Using a TRD Radiator Cap with Possible Head Gasket Leak

[paco1038]

Hey guys, I have an 04 V6, with a probable head gasket leak. Unrelated to the leak, I think, my coolant seems to be pressed out into the reservoir but unable to be drawn back out, and has overflowed on a few occasions. The temps have been fine and put in an OEM thermostat less than a year ago. The hoses are tight and not leaking, so I'm replacing the radiator cap. I like to upgrade where I can when stuff needs replacing, but I'm wondering if, in light of a bad head gasket, using the TRD cap is just asking for any leaks to just get worse. Is 3 psi a big difference in a cooling system? Enough to think twice about using the TRD cap before fixing the gaskets?
Any input is greatly appreciated!
-Caleb

 

[little_titan]

I honestly think the original denso radiator cap from toyota is the best way to go.

You dont have a V8 and if your V6 is a stock engine then the trd rad cap will not benefit you.

 

[paco1038]

I honestly think the original denso radiator cap from toyota is the best way to go.

You dont have a V8 and if your V6 is a stock engine then the trd rad cap will not benefit you.

Do you think it could possibly hurt it though? Not sure if it will directly impact pressure within the engine, since the water pump would still be pushing coolant through at the same pressure as before.

 

[fatherdoug]

Might also look at the tube that connects to the cap in the overflow reservoir. If that tube has popped off, you will get coolant into the reservoir, but not back out.

 

[paco1038]

Might also look at the tube that connects to the cap in the overflow reservoir. If that tube has popped off, you will get coolant into the reservoir, but not back out.

Oh the coolant straw? Lol Yeah it’s on there

 

[81runner]

Do you think it could possibly hurt it though? Not sure if it will directly impact pressure within the engine, since the water pump would still be pushing coolant through at the same pressure as before.

The water pump just does what it's name indicates, it pumps. The radiator cap is designed to lift at a certain pressure, and the trd cap is rated higher than stock because it helps to keep everything from boiling over, hence why it's a high performance cap. That being said, if you have a possible leak, I can't imagine increasing pressure is going to be good for that...

 

[2021nightshade4x4]

I honestly think the original denso radiator cap from toyota is the best way to go.

You dont have a V8 and if your V6 is a stock engine then the trd rad cap will not benefit you.

What, specifically, about the V8 stands to benefit from the TRD radiator cap whereas the V6 doesn’t?

I was on parts.toyota.com yesterday looking at accessories and I am able to buy a TRD coolant cap.

I’m asking this from a totally neutral standpoint, I’m not buying one, nor do I need to build a case in support of one, but am definitely curious.

To answer OP’s inquiry:

It would seem a bad idea all around, to increase the relief PSI in a coolant system we know is malfunctioning. If you raise the cap pressure, you’re daring other components to fail next. How do you think it will turn out when you pit a plastic tank against some rubber hoses? It’s anybody’s guess! [emoji23]

I have a Jeep and two Dodges, 1995-2004 and none of them have a pressurized overflow tank for coolant. They all have an old school flip cap, yet don’t need topping off as they run day to day.


Sent from my iPhone using Tapatalk

 

[aemravan]

so you are almost certain you have a (at least partially) blown head gasket.. what is the reasoning behind replacing the radiator cap to start with? Are you under the impression that you're not drawing coolant back in because of the cap? If you have a blown gasket your coolant system is compromised and you constantly have air forcing its way in, I don't see how replacing a cap, trd or not, will allow it to operate like it should in a sealed system. You're reservoir is overflowing because you're constantly pushing coolant into it, and not because its expanding, but because its being displaced.

with regards to "upgrading where you can" I fail to see how getting a higher psi cap is really going to benefit you at all unless you're towing or racing your rig constantly and need the little extra assurance that your coolant wont get to boiling temps. Save the money on the caps and put it towards fixing the actual issue is my suggestion..

 

[paco1038]

The water pump just does what it's name indicates, it pumps. The radiator cap is designed to lift at a certain pressure, and the trd cap is rated higher than stock because it helps to keep everything from boiling over, hence why it's a high performance cap. That being said, if you have a possible leak, I can't imagine increasing pressure is going to be good for that...

I understand that pumps pump, but by nature, pumps generate pressure. That’s what I was questioning, but since the water pump is more of just a fan, not a pump with valves and whatnot, I can see how that wouldn’t be the deciding factor on pressure in the system.

Thank you and everyone else who commented, I’m just gonna wait to use the cap after I do the head gaskets. Especially since after cleaning the old one, it’s been able to pull the coolant back into the system again so I can just ride it out with the old one for awhile longer. Thanks again guys!

 

[paco1038]

so you are almost certain you have a (at least partially) blown head gasket.. what is the reasoning behind replacing the radiator cap to start with? Are you under the impression that you're not drawing coolant back in because of the cap? If you have a blown gasket your coolant system is compromised and you constantly have air forcing its way in, I don't see how replacing a cap, trd or not, will allow it to operate like it should in a sealed system. You're reservoir is overflowing because you're constantly pushing coolant into it, and not because its expanding, but because its being displaced.

with regards to "upgrading where you can" I fail to see how getting a higher psi cap is really going to benefit you at all unless you're towing or racing your rig constantly and need the little extra assurance that your coolant wont get to boiling temps. Save the money on the caps and put it towards fixing the actual issue is my suggestion..

Yeah you’re totally right.
The reason for replacing the cap was that it wasn’t able to pull the coolant back in. My long time head gasket symptom is I slowly lose coolant and have to top it off a couple times a week. But when the cap was messing up, it wouldn’t seal and sent coolant everywhere in the right front engine compartment. Since deep cleaning the old cap, it hasn’t happened again since. It’s back to just calmly, slowly disappearing haha