1. Welcome to Tacoma World!

    You are currently viewing as a guest! To get full-access, you need to register for a FREE account.

    As a registered member, you’ll be able to:
    • Participate in all Tacoma discussion topics
    • Communicate privately with other Tacoma owners from around the world
    • Post your own photos in our Members Gallery
    • Access all special features of the site

What is this tan coating in my radiator and hoses? (pics)

Discussion in '1st Gen. Tacomas (1995-2004)' started by mtucker, Oct 16, 2020.

  1. Oct 16, 2020 at 1:31 AM
    #1
    mtucker

    mtucker [OP] Tacoma addict

    Joined:
    Aug 3, 2009
    Member:
    #20610
    Messages:
    355
    Gender:
    Male
    First Name:
    Matt
    Escondido, CA.
    Vehicle:
    03 Prerunner DC
    Replaced chrome badges with Sockmonkey black badges, painted billet grill black, K&N cold air intake, my corner light turn signal circuit, Speedfreek traction bars, RAAMaudio BXT/Ensolite, Stereo: Kenwood KIV-701 USB/Bluetooth deck, 10" Pioneer shallow sub behind the rear seat, Infinity 6822cf 6x8 front and rear doors, Fosgate P400-2 (sub), US Acoustics USX-4065 (four main speakers)
    Noticed my temperature gauge near the red (normally sits about 50-60%). Looked in my radiator and saw this. Tan coating covering everything with some lighter color stuff plugging up many of the tubes that carry the water down the radiator.
    Looking through the radiator cap hole (flashlight partially blocking view).
    radiator_cap_opening.jpg

    The coolant outlet from the engine has the same tan coating. The coating adheres to the metal pretty well. If you scrape some off, it comes off in chips and is a thin but hard material.
    engine_outlet.jpg

    The bottom hose of the radiator and the radiator bottom outlet look very clean... no tan crud.

    Here is where it gets weird. The upper radiator hose that is between these two places with the tan crud has a coating of red rust color stuff and it is very sandy/gritty feeling.

    upper_hose.jpg

    The water/coolant was very tan/yellow too. I drained the coolant, filled with distilled water (almost 2 gallons), and drove a bit to circulate. I repeated that again. Water was a lot better (more clear with a tan tint). I replaced the radiator this evening and will use another vehicle to get new hoses tomorrow.

    The history on it is a Toyota dealer replaced the timing belt and water pump at about 180k miles. A month later my original radiator developed a leak so I replaced it with Spectrum Premium radiator. Since the coolant was new (they used Toytoa red), I drained it into a clean bucket and reused it. I only had to add a little water to bring it to full (I assume I used distilled). I used new OEM upper and lower radiator hoses.
    It ran fine for three years (about 215k miles now) and this is what is going on now.
    The motor oil is at the right level and looks perfect.
    The transmission fluid is a little high, but looks fine (T-IV pink/red with a little darkness). No milkiness or strawberry milkshake anywhere.

    Anyone have an idea of what the tan coating is from?
    Thanks,
    Matt
     
    Taco critter likes this.
  2. Oct 16, 2020 at 2:21 AM
    #2
    Wyoming09

    Wyoming09 Well-Known Member

    Joined:
    Apr 24, 2015
    Member:
    #153833
    Messages:
    13,923
    Gender:
    Male
    New Tripoli Pa
    Vehicle:
    2000 Work truck 5 speed 4x4 3.4
    Super Springs
    My first guess is maybe something was in your replacement radiator that reacted with the coolant but the fact it worked fine for 3 years would almost have to rule that out

    Trans fluid is good not losing engine oil .

    It does not take much oil to make a big milkshake type mess when mixed with coolant.

    I am guessing no one worked on your truck that might have added any sort of stop leak product .

    Any one jealous or mad that might have done something ??

    First time any type of over heating issue since the radiator was replaced ??

    What ever happened it happened now.

    Best of luck.
     
