35d worsening gas mileage - solved- thermostat/fan/EGR cooler - DIY with pics - Page 24

dazzerbmw1 · #**231** 12-30-2017, 05:16 PM

I just did mine.Thank you OP for all the info. My X5d jade 75,000 miles and the temp was reading 74 degrees. After changing it to the new thermostat, it's now reading 85 normally. About a year ago, the egr cooler developed a crack. after that, one of the glow plugs went bad. All fixed by the dealership.

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crystalworks · #**232** 06-15-2018, 03:57 PM

Just wanted to thank sgrice for the writeup. Excellent info. Had to redo the wife's x35d as the shop I had to it (I was incapacitated after a surgery) had botched the job and pinched the gasket on the thermostat. Has been leaking for awhile I'm guessing judging from the coolant residue on the engine, trans, and of course the soaked engine diaper.

I ended up doing the water pump, thermostat, idler, tensioner, and drive belt. Maybe the shop that did the thermostat back in January will do the AC belt for me as a maya culpa. We'll see. Thanks again.

bfeng · #**233** 06-16-2018, 03:51 PM

How many hours would you budget for all this (experienced shade tree mechanic with extensive tools)?

Thanks

Mackskibum · #**234** 06-17-2018, 07:21 AM

2 hours should do it as long as the egr cooler bolts come out and go back in easy.

crystalworks · #**235** 06-17-2018, 08:28 PM

Quote:

Originally Posted by Mackskibum

2 hours should do it as long as the egr cooler bolts come out and go back in easy.

I'm sure some could do it in that time. I dropped one of the Vband clamp things for the EGR down under the intake and it took quite a while to fish it back out. Plus the 2 EGR bolts by the turbo weren't the easiest to get to.

It took me about 5 hours.

sunny_j · #**236** 06-18-2018, 02:34 AM

Quote:

Originally Posted by bfeng

How many hours would you budget for all this (experienced shade tree mechanic with extensive tools)?

Thanks

my mechanic deleted the egr cooler and installed the racepipe in 1 hour. He had all the tools though

MAH · #**237** 07-19-2018, 02:41 PM

OP, great post and very helpful, I'm not sure I would have tackled this if you hadn't put this together. As a point of reference I replaced the thermostat and water pump with the help of my 14 year old daughter in 4 hours.

Removing the fan made it much easier and was worth the effort. Also, I removed the final plastic air duct that enters the first turbo, that made removing and replacing the EGR bolts much easier, just make sure you jam a rag in the intake to prevent something falling into the compressor turbine.

I didn't see it mentioned, but you also need a gallon of distilled water to mix with the new coolant. I ended up using 1.5 gallons of 50/50 coolant mix to replace what came out. To make burping the system easier I refilled the upper radiator hose before I reattached it to the radiator and that seemed to reduce some of the problems some people had with trapped air.

Had I known how easy it would have been to replace the A/C and serpentine belt I would have replaced them as well.

sgrice · #**238** 07-20-2018, 01:40 PM

MAH - I agree with you that the serpentine belt is easy pickings when you're doing the other work. The AC belt, on the other hand, would require planning ahead. You may know this, but there isn't a tensioner for the AC belt - it is a stretch belt. There is a special tool that BMW recommends for getting the new belt on. That tool works great, but it is pricey - around $100. There is a Lisle stretch belt tool that is much more reasonable priced (less than $20 I believe) but it doesn't quite fit the lip of our compressor pulley quite right. While many have made do with the Lisle stretch belt tool, there a number of others who have described it as a challenge on our cars. Do a google search and you can make your own decision.

Anyway, glad the thermostat and water pump went well!

Regards.

Rigmaster · #**239** 08-01-2018, 11:30 PM

Just wanted to thank all the contributors to this thread for (hopefully) helping me fix my low coolant temp issue with my new-to-me 2011 X5D. I bought it about 1.5 months ago, and have put about 3000 miles on it. I never noticed it going thru regen, that's how I found this thread. Finally got the time to replace the thermostat today, unfortunately the coolant temp that was running ~76-82C before is now running ~75-79C with the new thermostat.

So, it looks like I need to replace the t-stat again. Good thing is I can probably do it in about an hour, maybe 1.5 hrs now thanks to experience.

Anyway, I'm a long time BMW enthusiast, I've owned (or own) most body styles from 2002's up thru the early 2000 models (E39/E46) and now this E70, which I LOVE so far, despite its minor annoyances.

AlpineX · #**240** 08-02-2018, 04:03 PM

Quote:

Originally Posted by Rigmaster

Just wanted to thank all the contributors to this thread for (hopefully) helping me fix my low coolant temp issue with my new-to-me 2011 X5D. I bought it about 1.5 months ago, and have put about 3000 miles on it. I never noticed it going thru regen, that's how I found this thread. Finally got the time to replace the thermostat today, unfortunately the coolant temp that was running ~76-82C before is now running ~75-79C with the new thermostat.

So, it looks like I need to replace the t-stat again. Good thing is I can probably do it in about an hour, maybe 1.5 hrs now thanks to experience.

Anyway, I'm a long time BMW enthusiast, I've owned (or own) most body styles from 2002's up thru the early 2000 models (E39/E46) and now this E70, which I LOVE so far, despite its minor annoyances.

Do you think you got a defective part?

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