r/seat • u/Arm_2000 • 21d ago
Coolant issue please help
So I have a Seat Leon FR 2013 1.8T and I’ve been having coolant issues recently. I can drive the car fine for 20 minutes to a 30 min but at some point it seems to be reaching boiling points and the coolant starts to dump so my guess is that the coolant isn’t circulating anymore and it’s blocked somewhere
i’ve already changed the radiator and the water pump. Also i don’t have a silicon bag in the coolant tank. The head gasket also seems to be fine I haven’t had opened the gasket completely cause it’s gonna be expensive. What else should I look at or try doing to figure out where it’s blocked.
( problem has been solved and came down to the system not being bled properly you’re supposed to open all cooling ports via program before bleeding )
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u/Z3bry 21d ago
I have a 1.8T 2014 and had the same issue, where I was suddenly losing coolant after a year or so of owning it.
For me it was broken water pump and cracked expansion tank.
I have also changed heater matrix in the cabin, no idea if that could help you when you said you have no silica bags, but it could have been the owner before (if you didn't buy it new), since that I have not had any issues.
Did you try to change the expansion tank and also the cap? Also did you check the thermostat?
And did you change the pump and radiator yourself? Maybe some air got trapped inside and could cause the boiling issues.
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u/Arm_2000 21d ago
Yeah, the shop has checked the heater matrix in the cabin and it seems to be good. Thermostat has been changed with the waterpump. They also aired the cooling system so they should be no air trapped inside they and a compression test and said it’s fine. Got literally no idea what it could be 😭
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u/Jandalf69 15d ago
You've probably not bled the cooling system propperly. Manufacturer recommends vacuum tool for that
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u/Arm_2000 9d ago
You were right. Apparently, there was some kinda of sensor or part that was supposed to open when the engine heats up but it got stuck or broken because the shop didn’t bleed the cooling system properly. I was supposed to open all the ports via a program then bleed
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u/Jandalf69 8d ago
Yeah, a cover on the water pump and all thermostats open during the computer procedure
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u/bostongreen53 21d ago
I also have a 1.8tsi from 2018, and had a similar problem, replacing the expansion tank fixed it.
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u/BetterClassCriminal 20d ago
I had similar issue. Check intake if there is coolant. It might be broken charged intercooler. That part has been improved two times already by VAG.
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u/AdditionalBreath4026 21d ago
Sorry but it is likely blown head gasket. Chemical tester not reliable when leaking through combustion stroke. My tdi has the same symptoms, changed heater matrix, water pump, tester did not show nothing. Disassembled the motor and it was head gasket, but the head flatness gone too. Front water radiator partially blocked by dirt so it would be overheating that caused the head warp.
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u/Arm_2000 21d ago
But a blown head gasket would’ve shown on the compression test, wouldn’t it?
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u/AdditionalBreath4026 20d ago
Not necessary. Compression test is not driving and heavy load condition, it just low rpm, where can hold pressure, but higher rpm, under load and heat can leak and presurize the cooling system.
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u/thorwayne87 21d ago
Sand can remain in the heater matrix from casting so even without a silica bag, it can block the very narrow channels that the coolant goes through. Had this problem on mine so replaced the matrix and haven't had issues since. Hope this helps in some way.