    Taco critter likes this.
  3. Oct 16, 2020 at 3:11 AM
    #3
    Taco critter

    Taco critter #mall crawler , patw and ,ttc#0247

    Joined:
    Nov 10, 2018
    Member:
    #272225
    Messages:
    70,640
    Gender:
    Male
    First Name:
    John
    Pottstown /stowe , pa
    Vehicle:
    02 tacoma 4x4 full mall crawler,
    Ome 3inch ,rims ,cold air intake ,,4 crawler body lift ,cb in ashtray mod,leds, jet maf,Satoshi grille,led roof bar,yakama roof basket ,smittybilt parts,spare tire mount in hitch ,rago fabrication parts, winch bumper ,winch ,285s on wagon wheels ,traction boards ,hi lift jack,wet oaklies,smittybilt ,bamf bedrack,loads more,TOO MUCH SHIT TO LIST
    Agree with Wyoming09, its either stop leak or some kinda of reaction
     
  4. Oct 16, 2020 at 4:21 AM
    #4
    ROAD DOG

    ROAD DOG Well-Known Member

    Joined:
    Nov 4, 2019
    Member:
    #309830
    Messages:
    1,328
    Gender:
    Male
    Vehicle:
    2019 I4 WHITE SR PRERUNNER
    FEW


    pull the spark plugs.......keep them in order

    have a close look at em

    if U cant account that any1 else has been fiddling/working on Ur engine

    i suspect water is mixing with oil likely under intake
     
    mtucker [OP] likes this.
  5. Oct 16, 2020 at 8:53 AM
    #5
    Ritchie

    Ritchie Well-Known Member

    Joined:
    Dec 24, 2012
    Member:
    #93649
    Messages:
    1,817
    Gender:
    Male
    San Diego (North County)
    Vehicle:
    RC Step side Pre-runner
    2.7 w/auto, 4WU 3 link, F & R Diamonds, ARB's F/R w/ Yukon 5.29's, Inchworm 4.7 Lefty, Deavers, ARB OBA, Schrockworks up front.
    Appears to be the outcome of a blown head gasket... assuming a head and or block are not cracked.
     
  6. Oct 16, 2020 at 9:34 AM
    #6
    mtucker

    mtucker [OP] Tacoma addict

    Joined:
    Aug 3, 2009
    Member:
    #20610
    Messages:
    355
    Gender:
    Male
    First Name:
    Matt
    Escondido, CA.
    Vehicle:
    03 Prerunner DC
    Replaced chrome badges with Sockmonkey black badges, painted billet grill black, K&N cold air intake, my corner light turn signal circuit, Speedfreek traction bars, RAAMaudio BXT/Ensolite, Stereo: Kenwood KIV-701 USB/Bluetooth deck, 10" Pioneer shallow sub behind the rear seat, Infinity 6822cf 6x8 front and rear doors, Fosgate P400-2 (sub), US Acoustics USX-4065 (four main speakers)
    Thanks everyone for the replies. I haven't used stop leak in a few decades, but yes it does kind of look like stop leak. Other than the water pump/timing belt and Valvoline drive through oil changes (where I can see what is going on), I do all the maintenance and repairs (which fortunately has only been things like shocks, O2 or MAF sensors, yearly drain and fill of transmission fluid). She sits tucked into the garage every night. I have never come out to find the hood open. This is the first time it over heated. I smelled the coolant when the original radiator developed a small crack so it never over heated before up until now.

    I guess some kind of reaction is possible with the radiator and the coolant from the Toyota dealer. Head gasket seems like a possibility. I will monitor the fluid every few days to see if it starts changing colors. Does a head gasket leak with either oil or exhaust gasses getting into the coolant normally make for milky streaky coolant? The fluid was a uniform tan and not milky at all. It is almost time to replace the plugs so I will look for weirdness on any of them when I replace them.

