OK, this is going to sound really dumb to you experienced old hands, but how do you top up the fresh water coolant on an M35? Via the header tank, or via the water cap on the engine?
Quotehow do you top up the fresh water coolant on an M35
Just like your car. Fill the expansion tank to the mark. The coolant should be full to the pressure cap. If it's not top it off. If the coolant is very low may need to burp the system.
Hope that helps, a question is never dumb.
Jim
Thanks Jim. That's what I've been doing, but the engine runs hot and the expansion tank always seems dry.
So, I read one method for burping the system which involved watching the flow into the expansion tank until no more bubbles appear. Seemed to imply a cold system. That got me wondering if the expansion tank should normally have coolant in it even when cold. Hence the dumb question!
Keel : If the recovery tank goes dry - you are loosing coolant somewhere!! Make sure your pressure cap is on tight!
The first items to check are on the hose clamps. If you haven't put oil diapers under the engine and on the sides do so!! - so you can find out if and where you have an external leak!!
Sure hope it's not an internal leak!?!
A few thoughts
Thanks Ron,
So in normal use, even when cold, the recovery tank should have fluid in it?
EDIT: Just read Jim's comment properly! Seems like I've been running it with too little coolant ever since I bought it. :?
Keelsom, If memory serves me correctly the expansion tank is about half full cold. PO put tape at full line. Shamrock doesn't loose coolant. Go multi seasons with out adding. In addition to Ron's suggestion, take a good look at the coolant pump, if that's leaking it's often a spray when running but no drip when not. Next step would be to go to an auto store that rents or loans tools and get a pressure tester. That will tell you if you have a leak.
FWIW Shamrock never runs hot.
Jim
Keelson,
It sounds like you've got a couple of things going on here; possible coolant loss, and running hot. First things first, generally when filling water cooled engines you fill to the bottom of the tank or radiator cap neck. If you overfill the system it will expel the additional coolant after a couple of run cycles. If you're continually losing coolant you need to find out where it's going before you can fix it. If you do have a leak it's probably not internal unless you've got a lot of white steam coming from the exhaust.
It's not clear from your post if you've just been running with low coolant or you've been adding coolant and it keeps running low. In either case you probably have air in the system which combined with low coolant would certainly lead to over heating.
If you have a leak and fix it then you can top up the tank, if at that point the motor runs normally you're good to go. If it overheats there's probably air in the system and you'll probably have to burp it. While there are a number of ways to burp the system I've found this one to be the easiest. Remove the cap, place rags around the neck, start the motor then goose the throttle a few times, 1500 rpms should do it. The coolant will bubble out the opening (reason for the rags) along with any trapped air and the tank level will drop. Then just top it up and you're good to go.
Keel : The "coolant recovery" system that you have on your C34 is identical to the coolant recovery system that you have on your auto/s.
It is a closed system. When the engine runs the coolant heats and expands. The "overflow expansion" goes in to the recovery bottle and when the engine cools the coolant contracts and moves from the recovery bottle back in to the engine. There is never a need to remove the "radiator cap" and check - just look at the bottle level! The bottle should have 2 markings - Hot/Warm and Cold
What you need to do is start over by refilling the system with 50/50 mix of water/Prestone(full strength) (or pre mixed 50/50). Remove the cap and fill the engine reservoir and fill the recovery bottle to the "cold" mark. The "burping of the engine" is when an air bubble gets caught (usually) in the hoses to the water heater. If you have that air bubble the engine will heat up and start to overheat (because the coolant is NOT moving by being blocked by that bubble) Look in the Critical Updates and Burping posts to clear that bubble - so the coolant flows freely.
Like I previously posted, I believe you have a leak somewhere?? Hope this explanation helps.
A few thoughts
Thanks guys. Great info.
I too am not clear whether I have a leak or have simply been running it with not enough coolant. I bought the boat 18 months ago and the PO pointed to the expansion tank and said something like "it never seems to fill so I don't touch it". So, I took it from that, that I never needed to look it. Now, I'm going to pay it some close attention.
