2008 185 Sport - Temp Alarm?

MarkD

MarkD

Member
Oct 5, 2006
355
Hudson River
Boat Info
1990 35' Sundancer
Engines
twin 454 inboards
i have a 2008 4.3L TKS, Alpha 1 drive 185 sport (raw water cooled). I was out this weekend with a buddy just doing a shakedown cruise. I had been running at slow rpm (under 1600) for 3 miles down our creek. When I got to the channel I opened it up a bit to 3000 rpm and ran it for a few minutes. The boat seemed to be at normal operating temp. when i raised the throttle to 3200 or greater, there was a high pitched beep or alarm that went off. I looked at the temp and it seemed to be fairly normal (maybe ~180) and i backed off to 3000 rpm. The alarm immediately went away. i tooled around again close to home keeping an eye on the temp. i then opened it up again to 3600 and after a minute, the alarm went off once again. after that i came back in and shut it down at dock. I checked oil & drive levels, obstructions in the drive (i.e. plastic bag/grass caught in the drive) etc. Nothing.

Now, I had winterized the boat with that Camco ear muff and jug kit, but it did seem to get very hot (temp wise) when I did it...temp alarm went off back in december; not overheating but hotter than 180. I am leaning towards having a fried impeller and possibly a stuck thermostat, but honestlyt I am a little unfamiliar with Alpha drives. So, does the Alpha have a built in impeller inside the lower unit? I dont recall seeing any seawater pump attached to my 4.3 liter engine.... Can someone clarify that for me?

Is this something I can do myself or just take to a shop? I have decent mechanical skills and some basic tools. How much would an impeller be to replace (parts wise).
 
The impeller is located in the lower unit and is fairly easy to replace. The parts are not expensive either.

I don't think you have a problem with the impeller though. If the impeller was out, the engine would get hot very quickly and stay hot, regardless of RPM.

I am actually having the same mystery with an engine alarm on my boat... anytime the boat is loaded with people, the alarm sounds when I start to get above 4,000 rpm (all gauges read normal). Pull back on the throttle and the alarm stops sounding. The interesting thing is that when it's just me and the wife on the boat, I don't have that problem (up to WOT). I'm thinking it's a sensor issue, but not sure where to start looking.
 
Well, it could be the thermostat I guess... i have not changed it in 2 full seasons. I am in completely fresh water though and wasnt going to mess with it until end of this year or before I commision again in the spring of 2011.
 
Texas.... I am pretty sure yours is the gear oil. It's low enough that with a light load it won't sound the alarm but loaded it's moving the oil enough to set it off.

Mark, check yours too just to be on the safe and cheaper side. Then dig into the thermostat 2nd
 
Thanks for the input Fire. I'll check that when I get home tonight. The last time I checked though, the remote reservoir was to the 'full' mark. Could it not be flowing correctly? How could I check that?

Also, can you explain a little more about how the alarm works (and why it sounds with a load, but not without one)? I can't picture it in my head at this time......
 
Inside the overflow bottle there is a sensor. When the fluid gets low it basically loses it's ground(the fluid acts as a conductor and makes the connection as long as there is ample fluid in it) when under a load and depending on how the fluid is sitting in the bottle it can shift just enough to cause the sensor to go off. If the bottle is full. Then that is not the problem. Look at the fluid again and see if it burped a bubble and the level dropped. Also double check the wiring on the bottom of the bottle to see if the connections are tight. If that doesn't solve it we will go from there
 
MarkD said:
i have a 2008 4.3L TKS, Alpha 1 drive 185 sport (raw water cooled). I was out this weekend with a buddy just doing a shakedown cruise. I had been running at slow rpm (under 1600) for 3 miles down our creek. When I got to the channel I opened it up a bit to 3000 rpm and ran it for a few minutes. The boat seemed to be at normal operating temp. when i raised the throttle to 3200 or greater, there was a high pitched beep or alarm that went off. I looked at the temp and it seemed to be fairly normal (maybe ~180) and i backed off to 3000 rpm. The alarm immediately went away. i tooled around again close to home keeping an eye on the temp. i then opened it up again to 3600 and after a minute, the alarm went off once again. after that i came back in and shut it down at dock. I checked oil & drive levels, obstructions in the drive (i.e. plastic bag/grass caught in the drive) etc. Nothing.

Now, I had winterized the boat with that Camco ear muff and jug kit, but it did seem to get very hot (temp wise) when I did it...temp alarm went off back in december; not overheating but hotter than 180. I am leaning towards having a fried impeller and possibly a stuck thermostat, but honestlyt I am a little unfamiliar with Alpha drives. So, does the Alpha have a built in impeller inside the lower unit? I dont recall seeing any seawater pump attached to my 4.3 liter engine.... Can someone clarify that for me?

Is this something I can do myself or just take to a shop? I have decent mechanical skills and some basic tools. How much would an impeller be to replace (parts wise).
Click to expand...

I've had a similar problem in the past... turned out to be a bad oil pressure sensor. I'm not familiar at all w/ your engine... not even sure if it would have a oil pressure sensor, could just be the analog oil pressure SENDER. Worth giving that a look as well.

