3.0T thermostat R&R Detailed, manual inc. plus photos and tips

DIY/TECH/INFORMATIVE
#1

This took 8 hours with 2 people the first time. We both think about 6 hours or less the next time. We didn’t know the water pump pulley, vacuum pump and air box removal was required. The supercharger part is easy the stuff in the tight quarters up in front not so much. In the end I saved $1250 plus would feel comfortable doing this on friends vehicles.


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SUPERCHARGER REMOVAL

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1- Engine lifting eye

2- Bolt
27Nm

3- Supercharger
With charge air coolers
Removing and installing supercharger.
Charge air coolers - exploded view.

4- Insulating plate

5- Bolt
5Nm

6- Rubber grommet
2x

7- Intermediate flange

8- Bolt
Tightening torque*>*Rep. gr.24

9- Throttle valve module -J338-
Removing and installing > Rep. gr.24

10- O-rings
Renew

11- Connection

12- Bolt
Tightening torque and sequence > Rep. gr.24

13- Bracket For change-over valves

14- Bolt
9Nm

15- Bolt Tightening torque and sequence > Rep. gr.24

16- Intermediate flange

17- Regulating flap control unit -J808-
Removing and installing > Rep. gr.24

18- Bleeder screw For charge air cooler (left-side)
1.5 … 3.0 Nm

19- Bolt
Tightening torque > Rep. gr.24

20- Intake air temperature sender -G42-
Removing and installing > Rep. gr.24

21- O-rings
Renew

22- Nut
20Nm

23- O-ring
Renew

24- Threaded pin
17Nm

25- Bolt Self-locking
Renew
Before assembly, always remove residues from threaded holes using a thread tap
10Nm

26- Charge pressure sender
Cylinder bank 1 (right-side): charge pressure sender -G31-
Cylinder bank 2 (left-side): charge pressure sender*2 -G447-
Removing and installing.

27-Seals
Renew

28- O-ring
Renew

29- Connection For crankcase breather
Installation position*>*Fig.

30- O-ring
Renew

Removing:
Remove poly V-belt for supercharger.
Remove both belts:
Supercharger easiest from underneath. 16mm
Accessory belt from the top. 17mm

Place drip tray for workshop hoist -VAS 6208- beneath engine.

Tip* Extract the coolant from the reservoir, squish the radiator hose and this will force more coolant in to reservoir. No coolant will be come out of the supercharger hoses this way.

Clamp off coolant hoses using hose clamps -3094-, release hose clips -1- and detach coolant hoses from coolant pipes on supercharger.


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Tip* Take a silver and black sharpie and mark ALL vacuum hoses and connectors before removing.

Move fuel hose -1- and hose -2- from activated*charcoal filter clear at air pipe.
Detach vacuum hose -3- from connection on air pipe.
Remove air pipe. To do so, release hose clip -4- and clamps -arrows-.
Remove air box, optional but it makes for a lot more visibility.


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Unplug electrical connector -3- at activated charcoal filter solenoid valve 1 -N80- and detach vacuum hose -4- (press release tabs).
Detach activated charcoal filter solenoid valve 1 -N80- from bracket and move it clear to the side with hose still attached.


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Unplug electrical connector arrow at throttle valve module -J338-.


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Unplug electrical connector arrow at regulating flap control unit -J808-.


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Unplug electrical connectors 1, 2, 3.
Note: Mark position of vacuum hoses for re-installation.


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Disconnect vacuum hoses 4…7.
Unplug electrical connector 1 at intake air temperature sender -G42-/intake manifold pressure sender -G71-.
Note: Disregard arrows.


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If fitted, unplug electrical connector 3 and disconnect vacuum hoses 1 and 2.


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Move clear vacuum hose 1.
Remove bolts -arrows-on both sides and detach cover/bracket


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Move clear vacuum hose 2 leading to brake servo at bracket 1.


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Unplug electrical connectors -1- and -2-.


