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

[ninja_zx11]

Originally Posted by Tuesday

He said it isn't just a swap it had to be reprogrammed when swapped?

Wow!!! They said that new thermostat needs to be programmed?? Run away from that dealer if they told you so...

[ard]

Originally Posted by Tuesday

.Said I'd buy a new thermostat because they didn't change it because of no code?

Throw in a bit more words... I know you know what you meant, but maybe explain what this means??

[Tuesday]

He might have ment the dash needed cleared if it got hot and I just change thermostat on the road.But I'm sure he said it'd ( thermostat) needed programmed.
The car is still under warenty,they don't change thermostat without a code or them seeing car HOT.I told him I'd get a new thermostat in case it needed changed out on the road.He said it wouldn't do any good because they'd have to program it.Said it'd be in limp mode but I think he took those words back and said the dash light would have to be cleared.From what I've read ,when thermostat shows signs of messing up it's not long after it takes shit.

[Andras]

Thank you sgrice! Mine has 170k miles and discovered the thermostat was stuck open, plus had a code for the EGR Cooler Performance. I followed your instructions, without which I could not have done these procedures. I discovered that the door of the EGR cooler was stuck, and the inside all charred up. So I wound up replacing that as well. It passed NYS inspection and running fine ever since.

Here is what I did differently from you:
1) I left in place duct #3 before the MAF sensor, no need for Tite Reach tool.
2) I removed the plastic cover below the fan shroud, and the steel cross member underneath it. Originally I was trying to find the coolant drain cock, but ended up cleaning a lot of leaves and dirt out, and eased shroud installation.
3) I drained and collected about 2 gallons of coolant by disconnecting the long thin (about 35 mm) hose below the radiator shroud bottom cover. Minimal mess, and virtually no additional coolant leaking when later disconnecting any other hoses. Refilled the cooling system at the end with a vacuum filler.

Thank you again for the detailed work procedure that allowed me to brave this job!

2010 xDrive35d

[sgrice]

Andras - thanks for the comments. I have edited post #1 and added your comments about the tight reach tool not being absolutely necessary. In particular, I have since found that if the radiator fan/shroud is removed first, then there is adequate access to the air duct clamp bolts. Though I still think the tight reach ratchet is a handy tool to have on hand, you are correct that it's not totally necessary. I also added a reference about which radiator line to disconnect to minimize spilling/mess.

Appreciate the feedback - comments like these make it easier for the next person.

When you say "the door of the EGR cooler was stuck," do you mean the EGR valve, rather than the EGR cooler? I assume a replacement EGR valve would be a lot less expensive than replacing the entire EGR cooler. Regardless, glad you got it straightened out!

Regards.

[Andras]

Originally Posted by sgrice

When you say "the door of the EGR cooler was stuck," do you mean the EGR valve, rather than the EGR cooler? I assume a replacement EGR valve would be a lot less expensive than replacing the entire EGR cooler. Regardless, glad you got it straightened out!

The EGR cooler has a door in the middle, which was stuck partly open. The vacuum box could not pull it open and the spring could not close it. After disconnecting the vacuum box, I was unable to move it manually, not even with pliers. I replaced with new parts both the EGR cooler and the temperature sensor on it. That is the one with the short wires and the connector that you had so much trouble disconnecting. The EGR cooler comes with the vacuum box, mounting bracket, and one mounting bolt. The other mounting bolts are reusable per BMW. I'm glad I was able to contribute to your write-up in a small way.

[seattle]

Changed thermostat as part of long list of things done over past 2 weeks while on vacation.
Now seeing the temperature showing toasty 90-95C in town, up from 70-75.

[captpilly]

What gasket sealant should you use on the water pump and / or Tsat?

[sgrice]

I did not use any gasket sealant on either. The thermostat has a rubber gasket, and the water pump a metal gasket - those seemed to do the job for me. I've seen a number of people debating the pros and cons of additional gasket sealant. So some people recommend it, but I did not use any. The new thermostat comes with its rubber gasket in place. If you want to replace the metal water pump gasket (which I did), you need to order a gasket separately - it is not included with the water pump. You can check post #146 (and a few of the subsequent posts) for a discussion of torque values, and a method for removing the old water pump gasket.

[Dieseldonkey]

I ordered the following parts for my 2010 BMW x35d
143,000 miles

I ordered the following BMW parts

11517801063 BMW water pump
And
11517793796 BMW water pump gasket
And
11517805811 BMW thermostat with gasket and o-rings

Fcpeuro (water pump and gasket) and ECS for the thermostat had the best price shipped to my door!

Almost certain I ordered the correct partS

I'll have to look at the water pump gasket again as it doesn't look like metal