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Showing results for tags '520d'.
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The 320d had seen a slight drop off in economy, and also a marked increase in time taken to get to operating temperature. These engines, like the M47TUD20 in the 320d, have two thermostats - one is the more-or-less conventional item in the cooling system, and the second is associated with the EGR (exhaust gas recirculation) system. The EGR thermostat appears to be the one to most commonly give up, is generally the simplest to replace, and is also the cheapest. As good a place to start as any, then. A little internet searching turned up the video below. 3 minutes, huh? Can't be too bad! So it didn't take 3 minutes. The video doesn't show R&R of the plastic engine covers for a start, but they have to be taken off for just about anything. Some differences (from the video procedure) experienced: The screw holding the vacuum pipe in place on my car has a torx head The hose on the right hand side of the EGR thermostat is held by a fancy clip, not a jubilee-type one. There's an engine lifting bracket behind the EGR thermostat The hose connecting the vacuum pipe leads into a solid pipe, which will not lift out of the way as shown I followed the same process with the necessary changes for my car. When it came to removing the two 10mm bolts to release the thermostat, I had to use a 1/4" drive 10mm socket, a UJ coupling and a short extension. This is awkward but not impossible to get into position - the biggest challenge is not rounding the head of the bolt when removing or refitting. Something I don't think the video shows is replacement of the yellow o-ring that fits on to the thermostat. I smeared the tiniest amount of Hylomar around the shoulder this sits on to before refitting. OK, so it's not a 3-minute job. End-to-end, including finding the right tools, it took perhaps 30 minutes. As with so many tasks of this nature, it'd probably be quicker if doing it again. Result? Well, the engine comes up to temperature much faster (again). Can't yet comment on the economy, and maybe it was psychological, but I felt the car was generally running better post-swap than before. Nothing tangible, nothing serious, just seemed a little smoother. I may have imagined it. I bought the parts from Coombes Johnson in Hamilton and cost was about $100. You can find them cheaper online, but I was in a bit of a hurry to get it sorted. Ordered Thursday, collected Friday, fitted Sunday. Edited to correct the engine designation.
