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Baja with coolant in oil...need help!


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I have a 2005 Baja. Recently I replaced all of the spark plugs, removed and cleaned the injectors, and removed the intercooler to clean the throttle body. Also, before doing all of this, I Seafoamed the upper and added some to the gas and oil. This was all to correct intermittent misfires and very rough idle. Good news is idle and misfires are gone. Bad news is, after doing all of this I changed the oil and found that it had coolant in it. At first I suspected head gasket (as we all know Subaru's and head gasket issues) but, what confuses me is, there is no oil in the coolant, engine is not overheating, no bubbling back through the fill tank from combustion pressure, and absolutely no loss of power. Other weird thing is, when I drain the oil, after the diluted oil has run out, mostly coolant mixed with a bit of oil will continue to slowly drip out for hours. Even overnight! By the way, obviously it's the 2.5L turbo and it has around 130k miles on it. If anybody has any suggestions please help. As of now I'm a bit stumped and don't want to tear into the heads until I'm sure that's what it is. Is there anything I can check to be absolutely confident that it's the head gasket(s)?

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No, I'm sure I got everything connected back right. As you said, it's pretty idiot proof. Don't know if it was like this before I did the work or not. It's actually my father in law's and I've been driving it and doing some work on it for him. Just included that background information in case it helps.

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You're SURE it's coolant?

It's the same (or similar) color to what's in the radiator? And the coolant level in the radiator has dropped sufficiently to indicate a leak somewhere?

 

Head gaskets seal multiple areas at one time. They seal coolant away from oil passages, oil away from the combustion chambers, and combustion chambers away from the coolant jackets that surround the cylinders. Any of these can have a leak between them without affecting another section.

 

You can have coolant leaking from a lower jacket into the oil return ports at the bottom of the block (where oil flows from the heads back to the oil pan). With this type of failure the fire ring around the combustion chamber is not breached, so compression and exhaust gasses are not forced into the cooling aystem. This is the most likely scenario in this particular case.

 

You can also have oil under pressure from the oil gallery being forced into the upper cooling jacket, which would yield a large amount of engine oil in the cooling system, but not much coolant in the oil, and again with no breach of the fire ring, there would be no exhaust gasses in the cooling system.

 

The most common on the older DOHC 2.5 is the failure of the gasket between the cooling jacket and combustion chamber, which is what creates the bubbles in the cooling system.

 

 

Other less common areas that coolant and oil can mix are in the turbo housing, and the O rings between the block halves.

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I get it when the coolant pasage next to the oil return passages headgasket gets worn down and lets coolant drip into oil pasage is on the lower corner of fire ring thru the headbolt and down in to the oil return pasage. Or block half red oring is leaking but very doubtfull have only seen this twice on very overheated engines. Preshure test coolant sestem My money is on headgasket

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Thanks for the help, guys and these are all very good points. Here's what I tried last night:

 

Did a pressure test on the cooling system. Started with the tester connected to the fill tank or secondary reservoir or whatever (this is one of the Subby's with a radiator, overflow, and the secondary reservoir or whatever on passenger side real close to the turbo). Pumped up to around 18-20 psi where the system began to release pressure back to the overflow tank. It released to about 15-16 psi and held steady. I removed both the oil fill cap and the dipstick. No pressure loss. I had already removed the banjo bolt for the oil feed line to the turbo. Looked inside the hole...only saw stagnant oil. No coolant spewing out or movement in the oil to suggest it was seeing pressure from somewhere. Left it on for a little while...no pressure loss.

 

Next I moved it to the actual radiator, core, or whatever the appropriate term is. Pumped to around 18 psi where it released down to about 15-16 and again held steady.

 

I guess the next step would be to drain the oil...again (this will be about the 5th time now) and pressure test with the oil system completely open to see if it still holds pressure?

 

Am I correct in assuming that, in this particular situation, a compression test or a leak down test aren't really going to show me anything?

Edited by mbrown1000
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The crankcase is not sealed airtight, it has breather hoses and a vent (to the PCV valve) so pressure would not be able to build and prevent coolant from leaking in during a pressure test.

 

How long did you let the tester sit? Sometimes a slow leak will not show a drop in pressure right away. Leave the pressure tester on overnight and see if there is a drop.

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The crankcase is not sealed airtight, it has breather hoses and a vent (to the PCV valve) so pressure would not be able to build and prevent coolant from leaking in during a pressure test.

 

How long did you let the tester sit? Sometimes a slow leak will not show a drop in pressure right away. Leave the pressure tester on overnight and see if there is a drop.