    Would the best way to determine if I have a head gasket leak (while the engine is together) be a tester like this? https://www.amazon.com/Block-Tester...ds=head+gasket+test+kit&qid=1602866363&sr=8-2
     
    Last edited: Oct 16, 2020
  7. Oct 16, 2020 at 9:50 AM
    #7
    ROAD DOG

    ROAD DOG Well-Known Member

    Joined:
    Nov 4, 2019
    Member:
    #309830
    Messages:
    1,328
    Gender:
    Male
    Vehicle:
    2019 I4 WHITE SR PRERUNNER
    FEW

    best way is to compression test

    then likely a ‘ leak down ‘ test

    i sure U take very good care of Ur vehicle.......not the issue

    Ur trouble doesnt come from neglect or abuse

    pull thw plugs 1st..................keep them in order NOT a jumble

    the suspect cylinder might be obvious

    otherwise the prev mentioned tests usually reveal
     
    mtucker [OP] likes this.
  8. Oct 16, 2020 at 11:13 AM
    #8
    Wyoming09

    Wyoming09 Well-Known Member

    Joined:
    Apr 24, 2015
    Member:
    #153833
    Messages:
    13,923
    Gender:
    Male
    New Tripoli Pa
    Vehicle:
    2000 Work truck 5 speed 4x4 3.4
    Super Springs
    Looking forward to how this plays out.

    Head gaskets can fail in several ways .

    Coolant into a cylinder

    cylinder to cylinder .

    oil into coolant because oil pressure is higher.

    It really does not look like oil then I never saw Synthetic oil mixed with coolant .

    Do you use Synthetic Oil or regular ??

    It would not take much oil 1/2 a quart.
     
    mtucker [OP] likes this.
  9. Oct 16, 2020 at 11:22 AM
    #9
    MARSHBUSTER

    MARSHBUSTER Well-Known Member

    Joined:
    Sep 24, 2011
    Member:
    #64054
    Messages:
    916
    Gender:
    Male
    First Name:
    Jim
    Alamogordo NM
    Vehicle:
    2005 SR5 4X4 Tacoma TRD
    Grill Gaurd/ Winch Bumper, Mile Marker 9000 LBS Winch, Custom Head Ache Rack, Custom Rear Bumper, Marathon Camo Max 4 Seat Covers
    Easy way to tell if it’s a head gasket is take off the radiator cap. Start the truck. Watch for small bubbles. If you see bubbles. The bubbles are exhaust gases coming out through the radiator.
     
    JudoJohn likes this.
  10. Oct 16, 2020 at 12:14 PM
    #10
    mtucker

    mtucker [OP] Tacoma addict

    Joined:
    Aug 3, 2009
    Member:
    #20610
    Messages:
    355
    Gender:
    Male
    First Name:
    Matt
    Escondido, CA.
    Vehicle:
    03 Prerunner DC
    Replaced chrome badges with Sockmonkey black badges, painted billet grill black, K&N cold air intake, my corner light turn signal circuit, Speedfreek traction bars, RAAMaudio BXT/Ensolite, Stereo: Kenwood KIV-701 USB/Bluetooth deck, 10" Pioneer shallow sub behind the rear seat, Infinity 6822cf 6x8 front and rear doors, Fosgate P400-2 (sub), US Acoustics USX-4065 (four main speakers)
    I will update when I have more info. I assume the radiator will take care of my overheating issue based on how plugged up the radiator was. I'll probably drive it for a few days to see if the fresh water/coolant changes and if so how quickly. I am mostly working from home these days so it may take awhile before I get any miles on her.
    I use conventional oil. Never used synthetic.
    Thanks ROAD DOG for the suggestion of pressure test and leak down. That sounds like the way to know for sure if it is gasket/block.

    When I did the two drain and fills with distilled water, I would keep the radiator cap off until I could see fluid movement. I never saw any air bubbles come up. I used the Torque app to monitor the coolant temperature and as expected right about 180F I would see the water start flowing.
     
    Wyoming09 likes this.
  11. Oct 16, 2020 at 5:02 PM
    #11
    MARSHBUSTER

    MARSHBUSTER Well-Known Member

    Joined:
    Sep 24, 2011
    Member:
    #64054
    Messages:
    916
    Gender:
    Male
    First Name:
    Jim
    Alamogordo NM
    Vehicle:
    2005 SR5 4X4 Tacoma TRD
    Grill Gaurd/ Winch Bumper, Mile Marker 9000 LBS Winch, Custom Head Ache Rack, Custom Rear Bumper, Marathon Camo Max 4 Seat Covers
    When my head gasket went in my 2005 before we did the Block Tester we did the Air Bubble test. We saw the Air Bubbles almost right after starting the truck. Just to be sure we did the Block Tester and both tests showed I had a Head Gasket issue.
     
