The upper hose is hot and stiff, the lower hose is cooler and stiff.

HI Guy

My Tac is 2007 TRD Sport.
After the engine has reached operating temperature (or after a long drive) , touch the upper and lower hoses by hand , the upper hose is hot and stiff but the lower hose is cooler but stiff, too.

Did this is normally ? Any one check on this ?

thx.

 

It's normal for the cooling system to be under pressure at operating temperature and the lower hose should be cooler if your radiator is working properly, are you having a problem with overheating?

 

Hi Dm93

Thanks for your quickly feedback.
I don't have the overheating but i found my coolant level in the overflow tank will dispear slowily , and i can't found any leak?
I try to open radiator cap to chk and find some buble but make the co2 test (Wruth) it's show normal.
not sure where the problem is?

thx.

 

The bubbling and coolant loss could be caused by a leaking head gasket.

Find a mechanic. Describe the symptoms, let the mechanic determine the cause. There are simple tests which can be performed to determine the cause.

The hoses on the radiator are showing normal function.

 

How's that water pump weep hole look like?

My 2013 will "eat" a lil bit (maybe 3-4oz) a year from the overflow rez simply due to evaporaion

 

It's normal. The top hose is the inlet to the radiator. The bottom hose has fluid that has passed thru the radiator and is therefore cooler. The system is pressurized to ~14 PSIG so the hoses will be under pressure during operation. As said, it's normal to have to add a few ounces of coolant over months or a year.

 

The first thing I would do is replace the radiator cap. They wear out over time. Try this and monitor it for a little while. See if it slows the loss. In the mean time, you could have it checked by a trusted mechanic.

 

That’s what she said

 

Hi Knute

I was guess this , too.
And try to chk my friend's TACOMA with upper / down hoses , stiff (A little softer) but not like mine ...

So i go for mechanic to make some check :

Cylinder pressure -- normal.
CO2 leak tester -- normal.
radiator cap changed

but still will lost little bit water , don't know whats the real issue on it now @@"

 

water pump weep hole ? where can i found it ?

 

On the bottom of the water pump fan shaft housing.

If you have a leaking component a simple cooling system pressure test should locate it for you. You can borrow the tool at most parts houses.

 

Over how much time are you losing water and how much are you losing, that may help us narrow down your problem.

 

I will try to check it again.

Thanks.

 

Hi Dm93

Maybe 200mils lost 1-3oz ，each time the condition of less is different, so it is difficult to have a standard measurement.

 

Check your oil fill cap. If it has creamy brown sludge on the underside of your fill cap you probably have a blown head gasket. Ask me how I know!! 82k and mine blew! After getting mine all torn down we still couldn’t find the evidence. As we discussed it, another indicator is a spark plug that is difficult to remove. Apparently if the coolant leaks into the well it makes the plug hard to remove. My #5 cylinder was tough when I changed it at 60k. We went back and inspected the head gasket and could see a small spot but even then we weren’t sure. I religiously change my oil every 3k so in my heart I knew it was bad when I saw the oil fill cap. 5.5K repair!!

oh yea. When we pulled the plug the porcelain was a grey all the way around except for one spot - looked as white as when it was new. I had no other symptoms. Even did the chemical block test and it showed nothing. The shop did a compression test and nothing.

Not sure if this was the cause but my thermostat was bad also. Upper radiator hose was hot and the lower hose was cold. Once they replaced the thermostat and the lower hose wasn’t warm they said the leak was causing a vacuum that wouldn’t allow the thermostat to open and it had to be the head gasket. Like I said - when I saw the oil fill cap there wasn’t much doubt in my mind. I was just hoping against hope.

Guess the suspension upgrade will have to wait now. LOL

good luck.

 

Uh, wut?

 

The “mayonnaise” on the oil filler cap is normal for short-trip driving especially in cooler weather, and even with long trips in extreme cold.

The long oil filler tube provides a nice, cool place for the moisture in the blowby gasses to condense, forming the sludge you found.

Probably not the news you want after dropping that kind of coin.

 

After owning the truck since new and doing the oil changes myself the brown sludge never occurred. It wasn’t mayonnaise it was like baby poo. LOL

I know my truck. She was hurt. The overflow tank was empty and radiator fluid was low. Pretty sure they were shooting strait with me.

 

Check your oil fill cap. If it has creamy brown sludge on the underside of your fill cap <-- already checked it's normal.
I also just replace my spark plug and not found any problem.
I had no other symptoms. Even did the chemical block test and it showed nothing. The shop did a compression test and nothing. <-- i also do that testing , and all are normal.....now what i found is overflow tank was less slowly..
Upper radiator hose was hot and the lower hose was cold <-- lower is cold or warm ? my situation is upper hot and lower warm , and both hose touch was stiff...

 

That’s good news then!! No sludge then your head gasket is probably good.

Yea my lower hose was cold like the truck had never been started.

I am at a loss on this weep hole thing. Never heard of it and know nothing about it. Just sharing my experience in case it might have helped. Glad it’s not what I went through. Good luck!!