The engine starts to run hot if I run it above about 2100 RPM. The temp gradually rises to about 180 and there is a little steam evident in the exhaust. However, this could be an issue with the raw water side. I'm a little suspicious about the through flow. The discharge from the exhaust seems a little feeble to me.
I replaced the impeller, I've checked the thru hull and the water strainer. No obvious reasons for a blockage. So, next investigation will be the HX.
It's really frustrating not having good manuals for the boat and engine. Thank heavens for this website and all your great assistance.
QuoteIt's really frustrating not having good manuals for the boat and engine.
Keelson,
In case you don't know, the manuals are here. From the home page click manuals. I've loaded them onto my computer. That way I have them even without a Wi-Fi connection.
Shamrock has the same engine and cooling system as you do, never overheats. Even towing a 42 foot center cockpit all day. The water flow from the exhaust isn't a steady stream like some, more like splashing and spray.
Because you inherited the problem think you need to check out the entire systems, both the engine circuit and the raw water side. I would start by checking for coolant leaks and get the system full and circulating.
Curious, how is your hot water? If the coolant doesn't circulate it won't heat up the hot water tank.
Jim
Hi Jim.
I have the PDF manuals. The Westerbeke one isn't specific to Catalinas so it's of limited use for routine maintenance. The Catalina manual has almost nothing in it of use.
That's a good point about the hot water. Yes, it's fine.
As soon as I get the boat back in the water, I'm going to go through everything. My money's on insufficient coolant level.
Keel : I'd remove the pressure cap and fill the engine reservoir replace cap and fill the recovery bottle to cold. Then run the engine to operating temp. Let the engine cool to cold and see what happens to the recovery bottle. If you can run the engine to 2100 rpm I don't believe that you have an air bubble blockage - just VERY low coolant. Try it and let us know
A few thoughts
Will do Ron. But she's not back in the water until the end of March. If I try this in the yard she'll definitely run hot!!
Running at 2100 will be fun because I've yet to find neutral on this boat 🙄
I guess I'll just have to double up the warps😂
Keel : Before you go into the water take a half hour and with a screwdriver or nut driver and check ALL of your hose clamps to make sure they are tight. Don't try to KING KONG them - just tight!! Then fill your recovery bottle to the HOT level. Just leave the engine pressure cap closed.
I feel the your system is just very low on coolant and if I'm correct; when you run the engine to operating temp it will cool down and suck coolant back into the engine. You will probably have to add coolant to the recovery bottle.
On your transmission neutral - Go down below so you can look at the starboard side of the transmission under the aft cabin. You should be able to move the shifting lever by hand. All the way forward is Reverse gear and all the way aft is forward gear. Half way in-between is neutral (straight up). In that half way point you should be able to turn the shaft by hand easily in both directions. Then go to the wheel and look at the position of the Shifter!! The cable should be connected to the shifter lever on the transmission in the low hole on the shifter lever.
A few ideas - hope this helps!?!
Thank you again Ron for such helpful advice.
LA Lady's feel at the telegraph handle is like nothing I've experienced on any other yacht. There seem to be two 'slack' spots, both aft of the mid (vertical) lever position. Neither of them actually result in neutral!
Checking transmission adjustment is one of the many things on my ever-growing to do list!
@KG
How old is your Hx?
If it has a pinhole between the closed and seawater sides (a common occurrence over enough time) you will gradually lose coolant and eventually overheat.
My Hx was totally in freshwater and IIRC it lasted about 12-15 years before it developed the pinhole.
Less likely, but if you have a pinhole in the water heater between the potable water and engine coolant sides, you can lose coolant (depending on whether you keep the potable system pressurized)
The proper way to troubleshoot this, rather than chasing shadows around, is to (FIRST) pressure test at the "radiator cap" using a tester (loaner from an auto parts store.) That will reveal whether you have a tight system or a leak (a myriad of possibilities - hose clamp, hose chafe, thermostat gasket, Hx pinhole, water heater pinhole, head gasket, exhaust flange gasket, other cause.)