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Remove nuts -arrows- and lift off supercharger with charge air coolers.
Tip* Place long 3/8 extensions thru the engine lifting rings to provide a good hand hold.


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Seal openings on supercharger and all relevant ducts and hoses of the charge air system with plugs from engine bung set -VAS 6122-.
Detach noise insulation panels.

Installing

Installation is carried out in the reverse order; note the following:
Tightening torques. „Supercharger - exploded view“
Renew seals and/or gaskets.
Hose connections and air pipes and hoses must be free of oil and grease before assembly.
Secure all hose connections with the correct type of hose clips (same as original equipment)> Electronic parts catalogue.
To secure the air hoses at their connections, spray rust remover onto the worm thread of the used hose clips before installing.
Ensure that crankcase breather connection is positioned correctly > Fig. when fitting supercharger.
Install poly V-belt for supercharger
Fill up with coolant


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1-Bolt
9nm

2-Coolant*pipes (front left).
Removing and installing.

3-Bolt
9Nm

4-Bolt
9nm

5-Bracket

6-Bolt
22Nm

7-Retainingclip

8-Bolt
9Nm

9-Coolant*pipe (front)
Removing and installing.

10-Seal
Renew

11-O-rings
Renew

12-Coolant*temperature sender -G62-
Removing and installing.

13-Coolant pipe (bottom) on supercharger
Remove and install together with-item 17-.

14-Bolt
5Nm

15-Dowel sleeve
2x

16-Bolt
5Nm

17-Seals
Renew

18-Coolant pipe (top) on supercharger
Remove and install together with -item 11.

19-O-ring
Renew

20-Coolant*pipe (top)
Removing and installing .

21-Bolt
9*Nm

22-Seal
Renew

23-Bolt.
9Nm

24- Bolts.
9Nm

25- Coolant*pipes (left-side)
Removing and installing.

26- O-ring
Renew

Coolant Pipes Remove and Replace


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Removing and installing coolant pipe (front)

Special tools and workshop equipment required Pin Wrench 3212
Tip* You must remove the water pump pulley to remove the front coolant hose out of the thermostat. I bought a Pin Wrench off Amazon for Audi and VW. $14


http://i689.photobucket.com/albums/vv257/BRD-PREY/28_Front%20Coolant%20Crossover%20Pipe_zpscbn35xjh.jpg

Removing
Draincoolant.(or on vehicles equipped withcontinuedcoolantcirculationpump -V51- removecontinuedcoolantcirculationpump.).
Remove air duct -arrow-.
Remove coolant pipes (front left)
Remove poly V-belt:
Remove vacuum pump>Rep. gr.47.
*Tip 3 bolts you can then flip it up out of the way.
Remove bolts for Coolant pump pulley (counterhold with pin wrench -3212-).
Detach poly-V-belt pulley.


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Since we are not removing the coolant pipe all the way this is where we remove the 5 bolts holding the coolant pipe into the thermostat housing.
Unplug electrical connector -3- at coolant temperature sender -G62-.
Lift retaining clips and disconnect coolant hoses -1 and 4-.
Release hose clip-2-and detach coolant hose (top).
Loosen hose clip-5-.
Unscrew bolts-arrows-and removecoolantpipe*(front)


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Installation is carried out in the reverse order; note the following:
Tightening torques. „Coolant pipes - exploded view“
Note
Renew seals and O-rings.
Secure all hose connections with the correct type of hose clips (same as original e.~uipment)>*Electronic parts catalogue.
Clean or smoothen sealing surfaces for seals and O-rings.
Lubricate seals and O-rings with coolant and slide onto coolant pipe.
Connect coolant hose with plug-in connector>Fig…
Install coolant pipes (left-side)…
Install air conditioner compressor>Rep. gr.87.
Install poly V-belt pulley for coolant pump…
Install vacuum pump>Rep. gr.47.
Install poly V-belt:
„Removing and installing poly V-belt - vehicles with hydraulic power steering“.
„Removing and installing poly V-belt - vehicles with electromechanical power steering“.
Install coolant pipes (front left)…
Install continued coolant circulation pump -V51-…

Fill up with coolant:

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1-Bolt
9Nm

2-Bolt
20Nm

3-Poly V-belt pulley for coolant pump

4-Coolant pump
With seal
Removing and installing.

