I plan to diagnose my cooling system today. I'll be using the methods found in the service manual. I plan to check the following in order:


1. Radiator cap
2. Radiator

I contacted the previous owner and he told me that the thermostat he gave me is the old one (as is the PCV valve). Even though I didn't know the first thing about a thermostat prior to owning this car, I'm inclined to believe him because the thermostat appears to be open (judging from the pics I've seen of an open thermostat on the internet) and the service manual says that if the thermostat is open at room temp, it's no good.

I've included a pic so that a fellow ziner can confirm that it is indeed open: imgur: the simple image sharer

If no leak is found, I'll be checking the engine oil to see if it's mixing with engine coolant and vice versa for the radiator.

Since I know there's a leak, I won't be checking the fan motors.

I won't be checking the water pump due to having to remove the timing belt in order to inspect it.

If no leak is found after inspecting all hoses listed in the service manual, the radiator cap isn't leaking, and no oil/coolant mixture is found, I will conclude that the water pump is at fault.

==============

If anyone has any suggestions or objects to the methods I'll be using, please advise

 

So I thought I'd add what the problems are that I am experiencing. My cart tends to overheat when I am stopped at a stop sign or traffic light. The gear is in D5, fwiw. This doesn't happen all the time but it will happen every once in a while. When it does happen I check my radiator fluid and its usually not completely empty but it could use about two and a half water bottles. When I began the tests today, the radiator fluid was at the very top where the neck begins. I figured it would have lost some overnight, but it didnt. I'm almost done running the test and I will get back to you guys as soon as that happens along with the photos of my results.

 

The service manual recommends testing using 14-18psi. I went with 17psi.

Okay, here's the results:

Thermostat held 17psi for both 5 and 10 minutes.

Start: http://imgur.com/Z4yl8lw
5min: http://imgur.com/MMW2X5t
10min: http://imgur.com/JE6gBmk

Radiator dropped 1psi after 5 minutes, but held at 16 psi after the 10th minute.

Start: http://imgur.com/1zdvRLD
5min: http://imgur.com/UYQJ5O2
10min: http://imgur.com/6lbmZCP

 

Edit

 

Some more stuff I'm hoping someone canbhelp me out with (kibda lonely in here):

1. Sometimes the smell of engine coolant "farts" the the driver's side A/C vent (not sure if passenger side as well. What could be leaking near that area?

2. There's a strong smell of engine coolant by the front grill where the radiator is. Is this normal?

Anyway, I didn't find a visible leak and I forgot to upload a pic of the cooling system wiring to my Dropbox so I could have it on my phone, so I'll be doing another check tomorrow for leaks.

I also read that the water pump will and get under the oil pan (was for an MDX, not sure if it also applies to TLs). I'll be going under tomorrow with a paper towel to see if there's liquid there and if it's engine coolant.

 

to ck water pump put the car on ramps or jackstands
remove any lower engine splashguard/cover- not timing belt cover!!! needed to view water pump from below
It has a special hole that drips out fluid when inner bearing/seal has worn out
Coolant leaves a whitish trail or other stain looking stuff in a downward direction from hole on bottom of water pump

you DO need to know if both fans are working, and working correctly!
that loss of coolant- 2 bottles- is enough to screw with fan sensors making fan not run!
MUST burp system after coolant loss of that magnitude, just adding wont take care of the air in system, remember heat ON full hot while burping- its a mini radiator
Could be source of coolant smell inside car too! coolant passes thru it
Was there any wetness of driver/passenger foot/floor carpet after smell?

Smells-other potential places: from that wp drain hole, or from crack on seam of radiator- that's pretty common failure, a seam split -leak Ck for fluid present on outside of seams after you pressure test rad

Since it didn't lose coolant overnight under pressure I doubt its a head gasket- so far~
not losing coolant into cylinders= that's good
So the water pump becomes a more likely suspect = coolant is lost during engine running, temp rises when at idle then comes down once water is pumping again

there is no good reason to smell coolant when everything is closed up tight!

 

did you ck all the hose clamps? the thermo was replaced so at least 1 hose was off, could lose pressure there

 

I did and they all appear to be bone dry, but I'll re-inspect. I'll also check the thermostat by removing the housing and seeing if there's a leak.

