Bayliner 185 Tilt and Trim Motor issue and engine temp question

[acevedor2]

Had this posted to the boat repair section and they recommended I post here for greater visibility. Hoping you guys have some insight.

Issue one: Had the boat out for the first time in two years today and noticed when I got her home that the tilt/trim motor going down is making a strange noise. I didn't notice it when I was out, but that doesn't mean it wasn't there, just that I might not have noticed. It trims both up and down fine (or at least it appears to), but it sounds normal going up and sounds strange coming down. Almost as if it has air in it or a motor issue. I did notice the fluid might be a little low, but it wasn't super low - there was fluid in the reservoir. Video link below.
https://www.youtube.com/watch?featur...&v=PnL4Klc4sL8

Filled the reservoir after work today. It was a little low and took about 6 ounces. I then cycled it back and forth about 3-4 times up and down and it sounded normal and perfect. Just as it should. I cycled it a few more times and then the noise started again. I checked the reservoir again and it was a little low again. I assume the system had air in it because there are definitely no leaks. So I added more fluid and cycled it several more times. The reservoir did not go down anymore so I assume I got all of the air out (might be a bad assumption), but it sounds terrible going down. Any idea what it could be? Could it be air still? Why would it only be in the down direction that it makes the noise?
Here is a video of how it sounds.
https://www.youtube.com/watch?feature=player_detailpage&v=2HbI4FM5GngAlso,

Issue 2: I changed out the impeller last week and noticed when I took it out yesterday that the temp fluctuated between about 175 and 200 (between 175 and the next line - which I believe is 200). It ran fine and never got higher than 187 (again - the middle of the two lines 175/200). Is that normal and if not, what should I check. Motor ran fine and strong and had her up to about 43 knots. Should I change the thermostat? One other item of note is that water temp was about 83-85 today. Pic of where it was below:

Thanks for all of the assistance. I wouldn't even have gotten the boat out this year without the help from this forum!

 

[BrianNJ]

WRT Issue 2, were any pieces missing from the old impeller? If so, they may be causing a flow restriction in the system and need to be found.

 

[acevedor2]

The old impeller was pretty burnt up, but there were no real missing pieces (pic below). Also, when I had the lower half off, we blew out all journals, etc, to make sure there was no junk, trash, etc. Anything I should check? I did find it strange that the temp rose to that point (midway between 175 and 200) when I was at throttle (about 40 kts). I would have figured the more rpms, the cooler it would run because of more water - correct? Again, it hasn't fluctuated much, but I am not sure it should be fluctuating at all...Thoughts?

 

[alldodge]

Issue 1, I don't hear or see a problem. Pressure in a trim motor is different depending if it is going up or down. The harmonics from the motor is not a current issue IMO.

Issue 2, is you engine closed or open cooling, and is it an MPI, EFI or carbureted engine? What year is the boat/engine or the serial number of it?

 

[acevedor2]

No Title

Issue 1, I don't hear or see a problem. Pressure in a trim motor is different depending if it is going up or down. The harmonics from the motor is not a current issue IMO.

Issue 2, is you engine closed or open cooling, and is it an MPI, EFI or cerebrated engine? What year is the boat/engine or the serial number of it?

It was never making the noise it is making until now - up or down. In person, it sounds very unnerving. And the harmonics should not just have started unless something physically changed. One other thing I did based on a post someone recommended was to try and move the outdrive slightly, up or down, manually. They indicated if it moved at all, that I might have air in the lines. It does give a little, but not much at all - very little - Not sure if that is an issue but the video is below.
https://www.youtube.com/watch?featur...&v=HYn5Ql6X-fw

Again, I don't see how this noise, which really sounds like a cross between sucking air and grinding gears (best way I can explain it) can be normal and have just started. My concern of course is that if it is going or there is something wrong - it will of course happen when I am out in the water...

With respect to the second, open cooling to the sea, and my boat is a 2008 Bayliner with carbureted 4.3. Outdrive is an alpha one gen 2. Picture of old impeller

 

[acevedor2]

Found this on youtube and it sounds damn near like my video. What do you think? https://www.youtube.com/watch?feature=player_detailpage&v=gey1O0fpEQA

 

[acevedor2]

Got a hold of the gentlemen that made the video above. He replaced both trim arms and still has the same issue. Looks like it is a motor/pump issue. That said, it still goes up and down...

 

[acevedor2]

Going to try and address the engine temp issue today.Intent is to drain system and make sure I have no blockages in the obvious passages. Then i will pull the T-stat and make sure there is no garbage preventing it from properly opening. I have a new Stat so once I have checked the system and run it to ensure no junk (impeller residue, etc) in the system, then I'll replace it.

I have replaced a lot of car t-stats, but never one on a boat. Does anyone have any tips, vids, or links to the manual for torque specs, etc? Ironically, my google-fu did not turn up much. Maybe I am just not strong with the force today...

Thanks!

 

[acevedor2]

Didn't end up getting to it today, going to hit it tomorrow morning. Does anyone have a good link to the manual with the instructions for changing the t-stat?