    mtucker [OP] likes this.
  12. Oct 16, 2020 at 9:25 PM
    #12
    MARSHBUSTER

    MARSHBUSTER Well-Known Member

    Joined:
    Sep 24, 2011
    Member:
    #64054
    Messages:
    916
    Gender:
    Male
    First Name:
    Jim
    Alamogordo NM
    Vehicle:
    2005 SR5 4X4 Tacoma TRD
    Grill Gaurd/ Winch Bumper, Mile Marker 9000 LBS Winch, Custom Head Ache Rack, Custom Rear Bumper, Marathon Camo Max 4 Seat Covers
    Did you ever see and white crusty material around the cap of your overflow bottle? Or did you ever hear boiling in your overflow bottle when you shut the truck off?
     
  13. Oct 17, 2020 at 3:10 PM
    #13
    mtucker

    mtucker [OP] Tacoma addict

    Joined:
    Aug 3, 2009
    Member:
    #20610
    Messages:
    355
    Gender:
    Male
    First Name:
    Matt
    Escondido, CA.
    Vehicle:
    03 Prerunner DC
    Replaced chrome badges with Sockmonkey black badges, painted billet grill black, K&N cold air intake, my corner light turn signal circuit, Speedfreek traction bars, RAAMaudio BXT/Ensolite, Stereo: Kenwood KIV-701 USB/Bluetooth deck, 10" Pioneer shallow sub behind the rear seat, Infinity 6822cf 6x8 front and rear doors, Fosgate P400-2 (sub), US Acoustics USX-4065 (four main speakers)
    The tan stuff that is suspended in the water turns a bit white when it dries on a surface, but there was no sign of white crust on the radiator or overflow when I first looked at it. I have not seen any bubbles or heard any bubbling (before or after the thermostat opens). If there is a head gasket problem, it doesn't appear to be from the exhaust to the coolant.

    The new radiator and hoses are in and the temperature looks good. It is now 192-195F even with the AC on during a 90+F degree day. I've done two fill and drains with the new radiator in, but the water turns tan again after I drive it for 10 minutes. It doesn't seem to be getting better with each drain and fill which makes me think something is consistently adding the tan stuff to the water.
    I am going to have a family acquaintance who is an experienced mechanic look at it. If there is a head gasket problem, that is more than I want to take on so I would have them repair it or at least diagnose so I can decide if the cost is worth it. She is in good shape still so I would drop some coin to get her fixed.
     
  14. Oct 17, 2020 at 5:55 PM
    #14
    ROAD DOG

    ROAD DOG Well-Known Member

    Joined:
    Nov 4, 2019
    Member:
    #309830
    Messages:
    1,328
    Gender:
    Male
    Vehicle:
    2019 I4 WHITE SR PRERUNNER
    FEW


    oil + coolant + = milkshake

    where the 2 are mixing remains to be seen

    this time o year keep water drain going ............ No chance o freeze up loosong the block or head

    the temp changes from driving

    something expands allowing a crack/hole ( device ) to release fluid allowing both to mix

    resulting in the milkshake
     
  15. Oct 17, 2020 at 9:27 PM
    #15
    MARSHBUSTER

    MARSHBUSTER Well-Known Member

    Joined:
    Sep 24, 2011
    Member:
    #64054
    Messages:
    916
    Gender:
    Male
    First Name:
    Jim
    Alamogordo NM
    Vehicle:
    2005 SR5 4X4 Tacoma TRD
    Grill Gaurd/ Winch Bumper, Mile Marker 9000 LBS Winch, Custom Head Ache Rack, Custom Rear Bumper, Marathon Camo Max 4 Seat Covers
    How many miles are on the motor?
     
  16. Oct 17, 2020 at 9:41 PM
    #16
    Sicyota04

    Sicyota04 Slowly but surely.

    Joined:
    Jan 9, 2015
    Member:
    #145940
    Messages:
    3,116
    Gender:
    Male
    First Name:
    Morgan
    California
    Vehicle:
    04 DC 4x4
    It says 215k miles in the first post
     
  17. Oct 17, 2020 at 9:48 PM
    #17
    cruxofthebisquit

    cruxofthebisquit Well-Known Member

    Joined:
    Jun 26, 2009
    Member:
    #18936
    Messages:
    4,787
    Gender:
    Male
    First Name:
    John
    Orange Texas
    Vehicle:
    2000 TRD
    OME and worth every penny.
    Last summer (2019) some kids working for us checked the coolant in my Sienna and forgot to put the cap back on.

