2004 Tundra 4WD keeps blowing off coolant.

I'm no stranger to Rockauto as to brake components, A/C, Coils, plugs and and such, but I am picky in other things like the thermostat and radiator cap here. I tend to knock around and put together OEM stuff for the systems... There are a number of Toyota Dealerships on ebay that are retailing older parts for discounted prices.

That said I'd count $250 for the whole works as a really good deal.

 

The Aisin kit is the OEM supplier. Denso for coil packs and O2 sensors. Lots of various OEM suppliers for parts that can be purchased from places other than Toyota. Save a little coin for the exact same part. Often comes with “Toyota” on the part, just not in the Toyota box.

 

Some nightmare fuel for you, that fortunately ended well

https://www.tundras.com/threads/i-dodged-a-bullet.122863/

 

Yeah, but using Toyota's Parts system to order from participating dealerships, I can usually beat any legitimate dealership's price on fleaBay, sometimes significantly. And fleaBay just isn't worth the risk, you never truly know if it's actually a dealership on the other end or not, nor where the seller picked up their inventory from. It's (edit: using the Toyota Parts system is) usually what I'm doing if I can't find the part from Denso/Aisin directly and have no choice (and/or no desire) except to buy from Toyota direct.

 

Not arguing the point at all, however I have been in manufacturing most of my life and unless said part does have, for example "Toyota" on the part, I have serious doubts as to the "being just as good". It doesn't mean it IS NOT as good but even Manufacturer Suppliers cut cost when their feet are not held to the fire by contract. My current employer sees that sometimes even when it is simply closing out an older model and has a parts shortfall. I am pretty sure there are plenty of 4.7l NOS parts out there to be had at something of a discount.

I can remember in the early 2010's getting a OEM Equivalent Datsen A/C compressor for a Honda Civic from RockAuto and while the item superficially looked like the original, it weighed about 1/3 less (even allowing for fluid content,etc...) and the connectors were not nearly so robust. My Wife's BnL worked as a sales manager for a local Honda dealership. He was no help on getting any real price breaks but it would be something off. When I got there the part in the box had a manufacture date about a year old and was almost identical to the one removed... Now I will say the parts counter guy told me the RockAuto part would function just as well and for probably just as long as the OEM offering.... (Probably the only real benefit to having "kin" working there). I went with the Rockauto part and it was operating fine when I sold it 6 years later.

Now all that was to say I am not averse to your thinking and appreciate the input but I do have that (a) quirk as to parts that can leave ya on the side of the road....

 

Agreed.... I usually do a quick search for the Dealership online and have inquired, if I thought something seemed a bit off, as to whether they actually sold on ebay. One dealership in Ohio was pretty candid as to what went to ebay.... VOM.... Is that good or bad?...

 

Go out and look at parts on your truck such as the master cylinder which will say Aisin instead of Toyota, and the alternator which says Denso instead of Toyota. Plenty of original parts on your truck that are Aisin and Denso and not Toyota branded.

 

So much for a day without heartburn... Just dang! I never have heard of coolant doing damage to parts like belts.... That WOULD be a good reason to discontinue the "Weep Hole" concept for the water pump as they are almost all housed inside the belt areas instead of outside these days... Just dang!

 

Absolutely nothing wrong with going straight OEM. Toyota will “discontinue” some part skus over time. Those same parts will still often be available from the original OEM supplier. Sometimes they won’t, and a non-OEM alternative must be used. You should be able to get all these parts from Toyota at their premium. There are discount dealers that will save you some coin on those Toyota parts.

 

McGeorge being one forum favorite. For me, if I'm not in a rush and ordering something over $75, I'll cash in on the free shipping (coupon: FREESHIP) and tax-free purchase from Serra Toyota in Alabama (their Birmingham dealership, not the Decatur one, Eric at the Decatur shop is lazy and dishonest). For whatever reason, I guess AL at the state level doesn't require tax on internet orders? But Serra usually runs anywhere from 10%-40% off MSRP.

