This might show up on the plugs. Worth a look besides a compression test. Good luck.

 

 

That guy is a little annoying but I learned something from this video.... pretty neat prognosis method for a problem I hope never to have on either of my Subarus.

 

It's very rare for this particular engine to have a bad head gasket, especially with that low of miles. For some reason, I noticed as well as the guys I worked with that had newer Subarus, that the blue long life coolant tended to evaporate a little over time. Say in a year, 25,000 miles, maybe would lose from the full line to no more than the cold line. All of us experienced the same thing. Been posted on here about it also. Here is one example.

Subaru Long Life Coolant ???? XV & Other Models

I know this is being a nit picker but just reading further into the owners manual, I was looking to see what the interval for " Coolant flushes would be " Future reference, to my amazement came across this, 11 years ??? Subaru using a Long Life Coolant that should last that long ??? Most of...

www.subaruxvforum.com

 

The block coolant is separate from the head coolant. It almost not possible to have an actual HG leak.

 

That sounds odd? How. There are coolant passages running from the block to the heads and heads to the block. All one coolant. Unless there is something special about the FB?

 

Still all goes to the same radiator and overflow bottle.

 

Just saying it's almost impossible to leak coolant at the HG area

 

Besides the other suggestions, you might consider:
1) drop the plastic under pan(s) and take a good hard look with an small LED light, above and under the engine area
2) check the side seals of the rad(difficult with ducting there) and around the plastic coolant connectors/flanges
3) check the coolant caps.
If you've added a fair bit of coolant, and your using the factory super coolant, the dried blue crust should be evident where the leak is happening. As the other poster suggested, if it's going into the combustion chamber, there will be evidence on the spark plugs. In the end, a pressure test might be needed to find the leak if you've exhausted the other options.
regards

 

Besides the other suggestions, you might consider:
1) drop the plastic under pan(s) and take a good hard look with an small LED light, above and under the engine area
2) check the side seals of the rad(difficult with ducting there) and around the plastic coolant connectors/flanges
3) check the coolant caps.
If you've added a fair bit of coolant, and your using the factory super coolant, the dried blue crust should be evident where the leak is happening. As the other poster suggested, if it's going into the combustion chamber, there will be evidence on the spark plugs. In the end, a pressure test might be needed to find the leak if you've exhausted the other options.
regards

Thanks for your advice. Already had it up on the lift with my mechanic inspecting for external leaks, with nothing found. He did remove the plastics for inspection as well.
I will say, I posted on this forum just to document this issue for others; I don’t expect to find any miracle solution. I am using the factory coolant.

 

Adding some coolant is normal, it evaporates slowly. I've already had to add some to my 2020. Remember that it's not a sealed system.

 

I am in the process of a head gasket failure project on a 2013 Crosstrek. Oil was in the coolant reservoir (half inch) and under rad cap. Doing a bunch of other stuff as well. Heads have been machined at a shop, waiting for the new valve shims to get it in spec.

But I believe the main culprit here was the wrong coolant used. It was green, so probably Prestone. It may have had oil in the cooling system beforehand when the used car dealer bought it, and wanted to cover it up by flushing it cheaply with "universal" Prestone. Or maybe the used car dealer bought it with green coolant. Don't know.

Either way, this FB20 engine had a blown head gasket, and I know its rare for these.

There is lots of leakage around the engine head area, and even oil seemed to leak out of the water pump gasket, and the thermostat and water pump rubber gaskets were deteriorating from the oil in the cooling system, and are going to be replaced.

If you don't have any leakage, nor oil in the coolant, nor coolant in the oil, nor smoke upon startup. Not sure if its HG. =/

 

We had the same issue with our '14 except we would smell coolant. We had it in for service many times and different dealers almost immediately after buying it, they pressure tested the system over and over and never found anything wrong (not head gasket). I would record the coolant level at the same time every morning and mark the overflow bottle with a little sharpy dot as it dropped. We still have the car with the original coolant, it now has 71k or so and still occasionally smells of coolant. In summary, it is what it is. Pour in a little distilled water once in a while and stop worrying about it. As all the dealers told me, "It's normal". The cheap blue-dyed coolant evaporates from the reservoir when the car cools. Soon I'll get around to changing it out with a good quality coolant now that our extended warranty expired. Good luck.

 

…Soon I'll get around to changing it out with a good quality coolant now that our extended warranty expired. Good luck.

From what I’ve read, the OEM blue-colored coolant is designed to reduce the risk of head gasket failure over typical ethylene glycol based coolants you’d buy at the local auto store. I’d be hesitant to start using non-Factory-approved coolant in these cars.

Thanks for your advice. I’m going to be recording the amount of coolant I have to replace more diligently from now on. The problem for me is that since COVID, the car gets little use, so it’s really hard to quantify based on mileage, in a reasonable time interval.

 

 

Ummm ….no.

 

I also have oily residue in the coolant recovery tank.....curious why this is happening... I dol8ve inAK so the temperatures are a bit extreme in the winter... any thoughts?

 

If you're not seeing oil/coolant mix in your oil, it could be that it is leaking into a cylinder. There is this kit I've seen on YouTube. It is a little pricey but may be worth it before you go digging.

75500 Combustion Leak Detector | Lisle Corporation

 

If you're not seeing oil/coolant mix in your oil, it could be that it is leaking into a cylinder. There is this kit I've seen on YouTube. It is a little pricey but may be worth it before you go digging.

75500 Combustion Leak Detector | Lisle Corporation

OP is no longer posting. Probably from the honda board.