Hey all,

I've had several Toyota trucks over the past 20yrs, and just got an 00 Tundra last week, and have now seen something I have never seen before...

I was rechecking fluids today, and noticed the coolant reservoir was low, so I pop the cap and look. I see "orange sherbet milkshake" in the bottom and think "No way!!... :("
Popped the radiator cap, and yup, same thing.
i had just checked the oil, and its pretty fresh and clean.

So, I'm figuring somehow I'm getting pressurized air into the coolant somehow? I've seen oil shakes in the coolant from blown headgaskets before, but doesnt seem there's any oil in this mess.

Cracked block?

Anyone seen this happen on the 4.7s before?

I've been wanting to test the cylinders and check the plugs, but been busy all week, and wont be able to get to it till next week, as I have my son this weekend. :(

Thanx!

The trans cooler in the lower part of the radiator is leaking and thus the coolant and the trans fluid are mixing. You'd better STOP driving it soon, flush the trans, repair/replace the radiator & then refill with Toyota RED coolant. Your auto trans fluid is also contaminated with coolant, so it will look different than normal on the dip stick.

Hmm.... I thought these had separate tranny coolers? I have a radiator, with another large "radiator" in front of that, which I assumed was the tranny cooler, AND a smaller cooller in front of that, for the A/C... ???? (I've ALWAYS had manual trannies till now....)

AND, its a new radiator...... :(

The tranny fluid looked fresh and normal when I looked at that too, though it did have a bit of a pungent smell.

Not saying your wrong, or disagreeing with you, just giving more info, and I know just because the tranny fluid/oil look good now, doesnt mean the PO didnt do fresh fills to dump the truck on some unsuspecting fool...(Which I'm beginning to suspect was me... :( lol )

I guess I better follow all the tranny coolant lines, and see whats hooked up where, and why I have 3 coolers if the tranny one is integrated in the radiator, which I know Toyota sometimes does.

Well, I'm kinda hopin if anything goes, I'd rather replace the tranny with a 5 speed than have to replace a motor... :D Just wish I hadnt gotten rid of my spare R151 turbo tranny with my old PU.

No matter what, if you have an auto trans then you have a built-in trans cooler in the lower part of your radiatior. If you have a small black radiatior-type thing in front of the radiatior then that's an external trans cooler (usually included with a towing package). You may or may not have an A/C condenser coil (usually aluminum color) directly in front of the engine radiator but only if your truck has A/C of course.

From what you described, you have an external (small) trans cooler up front, then an A/C condenser coil, then the engine radiator (with a built-in trans cooler in the bottom. If you drop the skid plate you'll see two rubber hoses connecting into the bottom of the radiator, one is coming directly from the trans, and the other is going to that small external cooler in front, and then from that trans cooler back to the trans.

Yup.....I just looked at the FSM, and even though I thought the large "radiator" was for the tranny, thats actually the A/C condenser (Dang, that thing is HUGE!) lol,
and it seems I have the air cooled tranny cooler thats supposed to be part of the towing package....

Which means, yes, I need to see exactly what the tranny lines are hooked to.

Also, is the air cooled cooler usually in ADDITION to cooling supplied through the radiator, or is it the ONLY cooler for the tranny, used IN PLACE of the one in the radiator?

Thanx, marvbest!

Unless the previous owner (or some repair shop) has bypassed the trans cooler in the bottom of the radiator, your trans fluid is routed first to the cooler in the radiator, then to the external cooler (small black one in front of A/C condenser coil), then back to the trans.

OK, thanx. Yup...I just went out and looked, it IS hooked up as an extra cooler. Dang it!...Its definately a new radiator. Now I have to look and make sure I have the receipt for it from the PO, and hopefully (like he said it was), its got a lifetime warranty on it. If its not the radiator, is it possible the tranny could be cracked somewhere internally?.....Is that a somewhat common occurance with these trannies? I assume I have the a340F vs the a340E, since I have the 2UZ and not the 5VZ?

With the V8 you have the 340F trans, and it's not a problem with the trans as the engine coolant doesn't go thru the trans, just the trans fluid goes thru the radiator. If you have a new radiator then it's surely defective if it's allowing the coolant and the trans fluid to mix internally.

There is one other SLIGHT possibility. That is IF there was a previous internal leak in the radiator, which contaminated the coolant with trans fluid, then the radiator was in fact changed, BUT the engine block wasn't flushed, then after a filling the new radiator with new coolant it mixed with the contaminated coolant remaining in the block, thus the strawberry milkshake in the radiator now. Just stating that could be what happened, since you think you have a new radiator.

Stone-Blue - You'll get lots more responses if you post in the 1-Gen Tundra forum instead of here in the engine & drivetrain sub-forum. Your problem definately deserves more eyes & opinions so I'd say you need to get into the mainstream forums instead of the back-woods as you are now.

Hmmm...Good thinking....I'll have to flush it Monday, and see what happens after. I still have to have it inspected, and have the A/C pressure tested, as well as the cylinders. Maybe I'll have them pressure check the coolant after I flush it. If I do I guess I'll tell them to unhook the tranny lines at the radiator, so it doesnt force anything back into the tranny, and I assume it would be easier to see if there is pressure escaping out of the cooler nipples.

Thanx marvbest....This may not be as bad as I feared. ;) A bad radiator I can handle...$$$

Stone-Blue - You'll get lots more responses if you post in the 1-Gen Tundra forum instead of here in the engine & drivetrain sub-forum. Your problem definately deserves more eyes & opinions so I'd say you need to get into the mainstream forums instead of the back-woods as you are now.