 

Agreed.... throw NTK in the mix as well... I know this is becoming more the case as the years tick by.... As I pointed out above, from personal experience I have seen OEM manufacturers supply one thing for new model install and another for replacement.... It is just the nature of the beast. Manufacturers are required to inventory replacement / warranty parts for so long as the Warranties they offer or Government requires (emissions) are enforced... "IF" a warranty on a vehicle is 3/36 it would mean that assuming the last year of a model was 2000 they have to maintain inventory until 2003. It is plain that those parts do not evaporate in 2004. Some will overlap on continuing models and serve as replacements provided there is no new part designation. Hence the way VOM/NOS comes to be. Bulletproof things like 4.7l, or 2.7l, engines lie around gathering dust. GMC 3.8l? Not so much....

 

Yep. I like your thinking. I'm ALM, Pleased to meet you.

 

Writing down the name.... Tks!

 

McGeorge is another solid one not to be forgotten. Just know: They have three different websites for their parts area, each has its own discount and possibly other changes

 

Noted!

 

Nooooo. That's how to burp a Frontier, that method may or may not work for a Tundra. It won't normally hurt being parked on a slope but some vehicles I've done have had three bleed points at various high spots and require being parked on a level area and bleeding each nipple in a specific order, after squeezing various pipes, etc, etc. No doubt a 1st genner (or Youtube) can tell you the proper bleeding sequence.

 

I'll say, I had no issue with coolant bleeding on mine after I replaced the radiator. Did the 'normal' thing (the thing that seems to always happen to me on vehicles after coolant dumps, in that it right after filling and running, it slightly overheated (needle 3/4s up instead of 1/2), I shut it off, let it cool for an hour, re-filled the overflow, and that was it.

 

I'm confused, generally speaking, if a vehicle has a 'burping pip' then getting excess air out isn't going to happen without opening that valve - could the OP have a different coolant system to yours Aerindel?

 

Let's just say if you had an air bubble causing this issue, you definitely wouldn't be the first to have it happen in this forum. Typically overheats happen, but assplosions too.

 

All systems work a similar way, the radiator cap is a pressure sensitive valve. When the system heats up and pressurized, it pushes whatever is at the top of the radiator, into the overflow tank, and when it cools, it sucks fluid back in from the tank (as long as there is enough fluid in the tank, to cover the end of the pickup tube. This self purges air every time your engine heats up and cools down and keeps topping off the fluid in your system, provided your overflow tank isn't empty.

Since the radiator cap is usually the highest place in the system, any bubbles in theory work their way into the radiator, get purged with each cycle, but this can take a few cycles as it only pressurizes so much each time, and if there are bubbles stuck in a tube somewhere, they can just hang out until tilted etc to get them moving to the radiator.

The system is designed to self purge, but only small amounts at one time.

And if the overflow tank gets empty, when the engine cools, it pulls air back into the cooling system, instead of fluid.

If you keep having to add fluid, it's because it's leaking out somewhere, or its being displaced by exhaust gas from a blown head gasket.

 

Perhaps it's less of an issue with vehicles built for the US market because they are so big that it's easy to keep the radiator cap and header tank as the highest points in the system?
Citroens and Audis would warp a head before purging air, if you didn't open the bleed valves and close them in the right order when filling the system. When I was growing up purging a vehicle was easy - fill system, leave rad cap off, turn heater on full and then leave it running until the thermostat opened and you could physically see the coolant flowing, trouble is European vehicles have gotten a whole lot more complicated since the 1970's....

 

Post #17 suggests that it's not just a Tundra thing either!

 

Figured as much. Thinking at worst it was worth a shot as ya couldn't beat the price.

I seem to remember, back in my deeper, darker past, having a similar problem with a 1984 T-Bird Turbo Coupe... Only in that case the air bubble always seemed to find it's way to be trapped in back of the water pump casing. It revealed itself by producing a rather loud "Poomp! Poomp! Poomping! sound and literally shaking the hoses clamped to the pump even before it would overheat. This happened every time you did a repair that required loss of coolant. In that case you loosened a connection of one of the hoses and turned the engine over until coolant came thru with no bubbles. Tightened it back, top off the coolant, and you were good to go...

 

That makes a certain amount of sense.