I also did the radiator test wrong as I forgot to top it off with engine coolant. I thought it had some left over but that was a visual inspection rather than actually sticking my finger inside to check. When I refilled with engine coolant later that day, it looked like it still had coolant but my friend checked with his finger and it was just the walls that had coolant in them. Hopefully with the radiator topped off, the leak will be apparent.

I'm beginning to think it's the Heater Core. Symptoms include loss of engine coolant in 1-2 days, no obvious signs of leaking, a "fart" of engine coolant from the driver's side once in a while and afterward the engine coolant can be smelled when I step out the car. However, there isn't a puddle of coolant on the floor near the firewall nor does the smell last. My windows don't fog up and it doesn't smell like radiator fluid the times I've turned on the heater to cool down the engine from overheating. Plus the fact that my radiator smells like engine coolant and I'm pretty sure that's not normal.

What do you think?

I seriously hope it's not, but knowing my luck...

Thanks for the reply, btw. I can live with the other problems I've had, but I cant have the car overheating and potentially leaving me stranded.

 

I'm writing all this down to check tomorrow. Burping will be the last thing I do as it involves money ans having to apend $20 on Honda Type II engine coolant over and over will burn through my wallet.

BTW, can I use another type of engine coolant as long as it's 50/50 and antifreeze/coolant?

Not sure if you read my previous response yet, but I believe that the radiator lost coolant overnight. I'm gonna top it off with water before going to bed. Please don't let it be the head gasket, car gods!

 

Cheap brand 50/50 coolant is fine i recommend using the spill free funnel for bleeding the system it'll make your life easier. =]

 

I found a leak just now: imgur: the simple image sharer

Also, I noticed this a whilw back. It seems this green stuff (radiator fluid IMO) had seeped down at some point in the car's lifetime, but I have yet to see it wet: imgur: the simple image sharer

^ also, notice in the second pic how the radiator fluid disappeared. That little bugger sure is tricky. I got lucky to find it.

Where do you guys think I should go from here? I haven't gotten to the water pump, thermostat, nor the fan motor inspection yet.

I'm thinking I should drain the coolant, remove that hose, inspect and replace if necessary, then dig deeper into what that fluid down the seem was to see if there is indeed another leak there.

 

I went around the back to check out that seam that was dripping and I found two things:

a) a drop of what appears to be radiator fluid that has gummed up: http://imgur.com/RTjKTYx

b) the seam is wet in the back side. In the original pics, it was dry. I know this pic doesn't show it too well, especially the sides, but here it is nonetheless: http://imgur.com/RTjKTYx

What do you guys think? I've yet to look at the service manual to see the assembly of that piece. Being a beginner mechanic and taking a shot in the dark, I'd say there's a gasket/seal there that's bad.

Also, I texted the previous owner to see if he bled the coolant after installing the thermostat. Just waiting for his response.

 

Edit. Posted the same pic twice.

 

Check all of the coolant hose's connecting clamps. Anyplace ya see a leak, closely inspect the hose's end condition and replace the clamp if the hose is still good.

 

http://imgur.com/R7b3Z6i

Looking at the service manual, there's supposed to be a rubber seal where the thermostat housing is. In my car, it looks like it's metal-to-metal.

will do. Looks like I'll be headed to the junkyard for some parts.

 

did seller use a real Honda 2 stage thermostat? if not throw it out and get the right one

obvious there was and probably still is a leak at thermostat housing gasket and those hoses look swollen- are they soft? that can suck in and stop the flow of coolant!

not all pics working for me, did you find a rad seam leak? hows the wp?
ck price of junkyard and rad repair shops- they get new rads at good price

 

burping does not require adding mass amounts of coolant, just topping off a little bit during procedure, as air is displaced = coolant replaces it!

 

He gave me the receipt when he sold me the car and he got the part directly from the acura dealer.

I don't have a baseline to which I can compare my hoses to. Are they supposed to be stiff? I'm able to squeeze them about less than half an inch. This is the first car I've ever been so engaged in mechanically so you'll have to pardon my ignorance on the subject.

I'll check all links and post back if any of them don't work. You may have to copy and paste some into your address bar as acurazine didn't convert them to clickable links.

The rad seams don't appear to be leaking. I only checked out the top and side seams. I plan to check out the bottom seams when I remove the rad and goce it a good cleaning.

I haven't checked the WP yet cuz it requires a jack and I don't have one so I'll have to go to my friend's house to use his.