ONLY AFTER TESTING, isolate the leak source (another post depending on the test results.)
Keelson,
Thank you for your post. I have the exact same issue and concern as you describe.
My throttle has a stop so that I cannot rev the engine above 2100rpm, as soon as I go over 2000 and push towards 2100 I notice that the temp increases towards 195.
My overflow tank has been bone dry for the last two season and coolant level in the engine never needs topping off. I had the HX completely cleaned out before the last season but no change in temperature behavior. No leaks to my knowledge but I do have some white smoke in the exhaust.
I keep wondering why the throttle is limited and not able to reach crushing rpm of 2600 but on the other hand then it will overheat. By the way, with 2000rpm I reach cruising speed of 6 knots.
You definitely have some problems. I AM NOT A MECHANIC, but have no problem offering some observations. :abd:
1. The engine should be able to reach WOT, 3000+(?) and not have an RPM stop/limiter at 2100.
2. The coolant overflow bottle should never be "dry".
3. I suggest you bite the bullet and hire a competent mechanic to inspect.
You might be over prop-ed. I have a prop on my boat that only allows max rpm of about 2250 - 2300. At 2k, I go about 6-6.25kts through the water. At idle, she goes about 2.5-3kts 8-| I have heard this was a strategy to lower the fuel consumption while achieving the max cruise. Though I haven't gotten there yet, I plan to re-prop to get the engine to reach max hp/revs.
Interest thought Alex. What size prop are you currently using?
Noah,
I didn't know to look when the boat was out of the water upon delivery. It looked to be quite "power boat" looking though. Very large ears and very little blank space between them when viewed from directly astern.
How about you take a swim and get back to us on that? :shock: :D
Oy!!! The last temp I saw for the slip I sit in was 54 degrees!! The divers bring heated water to pour in their wet suits!
Thank you for the feedback Noah and Alex,
Keelson - I hope this is valuable to you as well.
I think this can be valuable information, for what it is worth my prop on the M35 is a Michigan Sailer 8/89, 15RH12.
Based on boat being produced 1990 with hull #1024 could it be possible that the Prop has been an original if produced 8/89?
My cruising speed does not seem to suffer with around 6 knots at 2000rpm, seem to be running at about 185 temp but the cruising temp should be 165 temp. When I cruise at full speed the stern sit pretty deep in the water being pulled down by the prop.
I will fill the overflow tank and try to burp the system before I bite any bullet with an experienced mechanic. Engine has been working like a champ with 2000-2100rpm during long motor cruises.
Appreciate all the feedback.
Quote from: BJeansson on March 14, 2023, 05:04:02 PM
I think this can be valuable information, for what it is worth my prop on the M35 is a Michigan Sailer 8/89, 15RH12.
Is that 3-blade or 2-blade?
If that is a 3-blade prop, then IMO you are probably WAY over-propped. Most 3-blades for this boat are 15x9 (mine is, and my M35B has 17% higher horsepower than your M35). Some people get away with 15x10 on the M35B. I've never heard of a 3-blade 15x12 on a boat/motor this size. You're probably lugging your motor, generating a bunch of soot that could plug your exhaust elbow, and pushing the limits of your HX capacity. Remember, if your motor runs slower, your raw water impeller is pumping less water, which may be why you are seeing steam.
Many people fool themselves into thinking that lower RPM always equates to better fuel economy. It doesn't work that way. Would you drive your car in 5th gear all the time?
I second the suggestion to hire a good mechanic. You've got multiple warning signs in several areas, and they're probably interconnected.
FYI, your M35 is spec'ed for a max speed of 3200 RPM. You are so far below that that you really need to do something about it. https://www.westerbeke.com/universalengines.htm
This has been a very useful discussion. Thanks folks. Apart from the new overheating issue, my engine starts in and instant and runs as sweet as a nut. So i'd always assumed it was fine. Back in the water in the first week of April so I'm going to take a closer look at it then.