5-Bolt
9Nm

6-Bolt
Tightening torque>Item

7-Washer

8-Idler roller for poly V-belt

9-Connection
For coolant hose

10-Gasket
Renew

11-Gasket
Renew

12-Thermostat

13-Bolt
9*Nm

14 -Coolant valve for cylinder head -N489-

Thermostat Remove and Replace

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Checking Thermostat

Heat removed thermostat in water bath.

Starts to open
Fully open
Opening travel
approx. 87 °C
approx. 102 °C*1)
at least 8 mm
1)Cannot be tested.

COOLANT FILL and BLEED
Place a cloth underneath to catch escaping coolant.
Tip* A mechanical impact driver with a #3 phillips is best for loosing the bleed screws.
2000 rpm is required for coolant to be forced into the supercharger and heater core.

Open bleeder screws -1-and-2- one after the other until coolant flows out.

Close bleeder screws.


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http://i689.photobucket.com/albums/vv257/BRD-PREY/Hammer%20impact%20screwdriver_zpsaisazjgv.jpg

Pull seal off plenum chamber partition panel.

Remove plenum chamber cover >Rep. gr.50.


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Release coolant hose going to heat exchanger and pull back hose until coolant flows out at bleeder hole -arrow- in coolant hose.

Push coolant hose back onto connection andsecurewith spring-type hose clip.

Onvehicleswith auxiliary heater, switch heater on (for about 30 seconds) and then off again.

Tighten filler cap on expansion tank, making sure it engages.

Start engine.

Set temperature to „HI“ for all zones and select lowest blower speed (= 0).

Switch off air conditioner compressor (press AC button).

LED in button should not light up.

Run engine for 3 minutes at 2000*rpm.

Allow engine to run at idling speed until two large coolant hoses at radiator become warm.

Run engine for 2 minutes at 2000rpm.

Switch off ignition and allow engine to cool down.

Install noise insulation > Rep. gr.66.


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Check coolant level.

The coolant level must be at the MAX marking when the engine is cold.

The coolant level can be above the MAX marking when the engine is warm
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#2

Extremely detailed as always.

#3

Very good DIY. I like the in-depth detail.

Please let me add some helpful tips to make this easier still. I noticed these things after doing over a hundred 3.0T thermostat replacements during the RVU that came out for the C6 A6s, B8 S4s, B8 S5 convertibles, and Q7s.

  1. If you don’t already have these things then get them:
    A. a small flashlight - to see the small T30 bolts that hold the front metal coolant pipe on.
    B. a small expanding magnet like pictured below - for removing/installing the bolts for the front coolant pipe
    C. some spray silicone to use on all the rubber hoses and o-rings - it makes things a lot easier to take off and go back on.

http://www.expeditionexchange.com/ullmandevices/ullman001%20041.jpg

  1. Get a serpentine belt tool like this for releasing the tension on the belts. With a tool like this then you can easily get to both tensioner nuts from the top.

http://www.harborfreight.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/i/m/image_16281.jpg

  1. If you are doing this on a B8 S4 or B8 S5 convertible then you want to disconnect the battery in the truck before starting to take stuff apart. Make sure to leave the trunk lid open while doing this repair. I had a tendency to cause sparks by touching the big wires for the fan control module.

  2. Remove the flexible section between the air box and the core support to get more room to turn the tensioners with the serpentine belt tool. It just pulls out.

  3. Removing the belts is not necessary. You can get away with just taking them off the pulleys. (SC and water pump)

  4. Before you take the serpentine/accessory belt off, use an allen key to loosen the three bolds that hold the water pump pulley on. Same idea for tightening the pulley bolts after reinstalling the serpentine/accessory belt. That way uses the tension of the belt to hold the pulley in place and you don’t have to buy the special tool.