 

Damn, I was thinking of flushing the coolant. Had to watch a video to see what you meant. Sorry, I'm still a noob to all of this. I'll do this tomorrow.

BTW, the links work, you just have ro copy and paste the ones that aren't clickable. Sorry about the inconvenience.

 

if you want us to see the pics please use the link that says- display in web page/web forum, that should put them up directly

what are you talking about remove and cleaning the rad? this is not a rinse with hose in driveway type job! a special shop takes it apart and boils and rod ram thru's etc

I don't recall- do we have plastic side panels on the rad? back in the day those were throw out items once clogged or leaking at seams
Call a few rad shops and ask if that rad is serviceable or toss only

 

I can tell from the pics those hoses are beyond use! aftermarket is ok to use

they are fairly solid rubber when good-ck new at parts store for comparison
When soft spots or overall soft its likely to shed internal material or get sucked closed under pressure! and those are right to the thermostat!!
those have swelling and expansion, obvious signs of issues
get new SCREW TYPE clamps too- its important to go modern- the OE were designed to be fast for a robot to install- but maybe not the best thing for the purpose

remove all the buildup of crud from hose connections, ck for pitting or other ways for it to leak

 

Alright, I was just hesitant to do that since all my pics are a large resolution.

Ahh okay.

Not sure;I looked everywhere but under since it's covered by the bumper.

 

Alright, I'll buy the hoses at my autoparts store along with the screw type clamps.

I'm guessing you want me to check all the hoses and not just the upper and bottom hoses, right?

 

Hey AMart83, ya are really overthinking this whole thing, IMO.
~Did the original coolant appear discolored or rusty ?
~How did the radiator look inside from the top, any residual build-up ?

If a new Honda T-stat was correctly installed along with fresh coolant, check for any apparent leaks once the motor is up to operating temp. Pinhole leaks around the hose end clamps are sometimes difficult to spot. If the upper and lower rad hose appear to be the originals, buy some new ones along with retaining clamps. Make sure that the mating surfaces are in good shape.

Once everything is installed and secure, bring the motor up to temp and "burp" the air pockets from the system. Make sure that the cooling fan activates. If ya still have issues, consider replacing the T-stat and rad cap. Put a piece of cardboard underneath the motor when ya shut it off to see if any coolant drips down from the WP. Retighten coolant hoses as necessary.

 

I suspect ongoing leak at thermostat housing and hoses, possible wp failure leak too
rad clogging always possible

Yes! ck and replace the lower rad hoses,,ck the hoses to heater core too - its all the same system

by looking at top of rad- you can see and touch the top outer edge side part -that holds the rad together, from metal used as the top of rad

Radiator gurus or someone willing to look under their hood tell us the answer please!
my car is all the way outside......

 

iirc the Honda t-stat has a dot stamped on it that you have to line up to another inside- is that correct -
anyone who has done the job?
could mess with its operation- I am looking for stupid out of the box things that go wrong - while suspecting the last thing done is still the culprit!

looking inside rad- you should see clean opening slots- not grunged up- easy to tell

As the last owner had new tstat and other steps to fix overheat, I doubt there is any telling of what was going on in fluid before
based on hoses I say its been a while since coolant changed- when was last wp change?

After 5 years -or less with some brands, the additives in coolant go bad and the mixture turns acidic in an aluminum environment - that's totally not cool

pitting of the hose connections is very possible as well as internal clogs of rad
hopefully no internal pitting damage to cooling system
Even the water pump suffers with old coolant

this reminds me, its been 2 years = time to change the coolant in my Honda 2 wheeler
If you think that's often, you should see how much the oil has to be changed!! vtwin 1100 and cruises at 4000rpm,,lots of stress on the oil

 

Also, just want to throw out that I when I checled the hoses before, it was with the engine cooled (not cold), so there was a lot more play. After checking the hoses with the engine up to temp, they were a lot more firm and didn't squeeze much at all.

Looks okay to me (yeah, I realize my reservoir is all the way to the top. Ive been topping off the radiator with water ever day and it hasn't helped, fwiw. I'm, gonna empty it out half way tomorrow rather than tonight b/c some hippie says that's it's bad for the environmen if I don't dispose of it properly. Also, not sure where the reservoir should be at b/c the owner's manual tells you to have between min / max in one page and then it says to have it max on another and it also never tells you what temp the engine should be in the instructions they're referring to. I guess they figured it'd be a lot more fun if the owners had to figure this out for themselves).