It isn't a thing just to argue, but it seems there wouldn't BE (Caps for emphasis) a burping procedure (assuming there IS a burping procedure) if things always evened themselves out in that fashion. I am the first to admit I have no idea why/how I am losing coolant, (Heck, I wouldn't be here if I did, right?), but I am not seeing incremental losses for the most part. As I posted I am seeing what appears to be larger losses of coolant sprayed all over rather than a little here and a little there. The coolant levels tend to only go so low for the most part, (I simply am not willing to test if the loss of coolant further than that early loss is primarily all there is), but over filling the overflow tank (Hot level line as opposed to the Cold level line) simply has the coolant nearly immediately puked all over the place. Adding to the Cold Level point doesn't seem to do a whole lot as to stabilizing the over all coolant levels.

I am perplexed with the idea that I can't seem to make the event happen such that I can SEE what is actually happening real time. It is literally like trying to watch water boil. The Temp gauge seems to be working properly, (I have not actually put a thermometer in the coolant at any point) and, with the temperature reading in the middle, it does not offer to boil over. Grabbing a large wad of rags and opening the cap while hot doesn't produce any kind of gush of anything, fluid, steam, whatever from the system.

As posted earlier I am not finding signs of cross contamination in either coolant or oil, and no bubbles that I can see in the over flow... For all I know I am trying to cram more coolant into the system than it is designed to hold... (A little being good, so more is gooder?...) From advice found here I have genuinely been able to approach this in a better, more orderly, manner...

Thanks Team!

 

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Sure, its because it can be a PITA to get all the air out when the system is completely drained and re-filled and mechanics, dealerships etc want to be able to do it quickly and give it back to a customer rather than telling them to let it cycle a few times etc.

My main point is just that air in the system, should not be an ongoing problem. Every time you run your truck, it should be getting better, in fact, it should have self corrected the first couple times and not happened again.

If you are continuing to get more 'new' air in the system, to the point where its pushing out the overflow on a continual basis, something is wrong.

My main theory is a leaking head gasket, It may only be leaking when under load so you aren't seeing bubbling at idle.

OR

A bad radiator cap. A bad cap, will not hold enough pressure and can allow your radiator fluid to boil, causing overflowing.

As for more coolant in the system than it is designed to hold, the only way this can be the case, is if you fill the overflow tank to the top, when cold.

And even if you do, the first time you heat up the truck, that level will rise, the extra will pour out, and that will be the end of it. You can't cram more in that its designed to hold, the system automatically relives any extra when it's hot, and tops it self off when it cools down, if there is any 'extra' room in it, because it had air.

This is all assuming, you don't have a leak anywhere and that your actually only losing fluid through the reservoir.

I had a Subaru once, with a cracked radiator, that would spray fluid, but only at about 4K rpm. Took me a while to figure that one out.

 

Yessir.... My experience is sorta leading me to the conclusion I have some sort of issue in the coolant system itself that might be losing coolant as you suggest. Another idea occurred to me that there may be a pin hole on the sucking side of the water pump that does draw small quantities of air and that air accumulates while operating and this causes the problem when it cools and the air finds the same point of collection. When, after restarting, the air reheats it expands and overflows the reservoir. I don't know if that makes sense but there seems to be no running symptom on the combustion side of the equation. As posted before the oil is dry, the coolant not oily. The coolant in the overflow smells of antifreeze rather than petrol or exhaust fumes. The spark plugs are clean, as in normal fuel burn with no sign of oil consumption. The electrodes have no appearance as to being "Steam Cleaned". A mirror held at the tail pipe does not gather condensate... The Truck starts with no thought needed just turn the key... If it turns over once or twice it is running...

I did replace the Original Radiator cap with an OEM replacement that is listed at 24.1 psi.... Unless that is not the correct value it seems to be working properly.

 

Too high. And probably not working correctly.

Should be way less. Put your original on there or get a denso, koyo or other good brand cap and see what happens.

 

!!! Too high? The original had no designation on it at all. The next down is something like 18.1 psi.... I got no problem getting another but the vin search gave me that cap.... Sorry, the 3001 final designation was the thermostat part number... It was in my head but not the cap's part number.

The original was broken and in two pieces hence this is where the problem began...

 

Should be around .8-.9 bar. 13ish psi give or take a couple psi.

 

I like it. Our local O'Riley's will lend you a tester.... Might see what Harbor Freight has to offer...