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2003 Honda 225 false overheat alarm?

B

BrineTime

New member
Hello. I’m Greg thanks for welcoming me here.
I have what appears to be a false alarm issue.

Backstory:
Motor hit 1000 hours and was producing carbon from both upper exhaust ports. So recently did a valve adjustment, water pump impeller, spark plug change, timing belt inspection and deflection test, replaced both thermostats ( some corrosion and both stuck open).
This all followed a 8 month stint of salt water not being flushed from engine due to health event.
Motor ran great, fuel economy went up, engine stall at shift stopped. Things were sweet!
One 14 hour Tuna trip and multiple salmon trips later I got an overheat alarm while running. These alarms didn’t come with any symptoms and the motor restarts runs fine.
This is becoming more frequent and has done it twice at initial startup way before overheat could occur.

Im thinking water temperature sensor is my starting point. What do the experts think??
 
Hi,

Yes! Welcome to the forum!

I don't work on these and never have. Just answering to say that I've seen several instances here where many of the V6 owners report that buildup inside the water hoses at exhaust manifolds (items 6, 7. 8 and 9 in link below) will cause alarms and often overheating too.
I certainly wouldn't argue with the temperature sensor possibly causing this and checking out that "angle" as well seems wise to me.


Also. you might benefit from what member chawk_man has to say since he does all of his 225 maintenance and has forgotten more about these outboards than most will ever know.

Hopefully he'll post up an opinion for you soon.

Good luck and looking forward to what you find with yours.
 
OK, Jimmy, but I'm just a plain old owner of a 2007 BF 225 that's too cheap to pay others for maintenance if I can do it myself.

Let's start from the top. If you got an alarm, then the ECU threw a code to the EPROM. So, pull codes. I've attached the procedure for doing that, and what the codes mean. So first step is to record the current codes, then clear those codes, and then run the engine until it alarms again, and see what is triggering the alarm. BTW - if the engine runs up to 20 seconds in an overheat situation, it is supposed to shut down completely until it cools off.

Your engine has three heat sensors - one on the top of each manifold and one down deep in the V of the block. Each has its own MIL code. Code 6 (six short blinks) is the ECT or block sensor. Code 24 (2 long and 4 short blinks) is manifold sensor 1 (i think starboard) and code 25 is manifold sensor 2. So find out which one is triggering the alarm. If codes 24 or 25, check wiring and connectors. If all god, replace the sensor. It's very easy to do.

If code 6, it's more complicated. You must remove at least one of the cylinder heads to get to the sensor. That's a PITA.

Before doing that, follow JGMO's advice and clear the water hoses coming out of the exhaust manifolds.

If that doesn't help, fish around for a six-prong connector coming out of the space between the heads. Check and clean the contacts. Retest.
 

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It may have some caked salt in it, do a major flush in a barrel with 4 jugs of vinegar or some other cleaner. See if your telltale hose is clear.

If it sat for 8 months with salt in it, it may be badly caked and some flakes/crud let go and is plugging your cooling system.

I’m no expert on these 225’s like chalkman, but my 1999 BF 130 acted like this after I rinsed it in a barrel with vinegar. I also drilled out the plastic telltale sprayer nozzle to allow small chunks of salt out.
 
jgmo said:
Hi,

Yes! Welcome to the forum!

I don't work on these and never have. Just answering to say that I've seen several instances here where many of the V6 owners report that buildup inside the water hoses at exhaust manifolds (items 6, 7. 8 and 9 in link below) will cause alarms and often overheating too.
I certainly wouldn't argue with the temperature sensor possibly causing this and checking out that "angle" as well seems wise to me.


Also. you might benefit from what member chawk_man has to say since he does all of his 225 maintenance and has forgotten more about these outboards than most will ever know.

Hopefully he'll post up an opinion for you soon.

Good luck and looking forward to what you find with yours.
Click to expand...
Thank you for sharing. All information is useful. I will look into the hoses. I was considering doing the Salt Away backfill when I changed out the Tstats. Should have done it.
 
chawk_man said:
OK, Jimmy, but I'm just a plain old owner of a 2007 BF 225 that's too cheap to pay others for maintenance if I can do it myself.

Let's start from the top. If you got an alarm, then the ECU threw a code to the EPROM. So, pull codes. I've attached the procedure for doing that, and what the codes mean. So first step is to record the current codes, then clear those codes, and then run the engine until it alarms again, and see what is triggering the alarm. BTW - if the engine runs up to 20 seconds in an overheat situation, it is supposed to shut down completely until it cools off.

Your engine has three heat sensors - one on the top of each manifold and one down deep in the V of the block. Each has its own MIL code. Code 6 (six short blinks) is the ECT or block sensor. Code 24 (2 long and 4 short blinks) is manifold sensor 1 (i think starboard) and code 25 is manifold sensor 2. So find out which one is triggering the alarm. If codes 24 or 25, check wiring and connectors. If all god, replace the sensor. It's very easy to do.

