The coolant in the reservoir will be low and I'll fill it up halfway. Drive as usual for a week and check again and its back at low. I checked for any signs on my garage floor but don't see any. What I do see is when I get to work, I'll check under the engine and I'll see some kind of liquid (probably coolant) but in a tiny puddle. What other signs should I check for ? what could it be? Thanks in advance guys and its a 2006.

 

Did you check for any signs of cracks on the reservoir itself? It could be puddling up on covering underneath the car and not making it to the ground. Another explanation is that you couldve been low on coolant and it could be in the core.

 

mine's always been low, I fill it ever few months with a little. I know it's not supposed to do it, and it's not leaking, haven't notice any signs of it burning off on the engine or internally. So I just kind of accept it unfortunately.

 

On my 05 it go low also after a while. See no leaks also.

 

my 04 has been like that for 4 years and i have no problems. after a few weeks the reservoir go down to the lower line

 

Necessary question.. are you checking the res when the car has been off for several hours?

 

I for one can say yes.

 

Then check the oil, your passenger side carpet, and your firewall. If it's leaking somewhere it'll be noticeable. Either your oil will be milky, your carpet will be damp or there'll be dried coolant all over your rear mount, brake & fuel lines.

 

Will do asap. But can say all ready nothing is on carpet.

 

Just checked,No evidence on my car of a leak.

 

If you want to be sure your coolant system has no leaks, go to Autozone and borrow a coolant pressure tester. It is basically a pump with a psi gauge. You pressurize the system to what the psi reads on the radiator cap. If the needle on the gauge stays solid then you have no leaks, if the needle goes down however then you have a leak. While the needle is going down check for the leak.

Worse case is the head gasket is bad and the coolant is leaking back into the block. You can tell this by looking underneath the oil cap or shining a light into the fill whole. If you see a dirty milky build up then you know where your coolant has been going. This is usually not the case if it has been happening for while since you would probably have noticed your engine knocking. I know first hand since I blew a 5.7l this way and seen it a couple times when I worked at a shop. Every day for a couple months the coolant would be low,the engine started knocking, I went to drain the oil and it looked like chocolate milk.

 

Good info, thank you.

 

Agreed. And to add to that, check right around the rubber hose that goes to the reservior near the radiator cap. Mine leaked when brand new. Not enough to see unless you were really looking for it. A small ziptie cured it.

As Mojofo said, check when dead cold like first thing in the morning or when hot as soon as you shut it off but make it consistant. If can vary by 2" from cold to hot.

 

Also remember to test the radiator cap with the pressure tester.
I had a bad cap once, but it was the last thing I checked.

 

so....i have spent the last week every morning when the engine is dead cold, and as soon as i got home everyday. Have checked my oil, carpet, and everything mentioned on here. BUT i did find a problem. the reservoir is made of plastic and the cap in which covers up the hole where you pour the coolant in has cracked on top. it still tightens but there is a tiny crack in the cap. but how does it explain why im losing coolant ? its on the very top of the reservoir so its not leaking out,is it?

 

There's some evaporation with coolant. It's not as much as straight water but a crack could be enough to lose a few ounces of hot water in a week.

 

WOW that's scary because mine has been showing low coolant In the reservoir and I hear some kind of knocking on the engine but someone told me that I needed my valves adjusted. Hope that all it needs
Any suggestions on how to tell the difference on the knocking?

 

I just noticed this today as well. I have the crack in the reservoir cap. My coolant gets low pretty quick too and I didn't see any leaks.

Anyone have the part number for this? or would some super glue suffice?

 

http://www.hondapartsunlimited.com/i...RESERVE%20TANK

part #2
002 19102-PM5-A00 CAP, RESERVE TANK 2004 TL 1.45 1.09

you could just goto a junkyard and find one off any honda/acura model. they are almost all exactly the same. my original cracked and im using a cap from a honda odyssey

 

mine gets low from time to time, as well. maybe twice in 3 years I've added. I'll check the cap but sounds like it's somewhat consistent.

 

Was having this issue in my 08 and sure enough it was a cracked reservoir cap. Replaced with a new one and now the coolant stays at a consistent level

(Holy thread bump batman)