Good Luck.
 
Thanks again Fire. I'll give that a look when I get home tonight. Unfortunately, it's going to be a couple of weeks until I can get to the lake though, so I won't get to test it until then.
 
Ugh, that's horrible.... A couple weeks? I am going thru withdrawals for u! Well keep me posted.
 
Thankfully, I'll be on the lake between now and then, it just won't be with MY boat. I will still miss it, but sometimes it's nice not to have to drag it out and then clean it up!

FYI, I checked the bottle last night, and it's as full as it should be. I'll check the wires the next time I'm in the boat for something. I took the bottle out last year to drain it when I replaced the drive oil, but I don't recall seeing any wires. I could be just forgetting though.... are they in the very bottom of the bottle?
 
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Yep, should be. There should be a big nut looking object with two wires coming out of it.
 
Okay, So I am having the same problem with my 2008 185 Sport (4.3 A1 Mercruiser).
Except, mine runs great right off the bat, but if I stop for awhile to eat lunch or play on the beach, I start getting the alarm during sharp turns or side chop..then it stops beeping in smooth water. When I get back to the house, I check gear lube and it looks good. When I unscrew the cap it seems to let some pressure out and then the lube in the resevour lets a few bubble out. Then the boat is good to go without any more alarm.
Is the cap of the resevour suppose to equalize the pressure in the resevour??? Why does the lube release bubbles when I unscrew the cap?
BTW, Oil pressure the Water temp were all normal.

dave
 
Is your lube full? If it's releasing bubbles then there is air in the return line, and sir compresses, thus it could be exposing the sensor and causing the alarm to go off. How does the lube look after u have ran the boat?
 
All this talk about the drive fluid oil level has me second guessing myself. As I said before, I ran the boat at idle to 3000 rpm without any overheating condition. What Firerooster & Texas have said makes sense. If the impeller was bad, my boat should overheat quickly or definately after a ride... It did not.

I did replace the gear lube in my drive this spring. I opened the cap on the resevoir and pulled both drain plugs in the drive (upper and lower) and let fluid drain. I then added about 1.25 quarts to the drive unit before it came out the upper hole. I then screwed the upper in, then lower. All seemed ok. The crush washers are new too. I wonder if some sort of air lock could be doing it, or something else. When i was running along, the drive fluid seemed at normal level too.... Is there some other test I could do before spending all sorts of money on impellers and dealer diagnosis? I will check the oil level and wire to sensor this weekend and report back. I will also keep an eye on the temp a bit closer because I truly doubt it overheated unless the temp gauge is bad. It looks fine to me however with normal behavior.

Thanks all...
 
Look at the crankcase oil too. Just to be safe. The buzzer is only set on 3 items. CrNkcase oil. Drive fluid, and water temp. If it's not over heating, my next guess is the drive oil. But when in there, check regular crank case oil, level and color
 
The Lube looks fine after the boat has been run. I had the boat serviced in Feb, so the lube is fresh. I checked the engine oil today after my son went wake surfing and it was clean and full. He did not have any problems ( and I can guarantee you that he put it through a pretty good pace .)
I just came back from a sunset ride and no problems. Just can't figure out why sometimes air is getting in the lube line and tripping the sensor.
I'm still looking at the lube resevour cap, 'cause there seems to be some sort of one way relief valve on top of it (looks like it would let air in to equalize the resevour to prevent a vacuum).
 
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Iceman, no alarms today....? That's good. Usually after a drive service there is air trapped in the line. Yes the cap is designed to help equalize the pressure and actually allow the fluid to travel down the line into the drive should there be a leak issue. Thus keeping water out of the drive and oil in the drive( this is not always the case but the idea behind it). If your reservoir is full, and no more alarms. Hopefully the air has all worked it's way up the line and out and no more problem. Keep an eye on it and watch for milky gear lube, oil floating on the water when stopped, oil on the transom when you trailer the boat and wipe it down. Sounds as if all is well now and you should be fine. If the alarms start again, watch and note the water temp gauge. And it may be a bad sensor for the crank case. But sounds as if you r good to go at this point. Enjoy the summer and happy floating.
 
How does the alarm work on the crankcase oil? If pressure gets too low, it will sound? Likewise on the water temp, I assume if it gets to high, it will sound?

As far as the gear oil goes, is the only sensor is in the reservoir? Do carb'd boats not have this alarm?
 
As for the crankcase alarm....I believe it is pressure sender.... honestly don't know for sure. Water temp yes it is heat sensor. As to the temp yours goes off....I cannot give the exact number. On mine it's 200 degrees. Guessing yours is similar. The gear oil is a ground sensor that when the fluid in the res, is low enough to expose the sensor the ground is lost and buzzer goes off. Yes it is the only sensor in the res. And yes your boat has the alarms. Here is the spec sheet and info on your boat. Just for gee whiz stuff

http://searay.com/Page.aspx/pmId/43696/pageId/10250/view/Overview/Past-Models.aspx
 
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