We are sailing in Mexico.. we are currently having an engine over temp issue.
1) if we keep the rpm below 1800 it seems to run ok.
2)over 1800 rpm the temp slowly creeps up to at least 200, then I put her in neutral and rev engine to cool her down.
3) when she is running hot, there is no steam in the engine compartment.
4) there is some gray soot (not black diesel) in the compartment below the head sink.
What I have done
1) pulled raw water pump look good, checked water flow to the riser and exchanger flow looks
Normal
2) pulled heat exchanger it was clean. We recently had it boiled at a radiator shop (2017)
Questions
1) is there a way to check flow on the freshwater (antifreeze) side. When looking at the antifreeze with the cap off there does not seem to be much flow
2) is there a way to see if there is a blockage riser?
Any thoughts would be greatly appreciated
Brad
This is an M25 w/ 3" HX?
You have normal coolant level in the exhaust manifold?
You can remove the closed cooling system hose between the Hx and pump inlet, but you'd have coolant flowing that you'd have to catch/save/reuse (presumably. If you hooked a water supply (not under pressure) to the inlet of the closed coolant pump you would (should) see water pumping through the block and out the 7/8" return hose to that pump. I'm not suggesting you do that - just answering your question.
You'll see some flow in the reservoir/exhaust manifold w/ the pressure cap off. If you rev the RPMs you should see the level being drawn down/go back up.
Perhaps your thermostat is not opening? If so you would have very little flow from the block -> to the exhaust manifold -> 7/8" to the Hx -> 7/8" back to the pump. If the 7/8" hose between the exhaust manifold and the Hx is cool, then you aren't getting hot coolant flowing to the Hx. I realize that It's not easy getting at those locations.
These might make might help you trace out the coolant flow.
https://groups.io/g/catalina30/wiki/Flow-directions-in-engine-cooling-hoses
https://groups.io/g/catalina30/wiki/Removing-the-Rube-Goldberg-valve-on-a-mk-I
It is a M25 / with a 2 inch heat exchanger.
I do see a the coolant level move when I rev the engine.
I put in a new thermostat. I may take it out just to be sure.
Yes I have the normal amount of coolant.
Brad,
Is it possible that you could have lost a vane off of the raw water impeller? If a vane has gotten stuck in the line it could be allowing enough water to bypass at low RPM to keep it cool but at higher RPM requiring a greater flow it could be restricting that flow causing it to overheat.
The impeller looks good. No parts missing. I have the heat exchanger off and soaking in a tube of muratic acid.
Brad
The remedy, quite simply, is to upgrade to the new(er) style 3" Hx. The 2"is undersized except for the coolest sea water.
The warning is all on the TechWiki - see service bulletin #195.
http://c34.org/wiki/images/6/6c/Wb_searchable_service_bullletins.pdf
Otherwise keep the RPMs down (don't try to outrun any banditos. :shock: )
Quote from: Brad Young on March 21, 2019, 08:37:01 PM
We are sailing in Mexico.. we are currently having an engine over temp issue.
1) if we keep the rpm below 1800 it seems to run ok.
2)over 1800 rpm the temp slowly creeps up to at least 200, then I put her in neutral and rev engine to cool her down.
3) when she is running hot, there is no steam in the engine compartment.
4) there is some gray soot (not black diesel) in the compartment below the head sink.
What I have done
1) pulled raw water pump look good, checked water flow to the riser and exchanger flow looks
Normal
2) pulled heat exchanger it was clean. We recently had it boiled at a radiator shop (2017)
Questions
1) is there a way to check flow on the freshwater (antifreeze) side. When looking at the antifreeze with the cap off there does not seem to be much flow
2) is there a way to see if there is a blockage riser?
Any thoughts would be greatly appreciated
What is the flow like coming out of the discharge? Is there steam? Have you checked the strainer on the raw water side? Have you checked your freshwater pump? What is the water temp where your at?
Brad - I know you are in cruise/crisis mode now but someday I would consider upgrading to a 3 inch HX.
Brad : Try "Burping" your engine heater hoses again - just to make sure that you don't have any air restricting the coolant flow.
A thought
Quote from: Brad Young on March 22, 2019, 08:49:43 AM
heat exchanger off and soaking in a tube of muratic acid.
I'm sure if there was scale blocking it, you would see "immediate" evidence from the MA reaction. Also, run a wire ("coat"hanger) thru each Hx tube to check for non-scale blockage.
Anything you can do in a pinch to cool down the Hx would help some until you can change to a higher capacity.
If you have a washdown pump and can somehow rig up a nozzle spraying against or water running across the Hx and into the bilge it would help cool it down and help cool the engine coolant. The same for a slight spray onto the exhaust manifold. Anything in a real pinch. Run the blower. One time my bro was totally isolated/stranded and overheated -- the only liquid he had to use as engine coolant was beer. It got him thru the pinch.
