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

[diegoX]

Originally Posted by sgrice

Amen about the egr electrical connection. I think I mentioned it in the first post, and it was mentioned again in one of the later posts - but it is difficult. It's hard to describe the technique, but it's not so much "prying" with a micro-screwdriver, as it is sliding it between the two parts of the connector. There is some sort of a internal "ramp" that the clip catches on. I put the micro-screwdriver flat blade inbetween the two connector parts (from the back side), slide it back and forth for about 30 seconds while pulling with moderate force, and then suddenly the connector separates. I've looked several times to see exactly what gets unlatched (and why the white clip doesn't seem to do much), but I really can't see exactly what's going on.

With regard to metal tabs on the water pump gasket, another option would be to cross-cut the metal gasket with a wire cutter/dikes in 2 or 3 locations, then twist the tabs back and forth like a paper clip until metal fatigue eventually takes care of the issue.

I am out of town right now, so do not have access to Rheingold. Thus I don't know the torque values for the egr valve and throttle/anti-shudder valve.

Interesting to see the carbon build up on the egr valve. It looks similar to what mine was like at 80,000 miles. Otherwise, congrats to you - looks like you've done the hard part!

Regards.

Again, thank you so much to sgrice and all those who contributed on this thread. Took me 4 days due to work schedules but I was able to get it done. Temp is finally working well back to 89-90 degF during normal driving.

Some of the frustrations I encountered.

Initially positioning the new metal gasket on the engine block (as per instruction) just didn't work out for me. I find it almost impossible to keep that area dry from coolant to hold the gasket in place despite the use of sealant. Made me realize the reason they used those tabs to keep the screw holes aligned. Metal gasket I got wasn't completely flat, pressing one side on the waterpump makes the other end pop up. Another issue: the moment it sits correctly in place, it easily slides off upon cramming the water pump in that limited space. Made a mess with the gasket sealant as shown below from the numerous attempts and had to wipe and clean them off again before they complete dry up solid.


Also tried with the screws on (taped to prevent it from dropping) to keep the gasket in place to no avail due to limited space. Braille method was not working for me looking for those holes as I was afraid to bend the gasket if forced in.



Had to take a breather.
Eventually, I went opposite the instructions and ended up having to rest the gasket on the water pump and let it dry in place pressed down against a flat surface before installing. This turned out perfect for me installing it easily.


I can't recall if there's something attached on this hook like thingy on the hard pipe that run into the thermostat.

[sgrice]

diegoX - Great job! Way to stick with it despite some frustrations!

Just for completeness (and for anyone who sees this thread in the future), the torque for the 3 M8x27 throttle valve screws is 19 Nm. I could not find a value for the four screws that connect the EGR valve to intake manifold. I suspect they are also M8x27 thread and have the same torque value, but do not know for certain.

Also, the heater element hose you asked about in post # 150 is part # 5 in this Realoem link. It can be purchased from ECS tuning for $75 (the link is here). A lot of money if all you need is a clip, but as someone else pointed out, the hose can deteriorate and be a source of potential vacuum leak.

I did not have any of the problems you had with the water pump gasket. Cannot remember my precise technique, but I think I just used one of the bolts to keep the gasket in position. Everything fell into place without a struggle - just lucky I guess. Your technique seems to be a good one - I'll put it into the memory bank in case I come across a similar situation in the future.

Last but not least, the hook like part of the hard coolant pipe has nothing attached to it on my car either.

Again, congrats on the perseverance. Hope the code p2457 is gone and stays away!

[trucky]

Just for grins and giggles I checked with the local BMW dealer and asked for a quote to replace just the thermostat...

$810.64
4.4 hours labor

[boredincl]

Originally Posted by trucky

Just for grins and giggles I checked with the local BMW dealer and asked for a quote to replace just the thermostat...

$810.64
4.4 hours labor

Ouch!
I didn't realize gold plating was optional.

[Shaman]

diegoX and sgrice, do I need order water pump gasket separately or it goes with water pump?
I assume you did complete coolant flush, how much coolant do I need to order?
and off-topic question: where are you usually shopping for parts?
thanks!!!

[sgrice]

Shaman -

1) The water pump gasket is a separate item - it is part #2 in this Realoem link.

2) I must admit that I took a short cut approach to the coolant flush - I did two "partial" coolant flushes (I define a partial flush as disconnecting various hoses such that the radiator/water pump/hoses drained, but not the engine block) rather than a "complete" coolant flush. Just seemed easier to me to do 2 partial flushes a week apart than try to find the engine block drain. Not as good as draining the engine block, but that's what I did. Doing it my way took just about one gallon of antifreeze and one gallon of distilled water each time.

3) Just to state the obvious, the water pump is separate from the original thermostat repair (though I would not disagree with replacing the water pump at roughly 100,000 miles as preventative maintenance if you need to do the thermostat anyway).

Hope that helps.

Stephen

[dalecan]

Given all these faulty thermostat readings, I decided to check mine and of course it was faulty. I had planned on changing this when my work schedule got a bit quieter. Interestingly, I called BMW Seattle today to book my X5 in to get the faulty DeNox reading fixed (hopefully under CA emissions) and to my surprise the lady on the phone said my vehicle had an open recall on a faulty thermostat. Mine is a 2012 X5d. Maybe some of you have the same open recall. I was very relieved to say the least.

[Shaman]

Originally Posted by sgrice

3) Just to state the obvious, the water pump is separate from the original thermostat repair (though I would not disagree with replacing the water pump at roughly 100,000 miles as preventative maintenance if you need to do the thermostat anyway).

Thank you, Stephen!
Regarding changing water pump - I had recently broken bolt under one of the pulley, so serpentine belt came off and I had a chance to check water pump for any damage and backlash. And it has very little one. So I think once I will be there - I will replace it.

Igor

[diegoX]

Originally Posted by Shaman

diegoX and sgrice, do I need order water pump gasket separately or it goes with water pump?
I assume you did complete coolant flush, how much coolant do I need to order?
and off-topic question: where are you usually shopping for parts?
thanks!!!

Shaman, I got my parts from the dealership (BMW Roxbury NJ). They were the only dealership in my area giving 25% off on parts. Other AEM parts I get from rockauto.com

[ZetaTre]

I think I was one of the first people around here to replace thermostat in my X5 35d.

I don't have the record with me, but it was about 2 years and some 30K to 40K miles ago.

I've noticed most recently that the temperature is starting to get twitchy again: when I commute to work I do notice that there's a certain downhill section along the freeway where the temepreture gets in the low 80s.

The thermostat is slowly degrading just like the old one and I suspect that coming winter time I'll replace it again.

Given that the ones available new appear to be just as bad as the one that was originally fitted (i.e. doesn't seem like nothing has changed) I'll probably not buy an OEM anymore.

I'm not entirely sure who makes it, but looking at pictures it doesn't seem to be Mahle, Febi/Bilstein or Gates.

Notice how in these 2 the center disk is attached differently.

Here's the BMW OEM from down below:



Here's the Gates:



I'll give Gates a try on my next one see if it's any better. The cross reference part number is TH35488G1