Coolant pooling on top of radiator

Prepping for a trip, checked all the fluids, saw something...weird?

The engine coolant in the overflow reservoir was a little low. I've had the truck for 4 years, and I've added 12oz of coolant (6 coolant, 6 distilled water) twice in that time - after 20K miles, again after 12K. It has been 20K miles since then, and today the overflow reservoir level was just touching the "LOW" mark, so I'll add some more.

I'm not sure what is normal and acceptable, but this doesn't seem extreme, and no mechanic has ever commented on any issues.

Today I thought I'd check the radiator cap and see what things looked like inside the radiator. This was the point at which I noticed coolant pooled along the top of the radiator.

wtf?

I can't be losing that much – I've only added about 24oz in the past 50K miles. It doesn't seem to be leaking from the radiator cap itself. Never have had temperature problems, even driving around Phoenix summers.

Is this normal? I can't imagine a leak from a radiator is normal, but maybe it's come kind of pressure overflow...but that's what the overflow tank is for?

2003 Tundra SR5 4WD access cab 150K miles

 

Top tank seal is failing.

 

Yup, time for a new radiator

 

Thanks for the feedback.

As I am leaving in the morning for the trip... is this something that will fail catastrophically, ruin my engine, and possibly leave me to die in the wilderness, or is it something I can address in a week when I return? I assume the latter, as it has apparently been happening, unnoticed, for some time at least.

And is replacing the radiator a reasonable DIY job or something to add to the mechanic's list when he does my timing belt and water pump?

 

And a new OEM cap to be sure. Does everyone like to do the thermostat at the same time as radiator or save it for the water pump time?

 

makes the t-belt easier to do not being in the truck, but it’s a simple DIY..


Never know when it’ll let go completely. But I drove with mine like that for a couple months

 

T stat with water pump is easiest

 

Well no coolant = no go. Lots of variables, maybe it'll make it maybe not, no one really knows. Yeah it is not difficult, just need correct tools to reach places without taking the grill off (long extensions).

Probably not enough time to deal with it before trip so plan ahead with extra water and coolant. Remember, if you plan well, you won't need the plan.

 

Extremely easy to do yourself. 4 bolts hold it in place. Remove those and unclamp the hoses and it lifts right out. If you are prepping for a trip I would do it now rather than wait for timing belt. Especially where you live in Arizona.

Also, good idea to drain all the old coolant and put fresh coolant in. There are two brass drain plugs on the bottom of the engine block. You can attach hose and drain directly into your catch pan.

 

FTFY

 

Yep, its an easy fix, only took me about half an hour to change mine out, and that was in the the middle of winter in a foot of snow. I would just do it. If it fails all the way you will be stranded.

 

Thanks for the quick and good answers - y'all are great, as always.

Ok, so just so I'm clear: this isn't something to repair: I need to replace the radiator, can't just replace a seal? I'm assuming I need to go with an OEM replacement?

And is it particularly unusual to have to replace the radiator after (only) 150,000 miles? Is there some other problem, just unlucky radiator, bouncing around off-road, etc?

The stealership near me says $280 for the radiator, plus a couple of gallons of coolant at $30 each.

Does that sound about right? Anything else I need? Hoses, etc? The parts guy only said fluid, aside from the radiator.

 

Right nothing to repair. The radiators typically only last about 10 years (before a leak develops or they crack) and many will replace them at that age for one simple reason: prevent pink milkshake. Many have lost the transmission because the seals to the trans cooler located inside the bottom of radiator leak, sucking in engine coolant into trans, causing that fluid to look like pink milkshake the ruining the trans fast.

That price is very reasonable for the labor involved and using a Toyo supplied parts (radiator, cap). Hoses s/b fine unless a visual inspection says otherwise. I'd jump on that. Luck on the trip.

 

Not easily repairable, no. And you wouldn't want to use a leak stop on this considering how easy it is to replace the radiatior.

Yes, go OEM. I think NAPA may actually carry the Denso model for our trucks if you can't order online at Toyota Parts website and pick up at a nearby stalership. DC and RC/AC truck parts are different, FYI, one is taller.