Guys : In a real emergency to cool down the engine when you have to still run the engine; I turned on the hot water faucet in the galley and in the head!! This helped keep the temp down.
Another time I turned OFF the engine and sailed to the dock on the jib - furling in the jib as we turned 180 degrees into the wind. My First Mate asked if we were going to practice this first!! My reply was simply, "No this is just like a wheels up landing - no practice " !!! :thumb:
A few thoughts
Took heat exchanger off, looked clean but soak it in Muratic Acid, cleaned and inspected everything from the intake thu to the "Y" nipplle. We out on a nice long run 1 hour, Ran at 2000 rpm and temp stayed at 165. Untilll .....
I ramped up the rpm to 2500 rpm. Then the riser started to gush. Got a nice crack near the "Y" nipple. When it rains it pours.
I have tried to enter into the tech notes but I can't get pass the longin. As far as I know I am a member. Any quick suggestions on taking off the riser? I got the bolts soaking in PBLaster.
As a side note: we came into the anchorage under sail and drop the hook. A little nervous with other boats around. Even though we had practice before.
Again, the answer to your overheating is the 3" Hx.
Are you SURE you want to tackle the riser away from home? The can of worms and rattlesnake den can get very huge.
The riser busted. Need to fix here.
[edited to add link]
Is the mixing wye cracked and leaking or is the riser shot?
If it was "just" a cracked inlet, IIWMB I'd try ANY plan but replace the riser away from home.
Fiberglass muffler wrap, rubber& hose clamps, silicone rescue tape, bubblegum, all of the above, ANYthing but get into that can of worms where you are.
But not having eyes on maybe not possible, and ya gotta do what ya gotta do.
Here's Paul's posts on his cracked wye that turned into a riser replacement - note that it's on an XP.
http://c34.org/bbs/index.php/topic,9026.0.html
Or limp home and see if you can maybe do the better plan, water-cooled riser (that, yes, is possible on the C34) as Biil installed.
http://www.c34.org/wiki/index.php?title=C34_Exhaust_with_Water_Cooled_Riser
There is a hole in the riser. About the size of a silver dollar. This is at the elbow just above the "Y" nipple It is rusted through. Working on pulling it it out.
Will get a guy here In Mexico to fabricate a new one.
We do not plan on taking DarBay back to the states for at least 2 or 3 years. So every has to be fixed here.
I replaced my Exhaust Riser 2 years ago & it is quite a job. Good idea soaking the manifold bolts with PB, give them time. In my case when I removed the old one it just fell apart, almost like the insulation was holding it together. I was in the US so I ordered a SS one from CD.
While reading through the forum to gather info to replace the riser I found a few people that talked about having a unit fabricated some used SS but others used Black Pipe (obviously will not last as long as SS). Also keep in mind the hump hose if it did not have one.
I have an old one sitting in my garage. It's the old SS original. I replaced it last year as a proactive step to avoid a remote problem. Let me know if you want me to ship it out for the cost of shipping. The heat shield is damaged but the riser still seems good.
Quote from: Ekutney on March 28, 2019, 08:43:46 AM
I replaced my Exhaust Riser 2 years ago & it is quite a job. Good idea soaking the manifold bolts with PB, give them time. In my case when I removed the old one it just fell apart, almost like the insulation was holding it together. I was in the US so I ordered a SS one from CD. >>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>>>>>>>>>
The last Mainsheet Tech Note on exhaust riser replacement was Feb 2016, Muffler & Exhaust Riser Replacement
http://c34.org/muffler-exhaust-riser-replacement-2015/
Brad : When you install your new riser make sure that you do NOT use the original stiff wire reinforced hose from the anti-siphon to the nipple on the riser. Use softer nylon reinforced hose instead!!
A thought
Brad
You didn't say what locally you were going to have them fabricate. I've always planned if/when I need to replace mine -- if I don't use the water-cooled riser, I would fab one using schedule 80 pipe rather than sch 40 so that it lasts 2x as long.
Replaced my riser last year, and bought the unit from CY. CD would not sell me a riser unless I also bought their insulation, which was wildly overpriced. CY included all the insulation needed at no extra charge. Replaced the hump hose at the same time.
Quote from: Brad Young on March 21, 2019, 08:37:01 PM
We are sailing in Mexico.. we are currently having an engine over temp issue.
1) if we keep the rpm below 1800 it seems to run ok.
2)over 1800 rpm the temp slowly creeps up to at least 200, then I put her in neutral and rev engine to cool her down.
3) when she is running hot, there is no steam in the engine compartment.