Got it set up. Holding steady for now. Will report back in the morning. Thanks.

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Is there any external leaks from headgasket seem ? I a'm doing heads on 01 legacy today was leaking coolant on uper ps side of head seam and runing down timing belt cover and down also had failure thru headbolt and thru oil passage thiss engine had coolant in oil and vice versa. Was realy bad had only 144000kms on it. Is there any chance it may have been frozen at all ? always had good strong coolant in it ?

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The crankcase is not sealed airtight, it has breather hoses and a vent (to the PCV valve) so pressure would not be able to build and prevent coolant from leaking in during a pressure test.

 

How long did you let the tester sit? Sometimes a slow leak will not show a drop in pressure right away. Leave the pressure tester on overnight and see if there is a drop.

 

 

Got it set up. Holding steady for now. Will report back in the morning. Thanks.

 

When I left it last night it was at about 16 - 17 psi. This morning it was at about 12 psi. Could that little bit of drop be explained by overnight atmospheric conditions? I'm also not 100% sure that the test cap I used had a perfect seal. Going to try it again tonight with another adapter.

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Is there any external leaks from headgasket seem ? I a'm doing heads on 01 legacy today was leaking coolant on uper ps side of head seam and runing down timing belt cover and down also had failure thru headbolt and thru oil passage thiss engine had coolant in oil and vice versa. Was realy bad had only 144000kms on it. Is there any chance it may have been frozen at all ? always had good strong coolant in it ?

 

As far as I know it's always had good coolant in it. I live in the South (Kentucky) so it never really gets cold enough to freeze coolant unless it's just straight water (and even then it would probably be fine). There are some minor external leaks on the bottom passenger side. Really more like just a little seepage. Not sure about the top side as I don't think I can really see it. The thing that really still get me is that there's no oil in the coolant. I even flushed it a couple of times with just distilled water and then drove it for a few days filled with just distilled water. When I drained the water, it had no hints at all of having oil in it. And the antifreeze that's in the oil is clean. I've seen cars with bad head gasket failure and the oil looks like thin chocolate milk. Mine still looks like perfectly colored oil with a slightly green tint to it. The whole thing is just really confusing me.

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Oil and coolant down mix. If coolant drips into the oil it will settle to the bottom if its not agitated and you will get a puddle of slightly off color coolant and all of the oil floating on top of it. The green tinting in the coolant will not fade into the oil. Pour some of your oil into a bottle and pour a bit of coolant on top then let them settle out for a few hours and you'll see what the two do.

If the mixture is agitated, the two blend together into a frothy disgusting mess that looks like bad chocolate milk, but it will still not be green.

 

Some oils have UV dye in them to assist with finding leaks. Shine a black light or UV light on it, or look at it in direct sunlight and it may have a fluorescent/neon orange or green hue.

Open a bottle of fresh oil (the same kind that's in the car now) and see if it has the same greenish tint.

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Not on subarus they leak combustion into coolant sestem 180 psi vs 14 psi it realy wants out the one i did yesterday had a track from fire ring out the side of headbolt down past the oil pasage and out the side. On theese engines the lower part of headgasket breaks down alowing coolant to get into the oil. The pcv sestem can remove the water but sugars and additives stay in oil riuning oil and pos engine damage. Any external leaks is good indacator of internal leaks is its seeping its leaking headgasket is still my gess

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Not on subarus they leak combustion into coolant sestem 180 psi vs 14 psi it realy wants out the one i did yesterday had a track from fire ring out the side of headbolt down past the oil pasage and out the side. On theese engines the lower part of headgasket breaks down alowing coolant to get into the oil. The pcv sestem can remove the water but sugars and additives stay in oil riuning oil and pos engine damage. Any external leaks is good indacator of internal leaks is its seeping its leaking headgasket is still my gess

This makes a lot of sense. If the gasket is leaking between the water jacket and the oil passages, but is still good at the fire ring, then a leak down test or a compression check aren't going to show anything. Right?