  5. It can be difficult to get the activated charcoal filter solenoid valve 1 N80 disconnected from the supercharger since the plastic connector is finicky. It also likes to break on higher mileage cars. So I would leave the valve attached to the supercharger and disconnect the rubber line from the back of the N80 valve. To do that pinch the clamp with a pair of pliers so that you can move it farther back and then disconnect the rubber line.

  6. I like to remove the little black plastic trim pieces going down the sides of the supercharger. They have two T25 Torx bolts holding them on.

  7. Have someone else help you remove the supercharger since it is awkward and heavy if you try to do it yourself. We had a tech try to do it himself and when he was going back together he dropped the SC onto the studs. So he had to replace the core on one side since it poked a hole and caused a leak.

  8. You don’t have to remove the vacuum pump. Removing it makes it easier to get access to the bolts below it but it isn’t required. It can be a pain in the ass to get the vacuum pump back into place.

  9. Remove bolts on the left side and in the middle of the front metal coolant pipe and just loosen the two right side bolts below the vacuum pump a little bit. That way the metal pipe can be moved enough to get the thermostat out and it is a lot easier to get the other bolts back in. A flashlight is very handy here to get a good view of the bolts.

  10. I liked to loosen the left side bolts for the front metal coolant pipe and then use the small extending magnet to remove the bolts. Same thing with going back in. Use the magnet to get the bolt in the hole and then get the socket and ratchet in place to turn the bolt in place.

  11. A 1/4" drive air ratchet, 2" long 1/4" drive extension, and a stubby 1/4" drive T30 socket makes it a lot easier to deal with the front metal coolant pipe bolts.

  12. A vacuum filler tool for the coolant system should be required for this repair. Otherwise it takes way too long in my opinion to bleed the system.

#4

Great work guys. That’s a ton of great information. Thanks for putting in the time

#5

Wow excellent addiction.

+karma

#6

Thanks for the add on.
Ironically I have the serpentine belt tool and used it.
I used my magnet on the screws.
I left the belts on too.

So, real accurate add on.
Ed

#7

Anyone mind expanding on how to get coolant back into the system? I am installing a CPS and trying to understand the best way to bleed the air from the system. I have already added a good amount of coolant to the system, but messed up on the supercharger loop. I stripped out the rubber bleed screws (don’t ask lol), so will have a little downtime to plan my approach until I get some replacement screws from the dealership.

I did a decent job getting air out of my alpha reservoir and the heat exchanger.

Is it simple enough to hold a filled funnel into the main reservoir above the bleed screws and wait till coolant flows out of them?

How exactly does the coolant system “burp” air out? Air just comes out into the coolant reservoir on its own? Wish I had the vacuum setup but I don’t. Thanks for any help, any tips are appreciated! You can probably tell I’m not a very experienced at wrenching ;D

#8

The procedure is above. Basically fill reservoir to max, start engine let temp rise, run rpm up to 2000, open bleed screws on supercharger, then go undercover near wipers pull the hose with a little circle and line mark back until the hole drilled in it uncovers. This also must be done at 2000 rpm. When coolant flows out your done.

Stripped bleeders see the $7.00 tool from harbor freight above. Hand impact screwdriver.

#9

Thanks for that, I really appreciate the advice. Cool tip on the impact too, grabbed one from HF.

As a follow up: the tool worked great! Thanks again for the tip.

#10

I just did a local S4 from our club. We got it done from start to finish in 4:50 mins. Followed the procedures above only difference is we loosened the water pump pulley while the belt was still connected as suggested.

#11

Just came across this and it’s a great writeup. If you are looking for an improved Thermostat & Housing I just found the Merc Racing one, pricey but the housing will never fail and less chance of leakage. Over the years Audi did improve the Thermost design so they fail less but the housings do ocassionally leak.