    It of course blew out all the coolant but strangely, the gauge never showed hot. It started clattering and when I turned on the heater to feel how hot it was blowing, was just cool air. Hmmm, pulled over and it was horrible sounding. Nothing but brown mud in radiator and looked like lime dust under hood. (our similarity)

    I actually put it in shop and told them to test every which way they could and get ready to just replace engine. Flushed/Refilled it and everything checked out. Blew me away that it wasn't a major meltdown.

    It's likely it's hurt but you may luck out.

    edit: Oh yeah. Most important. The brown stuff. It was oil. Intake had warped some and was allowing a but past. It also had knocked and rattled so hard it broke the knock sensors. Found a water leak there afterward while changing those. (cap was still cause though) I just had forgot after expecting the worst.
     
    Last edited: Oct 18, 2020
  18. Oct 18, 2020 at 2:04 AM
    #18
    Wyoming09

    Wyoming09 Well-Known Member

    Joined:
    Apr 24, 2015
    Member:
    #153833
    Messages:
    13,923
    Gender:
    Male
    New Tripoli Pa
    Vehicle:
    2000 Work truck 5 speed 4x4 3.4
    Super Springs
    It can very well be only a small amount of oil getting in the coolant. So Your not really seeing a major oil loss yet

    If this is the 3.4 and has a oil cooler I would look very close at the cooler.

    The more oil getting in the coolant the thicker it gets

    I had a major failure of a oil cooler I can only say about as thick as peanut butter but more grit and grainy appearance.
     
    cruxofthebisquit likes this.
  19. Oct 18, 2020 at 9:20 AM
    #19
    mtucker

    mtucker [OP] Tacoma addict

    Joined:
    Aug 3, 2009
    Member:
    #20610
    Messages:
    355
    Gender:
    Male
    First Name:
    Matt
    Escondido, CA.
    Vehicle:
    03 Prerunner DC
    Replaced chrome badges with Sockmonkey black badges, painted billet grill black, K&N cold air intake, my corner light turn signal circuit, Speedfreek traction bars, RAAMaudio BXT/Ensolite, Stereo: Kenwood KIV-701 USB/Bluetooth deck, 10" Pioneer shallow sub behind the rear seat, Infinity 6822cf 6x8 front and rear doors, Fosgate P400-2 (sub), US Acoustics USX-4065 (four main speakers)
    Can you tell me more about the oil cooler? Yes, it is the 3.4L. I did some searching and saw references to an oil cooler near the oil filter. I looked around and see a hose coming off the engine about where the thermostat is and it runs back to what looks like a cylinder that sticks sideways out of the engine. I was looking for a radiator type device, but didn't find one.
    OK, found a good diagram posted by someone on TW. Yes, I have an oil cooler. One more place for oil and water to mix. I let the drained water settle overnight and it does look like oil.
    That is an expensive part, $500 to $800 depending on the place selling it.
    https://parts.toyota.com/p/Toyota_2...AT/Engine-Oil-Cooler/62995838/1571062050.html
    If this is the place of mixing, could it just be a gasket or o-ring? It sounds like there is a coil in there that the water circulates through to cool the oil.
    [​IMG]



    Thanks,
    Matt
     
    Last edited: Oct 18, 2020
    Black DOG Lila likes this.
  20. Oct 18, 2020 at 10:43 AM
    #20
    Wyoming09

    Wyoming09 Well-Known Member

    Joined:
    Apr 24, 2015
    Member:
    #153833
    Messages:
    13,923
    Gender:
    Male
    New Tripoli Pa
    Vehicle:
    2000 Work truck 5 speed 4x4 3.4
    Super Springs
    gasket or oring In that case your more likely to have an external leak

    It can also be a cracked head from an oil passage to coolant passage

    Just an idea something to think about.

    Cooling system pressure test .
     

Products Discussed in

To Top