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Coolant leak from expansion tank mounting bracket?

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25K views 7 replies 5 participants last post by  jmo69  
#1 · (Edited)
Hey all,


Been lurking here for a few months and I want to start off by saying the community here is great, and the forums have been immensely helpful. That being said, the coolan systems in these things are a nightmare you guys weren't kidding...

Back in August I purchases a 2002 325i, auto m54 with 110,xxx. Drove fine, after about 1,000 miles the coolant light came on and the car overheated. I've been replacing parts over the past two months to try and figure out what the problem is and it feels like once I fix one thing another breaks.

So far I've replaced:

  • Expansion Tank
  • Thermostat
  • Upper and Lower Radiator Hoses
  • O-ring for temp sensor in lower radiator hose
  • Heater hose that connects from Expansion Tank to rear of Engine Bay
  • ATF Thermostat
  • Expansion Tank Mounting Bracket
  • Water Pump

Just finished installing the new mounting bracket and drove her for about an hour. Everything seemed fine then all of a sudden the light came on and the temp guage started moving to the red. I pulled over and shut it off and under the car it seems that the ET mounting bracket came loose from the raditator. When I first installed the bracket it didn't seem to "snap" into the radiator (like the snap I felt when connect the ET to the mounting bracket). It didn't seem to take much force to pull the bracket out from the radiator either so I assumed this might be problematic.

Is there supposed to be a screw that connects the ET mounting bracket to the radiator? Or is it supposed to "snap" in and stay snug? I'm thinking I might have to replace the radiator at this point. Any insight greatly appreciated!

Joe
 
#5 ·
It's leaking from the bottom of the bracket where the nipple of the bracket goes into the radiator. The tank is seated correctly and fits very snug. I'm hoping it's just the missing screw that is causing the bracket to come loose when coolant is running through the system.
 
#4 ·
You have an automatic so there are two screws holding the mount in place. One on the side and one on the bottom, both 7 and 9 in the pics that steveintheburgh posted. They are sheet metal type screws, I dropped one of mine behind the filter housing and used a hex head #10 sheet metal screw to replace it. It doesn't have to be much more than Âľ" long.
 
#8 ·
There's an o-ring on that small nipple that goes into the radiator, that might be the problem with no screw to hold it tight. When I bought my new mount I bought the o-ring not knowing it came with the new mount so I have an extra or at least one that's it original shape and dimensions.