If code 6, it's more complicated. You must remove at least one of the cylinder heads to get to the sensor. That's a PITA.

Before doing that, follow JGMO's advice and clear the water hoses coming out of the exhaust manifolds.

If that doesn't help, fish around for a six-prong connector coming out of the space between the heads. Check and clean the contacts. Retest.
Click to expand...
Thank you. I always forget that antiquated code diagnostics is available. I will start there. I found a video on ohm testing the temp sensors. But at $23 if I pull them they’re getting replaced. In that video it was a corroded connector plug.
Is that 6 prong connector one that needed unplugged when I did the tear down for valve adjustment. If so maybe I didn’t get it fully seated upon reassembly?
Wrenching has become quite challenging with this damned inflammatory disease.
 
NSDON said:
It may have some caked salt in it, do a major flush in a barrel with 4 jugs of vinegar or some other cleaner. See if your telltale hose is clear.

If it sat for 8 months with salt in it, it may be badly caked and some flakes/crud let go and is plugging your cooling system.

I’m no expert on these 225’s like chalkman, but my 1999 BF 130 acted like this after I rinsed it in a barrel with vinegar. I also drilled out the plastic telltale sprayer nozzle to allow small chunks of salt out.
Click to expand...
Thanks. The tell tale is good. Very good flow. As I said above I should have back filled the entire engine with Salt Away when the tstats were out. Wish I had thought of it before I was in a rush to get it back together for memorial weekend. I have no doubt the system is compromised to some degree.
 
So I attempted to pull the codes and found that the mil lights needed don’t work. I hadn’t realized that they were not functioning because I had no idea what their purpose was. The two lamp dash panel is there but there isn’t any legible labeling.
The panel has a harness connected that runs downto the control box but isn’t connected to anything. Where should this black harness plug in? See pics.
I haven’t clipped any zip ties and there is quite a bundle of wires. But the only other connector I found not plugged into anything is this white 6 pin. See pics.
Am I missing a harness that connects these two or is the correct connector just bundled up in the mess?

I am hesitant to unravel the rats nest. Does theMIL plug into controls or does it plug into a harness that runs to the engine?
 

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Cannot answer in detail. Quick question. When you turn on key switch do you get two short beeps and the panel lights blink on briefly? Do you have four lights on the panel?
 
Hi chawk_man.
The only lights working are the oil and temp lights on the shift control box where the ignition is also.
There is a two light MIL panel on the dash. From my research that is a red and green lamp for voltage and alarms. The harness with the black connector goes to that panel.
 
Well I guess I will just move on without codes.
I will pull the new thermostats and check that they open at 160 and that they are seated properly even though they were carefully installed. Im going to begin throwing parts at it. New temperature sensors will be here Monday. I purchased a new Salt Away flush attachment. Mine was broken and I have half a gallon of treatment left. I’m also going to top fill with 100% solution when the thermostats are out. Let it sit a couple hours before I use the mixing attachment.
 
Took it to the dealer. They did some troubleshooting with the computer. They called with their game plan of pulling port manifold. I asked some questions and was told in detail their findings. I was already suspicious of the new thermostats I had installed when I did the valve adjustment. I asked him to pull the stats and run it prior to pulling manifold. Problem disappeared so there was no blockage in the manifold.
Port side was intermittently being starved of water due to thermostats not opening properly.

The oddest part about this was the fact the boat had two 14hour offshore Tuna runs on it after swapping stats with zero issues. It wasn’t until my Labor Day weekend 3 day salmon trip that I began getting intermittent alarms.

Not the first time I have installed bad off the shelf parts but this was the most expensive reminder that NEW doesn’t mean they’re good.
 
Ebay. They were packaged and sold as OEM. My Honda dealer mechanic believes they were counterfeit. They were a stainless steel thermostat. The part and packaging looked very legitimate.
Genuine Honda OEM is not a guarantee. They have a failure rate also.
Seller swears they are genuine OEM but I reported to EBay. I will not name the Marine Dealer ( Seller) because I have no proof of counterfeit.
 
Did the seller replace your thermostat?

Were the new good thermostats identical looking?

Of course not impossible for a new legitimate part to fail.
 
BrineTime said:
Ebay. They were packaged and sold as OEM. My Honda dealer mechanic believes they were counterfeit. They were a stainless steel thermostat. The part and packaging looked very legitimate.
Genuine Honda OEM is not a guarantee. They have a failure rate also.
Seller swears they are genuine OEM but I reported to EBay. I will not name the Marine Dealer ( Seller) because I have no proof of counterfeit.
Click to expand...
When I was replacing the t-stats on my Honda 225 I noticed Amazon had stats advertised as Honda OEM but they looked different, they were half the price of OEM. I got OEM one's from Boats.net, You need to be careful with critical parts, people play fast and loose with the OEM claim.
 
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