Leaking coolant

It finally happened - I noticed fluids on the ground below the truck (2000 AC V8, 133k miles). I just crawled under, and I had fluids on the front diff and passenger side shaft, on the oil pan, some coming out of the hole where one of the bolts for the skid plate is located.

The fluid that is leaking is green, and I know I am losing coolant - until recently I was just losing it without a trace, but about a week ago is when I noticed the leak underneath.

After wiping everything down, I couldn't identify the source for the leak. Letting the truck be for a little while, I came back to find a few drops gathering on the suspension pieces on the bottom again. Facing the truck from the front, leak is manifesting about the same depth where the axle is, and it is located at the center of the truck and to the passenger side.

I don't see any leaks from the top, everything is bone dry around the radiator, water pump, expansion reservoir, and the hoses around the fan.

I checked the oil levels, transmission fluid, brake fluid, steering wheel fluid - all good. Only low levels are in the coolant system.

My question is - what kind of a coolant leak can I have that far back? Maybe around the heater core? I took 5/24 off and will have a very long Memorial Day weekend to tackle my drivers side exhaust manifold and oxygen sensor. I can dedicate some time to this issue as well, but I have no idea where to even start. Anyone have any ideas where the leak might be?

Also, is FiberLock a good idea? I never used anything like that.

Thanks!

 

Have you ever changed your radiator? My radiator had a hairpin crack on the plastic. Hard to tell where it is coming from with the fan running. Blows it all over the place.

 

Nope, original radiator. I rented one of those coolant pressure testing kits a few weeks ago when I noticed I was losing coolant, but didn't see any leaks at that time. It might be the time to go to the shop...

 

19 years is a good run for a radiator, even with your low miles. Replacing the radiators in our trucks is extremely easy. I posted some pictures a few weeks ago when I replaced mine. Send me a PM if you need any tips. The hardest part was reaching the drain plugs on the engine block. Make sure you use coolant approved for our trucks like Aisin or Zerex.

 

I'm not familiar w 2000s but what about hoses to thermostat or housing A little stub hose to the thermostat or the thermostat housing was where I found leaks in two other vehicles I had that was hard to spot a leak.

 

I would bet your leak is under the intake. I changed out the emission valve which sits under the intake back at firewall and there’s a valley pan that sits on the block and mine was seeping coolant. There is no gasket for it. The pan sits in a bead of silicone

 

Oops. I was referring to 2nd generation. 5.7 engine. I’m sorry.

 

I had a leak from this fitting. (The vertical plate with the small hose attached directly above the belt) It was hard to find. Easy to fix.

A month later I also had a leaking radiator.

 

Thanks ya'll! I just had a mechanic buddy of my stop by and he found a leak in the radiator almost immediately - I am ashamed to admit that I didn't even see it until he pointed it.

He also found one of the hoses in vacuum system disconnected and he fixed my check engine codes with his handy reader.

Now, to buy an OEM radiator for $240 at my stealership, or order from another one for $151 and wait, or $100-ish for third party...

 

$240 for an OEM radiator is actually really good. I'm surprised it's that low. My dealership wanted $340 or something stupid... The Denso one on Amazon is around $130. The Spectra I bought cost me $180(long story).

I would buy the OEM and not look back. If it hasn't been replaced yet I would also do the serpentine belt and the thermostat. The belt is a lot easier to do with the radiator removed.

Picture of the drain on the passenger side of engine block. You'll be surprised by how much comes out.

 

$240 is acceptable, but Toyota dealership in boulder has the same item for $150-ish. I’ll see if my guys will price match. If not, I guess I’ll have to decide if two hour round trip make sense for $90-ish.

 

Bought a Denso off Amazon for $100. Arrived in a unpadded caradboard box, beat to hell with the fittings bent. But I needed it so I used it anyway. I think it was pretty well made before it got shipped...in the Denso box BTW...they should be embarrassed at what passes for packing. I have mail ordered several radiators over the years and all the others where elaborately packaged, this one was just in a box with no padding, no support.

 

Mine came the same way. Everyone on Amazon said the same thing.

 

Well, the saga continues. I replaced the radiator - local stealership sold me an OEM one for $176+tax. I bought 3 gallons of coolant, replaced it all (so damn easy, I wish everything was so easy on this truck). Refilled with coolant, no leak, turned it on, no leak, hit the gas - leak. My buddy came and looked into it more with the skid plate removed, and is now pretty sure it is the water pump.

So, I just spent $170 on

$183 AISIN TKT-021 Engine Timing Belt Kit with Water Pump - Compatible with Select Lexus GS400, GS430, GX470, LS400, LS430, LX470, SC400, SC430 Toyota 4Runner, Land Cruiser, Sequoia, Tundra

this kit and another $50 on serpentine belt. My mechanic buddy will do the timing belt and water pump replacement for $700, plus he will replace my seized drivers side oxygen sensor by replacing the exhaust manifold for that price as well.

At this point, I am at close to $3000 invested in this truck since my old man gave it back to me, and the clinking noise in the back hasn't been addressed. Still cheaper than buying a new one, but damn if I wasn't temped with that Jeep Gladiator lease offer for $143 per month and $2-3 grand down for 24 months.

 

Nothings cheap anymore. These Tundras need lots of love after years of worry free service. The investment spikes around this age for Tundra, where other trucks would just die on you with no chance of even considering reinvestment leaving you with a $500 pile.

For 16 years the only thing I did was change fluids and tires (other than timing belt was big $). Not bad when you consider the long haul.

 

$3k sounds about average. I'm at about $1500 and 20 hours labor in mine. I need about double that to get it tip top. But it was a free truck so I cant complain! Plus I'm learning a ton about working on vehicles.

 

I have far more than that in mine but I'm ok with it. It's still so much cheaper than buying a new truck and the "3rd" gen Tundra are hideous. Ugliest trucks on the road. If something happens to my truck I'll go buy another first gen.

 

Well, I am at 19 years and 134k miles. The mileage is really low for the age, so that is why I am still throwing money at it. Once I am done with brakes, and once I figure out the noise in the back, all that's left will be suspension bushings in the front, and hopefully then, I'll have a truck in good shape. Of course, I imagine sensors and electronic pieces will start going bad by then... there is a good chance I'll be looking into a replacement very soon after this truck becomes my daily if it is not super reliable.

 

Other than the size, I love the 3rd gen, but taste is subjective. My dad just got a 2018 TRD Sport and I think it's the best looking truck on the road.

 

Truck is back with the new water pump. No more leaks, yay! 134k miles on her, we did the timing belt at 90k, but my dad is not sure if the mechanic replaced the water pump. Anyway, new pump, new timing belt, new serpentine belt and she's all better!

 

I had mine serviced at a good dealership. The price was right and I was eating up overtime so I didnt mind but.... they didn't replace the thermostat at the time. Fast forward a year and a half later and I had to do it. It caught me off guard since I would have thought that would have been a part of the service but they said that isnt the case.

It's one less thing when you're on vacation. If you haven't done it I certainly would.

 

I replaced the thermostat a month or two ago while I was hunting for my “no heat at idle” issue. Surprisingly easy.