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Fresh oil in coolant... Crack in bore?

PostPosted: Sat Jun 07, 2014 10:25 am
by Aidos
Hey guys.

Here goes the story.
Had wagon in for major service and timing belt. Found oil in coolant. All tests done. Had radiator out and tested. No faults found in any of the pressure testing. But clean oil keeps coming through in to the coolant.

Mechanic says that in his opinion it has to be a slight crack in bore that only happens under operating pressure and temps. How does this sound with everyone who has gone down this similar path of problems?

I'm currently putting together a list of upgrades for when/if we need to take motor out. Any advice in this area would be much appreciated too =) keep in mind that I'll be going to E85 at the same time!

Re: Fresh oil in coolant... Crack in bore?

PostPosted: Sat Jun 07, 2014 10:35 am
by HighTech RedNeck
can also be a head gasket

Re: Fresh oil in coolant... Crack in bore?

PostPosted: Sat Jun 07, 2014 10:41 am
by Aidos
That would show from doing their pressure tests though I'd imagine?

Re: Fresh oil in coolant... Crack in bore?

PostPosted: Sat Jun 07, 2014 12:00 pm
by jaydece
pressure tests are not the end all be all ....it could only occur if you really give the engine a hard time....so under normal conditions things would seem normal...

your heads could of lifted
head stud bolts are stretched
bore crack as stated
block has warped / heads warped
list goes on and on...

what tune you running?
timing? boost? targets?
fuel running? been running LV's lately? any signs in there?

Re: Fresh oil in coolant... Crack in bore?

PostPosted: Sat Jun 07, 2014 12:51 pm
by kiahatsiu
Munted turbo?

Re: Fresh oil in coolant... Crack in bore?

PostPosted: Sat Jun 07, 2014 5:20 pm
by KiDo_Tuning
kiahatsiu wrote:Munted turbo?


My thoughts too since it is a AVO 450.

Re: Fresh oil in coolant... Crack in bore?

PostPosted: Tue Jun 10, 2014 3:07 pm
by Aidos
Disregard my stupidity.. But I didn't think coolant went through the turbo? Isn't it oil cooled?

Re: Fresh oil in coolant... Crack in bore?

PostPosted: Tue Jun 10, 2014 4:02 pm
by shav
I reckon you need to do a LV screenshot and logs of the current tune and send it to Matt (kido) for his opinion Aidan. See if you can pinpoint the cause of the issues. There should be someone living close to you with an open port that you could spend 20mins to help you out surely?
PS. Im glad your looking for second and third opinions on this.

Re: Fresh oil in coolant... Crack in bore?

PostPosted: Tue Jun 10, 2014 4:03 pm
by kiahatsiu
Some turbos are oil cooled, some are water cooled. Stock subaru ones are water cooled.

Re: Fresh oil in coolant... Crack in bore?

PostPosted: Tue Jun 10, 2014 4:37 pm
by KiDo_Tuning
Aidos wrote:Disregard my stupidity.. But I didn't think coolant went through the turbo? Isn't it oil cooled?


Coolant lines are the top one going the to the top bottle to cool the tubro and oil for lube

Re: Fresh oil in coolant... Crack in bore?

PostPosted: Tue Jun 10, 2014 8:55 pm
by alexeiwoody
You can tell if it's water cooled if it has waterlines going to the turbo core as well as oil lines, should have 4 lines in total with the water ones being thicker.

Are you losing coolant? Are you spraying coolant anywhere on full boost (esp. out of the overflow tank)?

I don't think ECU logging will help diagnose this one Shav....as much as we love logging, there are some things that laptops just can't pickup!

Re: Fresh oil in coolant... Crack in bore?

PostPosted: Tue Jun 10, 2014 10:27 pm
by KiDo_Tuning
alexeiwoody wrote:You can tell if it's water cooled if it has waterlines going to the turbo core as well as oil lines, should have 4 lines in total with the water ones being thicker.

Are you losing coolant? Are you spraying coolant anywhere on full boost (esp. out of the overflow tank)?

I don't think ECU logging will help diagnose this one Shav....as much as we love logging, there are some things that laptops just can't pickup!


Helped a guy in Brisbane diagnose that his heads had not kifted / no HG failure etc via logging. Then confirmed by his mechanic with a TK test. Ended up being a split Throttle hose. Everyone was telling him HG.

Some things can be diagnosed

Other thing is that this car is an auto, so it could be a cracked trans cooler pipe in the radiator or even the oil cooler on the oil filter has a crack

Re: Fresh oil in coolant... Crack in bore?

PostPosted: Wed Jun 11, 2014 12:06 am
by alexeiwoody
KiDo_Tuning wrote:
alexeiwoody wrote:You can tell if it's water cooled if it has waterlines going to the turbo core as well as oil lines, should have 4 lines in total with the water ones being thicker.

Are you losing coolant? Are you spraying coolant anywhere on full boost (esp. out of the overflow tank)?

I don't think ECU logging will help diagnose this one Shav....as much as we love logging, there are some things that laptops just can't pickup!


Helped a guy in Brisbane diagnose that his heads had not kifted / no HG failure etc via logging. Then confirmed by his mechanic with a TK test. Ended up being a split Throttle hose. Everyone was telling him HG.

Some things can be diagnosed

Other thing is that this car is an auto, so it could be a cracked trans cooler pipe in the radiator or even the oil cooler on the oil filter has a crack


I have some questions -

How did a split Throttle body hose cause HG symptoms (spraying coolant everywhere, coolant running out, oil in coolant, overheating issues or if severe - white smoke and rough idle etc)?

If you diagnosed it 100% through logging, why do a TK test to confirm?

Aside from those things.....for constructiveness' sake, how would you go about logging for a HG failure? My HG showed no symptoms in logs. I guess you could use coolant temps to help diagnose, but by the time they reach boiling point even the stock needle will be skyrocketing.

As convenient as logging is - in cases like this the mechanical side of things becomes more important and logging only takes on a secondary role to maybe check if you're on the right track. It is so much easier to test for a HG mechanically than it is to log it. If it was a crack in the radiator - I imagine his radiator pressure tests would have come up looking sour.

Could be the oil cooler....could be the turbo....if we can eliminate the block as being the culprit, that saves the OP some $$...although it sounds like he's already thinking evil thoughts about a built E85 running monster block :lol: :twisted:

Re: Fresh oil in coolant... Crack in bore?

PostPosted: Wed Jun 11, 2014 8:33 am
by bigBADbenny
So if the op pulls the spark plugs and none are steam cleaned, that would eliminate a coolant to cylinder bore leak but still leave coolant to oil gallery on the table?

Re: Fresh oil in coolant... Crack in bore?

PostPosted: Wed Jun 11, 2014 11:39 am
by alexeiwoody
bigBADbenny wrote:So if the op pulls the spark plugs and none are steam cleaned, that would eliminate a coolant to cylinder bore leak but still leave coolant to oil gallery on the table?


If the spark plugs are steam cleaned you'll have a lot of white smoke come out of the exhaust during operation.

If there is coolant in the oil, oil will be milky.

If it's a headgasket you need to take the coolant overflow tank hose, stick onto your windshield, drive and see if it sprays coolant on full boost.

Hopefully Aidos has some updates for us :)