DIY: 2005 XC90 Heater Core Replacement Topic is solved

[cn90]

DIY: 2005 XC90 Heater Core Replacement

- 2005 XC90 2.5T with 109K miles.
- Heater Core did not leak but only put out 145F at center vent (heat max, tach at 2500 rpm cruising speed).
- After replacement, the center vent reads 160F (heat max, tach at 2500 rpm cruising speed), so I am ready for winter.
- Time for new Heater Core. A little research showed that Nissens ($90) may leak at the crimp. A little more research showed that Behr is OEM, bought it for $95. Make sure you get the 2 new Volvo O-rings, the factory O-rings broke apart during removal.

PARTS:
- Behr Heater Core (Made in France)
- Two (2) new Volvo O-rings
- Plastic Bag
- Torx #25 key
- Coolant + Distilled water
- Pair of channel-lock pliers

PROCEDURE:

1. Remove Trim (pull it out toward you) and Under-dash trim (2 T25 screws, on the LEFT side, there is a little tab...pry it out).

2. Place plastic bag to collect coolant, then gently pry the metal clips. The LOWER metal clip will hit the plastic housing, so turn it downward to remove it.

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3. For the UPPER clip, I used this setup: something to act as a cushion so I could pry the clip out:

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4. Disconnect the pipe: pay attention so you don't damage anything. I damaged the arm that controls the driver's side temp control (what a bummer, I will fix this later!). You need to bend the pipes a bit to the FRONT to allow the old heater core to come out.

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5. Remove the single T25 screw holding the HC. Remove the old Heater Core. In the XC90, there is more room, so no need to remove steering column or pull hard like the S80 (which can cause some dent in the heater core, see rpsi video on youtube).

- Pay attention to the factory foam, do the same for the new heater core.

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6. During installation:
- Clean the pipe ends with fine sand paper to remove old O-ring material.
- I used a bit of grease on the new O-rings, install them on the pipe side, not the HC side.
- Install new HC.
- Re-bend the pipes back and insert them in. Gently tap with your hand to be sure it is fully seated.
- The metal clips: if bent, straighten them out before insertion. Re orietation: I switched the LOWER clip around b/c it is easier this way.
- Re-install the single T25 screw holding the HC.

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7. Refill with coolant + distilled water, you will need approx 1/3 gallons or so.
Fill it to about 1" above MAX. Reinstall the cap. Test drive around the neighborhood for leak etc. Carry some distilled water with you in case you need to stop and add coolant (add only to cold engine).


8. Re-install trim pieces.


That is all!

*** I broke the arm controlling the driver's side temp control. I will have to fix this later, what a bummer!!!

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[cn90]

After a little search, I am relieved.
The part I broke is Volvo PN 9171544.

There is a thread on S80 forum talking about this broken part (the driver's side temp control arm):

viewtopic.php?t=77327


This is Volvo PN 9171544 looks like:

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[cuhfs]

Thanks for the post!

[cn90]

Received the Linkage for Temp Control today.
Spent 1h fooling around, only to find out you can do this in 10 minutes!

Here are the tricks:

1. Move the seat all the way rearward.
Remove the two (2) T25 screws holding the small electrical motor.
- Gently pry the plastic arm of the motor.

2. Look carefully at the new part. The two (2) plastic pins can only fit one way into the flap door recess holes.
- Study the plastic pins carefully and the slots the flap door recess holes.
- When in doubt, look at factory setup (photos in my DIY above).
- Now slide the linkage behind the 2 aluminum pipes (that feed the heater core).
- Align the plastic pins so they slide easily into the housing.

3. Now insert the plastic arm of the motor into the housing (only fits one way, check the housing slots to be sure).
- Connect the electric motor arm to the linkage. This is easier said than done!
The TRICK: use a small screwdriver and place it behind the link arm, EXACTLY where it goes into the little
beveled head on the electric motor, then gently pry the screwdriver to snap the linkage arm into the beveled head on the
electric motor. NOTE the shape of the beveled head on the electric motor.

4. Install the electrical motor slowly, there are 5 slots. Rotate the linkage a bit here and there to align the motor.
Once the motor is fully seated, install the two (2) T25 screws gently.

5. Key in Position I, turn on HVAC fan (1-2 speed is fine), turn temp control to COLD (Blue) or HOT (Red), the linkage should move back and forth.
- Once you are happy with the results, tighten the two (2) T25 screws snug.

That is all if you follow these tricks...

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[oragex]

Would be interesting what the issue was. Someone got the grinder and split the core open, only to find some plastic separator inside was in pieces.

[cn90]

I think I found the reason why I broke the Temp Control linkage! My Temp Control knob was in COLD!
When set in COLD, one of the arms in the linkage blocks the HC, so when you pull the HC, you will break one of the linkage arm!
So, turn key to position I, fan at some low speed, turn the driver Temp Control knob to HOT, then remove the key.
You will see the linkage arm moving out of the way.

See the Video below from a 2001 Volvo S60 and you will see why:


[youtube][/youtube]

[cn90]

UPDATE, outside temp today was in 32F.
Normally, it is lukewarm with the OLD heater core.
With this brand-new Heater Core, it is so HOT that I have to turn the fan down to minimum speed and the temp control down to near the BLUE color.

Anyway, if you have heat issue, do 2 things as mentioned:
1. New thermostat (see the DIY I posted).
2. New Behr Heater Core.

You will be happy. It will make windshield cold weather and snow defrost a lot better too.

[cn90]

Update on heater core of 2007 S60 with 115K miles...

- Same Behr heater core as the XC90. Space in the S60 is a bit tighter than XC90, but doable w/o the need
to disconnect the steering column.

- The brake pedal switch, make sure you watch the youtube video by @Peppermint to see how the switch works
and how to remove/install it. The brake pedal switch is tricky bc during installation, you need to wedge the brake pedal down a bit, this will allow easier installation of the switch. Once all done, test the brake pedal lighting system (key must to be in position I or II or so).

- The linkage system: I almost broke it even with caution and even set it to HOT position. So, you may want to loosen
the 2 screws holding the electrical motor a bit (no need to remove these 2 screws), this allows the linkage to move a bit
to avoid breaking it.
---> Test this after all done.

[Capsis]

Hello.mine broke the same way but i have a new part. the problem is the regulator motor where there is a pin where the lever should go but the motor pin is facing down. I'll post a picture. I have turned to warm and cold but the lever does not move enough.

[richhall77]

Quick question: Did you bother draining the coolant from the radiator before you removed the old heater core? Or did you just top up the coolant at the end? Not sure what the best approach is!

Trying to replace the Heater core on my freezing 2008 XC90 very soon!