As for the radiator top, there's some rustic stuff in there, but the times I've topped it off with water, it's always been green.





The upper hose has a Dayco sticker on it and it appears to be the same one that I bought. The lower hose doesn't have a sticker on it. Other than that sticker, I don't know how to tell if it's the OEM hose or not. I do know that both those hoses cost me $37.

I'm gonna have to get inside the thermostat housing because something isn't right as evident by the radiator fluid seeping out of it. I'm looking forward to replacing that rubber seal that the service manual says has to be replaced when you remove the thermostat since the closest dealer to me is an effin ripoff (shotbout to Braman Honda). At the same time, I'm concerned that it's seeping out of a metal-to-metal connection with no gasket or seal other than the rubber seal for the thermostat b/c that would mean there's something wrong with the seems for either side of the metals. I'm really hoping this a-hole previous owner just made a mistake that can be easily correct, like an incorrect installation or not tightening the thermostat housing back properly


Thanks for the tip on checking the water pump.

 

The service manual implies that the thermostat "pin" needs to slide in to the part it install to that has an opening for the pin and the gasket / rubber seal has a half circle that needs to align with the pin. None of this is explicitly stated, but the diagram does imply that that's how it should be.



Of course, to make things more fun, any pic you find of a thermostat shows that the gasket half circle goes in the opposite direction of the pin.



I posted pics of the radiator top. I know you can't see the sides, but there doesn't appear to be any grunge on the inside, but there is some rustic liquid stuff which I fear may be oil.

I doubt the water pump or tbelt has ever been changed. At least the service records on the carfax don't show it. First owner was probably oblivious to 105k tuneup. I know I was before I bought the car. And I definitely won't be changing them on an engine that's potentially flawed (waiting to fix this overheating problem before I run a compression test).

Not sure what I would look for that. I'm guessing that's inside the engine.

I'm not sure what pitting is. A Google search says that it's "make a hollow or indentation in the surface of".

 

The thermostat housing is definitely suspect, or the rubber seal / gasket I should say.

3.2 CL gave me a tip on how to check the water pump so I wouldn't have to buy jack stands. I eventually do plan to buy some jack stands to install the motor mounts, but not at the moment and not at the rate that I'm spending money to diagnose this problem. I'm not even sure about replacing the hoses just yet until I check out if the thermostat was installed properly.

I'm not sure how to check for radiator plug in, I'm guessing I have to take it to one of those specialists that you talked about in a previous post

I'll definitely inspect the lower hose when I take it out and I even post pics so you guys can give me your thoughts. I'll have to find out where the heater core hose goes to on the firewall. I'm pretty sure it goes on the passenger side, but I don't know what it looks like. I'll have to reference the service menu if they have a diagram of it.

The seams on the top of the radiator don't appear to have any leaks. Even when I ran the pressure test, I check the seams and there was nothing coming out of it.

 

Edit.

 

pics in parts sales sites are `representative` of the part sold and MAY/WILL differ from actual product!

that diagram is explicit that the PIN is important and has a correct installation place, says so right under the word thermostat AND has PIN marked clearly as well
It goes in 1 way for a reason. That's why we say buy genuine!

Wonder if the last owner installed without new GASKET/oring --ck if the part comes with, or a separate order- thats honda for you!! oh you wanted a gasket too??? wow man

So 1 hose was replaced- probably an obvious leak or popped hose!
You can tell old hoses from the swelling that occurs on short side of hose past the clamp
and indentations in rubber of the clamp indicate age

Soft is soft, face it- those hoses are 10 + years old and been subjected to some heat above normal range

Have you redone the pressure test with full rad and heater open?
Try with rad cap off- heater ON, start and warm engine till fan runs and turns off
Install pressure tester, turn engine off and set pressure
or pressure test with spark plugs removed?

the res bottle has 2 lines raised on its exterior- lower is level with engine DEAD COLD
Upper mark is when engine is warm (hot) and shut off- some fluid transfers and raises level~
In the morning it gets sucked back to rad to keep it full and free of air

Make sure the hose INSIDE res cap is firmly attached to its nipple, or no system transfer. ck hose from rad raised neck part to the res bottle
make sure it can transfer the coolant

