shahram72

If it was pristine and rust free, I would have found a cheaper repair or replacement engine for it. But maybe he was tired of the car anyway. I won't be springing for any repairs on mine over $1000 with the rust. Each person has different resources (not just talking money) and they have to make the best decision they can. This happens with cars. We had our old Pilot totalled and I toyed with the idea of getting another similar 06-08 Pilot(mine was an 04), but in the end we got a new CRV. We gave up A LOT! But it is new and serves it's purpose well. Here on the Acura site you guys know what I mean, but I just chuckle over on the CRV site with all the gung ho CRV owners with their $30K CRV's. It's still a cheap car. We got the LX. If you're going to go cheap, go cheap. If I was going to spend $30, I'd just go 36 and get the Pilot EX-L.

ultrab20

I have this same exact issue. Has anyone ever figured out what this is? Radiator was replaced in 2016 with thermostat. Just replaced both fans with the fan control brain. It's mostly with the AC on exactly how described here.

drolds72

If you are losing coolant, you need to find out where its going, otherwise you will wind up in the same spot as the OP. Pull you right front tire, pull down the plastic shroud by removing a bunch of the pushpin clips, and look for evidence of a weeping water pump. There are channels that will move the coolant down to the bottom of the block, and evidence will be a whitish blue residue. If that is the case, you need a new water pump. If not the case, you need to buy some UV die, dump it into your coolant, buy a black light for your trouble light and find the leak. If that does not work, you need to have somebody check for hydrocarbons (exhaust) in the coolant. If your state has emissions check, sometimes they will take the wand and pass it over the steam that comes out of a radiator neck..... And make sure both fans are functioning as they should when AC compressor is engaged

ultrab20

yeah will need to do a pressure test- we just replaced the fans last weekend and topped off both the reservoir and the radiator. It was fine monday- but yesterday it started misbehaving at low speeds under low load with the AC on- shut the AC off and it shortly after went down- came home and checked both fans were running- after it cooled i checked both levels of coolant and all was still full and well. Oddly i could smell coolant burning when it started to creep towards the red-but that could have possibly been from the residue left after changing fans on this past sunday. I found the below from the first gen RL forums and this is my exact problem as well:

ultrab20

im wondering if this could be an AC issue possibly and the overheating is just a symptom. It seems intermittent.

drolds72

I used to own a legend. HG failed in between cylinders, consuming coolant, and then you would see the temp gauge fluctuate as air got into system. This is virtually unheard of in the 2nd Gen cars. Start eliminating things....

ultrab20

Agreed. We were able to narrow it down. The fans are intermittently not getting the signal to kick on. Cleaned fan relay contacts and have another enroute. Not driving the car daily for now til it gets sorted. Tracing in circuit diagrams what all contributes to fan signal activity.

ultrab20

This is jackpot. Ac is coming on but sometimes neither fan is. It's intermittent so likely ground. Left headlight is flickering which is also the same ground G301... Possible

drolds72

that would be great if it was the ground, because changing the left headlight without removing the bumper is a biatch!

ultrab20

I replaced the radiator and fan control unit and lastly the fan relay- it was likely the fan relay by the left headlight under the air box. been fine ever since.

Matt W

Thanks man, I have been having this exact same issue with the exact same symptoms. My radiator was replace last year as well.

Is this the relay you are talking about?

Matt W

I looked today and I have a nice crack in the air flow tube between the engine and the air box. I only have the issue when stopped, it slowly creeps towards halfway on the temp gauge after sitting for a bit. I open the hood and both fans are running. Regardless I have an air flow tube replacement on the way. Could this be contributing to the temp gauge rising... the engine pulling in hot air from the engine bay through the crack? Seems a little far fetched...

projektvertx

iTrader: (2)

If it's the air tube I'm thinking of, that's the air intake tube for the engine. Sits right in front of the battery?

teh CL

iTrader: (1)

I think he's talking about the intake tube from the TB to the air box.

Quote:

Originally Posted by Matt W

I looked today and I have a nice crack in the air flow tube between the engine and the air box. I only have the issue when stopped, it slowly creeps towards halfway on the temp gauge after sitting for a bit. I open the hood and both fans are running. Regardless I have an air flow tube replacement on the way. Could this be contributing to the temp gauge rising... the engine pulling in hot air from the engine bay through the crack? Seems a little far fetched...

No chance. Have you had any work done recently?

Matt W

Welp you were right. The intake is not the issue (still needs fixed of course). I duct taped it up and engine heating issue persists. ANOTHER issue just started happening that is freaking me out and I am not sure if it is related, video below.

