Toyota sienna what coolant??

[diesel lover]

I would love to see how low the system is but it is a sealed radiator. Because there is no antifreeze in the recovery tank that to me means it's low. The recovery/ overflow tank is designed proportional to cooling system.

The radiator cap is on the top radiator hose placed near the valve cover. There is not a drop of coolant available.

I do agree and thought that someone has not bled the coolant from the system. Unfortunately it's not my car so I cannot make all the choices in repairs. She wanted to take it to Toyota to get her oil changed so that made sense to me that she wanted other repairs done there as well. If it were my vehicle than I would flush/ drain/ refill with the appropriate all makes all models vehicle only because I do not know the history of the antifreeze and type. Or I would fill with water and look for leaks.

Tonight I will be putting on jack stands and letting the engine idle while I add coolant. This is one of the best ways to bleed the system. You are making the coolant cap the highest point in the system so air is removed easier from the engine.

 

[3930dave]

A problem I've seen with modern cars is that the water pumps are designed to be what I should call Low Drag.

In another era, they'd have been just called Low Flow/Pressure.

GMs that don't produce defrost heat until rev'd up. Nissans that are so low pressure that the only way to bleed the system is to raise the front end about 3' in the air, and rev it over 2,000 rpm for about 15 minutes. VW's that are so close to the edge that when an aftermarket WP is used that has just slightly thicker walls on the impeller (therefore reducing each "bucket" volume marginally) you can't push adequate volume through the heater core.

I'd hope that minivans (given their higher payloads than many cars) still have decent volume WPs installed, but I know that WP performance in cars has definitely declined, in the interest of efficiency. Something to keep in mind, for people that tow with small cars in Summer heat.

Elevating the van may help, but don't be surprised if even a healthy system takes a few rounds to bleed fully.

Rgds, D.

 

[diesel lover]

Thanks Dave completely true!! The long and short of it is sealed radiators, new low drag water pumps, and systems that are hard to bleed without jacking the front end in the air. Ouch

 

[sixdogs]

Thanks Dave completely true!! The long and short of it is sealed radiators, new low drag water pumps, and systems that are hard to bleed without jacking the front end in the air. Ouch

I don't understand this jacking the car up in the front end. I never did this. What does it do and why do you need to do it?

 

[3930dave]

I don't understand this jacking the car up in the front end. I never did this. What does it do and why do you need to do it?

Not all vehicles are affected. Typical symptom is no interior heat after changing coolant. If you haven't encountered this, count yourself lucky.

One factor is how high up the heater core is, wrt. the water pump. In well jet-pump terms, some of these modern vehicles are at the edge of "one line" lift capacity. Raising the front end drops the "lift" height for these ___________ lousy low-flow pumps, and with enough rpms on the pump you can just manage to bleed the heater core of air.

In the case of the VW I mentioned, the not-that-old aftermarket WP had to be replaced; the only other choice for the customer was freezing all winter.

IMO, this is one more reason not to tow with a modern small car in the Summer.

Rgds, D.

 

[PeterK]

VWs use a completely different coolant and if you top up with "regular" glycol-type anti-freeze, it will form a clot as the two types don't play. This clot/blob of gel will eventually clog up the heater core and/or radiator. So I stick with the dealer brands for the vehicles.

On my BX, I used pre-mixed 50/50 when I change the coolant.

 

[diesel lover]

VWs use a completely different coolant and if you top up with "regular" glycol-type anti-freeze, it will form a clot as the two types don't play. This clot/blob of gel will eventually clog up the heater core and/or radiator. So I stick with the dealer brands for the vehicles. On my BX, I used pre-mixed 50/50 when I change the coolant.

Yeah my girlfriends car already had green coolant in it when I met her, we had it flushed when he water pump was changed and all we use is all makes all models. The VW coolant is 20 to 30$ per gallon!!! You void the VW warranty if you don't use it .

 

[3930dave]

VWs use a completely different coolant and if you top up with "regular" glycol-type anti-freeze, it will form a clot as the two types don't play. This clot/blob of gel will eventually clog up the heater core and/or radiator. So I stick with the dealer brands for the vehicles.

On my BX, I used pre-mixed 50/50 when I change the coolant.

Same issue with GM's Dexcool. I see so many GMs at my buddy's shop with this problem, that I'm beginning to suspect that you don't even need to mix anything with Dexcool to encounter this problem. I think one of the issues with this class of coolant is that if you have even a slight air leak (loose hose clamp) then the coolant will sludge up.

Rgds, D.

 

[diesel lover]

Same issue with GM's Dexcool. I see so many GMs at my buddy's shop with this problem, that I'm beginning to suspect that you don't even need to mix anything with Dexcool to encounter this problem. I think one of the issues with this class of coolant is that if you have even a slight air leak (loose hose clamp) then the coolant will sludge up. Rgds, D.

100% true. When air is allowed in the cooling system with dexcool the results are hazardous!!

 

[sixdogs]

100% true. When air is allowed in the cooling system with dexcool the results are hazardous!!

Why would any manufacturer allow this aggravating feature to be a part of their vehicles? Especially GM? What are they thinking?

Is it planned obsolescence to force people back into their shop, engineering stupidity, corporate arrogance that they are the smartest people in the room or is Dexcool really a desirable product? It's not like it's the only successful coolant on earth. What's the problem?