OK...Thanx.... I used ta be a regular on TacomaTerritory, iH8mud & a few other forums.......Getting used to how this one is set up. ;)

Good Luck & and I hope you can resolve the problem without big bucks and become a happy Tundra owner as I am.

Just to clarify a point in this thread... the Aisin-Warner A340E transmission is the 4-speed, 2 wheel-drive. The Aisin-Warner A340F is the 4-speed, 4 wheel-drive. Both are mounted to the 2UZ-FE engine in the Toyota Tundra.

It also might help the OP if reference to the ATF lines through the radiator's lower unit be called the ATF "warmer" rather than a "cooler" as it is used to take advantage of the rapidly-heating coolant to bring the ATF up to operating temp quickly.

I agree with you PARTIALLY about the coolant within the radiator warming up the trans fluid. That is only from engine start until the trans temp equals the coolant temp, mere minutes at most. At the point the trans fluid begins to heat beyond the 185 or whatever thermostat is installed, then the coolant LOWERS the trans fluid temperature. So, the lower portion of the radiator acts as both a warmer & cooler of trans fluid, just at different points in the heat cycle.

I ran Ford diesels for years, well decades really, and a problem with the 6.0 liter diesel was the oil coolers plugging. They could overheat and rupture sending oil into the cooling system creating a chocolate milkshake in your engine.

What was done to flush them, and recommended even by Ford, was to flush them with a simple green solution. don't remember the ratio used, but it certainly worked to get the oil out of the block and hoses. Water alone won't cut it, and you may be experiencing the results of a poor flush.

Thanx UPbuilder!!...I was just about to come back here and ask what would be best to use for a flush. ;)

Well, I wasnt able to flush it yet, but I DID pull the reservoir, which was "dry", except for about 2 inches of thick goo, and get most of it out. Filled it with hot water and dumped it 1st, and that sure wasnt cutting it, then added about 1/8 cup of dish soap, and 3/4 full of water and shook the heck out of it....Took a couple times to get clean water and no soap suds. Got all but a thin coating out of it. Also pulled the radiator cap, and used paper towels to wipe the the stuff off the coolant, the inside of the neck, and cap. There was only a thin layer on top of the coolant in the radiator.
Took the truck out for about 5 miles of 20-30MPH on a nearby seasonal road. Should be cooled off enough now to go pull the cap again and see what it looks like in there. The reservoir had some small amount of "shake" mixed in with it, but not foaming, or as thick as it was.

So yeah, I'm hoping a couple flushes will take care of it. I just hope the tranny didnt get coolant in it. It seems to be shifting OK, and the fluid is a clear red, like recent stuff.

I see there are two coolant drains on the block. Hard to tell from the diagram in the FSM....Is one in the upper valley, under the intake, or is each one on either side of the block? Also, are they drain cocks I can loosen and hook hoses to, or are they actual plugs that need to come OUT? Just wondering what kind of mess I'll have to make if I use them.

They are banjo type fittings on each side of the block. Put a hose on it and loosen the drain bolt. Sorry to hear about this. Please post back and let us know what you find out.

Thanx Tones!

So I removed the reservoir again today. After using dish soap & water to flush out most of the shake yesterday, there wasn't much more in the reservoir today, except the thick film around the sides, and a little suspended in the coolant, after another 10 mile jaunt.

Took some straight Simple Green and put some in and shook the heck out of it. It loosened up a little off the inside of the reservoir, but wasnt gonna cut it without being able to get in there with some elbow grease. Took a can of Engine Bright spray, and sprayed a couple cups worth in it, and shook it again for several minutes. That seemed to do the job. Did it a couple more times, with a rinse in between, and got the inside and outside of the reservoir completely clean, like new.

Guess I shoulda been taking pictures all through this....lol

Sooo...I need to get my hands on some Gunk Degreaser, and run that through the system after I drain whats in there now. Bought 6 gallons of cheap Super-Tech at Wally world today ($55 :rolleyes:), so I can fill it after the flush, run it about a week, drain and fill again, run THAT for a week or so (till I'm satisfied ALL the ATF is out of the system, then I'll drain and go back to Toyota Red.

Like marvbest suggested earlier, I think I got lucky, and it was just a problem with the ATF lines internal to the old radiator, which has been replaced. I'll be keeping an eye on the tranny and ATF too. I'm at 134K, and not sure if the water pump/timing belt were ever done, so I'll be replacing those soon too. If I can get the parts soon enough, I might do that just after the 2nd flush with the Super-Tech. I bought one of those Prestone kits that you put the "T" with a cap into the top heater line, then I could have the radiator drain, both drains on the block, the top "T", AND the water pump outlets all open at the same time for the flush.
I will probably pull the radiator and all hoses and flush & clean those all separately, too. NOT looking forward to pulling the heater core, but will if I have to. Also debating on pulling both hoses off the separate tranny cooler, and checking the ATF that comes out of it, and possibly flushing that also, if there's signs of "orange shake" in it.

Since I JUST got this truck, I'll probably pull the tranny pan to see what that looks like. I'll clean it and replace the filter, and drain and refill the ATF if necessary.
And yes, I've read the threads on recommending NOT to do that with high mileage neglected trannies.

Thanx everybody. I'll post updates in the next couple days after the 1st flush and refill.
Hopefully this will help someone get their system cleaned up if this ever happens to them. That ATF is quite thicker then just regular oil when mixed with water. I'm guessing the ATF suspends water and air in it, WAY more than oil does, and seems to be MUCH messier and stickier.