Rb26: Oil In Radiator

[Arkhaeon]

Hi all,

Got an RB26 here that has spun a bigend bearing and scored the block. Thats all well and good though, Understandable failure. Whats got me beat though, is why i've got oil floating at the top of the radiator but no water in the sump.

I've pressure tested the water side of the head (its already apart), and it comes up fine. I'd like to salvage the head as its recently been ported and polished, with all new valves etc. Theres no visible signs of damage to the head, and the engine was pulled out when the bearing noise became audible (before it went completely boom). Oil was found in the radiator when the engine was coming out, so it looks like it happened around the same time as the bearing failure.

Engine was only 11,000kms old after a rebuild with oversized forgies and a good head job.

Anyone have any insight as to where the damage is likely done?

Cheers,

-Luke

[boostin_r33]

hopefully nothing to serious!

[Beer Baron]

well sometimes since the oil system is under pressure of min 2 bar and anything up to 8 bar. the coolant system is only ever under 1 bar max. so if the two meet you can imagine what is going to happen...

[r33_racer]

yeh as beer baron said, oil pressure is generally always greater then your water pressure.

How was the headgasket? You said no damage to head, but normally oil in water means its squeezed in via leak in headgasket somewhere.

[luke20t]

Engine was only 11,000kms old after a rebuild with oversized forgies and a good head job.

-Luke

I could do with a good head job!

so the bearings werent replaced after the rebuild?

[Arkhaeon]

Bearings were replaced, was a great rebuild - the problem was that the old owner started thrashing it straight away and didnt service it in the first 11k of its life. It was a tight build, so it really needed to be cared for during run-in. It had a metal head gasket, and no signs of leaks through anywhere there.

I've picked it up just after its death, so i'm doing my best to salvage what I can (it'll be going into a sileighty).

Is this a problem anyone has experienced alongside a spun bearing before? We can't really work out if its the block or the head. If its the block, thats all fine and dandy, as I'm planning on using an RB30 block anyway, but if the head is f**ked, so am I

I've been trawling the forums for days and haven't seen any other cases of screwed gallery walls in the head, but I could just be failing at the internet.

Cheers,

-Luke

[unique1]

ok this is from experiences with a freinds rb26 that was very very recently run in from a rebuild and putting alot of oil in the coolant, and i mean alot!

his original engine when stock cracked a ringland and overheated apparently, so he got it rebuilt with new internals etc and head recond as well, plus a pressure test (so the shop says anyway), he does 1000km run in, all is fine, then a 400hp+ tune is done and its putting oil in the coolant but the oil in the sump is perfect. They pull the head and im assuming head gasket or something, so they pressure test the head and its ok so they thinking block,etc, well they did another pressure test on the head at higher pressure than the usual test (so the shop says again, unsure if i trust them) and found it had a hairline crack thats opening up under higher boost and causing the oil to leak into the cooling system, but when normal driving its not opening up and therefore the oil in the sump isnt getting any coolant.

this is possibly the problem, but u have said the head has been pressure tested so that could rule it out possibly...

just my 2c worth

good luck

Edited June 27, 2008 by unique1

[Arkhaeon]

Much appreciated mate, do you know where the crack was? I dont have the means to pressure test the head any more, so ill probably have to look with my superman xray vision lol

[nizmonut]

the only way to know is to get the block and head xrayed. how ever in saying that, most head gaskets will still leak a little after the rebuild untill it settel in, as rebuilder after a rebuild you'd run a monograde 30 oil and straight water in the cooling system as the antifreeze will eat at the gasket untill it is sealed properly, also vasaline on oil pump so it isnt damaged on its first start up and high qaulity lithium grease on all the bearings during the build as this will protect them long enough untill the oil reaches them, run the engine for its first hundred kms, never let it idle for more than a few seconds as it will start glazing the bores, after 100k's dump the oil and water you'll see all the vasalene, gasket goo, and grease come out as it will float in the oil in the drain pan. replace with a high grade thin oil that will flow easily when the engine is cold, you can now let it idle, after 500 kms give a resonable thrash but dont red line it, then 1000 its all yours, i have used this proccess on 23 engines now and only one has failed due to a snapped camshaft which we would have never had know unless it was exrayed for hairline fractures.

[unique1]

sorry mate im unsure about where the crack was i was relaying this info from the owner and even he never saw the head, the workshop was doing the work sourced another bare head for $1000 and did all the machine work again for free and fixed it for him.