 

[Howard Sterndrive]

get a turkey baster or oil sampling pump. Evacuate as much fluid as you can from the tilt/trim reservoir. Refill with new 5W20 or 5W30 engine oil.
run it for a week and repeat.
Make sure the vent on your reservoir is open and clean. (you can even see if it gets quieter with the fill cap off)

That sound is cavitation. They all do it. (in fact, all reversing hydraulic pumps do it, because unlike your typical unidirectional hydraulic pump, there's no way to make the suction port bigger than the discharge because the ports switch roles every time you go the other way)
If the oil you add is too thick, it will do it worse. The pump is spinning very fast going down and it tends to cavitate on the suction side at those revs.
Cavitation is actually cold boiling of the oil under suction vacuum. The vacuum bubbles then implode on the pressure side and it sounds like marbles going through the pump.

Or, don't worry about it. A trim pump runs about 2 hours for every 2000 hours on the engine. Cavitation won't cause serious harm in 2 hours.

 

[acevedor2]

Thanks Howard. That's the first explanation I have heard about this issue that actually makes sense! One question though - I bought some Merc/QS tilt/trim fluid. I used about 8 ounces topping it off the last time. Why 5/20 or 5/30? How is that viscosity different from the tilt/trim fluid? I definitely don't want to buy another quart if I don't have to - that stuff is $25 a quart! Also, any thoughts as to why that cavitation would just be starting now - again mine has never done it before until recently. Just wondering if there was a reason for it starting to do it now?

Also - with respect to the thermostat, I found the section in the manual and will be changing it today - I just want to make sure I got the correct one. I got the 160 T-stat - is that correct? I assume so since the engine generally runs at about 175.

Lastly, when I bring it to temp on muffs, is there any danger in bringing it up to about 3K RPMs? What I have read is that on muffs, generally more RPMs is better than lower because of water flow.

Appreciate all of the help! Thank you very much.

 

[acevedor2]

Ok - so it's a 160 degree stat. Just pulled the old one. Question: The new kit comes with a housing gasket with continuity rivets. Which way does that gasket get installed - words up or down? I think it might matter because the rivets in the gasket are wider on one side then the other - hope that makes sense. Also, page 6A-23 of the manual says not to use perfect seal in step 1 because it could affect the continuity rivets. However, it then says in step 5 to coat both sides of the gasket with perfect seal...Which is the right answer? Maybe use perfect seal but not on the rivets themselves?

 

[Howard Sterndrive]

Why 5/20 or 5/30? How is that viscosity different from the tilt/trim fluid? I definitely don't want to buy another quart if I don't have to - that stuff is $25 a quart!

you answered your own question there. Same viscosity. 1/10th the price.

Also, any thoughts as to why that cavitation would just be starting now - again mine has never done it before until recently. Just wondering if there was a reason for it starting to do it now?

Did you get a new battery or clean the connections to the trim pump?
or grease the pivots on the drive? Or add the weight of a stainless prop?
any of those can make the drive drop faster.
Or just cycling the trim rams a bunch of times can clean hard water scale off the rods and make it go faster.

 

[acevedor2]

Thanks Howard. In fact, I got a brand new battery just two weeks ago and the noise DID start after that. Not immediately, but it was after that. I also keep it on a battery tender now, so it is always charged up.

I changed out the T-Stat today. Also flushed out each drain with the hose. There was definitely some silt. I ran her for about 20 min. Ran it at 2500 rpms for about 15 minutes or so. Temp went up to about 185 and stayed there. Went down to about 175 while at idle for a minute or two, but then creeped back up and stayed at 185. Looks like 185 is the normal operating temp. Is that correct? Thanks!

 

[acevedor2]

OK - the more I think about it, the more I am still not happy with the temp. When I ran it on the lake about a year and a half ago, it was dead steady at 175. When I ran it last year on muffs prior to winterizing, it was dead steady at 175. It was overtemped because the impeller toasted itself as indicated previously, and was changed. Now with a new impeller and new t-stat, it's at 185 or so steady. It doesn't make sense to me that normal temp would have all of a sudden jumped by 10 degrees. Anything else I can check that might have been affected by the initial overheating? Could the temp sender be bad? I don't think there is a flow problem because again, it's fairly steady at 185. Again, it did dip to 175 for a short time today, but then right back to 185 and steady. I imagine I should have probably checked the engine temp with a laser temp gauge while I had her running today...

 

[acevedor2]

Hey everyone - finally got around today to putting her on muffs and checking temps with a laser temp gauge. Temp at housing was 169 - all normal! Gauge still showed about 185. So my guess is I have either a bad temp sending unit or a bad gauge. Any ideas as to which one it could be and/or how to test them? Thanks as always for the great help.

 

[Bondo]

Hey everyone - finally got around today to putting her on muffs and checking temps with a laser temp gauge. Temp at housing was 169 - all normal! Gauge still showed about 185. So my guess is I have either a bad temp sending unit or a bad gauge. Any ideas as to which one it could be and/or how to test them? Thanks as always for the great help.

Ayuh,.... Start at the t-stat housin',... It needs to be solidly Grounded,....
To test, Ground out the wire at the temp sender, the gauge should Peg to Hot,....

 

[acevedor2]

Which wire from the sender should I ground to test? there are two wires on the sender. That said, I am fairly certain it is grounded. When I installed the new thermostat and gasket a couple of weeks ago, I triple checked to make sure there was nothing preventing the rivets from making contact. What else should I check? Thanks!

 

[acevedor2]

Anyone?