Another thing to check when diagnosing RPMs is to make sure your tach is reading correctly—using a laser.
Regarding strobe tachometer, I stumbled across this yesterday $16. I already have one, but it cost a lot more than this:
https://www.amazon.com/Non-Contact-Tachometer-Precision-Backlight-Functions/dp/B07T25BCB1
If you do test, you should do it on the main motor pully. If for some reason you decide to do it on your prop shaft or coupler, be sure to account for the gear reduction ratio to calculate the engine RPMs.
Thank you Breakin Away, greatly appreciate your feedback.
The prop is a 3 blade.
I'm well aware that the max RPM is 3200 and I think cruising should be 2600, but as I mentioned the throttle is blocked not to exceed 2100 and then it runs hot.
You are right about the soot, plenty of that.
My prop "drag" when going reverse and parking is brutally strong.
So I suppose these are all signs of an over sized Prop. I think this prop has been mounted for the last 20 years.
The engine runs great, no issues during the two seasons I have owned this C34.
Thank you for your input.
A dirty, fouled injector(s) will cause all the symptoms described.
The engine will be low on power but will run hotter than normal. It will probably also reach max rpm in neutral. The reason for the elevated temps is because the fuel is still igniting in the cylinder, just not efficiently.
Buy one good (denso) injector and try it out. Install it in different cylinders. See if it helps. If it helps replace all four.
They're consumables.
Quote from: BJeansson on March 15, 2023, 03:50:11 PM
So I suppose these are all signs of an over sized Prop...
It's over-pitched, not over-sized. A prop shop can adjust the pitch of your current prop, although going from 12" pitch to 9" pitch may be more than they are able to do. You might want to inquire about this before launching this spring.
Note for others:
Never purchase a prop with larger diameter than the factory spec. Its clearance with the hull is carefully engineered, and an oversized prop may cause vibration, cavitation, or worse.
Guys : The Michigan Wheel "sailor" props have a much larger cord (& surface area of each blade) than the Catalina Sailor props made in Australia. So It's impossible to compare them, so I'll guess that "Breaking" is correct - that you are lugging down the engine. You need to get a picture (or an actual prop from a friend) of a Catalina Sailor prop and take them to a prop shop and see if your Michigan can be down pitched to match the resistance produced by the 3 bladed Catalina Sailor??
The best prop shops will have "Prop Scan" capability!!
A few thoughts
I had this situation in the spring after winter. Some coolant in the bilge, and the overflow bottle was dry. During the warmer months, engine had coolant and so did the overflow, normal operating engine temp. Turns out the fix was 2 things.
1 - new engine coolant cap
2 - new coolant hose towards the bottom of the engine
My guess is that the coolant hose, after 23 years next to the engine got more heat than the other hoses and deteriorated. It was showing hairline cracks. Over the -20 C winter months, my guess is that the hose contracted and over 5 months on the hard the coolant leaked.
The changes above stopped the loss of coolant over the winter.
Coolant cap, may or may not have been an issue, but cheap (and very easy) maintenance as it has a gasket in the cap that fill fail at some point.
Other than tightening all the hose clamps, I would see if you can inspect the condition of all the coolant hoses. Some run to the water heater... which I'm working up the courage to change...
Quote from: KeelsonGraham on January 29, 2023, 12:02:14 PM
Thanks Jim. That's what I've been doing, but the engine runs hot and the expansion tank always seems dry.
So, I read one method for burping the system which involved watching the flow into the expansion tank until no more bubbles appear. Seemed to imply a cold system. That got me wondering if the expansion tank should normally have coolant in it even when cold. Hence the dumb question!
pby : I like to use a clear hose from the engine to the coolant recovery bottle. That way I can see that there shouldn't be any bubbles in that line!! If there are - I don't have a closed system!!
A thought