[Rezlo]

A lot of SR20's also get this problem from sleeve cavitation when you run over 400wkw on the stock sleeves, the oil galley on the right side of the motor cracks right under the cooling jacket and slowely dribbles oil into the coolant but not the other way round, I would imagine this is quite a hard thing to do on a RB though with the aluminum vs. cast iron,,, also most leaks are almost imposible to test for when the block is cold, you actualy need them to heat it up past 90 in an oil bath or somthing. We landed up tapping every oil port and blocking it besides one and submerged the whole block in the oil bath and pushed 9 bar of air into the open port before we could see the bubbles, not sure how else you could do it?

You MIGHT be able to see it if you magnaflux the block, or if you find somone to xray it, might be cheaper than the above and most BIG Diesel shops have the ability to magnaflux or xray now days.

Edited June 27, 2008 by Rezlo

[Arkhaeon]

Wonderful info, thanks for all the help

Whats a ballpark cost on getting a head Xrayed? I can strip it and clean it myself to save money. Anywhere in particular I should be calling to find out more? I'm not worried about the block at all, as the RB30 bottom end will be replacing it.

[YLD-CHLD]

Wonderful info, thanks for all the help

Whats a ballpark cost on getting a head Xrayed? I can strip it and clean it myself to save money. Anywhere in particular I should be calling to find out more? I'm not worried about the block at all, as the RB30 bottom end will be replacing it.

Where abouts you located?

Theres a company in Wetherill park that does x-raying,toohey rd i think there in,just can't remember the name.

[Arkhaeon]

Im in the southern highlands (1hr south of campbelltown). Pretty much every shop is a day trip for me :lol:

[skygtsnt]

Hi all,

Got an RB26 here that has spun a bigend bearing and scored the block. Thats all well and good though, Understandable failure. Whats got me beat though, is why i've got oil floating at the top of the radiator but no water in the sump.

I've pressure tested the water side of the head (its already apart), and it comes up fine. I'd like to salvage the head as its recently been ported and polished, with all new valves etc. Theres no visible signs of damage to the head, and the engine was pulled out when the bearing noise became audible (before it went completely boom). Oil was found in the radiator when the engine was coming out, so it looks like it happened around the same time as the bearing failure.

Engine was only 11,000kms old after a rebuild with oversized forgies and a good head job.

Anyone have any insight as to where the damage is likely done?

Cheers,

-Luke

hey mate, i might be a bit late but i have had the same trouble with my r33 rb25det. it turns out that the oil seals (in the oem oil cooler off the side of the oil filter bracket) were shot. so what i did was just bypass the cooler as i also have a front mount oil cooler. it could also be the oil seals in your turbos as i have heard of this occurring before as well. not sure if rb26 had oem oil cooler. but if you haven't had any luck since your post, hope this helps.

i'm also interested to find out ehat it was that caused this to happen. that is if it wasn't caused by the above.

[MYRB30]

As above, check the oil cooler, comman trap for the unwary.

I dunno how many engines have had their head ripped off, stress and time wasted looking for a leak/crack.

Oil in radiator, check the oil cooler first, every time

[ming spec]

i have had this problem on a ca18det however the problem was over heating not a spun bearing. the problem was a ever so slightly warped head. got it recon and new gasket and all good!!

did you get the xray, do you have a diagnosis yet???

[Arkhaeon]

Its STILL sitting in the shed.. Finally got the SR20 running well, so money has been going back into that.

Id like to get something done with the 26 before uni goes back next month, but im still poor :lol:

thanks for that skygtsnt; the turbos were both shot actually - that possibility didnt occur to me at all! I cant remember if the 26 has the oil cooler setup.. I thought not, but I am mentally challenged in the memory department >.<

[WHT11]

i know this thread is old but i just thought i would add what i have found with this problem for anyone who does a search on the topic,

i had a very similar problem in a rb26 i had the hed presure tested at one shop they said it was fine replaced the block and did a full bottom end rebuild and still had a problem with water oil in the water! i bypassed the oil cooler and still the same. i pulled the head back off and took it to a different place to have pressure tested, now here is the thing?

when the head was cold it pressure tested fine however they boiled the head in a oil bath got it upto operating temp and re tested it hot and it showed a leak between cylinders 3 and 4 in between the water gallery and the and the oil gallery that feeds the vavlespring buckets. It was unable to be seen visually.

Make sure when you get the head checked you go to a well reputed shop that has the facility to pressure test it hot and cold

cheers

[Beer Baron]

yep, I am sure it's the head. I have heard this exact story too many times now. one guy I know even had it happen with a brand new head, he was understandably pissed.

it can be hard to find or spot the crack and is often missed in a pressure test. the sad thing is sometimes people have not found it only to have fkups again and again.

the head needs to be hot tested. when it's cold the crack is closed and can hold a reasonable amount of pressure. as the head heats up crack opens up and leaks. it doesn't have to be very much to spoil the party.