This noise happens randomly while at a stop, in both drive and park. When I shut the car off it persists for 1 second. If I immediately turn the car back on, the noise is gone.

No recent maintenance, I am approaching 190K miles, and was considering getting the timing belt/waterpump/tensioners and related parts replaced early since I feel like this could all be related.

This thread has a video that shows almost the same noise as mine with no resolution: https://acurazine.com/forums/second-...2006-a-920210/


EDIT:
Sounds similar to these videos which are saying failed timing belt tensioner...

teh CL

iTrader: (1)

Yea that definitely sounds like the tensioner..

Matt W

Welp, looks like I will be doing the maintenance sooner than later... the cheapest quote I got from a third-party shop was $960 for the timing belt/water-pump/tensioner... Fingers crossed that the engine heating issue is the water pump.

teh CL

iTrader: (1)

Could be the thermostat as well. Might as well get it all out of the way.

projektvertx

iTrader: (2)

+1 on tensioner and water pump then. Yikes, that tensioner sounds rough...

Matt W

Still haven't replaced anything yet. I have a combustion leak test coming tomorrow to be sure it isn't a BHG.

The temperature will creep up while idle, if I rev the engine around 2-3K RPMs the temperature drops back down to normal. Not quite sure what to make of that... from what I can find online it could be BHG or the thermostat... not sure if anyone else has any ideas.

projektvertx

iTrader: (2)

That honestly sounds like it could be a weak water pump too? Not generating enough coolant flow at idle.

01acls

First you should check the coolant level and the radiator cap for defects or replace if it wasn't replaced during last major service. Maybe try burbing the cooling system to see if there's air in it.

Next you should try swapping out the fan relays from another known good ones on the car if available, if not replace or power the fans directly by jumping the hot to the fans at the relay fuse box if you know how.

If the fans check out then you should replace the thermostat first before doing the water pump.

Matt W

Radiator cap is good. I've tried burping the system twice now. Fans are good as well.

I believe the thermostat is stuck closed, after almost 20 minutes there is no coolant coming through the upper hose to the radiator. Also after a long drive the upper hose is only warm and can be squeezed easily.

horseshoez

iTrader: (2)

Water pump failure?

Matt W

I will be replacing the thermostat this weekend when I replace the intake tube. I'm going to check to make sure the radiator isn't clogged as well, which I am leaning towards at the moment. I have a hard team believing the water pump failed as there is no sign of leakage and the temp gauge only gets up to about 70% and is fine while the vehicle is at motion, so fluid has to be circulating.

Matt W

Welp to update on this. I noticed I could not see any fluid in the radiator with the cap removed, even though the overflow tank lank level has always been between mid and max... so I picked up some more coolant to top it off directly from the radiator, and it ended up taking a whopping 1.5L of fluid to get it to the top! Some how the radiator was not drawing any fluid in from the overflow tank. I burped the system and have been driving like this fine for a few days, and the car is now working perfectly fine! The coolant level still did not seem to change in the overflow tank, so I took the tank off and cleaned it out, along with clearing the liquid out of the overflow tube. I put the tank back on, filled it to mid, and drove about 20 miles. Once I stopped it had almost sucked the whole thing dry. I topped it off and replaced the radiator cap with a new Gates radiator cap.

So in summary, it seems the coolant system was about half full and not drawing in liquid from the overflow tank and I think that explains why at 2-3K+ RPMs there was enough fluid circulating through the system to keep it adequately cooled, but idling at <1K RPMs the engine began to climb up to about 70% on the temperature gauge. When I had been taking the radiator cap off in the past it sounded like air was being sucked in... so maybe the radiator cap was bad, or the overflow tube was clogged... I was thinking going into this that maybe my head gasket had a slight leak, but I re-performed the combustion gas test and that was negative.

