blue02S

So yesterday i spent about 9 hours on my tl. I changed radiator hoses upper and lower, flushed radiator, adjusted valves, and cleaned egr intake and tb. The reason why i changed my hoses is because my top hose was sucking flat. I haven't had over heating other any other issues. When i went out to check the coolant level this morning i noticed my upper hose was flat again. So my question is, why is the hose going flat? Any input would be appreciated.

3.2TLc

When replacing the hoses .....did you properly "burp", purge the air from the cooling system after refilling coolant ? Air can get trapped in the heater core and the areas higher than the radiator. Check your manual for more info.

Is your T-stat and heater working ok ? Do the fans come on ? There could be a restriction or flow problem, maybe the water pump ?

01tl4tl

I agree,,follow owner book for burping www.owners.acura.com for free download
BUT
hose sucking flat is more than lowering coolant level
inspect all of system

was the heater on full hot to drain system, and during burping? CRITICAL!
what temp does it run? 1-2 lines below half? any higher is a problem

blue02S

That's the thing as far as i can tell everything is perfect i let it idle with rad cap off for over an hour to be sure its full. I did not drain the block just radiator. Fans come on gauge shows that temp is perfect and the heater will make you wish you were in Alaska. The only thing i can think of is t stat is stuck open and the pump force is pulling it flat (imagine drinking a thick shake through a straw).

3.2TLc

You should be able to notice a difference between feeling the hoses while the motor is warming up. If they stay the same....then your theory may be correct.

If you decide to pull the thermostat, be sure to replace the it with an "oem" 2 stage Honda part for best overall function.

victus1

A flat hose means there is substantial air in the system. So it may be an issue of proper air bleeding...i.e. let engine idle until fan comes on and off 3 or 4 times, while squeezing the rad hoses to flush out air pockets....watch rad inlet and keep topping it up. If you do open tstat housing, only replace with oem tstat.

blue02S

No i haven't noticed a difference it seems to stay the same.

blue02S

I have done all of that. I have checked the coolant level 3 or 4 time after i have driven and let cool and its full. In the first post i said i changed the hose because it went flat therefore it had the problem before i opened the system. But there was never ever low coolant leaking coolant or a high temp. So i can almost certainly say its not air in the system.

Skirmich

I bet its the Thermostat not fully Opening.. If replacing do so with OEM Only! Aftermarket Thermostats arent Reliable...

kaza

You need one of these Jack up the front of car maybe 1-2 feet off the ground and let it run through a few fan cycles with the funnel full. You should see air "burp" its way out.

victus1

Well, he said he burped it properly, flushed rad to ensure it's not impeding flow (hope he did the same to the small heater rad). Only thing left now is thermostat. It's a cheap oem replacement anyway and comes with a new gasket. I already changed my tstat + hoses as part of regular maintenance.

blue02S

I should have replaced the thermostat while i had it apart but wasn't thinking when i was buying parts. I will replace it soon however i now have a new problem. My starter has decided to go out so i think i will have a friend rebuild that then get back to this issue (my luck, when it rains it pours). Thanks for the help though.

TLer trash

Try a radiator cap, it sounds like it's not allowing coolant back from the overflow tank as the system cools down. Also check the overflow hose for restriction or kinking. Get the cap from acura or honda, rather than aftermarket.

spydercatt

Did you figure out what the cause was?

blue02S

No fix yet just got the new starter on last night gonna get back to this today after work. I didn't think about the cap that makes some good sense. May try that since its easier to get to and cheaper. Thanks again

01tl4tl

the upper hose was flat--correct? and still does that?
note: correct burping of the TL requires some use of 2000 rpm till fan cycles then idle set till fan cycles etc
see owner book,,,free copy at www.owners.acura.com

you did right with the heat on----- but the rpm seems to matter!!
NOT something you do on most cars--which means its standard on the TL~

feeling both hoses, one should be much warmer than the other = rad flowing properly
no temp at top hose = thermo closed so no hot flow out of engine

did we cover fan operation is correct?
ac on or off?

blue02S

Well i have not checked the temp of the hoses yet but fan operation seems to be correct. I just can't see it being air in the system since it was flat before i opened the system since.

3.2TLc

Hey Blue02S, if the new rad cap does'nt help....then just bite the bullet and replace the T-stat
with a new Honda 2-stage. If you're absolutely sure that the air has been properly purged from the system.....then you have something interrupting the coolant's flow.
Either a faulty T-stat or water pump ?