Plastic is plastic. Most failures are due to plastic cracks/separation. It's normal. 150k is fine. And really, the big concern is when the transmission pass-through seal fails, and you start mixing coolant and tranny fluid together. You want to do this replacement. Google: tundra pink milkshake

You don't want that. Radiators should probably be proactively swapped in these trucks every 10-15 years for added insurance.

Fair price, but know if you go to https://parts.toyota.com and order through there for pickup at your local dealership you may save up to 25% off their over-counter cost. Buying online like this is typically cheaper, pre-loaded with at least 7-10% discount.

If you wanted to do the two larger hoses, maybe? Just make sure you get correct orientation on the hose so it's not too close to the fan. Some guys install them backwards and don't realize the mistake until it's too late. Check clearances after.

 

I'd be surprised if that was including labor, I think it was maybe just the part?

 

Ok, good to know (and weird that I hadn't encountered this info in all my reading of this site). I don't think the PO changed the radiator in the 15 years he had it (no records of that) and I haven't in the 4 I've had it, so I guess I'm lucky.

Oh that's just for the part, no labor. But it definitely seems like something I can do, from what you all are saying.

Oh, ok. I figured ordering would take too long, but I'll try what you said – pickup at dealer. Good idea.

...when I go to that site, the dealers here in the Phoenix area don't come up. Only Tucson, then places in California, 300 miles away.

 

My coworker just ordered a Denso replacement for his GX470 from Rock Auto. After shipping and tax it was around $265 out the door. I'm assuming the price they quoted you is just for parts and not for labor?

 

Weird. You may not have any local participating dealerships, I'd find that strange, I assume you used the ZIP code locator to find one near you.

If you're in a pinch and need it now, PHX may be diff't but ... in ATL, my NAPA a couple miles away has Denso in stock and ready for pickup. But that's coming at a $50-75 premium. (Edit: Forgot, I'm on work VPN, so they're throwing out a weird address in another zip code closer to you, near our national HQ)

 

Although, I am skeptical they didn't ask for the cab type on that part. I swear I've read numerous times on here the DC radiator is ~1" difference in height.

 

The $279.99 was just for the radiator, no labor.

The parts guy at the nearest dealership (https://www.bergetoyota.com) did get specific - based on my VIN - to get the right one.

I did use the ZIP code search, and a few other ways (like kludging together a URL like parts.bergetoyota.com) to no avail. Nothing in the Phoenix area or Flagstaff came up.

It is almost $60 cheaper online, but if I'm doing this job today, I think I'm going to just suck it up.

 

If the local dealership has it in stock, they're clearly ~30% cheaper than NAPA for Denso. Go for it. Their ask is not a bad price, and the part plus correct coolant is still cheaper than NAPA for just the part.

 

Oh no! My truck is 22 years old with almost 130k miles now, how serious is this issue? Should I be thinking to replace soon?

 

Has the radiator ever been replaced?

This is what happens when the radiator fails and you end up with pink milkshake. Not always catastrophic if you catch it fast enough. But it's killed enough transmissions that "pink milkshake" is readily found in tens of thousands of posts on the internet.

(posted wrong thread) One not-positive-outcome case here, and pics of what fails: https://www.tundras.com/threads/rough-transmission-shifting.93323/

@mbreed2 if you're still getting tag notifications, how'd this pan out?

 

Thank you and sorry my math was wrong, she's a 2010, so 12 yrs old, not 22, but still almost 130k miles.

How susceptible are 2nd gen tundras to this problem? Where to look? Apart from basic maintenance, I'm super green at any truck repairs.

 

I don't think you'll find many of us here in the 1st Gen forum who are familiar with the 2nd Gen and its quirks, nor what's involved with maintenance.

Maybe a good question for the 2nd Gen forum: https://www.tundras.com/forums/2nd-gen-tundras-2007-2013.26/

This was the only post over there I could find over there referencing pink-colored milkshake: https://www.tundras.com/threads/low-coolant.79438/#post-2011216

Maybe they changed the radiator design in later models. I dunno.

