MY03 RX 2.5 – Coolant leak, liquid gasket sealant questions

[ffs]

Hi all,
First post here. I looked around a bit for some info but found a lot of conflicting advice so I thought I'd open up a fresh thread here.

I have an '02/'03 5spd wagon with about 215k on the clock. First car, love it so far. Only real issue is a slow coolant leak from the right front cylinder behind the timing case, as found in a service about 6 months ago. The mechanics reckon its most likely only external - no white smoke from exhaust, it doesn't feel down on power for its age, engine temp reads consistently fine on the dash and never creeps up even on long drives (however when stopping after long stints on motorways there is sometimes a bit of steam visible from the engine bay).

I bought a bottle of this stuff https://www.nulon.com.au/products/cooli ... ket-repair
and was hoping to get some advice, as I've read that you need to do an oil change after using fibre gasket sealers (apparently the particulates can be abrasive in the engine).

- How important is the oil change? Would prefer to avoid it to save $
- Does anyone have experience with this stuff or similar products, in this engine or other subaru engines?
- I understand the procedure is pour the whole bottle into the radiator, top up the reservoir with water, run the car for 15min with the heater blasting, let it cool down, and then good to go. Is there anything else I should be wary about?
- Is it even worth doing if the car basically runs fine (its not overheating)? I'm a believer in preventative medicine, but is it worth the risk if I get it wrong or it causes some other issue in the engine?

Thanks heaps for any advice! And happy hols.

Fraser

[bigBADbenny]

Maybe read reviews as similar products can severely clog the cooling system?

Personally, I’ve had a slow coolant leak from the crossover pipe orings, amazingly I simply monitored coolant temps (aftermarket gauge or obdii) and kept my coolant at the right level, yearly bleed, coolant change every 2 years or so, and that leak sealed itself, not that long after.

[BillyCorgi]

ALL EJ251 engines WILL DEVELOP an EXTERANL OIL LEAK!

Fix the head gaskets.
There is no other option available.

It is your right of passage to Subaru ownership.
You can do them in a weekend, plenty of us already have!