Appa, yip yip! 2006 Tundra DC 4x4

2006 Double Cab SR5 4X4

• Natural White
• Light Charcoal Fabric
• TRD Off-Road Package (Bilstein 4600 front and rear shocks, 16" 5 spoke allow wheels)
• Limited Slip Differential
• Bed cap with cross bars
• 159,700 miles​

Everything is pretty much OEM/stock specifications as it left from the factory!

Some notable things during previous ownership:

Parts replaced or added that is not OEM:

• Radiator: Koyorad, Part # A2376.
• Helper springs: Hellwig, EZ-990 Helper Spring Kit
• Backup Camera and add-on mirror: unknown model
• #1 and #4 ignition coils were replaced with Denso units (099700-2520, orange sticker). The rest looks to be original Toyota stamped units from the factory.
​

Maintenance (still sifting through records) :

• Water pump replaced @ 45,655 mi (Sep 2010)
• Front/rear differential oil: 61,000 mi (Jul 2012). Not sure if it was done again after that.
• Airbag replaced: @92k mi (Jan 2016)
• Lower ball joint and control arm bushings: replaced with OEM parts at 149k mi
• Coolant replaced @ 109k mi (Oct 2017), @153k mi (Sep 2023)
• Oil was consistently changed nearly every 3k miles, otherwise not more than 5k miles.
​

This Tundra expands the capabilities over the Subaru hatchback that serves as the dependable, snowstorm-ready adventure vehicle, and the Camry when going to the city or when we want an extra-large trunk. Between these two cars and depending on the logistics, we push their limits to configure various racks or cargo boxes to carry gear for skis, snowboards, kayaks, camping, road bikes, roof top tent, people and the doggo.

With the Tundra, we can now easily carry heavier mountain bikes, more road bikes, and larger cargo, while having more cabin comfort for all the passengers. Although, the Subaru with snow tires has gotten through some pretty gnarly conditions, and some mild off-road trails with proper tire placement, the Tundra will be able to handle the deeper, fresh snow and the trails that require high ground clearance.

We will be getting this truck to be dependable through snowstorms, hot deserts, high altitude mountains, and off-roading.

Upgrades/Mods

For now, we are using it as is, and will upgrade, replace, or add things as needed. There are many, many ideas, but we'll take it one at a time. ​

Upcoming Repairs/Maintenance/Upgrades:

• Replace fan fluid coupler with OEM unit (16210-50102). Coolant temperature rises when rev is below 1,500 rpm.
• Grease drivetrain zerk fitting locations with Valvoline Palladium (VV70112). Getting a single clunk sound going to and from a stand-still stop.
• Replace front diff breather with OEM unit (

$7 90930-03136 Toyota Breather Plug - 90930-03136

90930-03136)
• Replace transmission breather with OEM unit (90930-03168)
• Install rear diff breather extension mod
• Replace ignition coils (Denso 673-1303) and spark plugs (Denso 3297

$9 SK20R11 Iridium Spark Plug, Pack of 1

SK20R11)
• Replace transmission fluid, F/R diff fluid
• Replace driver door latch as it doesn't always close properly/smoothly. Might as well replace that motor too (69040-0C020)
• TEQ Offroad's Center Console Dash Modular Accessory Mount?
• Scangauge III with an A-pillar mount. Looking at this in near future to help monitor things. Not sure if there is a better alternative.
​

Things I don't know and things to check out:

• Will the Koyorad radiator perform in sustained uphill mountain roads or 110+ degree ambient temperatures in the desert?
• Why does the coolant in reserve tank not go back into radiator after it cools down? bad cap or radiator-to-reserve hose has a tiny leak?
• Inspect current condition of lower ball joint with my own eyes
• Fluttering/ticking sound on acceleration. It could be just regular noise seeping through, the steering shaft on firewall? Hopefully, not an exhaust header leak.
• Sometimes it takes awhile for heater to work. I have a feeling the previous owner rarely used the heater considering it was in a coastal area.​

 

Pretty cool truck man.

 

Tundra was being tested in 115F+ degree weather. Ended up replacing the fan's fluid coupler after an overheating event. Observed how and when the coolant temps rose. Basically, any combo of the following caused overheating, 1) RPM's <1,500, 2) low speeds, 3) ambient temps above 95 F degrees. Keeping rpms between 1500-2000 at long stoplights, while eyeing the temps, and checking the traffic light, sure kept me alert.