 

Thank you, I did not realize I'm in the wrong building. Will go ask there. Thank you, gang!

 

(By the time I drove up to Flagstaff there was pink stuff all over the engine compartment.)

Hi y'all, reporting back after my trip.

First off, yes, replacing the radiator is relatively easy. But it is not quite "oh just four bolts" easy. Here are some additional notes for future people finding this page:

Vehicle

This is all for my 2003 4WD Access Cab with tow package. YMMV.

Prep

• Have something ready to plug the transmission lines at the bottom of the radiator. I found that Sharpies worked in a pinch. Not much leaked out as I quickly plugged them, but I don't know what would work it's way out if they were unplugged. More on this in a bit.
• Have a catch pan and way to dispose of drained coolant. I got a little bit over a gallon out of the radiator.
• Have ample new correct coolant and distilled water ready to refill.

Process

This is a very rough overview mostly from memory. Please refer to a manual (Haynes, in my case) to make sure you get all the steps.

1. Remove skid plate (5 bolts). Necessary to access radiator drain stopcock.
2. Make sure the radiator / coolant is cool enough to safely work with!
3. Drain radiator from driver-side stopcock. As @shifty` noted, loosening the cap will speed the draining process.
4. Disconnect main top and bottom radiator hoses (large) and overflow tank hose (small). Inspect and replace as needed.
5. Disconnect small transmission fluid lines from the bottom of the radiator. (These are what I plugged with Sharpies.)
6. Unbolt fan shroud (4 bolts).
7. Unbolt radiator itself (4 bolts, in the front).
8. Lift out old, gently slide in new. Might be good to have a helper hold the fan shroud out of the way to avoid damaging radiator fins. Ooops.
9. Bolt everything in, connect the hoses, fill with correct coolant mix.
10. Run the engine at 2000-2500 RPM for a few minutes to get it up to temp, get stuff circulating, give air a chance to get out of the system, then top off the coolant level. I checked a couple of times over the next day and added a little bit more coolant.
11. Check transmission fluid level. Remember I said "not much leaked out" when I disconnected the hoses, but there is some amount in the radiator itself (which will leak out, too, so watch how you set the old radiator down).

(Sharpies plugging the transmission fluid lines.)


(Old, obviously.)


(Ooooh, purty. The top of this radiator, from a Toyota Dealer, has a "Denso" sticker. Box was labeled "Toyota / Lexus" in big letters on both sides.)

I've since heard that Toyota dealers might have two quality levels even for "OEM". Can't remember the first, maybe actually says "Toyota", and then mine (apparently the cheaper one) says "Denso". It was $280, and the cap was another $34. Coolant was $30 / gal for undiluted red. As noted above, if you can order it online, even from a dealer, it could be considerably cheaper. (Given my time and location constraints that didn't seem to be an option for me.)

Side note: got muddy out in monsoon Arizona Strip / North Rim backcountry. Took it to the car wash to clean it before my mechanic appointment for timing belt etc. Lesson learned: high-pressure car wash water can bend brand new radiator fins. Ooops again.



Thanks everyone for the quick and good info, helped me to get it done myself with relatively little stress before my trip!

In somewhat unrelated news, as of yesterday I have a new timing belt, water pump, thermostat, seals, bearings, yadda yadda. Mechanic did all that. And as of last week, new rear brake shoes, but that is a completely different drama.

 

I was able to keep my transmission lines from leaking simply by pointing them up. Gravity did the work. Good tip though in pointing this out in case it doesn't work for others. Good write up on the process too.

 

Nice work OP.

I actually love the sharpie idea.
I've seen the two quality level products you mentioned. And it's the same product, but instead of that Denso sticker, it's ground off and says "Toyota." Not worth the extra $150-200 in my opinion.

 

in hindsight, the mechanic probably removed your radiator to do the timing belt....perfect timing to replace at that time....

Sharpie..... will have to remember that.... novel concept.....I like it....

I just propped them in the upright position.....not much leaks out....as for radiator lines, just use right size vacuum caps to prevent tranny fluid from leaking out.