seen leaks from the tappet cover gaskets , Spark plug seals ( these are the ones in the centre of the tappet covers), the oil filler cap, the cam seals, the front crank seal , the rear crank seal , the blanking plugs at the back of the cams in the cylinder head , the oil filter housing , the oil pressure switch , the oil filter itself , around the main sump pan, around the lower steel sump pan , the sump plug , the dip stick oring, from behind the engine front cover ( oil pump) and even seen oil leaks from the head gaskets. As this is pretty much every gasket and oil seal on the motor I would suggest you get some degreaser and a water blaster and give it a clean and see where the oil leaks out.

Ive also had one leaking oil (and water) from a hole in the centre of the valley and another from the hole in the side of the block but I think its pretty safe to say your leak isnt from there.

Cheers

 

[gloverman]

If the motor is really clean you can also use an air duster and gently blow around the suspect area. ( not at the gasket itself) This usually mists up the oil. Also using your finger and see if it gets oil onto it. Or even a simple dentist style mirror. Cheers

 

[gloverman]

And the most common leaks are generally caused by old seals and gaskets so this doesn't really apply to a rebuilt motor. Did it get a little bit of sealant at the base of where the tappet cover gaskets go over the cam caps? Cheers

 

[ivan129]

Mmm missed that spot

No.. But they will get some tonight.

And the most common leaks are generally caused by old seals and gaskets so this doesn't really apply to a rebuilt motor. Did it get a little bit of sealant at the base of where the tappet cover gaskets go over the cam caps? Cheers

 

[JKav]

Use fluorescent oil dye:
http://www.motoiq.com/magazine_arti...-finding-oil-leaks-using-fluorescent-goo.aspx

 

[bzmotoninja83]

These "tools" are at autozone

Uv oil dye pn: 374
Uv leak detector pn: 438 or 439

438 has yellow glasses and a uv light, 439 is a different light, 374 is the dye. Usefull for gas and oil.

 

[UCF11]

Did you leave any out ??? LOl...
Yea mainly cam covers and front / rear main seals...

Haha.

Well yeah the rear main seal is the big one thats common and hard to replace.

Any of the seals which see movement can go, or high pressure points.

Amazingly my 1uz with its 75,000ks still hasn't leaked from the rear main seal.

Although Ill replace it when the next gearbox goes on.

 

[XR8tt]

Haha.

Well yeah the rear main seal is the big one that's common and hard to replace.

Any of the seals which see movement can go, or high pressure points.

Amazingly my 1uz with its 75,000ks still hasn't leaked from the rear main seal.

Although Ill replace it when the next gearbox goes on.

Aha yes some older domestic models came std with oil leaks..
Replacing RMS Rear main seal didn't do much to help...
Harley Davidson was much the same also...

 

[ash]

Where are the most common places on a 1UZFE that leak oil?
My engine swap leaks oil and of course drips from the lowest point on the engine making it difficult to spot where its coming from.

When u find the leak, use shelllite ( white spirits ) to clean surface , to apply new sealant.
Brake cleaner tends to leave a " white crust / salt"

 

[ivan129]

Thanks Found some on Amazon

Thanks for the idea. Can't find a distributor here in Melbourne so I've bought some from Amazon. Regards Ivan

Use fluorescent oil dye:
http://www.motoiq.com/magazine_arti...-finding-oil-leaks-using-fluorescent-goo.aspx

 

[ivan129]

Thanks will do

Thanks I have in the past used thinners or acetone but I do have some shellite so I'm give it a try. Got some UV dye on the way so hopefully I can nail where the leak is coming from. Regards Ivan

When u find the leak, use shelllite ( white spirits ) to clean surface , to apply new sealant.
Brake cleaner tends to leave a " white crust / salt"

 

[Drift99]

Old thread i know.

My rear seal is leaking and I would like to replace it. Have any of you replaced one before? whats involved? Can it be replaced simply by removing the trans and popping it out? Simple as that?

My leak is somewhat bad and am worried about getting oil on my clutch setup.

Thanks,
Jake

 

[Zuffen]

Remove the transmission and flexplate to access the rear seal.

The rear seal is in a carrier that bolts to the rear of the engine.

You can replace it with the carrier in position, but you'll find it easier if you remove the carrier.

The carrier has a chemical seal so clean the area well before applying sealant and re-installing.

Be aware the flexplate bolts reach into the sump area so you need to ensure they have sealant on them as well or you will have oil leaking out of the out threads.

 

[Drift99]

Thats exactly what I needed to know. Thanks Zuffen

 

[Zuffen]

What I should have also specified is to ensure the oil seal/crank interface are both lubed with oil or the seal will burn before it gets oil flung on it by the crank.

 

[t2d2]

I have seen leaks from the tappet cover gaskets , Spark plug seals ( these are the ones in the centre of the tappet covers), the oil filler cap, the cam seals, the front crank seal , the rear crank seal , the blanking plugs at the back of the cams in the cylinder head , the oil filter housing , the oil pressure switch , the oil filter itself , around the main sump pan, around the lower steel sump pan , the sump plug , the dip stick oring, from behind the engine front cover ( oil pump) and even seen oil leaks from the head gaskets.

That narrows it down. My '94 SC400 has a small leak where the oil filter threads on, but I cleaned it up before putting a new filter on recently and it seemed like a good, smooth surface to seat on. Still a slow leak... Anyone know which aspect of the oil filter housing might be leaking, as alluded to by gloverman?

I don't think it's dripping down from up above. The oil only seems to puddle up around the lip of the filter, and not enough for the dip stick level to drop measurably.

Edit: It turned out to be the gasket between the oil filter housing and the block was worn flat. It's a little double-o o-ring and costs around a buck to replace.