2010 335i xrive trans heat exchanger

markevo10 · 06-25-2022, 10:23 AM

Hello, I own a 2010 bmw 335i xdrive and recently had a coolant leak and made the very stupid mistake of putting stop leak in the cooling system. Now after I drive approx 20-25 miles coolant gets dumped out of the trans heat exchanger. My question is can I flush the heat exchanger or do I need to replace it ?? Thanks.
Mark R

flapeo · 06-26-2022, 04:06 AM

Well id probably replace it. Not sure what the inside of those looks like but its probably isn't easy to clean. The part new is 300, or you can buy a aftermarket trans cooler from BMS which is an upgrade that plugs the lines for 399. I would do that if you're going to modify you're car at all. Prolly order some coolant too and do a flush.

markevo10 · 06-26-2022, 04:32 PM

Thanks for the reply, Yes I think I am going to replace it. But I'd really like to know why it's dumping coolant out of the bottom where the thermostat is.. I just hope the new one isn't going to do that..

flapeo · 06-26-2022, 04:49 PM

Did you install an intercooler recently? When I did my intercooler I think I might have moved/messed up the fitting onto the trans heat exchanger. It leaks a bit and I top off my coolant once a month. Not worried because I have a BMS transcooler that ill install when my bumper arrives in a week or so

markevo10 · 07-04-2022, 05:26 PM

No i'm not doing any upgrades but I did replace the heat exchanger and flush the entire cooling system.. I think the problem is now solved.. Never EVER use stop leak in your BMW's cooling system.. Just fix the leak and bite the bullet..Do it the right way..!!!
Thanks,
Mark

06-25-2022, 10:23 AM	#1
markevo10 Registered 0 Rep 3 Posts Drives: 2010 BMW 335i xdrive Join Date: Jun 2022 Location: PA. iTrader: (0)	2010 335i xrive trans heat exchanger Hello, I own a 2010 bmw 335i xdrive and recently had a coolant leak and made the very stupid mistake of putting stop leak in the cooling system. Now after I drive approx 20-25 miles coolant gets dumped out of the trans heat exchanger. My question is can I flush the heat exchanger or do I need to replace it ?? Thanks. Mark R Last edited by markevo10; 06-25-2022 at 10:27 AM.. Reason: need to add my car model
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06-26-2022, 04:06 AM	#2
flapeo Private 17 Rep 76 Posts Drives: 2011 335i x drive Join Date: Dec 2021 Location: seattle wa iTrader: (0)	Well id probably replace it. Not sure what the inside of those looks like but its probably isn't easy to clean. The part new is 300, or you can buy a aftermarket trans cooler from BMS which is an upgrade that plugs the lines for 399. I would do that if you're going to modify you're car at all. Prolly order some coolant too and do a flush.
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06-26-2022, 04:32 PM	#3
markevo10 Registered 0 Rep 3 Posts Drives: 2010 BMW 335i xdrive Join Date: Jun 2022 Location: PA. iTrader: (0)	Thanks for the reply, Yes I think I am going to replace it. But I'd really like to know why it's dumping coolant out of the bottom where the thermostat is.. I just hope the new one isn't going to do that..
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06-26-2022, 04:49 PM	#4
flapeo Private 17 Rep 76 Posts Drives: 2011 335i x drive Join Date: Dec 2021 Location: seattle wa iTrader: (0)	Did you install an intercooler recently? When I did my intercooler I think I might have moved/messed up the fitting onto the trans heat exchanger. It leaks a bit and I top off my coolant once a month. Not worried because I have a BMS transcooler that ill install when my bumper arrives in a week or so
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07-04-2022, 05:26 PM	#5
markevo10 Registered 0 Rep 3 Posts Drives: 2010 BMW 335i xdrive Join Date: Jun 2022 Location: PA. iTrader: (0)	coolant leak No i'm not doing any upgrades but I did replace the heat exchanger and flush the entire cooling system.. I think the problem is now solved.. Never EVER use stop leak in your BMW's cooling system.. Just fix the leak and bite the bullet..Do it the right way..!!! Thanks, Mark
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