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After rebuild RB25DET Neo, 4Bar and small oil leak

ifixedit
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ifixedit Enthusiast

ifixedit

Posted
Posted (edited)

Hi. I hope to get some advice on my rebuilt neo oil pressure and a small oil leak..

After a catastrophic end to my engine months ago where timing belt idler came loose and fell off the head and some pistons got minced.

Anyways new head and rebuilt engine later.. 

First I want to ask if my oil pressure seems right. (New main bearings!!) Idle cold is 4.0Bar, idle hot is 3.5Bar, 4000Rpm goes up to maybe 4.5Bar. I have not hit high revs yet.. won't for a while! I'm using Repco 10w40 fully synthetic oil

Dash gauge being used! Not a proper gauge! So it won't be fully accurate!

Onto my little issue,

I am having a small oil leak from front of engine and cannot identify where it's coming from. It seems to pool to the right (passenger side) of the oilpump

I've once already tried to fix this by taking the radi out and the main pulley off to inspect behind timing belt cover.. tightening oilpump a little more. Also adding some more gasket glue to the sump/oilpump thinking the leak was that..

I honestly say that the timing belt is dry, the crankshaft timing belt gear and under it is dry (main crank seal is not leaking.., if it was leaking I think the inside the timing belt covers would be soaked?)

 

I saw a bit of oil from the timing belt idler pulley. The metal shaft of the pulley which bolts to the engine.. I saw a bit of oil under it, where it touches the block.. I don't know if it is flowing from there or somehow got some residual oil from the build! You know!! Oiling the bolts, and seals.. maybe it is not leaking there! (Won't know until I take off the covers again)

 

Has anyone ever had oil leaking from the bolt that holds the timing belt idler pulley?

Other then that I am thinking the oilpump/sump join is not sealed 100% or something..

But seeing oil as high as the idler pulley makes me think elsewhere.  It could be blowing around via the radiator fan.. / timing belt..

 

The cams are not leaking I'm 99% sure as it's bone dry that high!!

My dad keeps talking about blowby pressure being too high.. maybe making the oil seap.

Should I give it a week or two of driving and. See if this leak stops? 

 

Sadly the photos were taken 2 days ago when I had the bits removed.. it's now all complete and my test drive last night.. when I returned home.. had leak still..

 

Thanks.,

The image here shows the corner where it drops oil. (Passenger side corner front of sump)

20190523_111356.thumb.jpg.6c104c7a3901875e542caf30f6d6da2e.jpg

 

This photo shows the crank gear is dry? But the outside of the timing belt cover (right of pump is wet)

20190523_111421.thumb.jpg.bf05d14e49caa1b6d59ed49b1cfb8c57.jpg

 

This photo shows the water pump is dry.. (it is dirty. Didn't do such a good job cleaning inside the gap there!) so I am sure no oil is leaking from camshafts..20190523_111430.thumb.jpg.0158775742986f2cd2133133b261bcc2.jpg

Edited by ifixedit
GTSBoy Grand Master

GTSBoy

Posted
Posted

The options for where the oil is coming from are innumerable. Diagnosing this without taking it apart, across the internet, is not going to be possible.

Could be leaking from the oil pump gasket. You might have damage on the front of the block where the idler bolt is - which wouldn't normally be a suspect except for how your engine died last time.

Needs at least partial dismantlery to find it.

KiwiRS4T Grand Master

KiwiRS4T

Posted
Posted

Two things - you should run in a new engine with mineral oil not synthetic

- you should be pushing it from the get go - babying it will mean rings don't bed in properly and it will burn excessiveamounts of oil.

If you are pulling it down again put your stone down the bore and try to create a cross hatch again.

 

KiwiRS4T Grand Master

KiwiRS4T

Posted
Posted
1 hour ago, ifixedit said:

Not babied.

Just don't want to full rpm boost until at least 100km.

First 20km were with semi syn. Some cheapish cheif oil to flush and clean. Now running the good stuff she leaks..

My RB30 was first started and the main break in done on the dyno c/w full power pulls. Then dump oil and put in another lot of mineral oil and driven for 6,000km. Then  the synthetic oil and another tune.

You don't want even semi synthetic oil because it prevents the rings from bedding in. If you pull your engine down see if the bores look glazed. You need to put pressure on the rings so with a hot engine don't be afraid to rev it. Do not labour it and keep an eye on the water temp and oil pressure and check for leaks. This has been best practice for at least 50 years.

ifixedit Enthusiast

ifixedit

Posted
  • Author
Posted (edited)

Hi All,

I found the source of the leak.. turned out to be the bloody intake side Camshaft seal. 

when I installed the seal I did NOT place any gasket glue on the outer surface of the seal. Just a smear of oil for easy insertion.
Is it common practice to use gasket glue? or they go in clean? 

 

regards

Shaun

Edited by ifixedit
ifixedit Enthusiast

ifixedit

Posted
  • Author
Posted
24 minutes ago, NEO25T said:

I put a bit of red rubber grease on the inside of the seal and a light smear of gasket maker around the outside, loosen off the cam cap a touch, push seal in and retorque the cap.

This might be completely wrong but it works for me.

NICE! :) 

thats what I will do :)

thanks bud

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