Transmission fluid in cooling system and coolant in the transmission, what can this do to both systems?

2013 CHEVROLET CRUZE
75,000 MILES • 1.4L • 4 CYL • TURBO • 2WD • AUTOMATIC
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ARUNNEHRUKAMARAJ
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My radiator with a built-in transmission oil cooler has failed internally causing transmission fluid to go into the cooling system and coolant to go in the transmission system. If I drive with this condition for the short/long term, can it result in premature failure of cooling system components like Water Pump, Thermostat, Hoses, Gaskets, Seals, etc., due to coolant contamination with oil? And what damages can it do to the transmission system with oil contamination with coolant?
Jul 23, 2021 at 12:06 PM
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JACOBANDNICKOLAS
  • ASE Certified Mechanic
  • 110,194 POSTS
  • ASE Certified Mechanic
Hi,

If coolant gets into the transmission, it will damage bearing, clutch plates, and basically anything that moves. I strongly recommend not driving it like this. Additionally, it will cause sludge build-up in the cooling system.

What I recommend is to replace the radiator, flush the cooling system, and power flush the transmission. Transmission damage will not take long to occur.

https://www.2carpros.com/articles/coolant-flush-and-refill-all-cars

https://www.2carpros.com/articles/how-to-service-an-automatic-transmission

Here is a link to get you started on the radiator replacement:

https://www.2carpros.com/articles/how-to-replace-a-car-radiator

The directions attached below are specific to your vehicle.

Let me know if this helps or if you have other questions.

Take care,

Joe

See pics below.
Jul 23, 2021 at 9:53 PM
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ARUNNEHRUKAMARAJ
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Thanks, Jacob for your response. What's your opinion on this?
Can it result in premature failure of cooling system components like Water pump, Thermostat, Hoses, Gaskets, Seals, etc due to coolant contamination with oil?
Jul 23, 2021 at 9:57 PM
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JACOBANDNICKOLAS
  • ASE Certified Mechanic
  • 110,194 POSTS
  • ASE Certified Mechanic
Hi,

It can. When coolant and oil mix, they create a sludge-like material. That can cause damage to anything that requires a free flow of coolant.

I hope this helps. Let me know if you have other questions.

Take care,

Joe
Jul 23, 2021 at 10:17 PM
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