4) there is some gray soot (not black diesel) in the compartment below the head sink.
What I have done
1) pulled raw water pump look good, checked water flow to the riser and exchanger flow looks
Normal
2) pulled heat exchanger it was clean. We recently had it boiled at a radiator shop (2017)
Questions
1) is there a way to check flow on the freshwater (antifreeze) side. When looking at the antifreeze with the cap off there does not seem to be much flow
2) is there a way to see if there is a blockage riser?
Any thoughts would be greatly appreciated
I'm bringing the thread back up since this exact thing is happening to me right now. I've been out for 3 days, still got to get home. Of note, I used all my hot water, and I just ran the engine for 30 mins in a pass and it over heated gain, when I dropped hook their was no hot water still. Is this an air lock? The HX was warm, not really hot. To burp do I just loosen the deal in the photo and take her up to 3000rpm? Before this trip I changed oil, new fuel filters, topped up coolant, cleaned raw water intake even below water.
MQ : No that is not the "burp" hose. However, you can run the engine and see if some air comes out of that butterfly valve when you open it.
To "burp the engine" you need to take the hose off of the thermostat and make sure that it is full of fluid. Look in the critical updates and WiKi for the detailed procedure to burp the engine.
Then you really need to add a coolant recovery system (easily done WiKi)
A few thoughts
Quote from: senorquill on May 23, 2021, 01:39:00 PM
Quote from: Brad Young on March 21, 2019, 08:37:01 PM
We are sailing in Mexico.. we are currently having an engine over temp issue.
1) if we keep the rpm below 1800 it seems to run ok.
2)over 1800 rpm the temp slowly creeps up to at least 200, then I put her in neutral and rev engine to cool her down.
3) when she is running hot, there is no steam in the engine compartment.
4) there is some gray soot (not black diesel) in the compartment below the head sink.
What I have done
1) pulled raw water pump look good, checked water flow to the riser and exchanger flow looks
Normal
2) pulled heat exchanger it was clean. We recently had it boiled at a radiator shop (2017)
Questions
1) is there a way to check flow on the freshwater (antifreeze) side. When looking at the antifreeze with the cap off there does not seem to be much flow
2) is there a way to see if there is a blockage riser?
Any thoughts would be greatly appreciated
I'm bringing the thread back up since this exact thing is happening to me right now. I've been out for 3 days, still got to get home. Of note, I used all my hot water, and I just ran the engine for 30 mins in a pass and it over heated gain, when I dropped hook their was no hot water still. Is this an air lock? The HX was warm, not really hot. To burp do I just loosen the deal in the photo and take her up to 3000rpm? Before this trip I changed oil, new fuel filters, topped up coolant, cleaned raw water intake even below water.
Universal M25xp w/ 3" heat exchanger. I put a brand new HX on last year.
Quote from: Ron Hill on May 23, 2021, 02:08:52 PM
MQ : No that is not the "burp" hose. However, you can run the engine and see if some air comes out of that butterfly valve when you open it.
To "burp the engine" you need to take the hose off of the thermostat and make sure that it is full of fluid. Look in the critical updates and WiKi for the detailed procedure to burp the engine.
Then you really need to add a coolant recovery system (easily done WiKi)
A few thoughts
Okay. Do you think it is an airlock, before I mess with that? I have to coolant recovery just need to put it back on.
MQ : Yes, there is a airlock in the engine to water heater hose back to engine hose!!!
A thought
MQ,
The best way I've found to eliminate air from the coolant system (airlock) is to remove the radiator cap, start the motor, then gun it a few times up to around 2000rpm. That should blow any air out the cap opening, it will spit up a bit so you might want to place some rags around the opening.
You'll know it's successful if afterwards there's a significant drop in the coolant level in the coolant tank. Then top it up replace the cap and you should be good to go.
If you're not getting ANY coolant movement (to neither the Hx nor the WH) I'd think there's two possibilities- (a) an airlock in the pump itself (this happened to a friend with an XP after replacing the coolant pump and meticulously filling the system) or (b) an airlock in both circuits (to/from Hx and to/from WH).
There was a recent thread about an airlock cleared from the return hose from the Hx to the coolant pump.
If after purging all air you still overheat check the TStat to ensure it opens 160F, or it's cheap insurance to just replace it with your spare if it's got many years on it. Or remove it to temporarily run w/o a TStat until you can replace it.
I find that most times I can get all air out by bleeding at the pressure cap after she's up to temp and the TStat opens. We have a particularly difficult inherent airlock issue because the C30 mk-I's WH is high in the cockpit locker and a long run from the engine so air tends to settle in there, but the pressure cap method seems to work 9 out of 10.
Here's the coolant flow directions:
https://groups.io/g/Catalina30/wiki/9626