Coolant Leak Trivia Time (1 Viewer)

[AimCOtaco]

Hey folks, I know the 2UZ motor pretty well, did a timing job a couple of years and ~30k mi ago. Today I noticed a little driveway spot an a quick inspection and taste test confirmed a coolant leak. So the trivia question of the day is:

"What looks like a blown water pump and soaks coolant down the front of the 2UZ but in fact is NOT a water pump failure?"



I don't actually know the answer, I just hope you guys find one that doesn't require yanking out my fairly young Aisin water pump at this point in time.

 

[Trunk Monkey]

Gaskets on water pump or t-stat. Radiator leaks, hose leaks . . Get in there and see how high up the motor it goes and see if you can see any pink crusties where it may be originating and drying.

 

[DirtDawg]

Coolant crossover pipe is another possibility.

 

[abuck99]

Pressure test at radiator and look for the system leak. Is the weep hole under the harmonic balancer wet?

 

[Jeepster09]

Perhaps you have a local auto parts store close by that loans tools...borrow a coolant pressure tester and when engine cold put pressure on radiator and look for leaks using a flash light etc. Hose clamps, gaskets, hoses etc.

 

[Odyseuss]

oil cooler hose? this is fun but you gotta tell us what you find.

 

[AimCOtaco]

Good tips in here so far, I like the idea of pressurizing a cold system, that would allow a good test with the serpentine belt and timing covers out of the way at least.

I do see it wet at the harmonic balancer seep hole but can't tell if its really inside the housing or just all over the outside, current bet it it's wet in there.

Radiator, cap, and several hoses are young, a few hoses are older than I should allow on her, hope it's a minor hose or tubing leak.

I noticed this while home from the office mid day so now I'm headed in for a closer look...

Thanks all, I won't leave ya hangin'.

 

[AimCOtaco]

OK, picked up the rental pressure test kit and put about 8-10 psi into it, nothing gushingly obvious at that yet.

Under the oil cap looks great, smells like internal combustion fire, no gunky residue, evidence of moisture, etc.
Oil on the dipstick looks great, all good news in the oil sump.

The V galley down the middle is dry for sure.

There is plenty of coolant in the radiator, very full, actually had to pull a little down to make room for the tester.
Coolant looks just like it did when filled with Toyota Red.

I did a complete 90k service at 189,000mi in 2/2012 (all OEM, with the works; water pump/T-stat, idlers, tensioner, etc, etc)
I replaced the radiator/cap/coolant (blew out rad top crimp) at 216,000 9/2015
...we saw some high temps (that day on the pass, with the family, on a camping trip, on saturday afternoon) when she blew...

Today we're at about 230,000mi.

Here are a couple of pics that are not so dry:
View from above, red line visible around serp tensioner

View from below, looks to be wet inside and out

 

[AimCOtaco]

This sure looks like the place...
Note the water on the timing belt, on the pump face, pulley, etc.
Also though notice the red stain on the outside of the belt shroud above the pump? I'm thinking that may have been slung onto the covers and seeped out?

Definitely looking like a pump at this point, the two upper joints (extension and weird o-ring fitting) are bone dry as far as I can tell.

 

[benjrblant]

Taste test? You cray.

 

[AimCOtaco]

Taste test? You cray.

Ah, somebody caught that. Crazy? Probably
It was like red oily stuff in the wind so I wasn't sure if it was ATF or coolant from looking and smelling so next and nearest tool got used for the job.

Really though it takes almost 0 volume and I'll ingest and absorb more than that much just fixing the damn thing now anyway.

 

[abuck99]

Looks like it's leaking external and seeping onto the TB.

What ever that string/cord is hanging down, I'd look there.

 

[AimCOtaco]

Looks like it's leaking external and seeping onto the TB.

It's still really hard to tell, I'm hoping if that's the case the pressure tester will re-wet that area overnight, it's currently dry on top there. I'll know it's not being slung up there if it gets wet without starting the motor anyway.


The truck sat over the weekend and was last driven Thursday or Friday.

 

[bluecruiser]

If @AimCOtaco is stumped. I'm totally useless here. Got to find this before Moab!!!

 

[AimCOtaco]

Thanks man, I will fix it!

 

[Cannon88]

@AimCOtaco any update/problem solved?

 

[bucfl]

I have a similar issue in that area. Mike is completely dark and dirty wet. The AC was not cooling and noticed coolant low. I replaced everything when I did TB job. Looks like you and I have same problem.

How do you warranty a water pump? I purchased from @cDan. Is it a one year warranty?

 

[2001LC]

Andy hopefully it was not your WP.

What I'd do is; remove the Drive belt, tensioner pulley/bearing & idler pulley bearing to protect then. Then pressure wash every bit of coolant including weep hole area. Then watch very closely, every day, for leak point.

I've seen a few leaks at water inlet where FIPG is used to seal, they'll leak at that seal point. One cause but not only is many have used the $12 Toyota black 102 FIPG. It actually calls for the $80 1282B FIPG, which must set up before adding coolant. The 102 breaks down overtime and leaks. I've seen a few that used FIPG on large O-ring also, very bad practice, but some are leaking so I guess they used the FIPG there.

Also electrolysis is causing leaks in area as well, like the water by-pass to head gaskets. But your leak looks forward of this area. Also the small o-ring on back of water pump, which is about right for the frontal leak.

Water pump usually leaks from back side and runs down to weep hole. Some may get on belt but I wouldn't expect to see this most times above belt in these cases.

Or sometime electrolysis eat WP gasket but again usually seen from below only.

 

[AimCOtaco]

@Cannon88

So the way I recall this going was after looking at everything I could see I rented a pressure tester and put pressure to it for 2 days while I ordered and waited for a TB parts set.

At the end of two days I had not been able to force the leak to re-occur with the pressure tester and had a full set of parts on hand by then so I dug in and there was only very minor evidence of seepage at the water pump weep hole and more of the evidence was found externally (much easier to see after complete tear down).

I can't be sure the water pump wasn't seeping but I really think the majority was at the upper fitting where the 2 component FIPG goes as @abuck99 suggested at the time and @2001LC outlines above. I used the expensive permatex FIPG kit both times now..

Because I could see some seepage in both places and because the belt was already contaminated and my last timing job had around 40k mile on it I forged ahead and just did it all again.

That reminds me, I should put an old timing belt in a jug of old Toyota red and see how much it swells and attacks the rubber. Part of me belives that I could have just rinsed out the timing covers and re-sealed the top fitting and left it alone... but I try to wrench for the ultimate in reliability on this truck because of it's use (or that's what I tell myself when re-doing a 40k old timing job at least).

Have since been to Cruise Moab, on a Wheeling Weekend with Bill Burke, to HIH7, and some local trips with the club and not a drip of coolant.

 

[abuck99]

@AimCOtaco

What is the specific Permatex FPIG you used- Ultra Black?

I shudder at the thought of $80 for a tube of Toyota 1282B FPIG for one job done every 100k miles (that will surely be dry next time I go to use it) , but with SLL coolant I think the Toyota 1282B is the best and only option. Ive tried cross referencing ThreeBond fpig, but there is no equivelant.