^Blazing hot in the desert!


^Coolant temps normal on highway speeds, until I got to a hill


^Fun mess. Note the radiator cap, which will be under watch while keeping track of coolant temps.


^Quick trip to the dealership to get a new fluid coupler. Top left is a cracked fan from a Land Cruiser being compared with the Tundra's - the Land Cruiser's is much bigger. Left is the new coupler. Right side is the Tundra's fan, which was in good shape, and the old coupler.


^ So shiny!


^Initial testing showed coolant temps were steady at 190F (+/-) degrees. Hooray!

After the install, the air felt being blown was significantly stronger. And the next few days, coolant temps were back to normal.

In the meantime, swapped the K&N air filter with an OEM filter. Changed oil and used OEM oil filter.


^Oil after about 3k mi

Few days later after driving up a mountain, coolant temps did go up and reservoir tank overflowed a tiny bit. Then misfire on #2 happened, which was confirmed after swapping the ignition coil with #4. Bought a Duralast unit as a short term fix to be able to drive home.


^#2's temporary fill-in
Later that week, misfire on #6! Got me thinking that the rest of the original coils may be on their way out too, especially being subjected to 120F weather and constant mountain driving. So, out comes all 8 coils and spark plugs for a closer look.


^ 2-4-6-8 coils. Ignore the photoshop swap. #2 and 6 were the ones involved in the recent misfires. #4 is a newer unit.


^2-4-6-8 spark plugs. #2 and 6 were the ones involved in the recent misfires.


^1-3-5-7 coils. #1 is a newer unit.


^#7-5-3-1 spark plugs


^#2 coil's damaged boot


^#6 spark plug. One of the two dirtiest plugs at the threads/washer.


#8 spark plug. The second of the two dirtiest plugs at the threads/washer.

Observation for the ignition coils:
2 - damaged boot
4 - newer unit, looks good
6 - browned boot
8 - multiple cracks
1 - newer unit, looks good
3 - cracks
5 - cracks, dirty boot
7 - dirty boot

Observations from taking out spark plugs for the first time:
2 - a little too easy to take out
4 - ok taking out
6 - tighter, and threads/washer were dirty with a dark film residue
8 - a little too easy to take out, and was also dirty at the treads/washer with a dark film residue
3 - tighter
5 - ok taking out, dirty at the treads
7 - was tighter, dirty at the treads

Some research about spark plug tightness, especially on high mileage 2UZ's that ran on original plugs, led me to an important post from ih8mud.

https://forum.ih8mud.com/threads/ti...k-tick-spark-plugs-alert-alert-alert.1045750/​

It is a highly recommended read if you ever hear the "tick tick tick/pop pop pop" sounds that could be mistaken as exhaust manifold leak or gasket leak, which is a sound I have been hearing lately. I was originally suspecting a possible exhaust manifold leak or just noisy camshafts, so this is another thing to keep in mind. I'll be checking if the sparkplugs walk out around every oil change.

That's it for now. New coils and spark plugs coming up.


^This new set should last for a good 100k..


^When did these xxxxxx-xxxx stickers start being used? I've seen pictures of Denso coils using a black sticker with xxx-xxxx PN format.

 

Thank you! We love the truck!

 

Before installing the spark plugs, let's take a peek into the combustion chambers! The dot on the piston crown is the front mark. So, in the pictures, the dot at 3 o'clock has the front of the engine towards the right and dot at 9 o'clock has the front of the engine to the left.

Pictures labeled for easy reference.

Cylinder 2:


^#2A


^#2B


^#2C

Cylinder 4:

^#4A


^#4B


^#4C


^#4D


^#4E

cylinder 6:

^#6A


^#6B

cylinder 8:

^#8A


^#8B


^#8C

Cylinder 1:

^#1A


^#1B


^#1C

Cylinder 3:

^#3A


^#3B


^#3C


^#3D

Cylinder 5:

^#5A


^#5B


^#5C

Cylinder 7:

^#7A


^#7B


^#7C


^#7D


^#7E

That's it for the initial inspection of the combustion chambers.