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They only seem to leak when driving I dont even comp test them or combution gas test them just do headgaskets if it hasent been done and has more than 155000kms on it they get done if any external leaks vissabble at all. And keep in mind that the cooling sestem go's under vacume when it cools down witch could pull oil into it thru a bad sealing headgasket

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They only seem to leak when driving I dont even comp test them or combution gas test them just do headgaskets if it hasent been done and has more than 155000kms on it they get done if any external leaks vissabble at all. And keep in mind that the cooling sestem go's under vacume when it cools down witch could pull oil into it thru a bad sealing headgasket

Dropped the oil and coolant again last night. Lots of coolant in the oil. Or at least it looked like a lot, probably doesn't take too much to make all of the oil look tainted. Definitely had green glow from beginning to end of drain and then continued to slowly drip coolant/oil mix, I believe mostly coolant, overnight. Other than the green glow and massive reduction in viscosity, the oil looked normal...no foam, no chocolate look, nothing. And the coolant I drained was beautiful...absolutely no traces of oil whatsoever.

 

I drained the oil before the coolant and, before I drained the coolant, I pressure tested the cooling system with the oil drain plug and oil filter still off to see if it would leak. I pumped both the actual radiator and the secondary reservoir (separately of course, not at the same time) up to about 16-18 psi and...nothing. If there were a slow leak between the water jacket and one of the oil passages in the head, shouldn't I have seen at least a steady drip when I pressurized the system?

 

Like you guys, I still think it's the head gasket...just that none of this makes sense.

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If coolant were constantly dripping into the crankcase you would have water droplets on the dipstick and in the oil cap because the water would evaporate out of the oil and condense on the dipstick and filler overnight as the engine cools. There would be milk chocolatey sludge on both, and you would have a distinct layer of coolant in the bottom of the oil pan.

 

Did you check your new oil to see if it has the same tinting?

 

Drastic reduction in viscosity? Oil draining from anhot engine is much less viscous than the fresh oil you pour out of the jug.

 

I still think its UV dye in the oil.

Unless you've monitored the coolant level for several weeks and have had to add coolant because the level constantly gets low.

 

If you want to find out for sure what's in your oil. Take a sample and send it in to have it analyzed.

Coolant, gasoline, water, engine metals, etc., oil analysis will tell you.

Costs about $30. Oil Analyzers Inc. and Blackstone Labs are the most commonly used.

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If coolant were constantly dripping into the crankcase you would have water droplets on the dipstick and in the oil cap because the water would evaporate out of the oil and condense on the dipstick and filler overnight as the engine cools. There would be milk chocolatey sludge on both, and you would have a distinct layer of coolant in the bottom of the oil pan.

 

Did you check your new oil to see if it has the same tinting?

 

Drastic reduction in viscosity? Oil draining from anhot engine is much less viscous than the fresh oil you pour out of the jug.

 

I still think its UV dye in the oil.

Unless you've monitored the coolant level for several weeks and have had to add coolant because the level constantly gets low.

 

If you want to find out for sure what's in your oil. Take a sample and send it in to have it analyzed.

Coolant, gasoline, water, engine metals, etc., oil analysis will tell you.

Costs about $30. Oil Analyzers Inc. and Blackstone Labs are the most commonly used.

It was definitely coolant. And yes, there is water around the rim of the oil fill neck and I can see coolant on the dipstick (with the oil) when I check it. There was UV dye in the oil but it was just because I had added some dye to the coolant to help me troubleshoot. Oil/coolant mix definitely glowed under the UV light. Still no milky chocolatey sludge though. There's no doubt in my mind it's coolant and that's what confuses me so much. Why is there no milky sludge???

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weird

 

can you post any pictures of what you're seeing?

 

maybe start pulling breather, PCV, throttlebody and other lines and look for coolant/oil contamination. Is there signs of coolant in the IC? Also, compare all 4 plugs to each other. maybe the guilty cylinder's plug will look different.

 

Once you feel confident it must be a head gasket - you know what needs to be done. Ivan's post #7 seems likely. The oil return passages have lower pressure so, oil getting in coolant might not happen. Just coolant into oil.

Edited by 1 Lucky Texan
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only leak when they get hot or under load as they heat up the block and heads expand opening up any small leaks still think headgasket

Once again, makes a lot of sense and that's kind of what I was leaning towards as well. One question though, why would coolant continue dripping from the oil pan hours after the plug has been removed and the engine is cool? Could it just be taking that long to completely empty out to the point that it will no longer drip? I've never actually left an oil plug out any longer than it takes to get most of the oil out and it is no longer dripping any at all, so I don't know how long is normal for it to sit and drip. What you said would also explain why it is that, even when I put the cooling system under pressure with a tester, it won't leak. Could I artificially try heating the head and block in the area of the gasket from the outside via a heat gun while the system is under pressure to see if it starts leaking? Or would I never be able to 1) get it hot enough to expand and leak or 2) would it still not leak since the block and heads would have combustion pressure trying to push them apart?

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