I will continue to monitor and make sure the radiator stays full and the overflow tank level fluctuates as expected when the engine is hot/cold. I will flush and replace the thermostat sometime this summer as well, once it gets warmer out.

nickelrw87

i JUST had this happen to me, turns out the AC fan motor - drivers side - went bad. The part was like 400 something, and install was another 300. I went to the Honda dealership to diagnose. Now it doesnt even hit halfway

MarcinK

Hi All

Hard to say but I have similiar issue within my EU version of Acura RL, year 2007. Mileage is about 200.000 miles but engine was repaired about 35.000 miles ago (headgasket, shaft bearings replaced etc), Two weeks ago I have replaced thermostat and everything looked better but today driving with heavy loaded car hot outside 88F and driving in the mountains with AC turned on I can see temperature gauge went up to 60% when usually it is at 45%. My OBD scanner showed that temperature was 230F and fan was working hard then (manual says that fan should start at 220F. During idle temperature goes down and keeps 195F even if engine runs hours. During highway drive with speed 100mph temperature keeps about 100F stable.
But in the city when I start and it is hot outside temperature increase but after longer stable speed drive it goes down to normal level.
So it looks temperature increase during engine heavy load. They have also tested that there is no head gasket leak (no exhaust visible in the coolant - thested CO2 presence).
So what and how should be checked? Radiator to change? Radiator cap issue? Water pump? No coolant leak visible, radiator full.

Any idea?

Regards, Marcin

01acls

Check for blocked air flow through the AC condenser/radiator and/or missing radiator air deflectors.

With the cooling system cool/no pressure, remove the radiator cap and run the car until the engine is at normal operating temperature. Look for coolant flow through the cap opening as the themost opens and closes. The fan should also simultaneously turn on and off as the thermostat opens and closes. You should see a steady stream of coolant flow from one side to another. If not then the rad tubes are clogged so replace the radiator.

misdeismo

I know this is a few months old but this may help others have similar issues. I had similar symptoms of my car overheating, about 60-70% on the gauge when I was idling in traffic for a period of time. I changed both fans, the radiator and the radiator fan control unit. I changed out the thermostat, the old one was working by the way, then re-bled the system until I was absolutely sure there was no air in the system. Same problem. Some of the symptoms I began noticing:

1. In traffic, when it was pretty hot out (over 90deg) temperature would begin to rise after about 5mins
2. Speeds lower than 10mph would also cause the same overheating issue
3. If I had the AC blowing cold air, it would become warm when idling for about 5mins or driving at low speeds
4. Temp would go back to normal when driving at normal speeds
5. Fan would come on intermittently, I noticed that they didn't come on when the temp was increasing
6. Both fans work when activated (both fans should always come on together)

All this led me to believe that the fans weren't working as they should. Then I began thinking about the the relay. I learned from my Legend days that relays can fail intermittently (main relay in the Legend) especially when hot. So I figured the radiator fan control relay was failing in this manner as well. I replaced the relay and what do ya know, problem fixed!

So if your ac isn't blowing cold and your car overheats when sitting in traffic but gets better when driving at speed it's most likely the fan not working when it's needed the most, when there is no airflow. Since the coolant and refrigerant both cool via the fans blowing over their respective radiators, it was easy to begin making the connection about what was causing the problem.

Hope this helps others!

MarcinK

Interesting. Now I can see that issue started after I have replaced old radiator fan with new one aftermarket by Dorman (bought at Rockauto). I have to check it. BTW is fan 1 speed or more?

misdeismo

I believe the fans have two speeds depending on what condition triggers them to come on. It was a while ago but I remember getting Dorman fans from Rockauto as well.

MarcinK

I have checked how fans work today. There is quite warm today about 86F. I can se both are working quite fast but both together. If AC is on they start slowly but immediately and both, if AC is off then they start when engine is hot enough but again both at the same time.

And even after 30 minutes of engine working during parking temperature was perfect. So I would say that maybe AT is my issue root cause. Temperature increases after some starts and stops like usually in traffic jam.

misdeismo

Sounds like the fans are working properly to me. If the fans are working but the engine is still overheating in my opinion that would point to the thermostat being stuck closed. I know you just got a new one so that would seem unlikely but is the new thermostat OEM?

JCRamrod

The same thing happened to me, and it ended up being a bad radiator cap. After replacing it and topping off the coolant, all problems went away.

misdeismo

I also had a bad radiator cap at one point. So many points of failure just glad I never got to the point of getting a blown head gasket.

An an update on my specific situation, I replaced the fan relay and I thought that fixed the problem but problem came back after a few days. So I figured if it wasn’t the relay it was probably the actual radiator fan control unit intermittently failing.

I bought a new one a few days ago and when installing noticed something very interesting. The one that was on my car was aftermarket, OEM is made by Denso and says so on the unit. Another thing I noticed was the heat sink for the aftermarket unit was half the size of the Denso one WTF?!?!?

After the swap, the fans came on exactly whenever they were supposed every time unlike before. So in my case it ended up being a bad radiator fan control unit because it was aftermarket. Stuff like that, always get OEM.

Will update again in a few weeks.