ANY buildup on the cutouts inside the rad are bad news, it its a lot its really bad news
That's clogging

Pitting, imagine the metal part had acne scars- little holes and depressions on the surface. You want nice smooth metal the hose can seal against~
there are a few liquid brush on products- gasket cinch/gasket sealer that help seal any hose at connection, we use it on every coolant hose, even vac lines on the race cars and motorcycles

the heater hoses will be 2 approx. 1 inch diameter next to each other or stacked going thru the firewall- with rubber grommets to protect hoses
next to the heater valve assembly- a good flashlight helps

car ramps are 25$, or a curb works- all you need is to slide under part of the car to ck wp and other things dripping or pouring coolant from them
I have seen bad heater hose cause engine failure
definetly ck those right away!!

we should all ck all the hoses = 11-14 years is a long time for rubber products to last
The TL runs so well and looks so nice, its easy to forget the ol girl has been around the block a few hundred thousand plus times

 

iz that rusty corroided radiator? Mr. Honda think so...

 

its not looking too good = I have a lousy monitor and refuse to wear my glasses~
combined with swollen hoses, and probable ancient water pump, all equal the overheating issue

the rad shop guys will be your best guide- show them the original pics

 

I wish I could say I've been working on the issue. Unfortunately, the weather has been absolutely horrible in Miami and I don't have access to a garage. This is the upcoming week and it's pretty much been the past 3 months or so.





I'm hoping to tackle this on Monday or Tuesday, but I doubt it. I'm so depressed right now because I can't have my car overheating and the weather hasn't permitted me to work on it (real shitty timing for it to rain, to say the least). And with DST ending, my window of opportunity to work on the issue is really tight, if at all.

 

I had a mobile mechanic come by to inspect my overheating issue (he came highly recommend)

I hadn't told him anything about my car other than the symptoms (car runs fine for about 10 minutes, then when I'm stopped like at a red light, the temp gauge begins to rise).

He told me to start up the engine; he heard the misfire.

Then he told me to turn on the A/C (to test if the fans were working, I presumed).

He checked the radiator cap and the oil cap by looking under them and smelling them.

He topped off the radiator with engine coolant (the coolant was bubbling after it topped off).

I showed him that spot near the lower hose which I posted a pic of. He just touched it with his finger a few times and didn't make mention of it.

He told me that there's a leak inside the engine (head). He told me that when I start the car up, white smoke will come out of the exhaust. It didn't show up this time, but I can attest that it's been happening more as of late (I'd say around every 4-7 days).

He said to fix it would be costly. I brought up the possibility of swapping the engine. He told me that's a good alternative and he knows of a shop that sells JDM engines and he'd do the swap.

My main concern is that he didn't do a compression test or leakdown test to verify that the leak is indeed inside the engine. I know I'll likely have to swap the engine because because of that CEL I'm getting from my cylinders misfiring, but I'd like to know for a fact that the cooling system is good so I don't void the warranty on the new engine in case the car overheats again. That's my concern right now.

What do you guys think?

 

May want to consider a second opinion at a local independent shop familiar with Honda products.

 

Will do. There's some Japaenese Auto mechanic shops around me so I'm gonna shop around for quotes to diagnose it. I'm also thinking of taking it back to the first mechanic that I spoke with about my CEL. My only concern is that he'll just go along with the original problem that's causing the misfiring because it's more cost efficient to give me that answer (plus I'm sure they want the business of doing the engine swap).

Also, I texted the mechanic to make sure he was absolutely certain and I told him it was because it would void the warranty if the the engine overheated so I need to be absolutely sure. I'm waiting to hear what he says.

 

It's a lot cheaper to troubleshoot the cooling system for issues than to replace the motor.
Make sure that everything is working properly, have the system pressure checked and have a cylinder leakdown test performed before replacing the motor. It'll be evident if the heads were previously cooked
due to being overheated for awhile.

 

I've already pressure tested the cooling system (results were posted in this thread). Are you referring to a compression test for the engine?

Also, is a leakdown test necessary if the compression test fails (at least in my case where it makes more sense to replace the engine than to pay to fix the issue).

I can do a compression test by my own, but I don't have the means to do a leakdown test. Also, I would have to find a way to get the engine cover off since the previous owner stripped 2 of the screws.

 

I'm not questioning your previous troubleshooting tests, but if unsure get some professional help.