Catalina 34

General Activities => Main Message Board => Topic started by: mregan on August 01, 2020, 11:34:30 AM

Title: Just overheated the engine
Post by: mregan on August 01, 2020, 11:34:30 AM
Keep the engine key on the engine water intake  alive to remember to open it before starting engine.  Had left the valve open but put the key on it. Came down today, removed key and shut the valve not thinking.  Just got out of the harbor and hear noises crime the engine and smoke. Shut it down. Temp gauge was pegged at 250. Lots of steam coming out of the manifold cap.  Didn't see leaks anywhere else.  Anchored now. Engine back down to 140. Manifold very low so filled with water for now.  Assuming I can get back to the dock, about 10 min motor.  What should I look for when I'm back at the dock?
Title: Re: Just overheated the engine
Post by: Noah on August 01, 2020, 11:50:55 AM
First thing before re-runnind engine is to check if the impeller is fried, or you will have overheating even if raw water intake is open.
Title: Re: Just overheated the engine
Post by: mregan on August 01, 2020, 12:22:57 PM
Thanks. Just checked. Couple of teeth broken so replaced.
Title: Re: Just overheated the engine
Post by: Ron Hill on August 01, 2020, 01:21:23 PM
mre : Look for those broken blades if they are missing!  They are probably down in the exit (exhaust) elbow. 
If you have a tweezers, long nose pliers or forceps you might be able to easily pull them out? 

Good Hunting

A thought
Title: Re: Just overheated the engine
Post by: mregan on August 01, 2020, 01:57:37 PM
Thanks, found them just inside the housing so was able to get them easily. Was able to make it back to thr dock.  Was running at 175*. Little water coming out the back but not getting the big blast of water like normal.  Do I need to add water to thr muffler?
Title: Re: Just overheated the engine
Post by: Noah on August 01, 2020, 02:34:51 PM
CAVEAT: I am NOT a mechanic. However I say absolutely do NOT add water to muffler. That could give you more serious problems with backflow into engine. Depending on what thermostat you have, 160 or 180, a your reading of 173 may not be bad.  It also depends if you can trust where/how you got that 173 reading. Waterflow through the cooling system is what I would focus on. Perhaps there is another bit of impeller struck somewhere, weed in strainer, or air in the system? Try burping engine and checking coolant levels again.
Title: Re: Just overheated the engine
Post by: scgunner on August 02, 2020, 08:53:33 AM
mregan,

I'll second Noah, don't add water, the muffler will take of itself(how many times can you say that when talking about a boat). I'm not sure why you close the engine intake valve in the first place, I've had my boat for 32 years and the only time I close that valve is to clean the filter or exercise the valve itself, the rest of the time it's open, one less thing to forget.

Concerning your motor, that Universal Diesel is one tough little beast. Over the years I've pegged the temp gauge a few times mainly due to sucking up something in the intake(kelp, plastic bag), if you don't catch it on the gauge you'll see a telltale cloud of steam off the transom telling you it's time to shut off the and fix the problem.

One time singling the boat home from a particularly rough crossing and towing two dinghies I finally made it to the marina approach (and calm water), I started the motor and almost immediately pegged the gauge(it's always something!)In that situation and for reasons of safety I decided not to shut off the motor. I motored in that condition for about 20 min to my slip. Afterwards I checked everything and ran the motor for about 30 min everything was fine, that was hundreds of hours ago, like I said they're tough little bastards.
Title: Re: Just overheated the engine
Post by: Stu Jackson on August 02, 2020, 09:59:51 AM
I agree with Kevin.  I left our slip with a (rare for me) guest.   I forgot.  1/2 nm later I just opened it.  Lucky no broken vanes but never bothered to look 'cuz she pumped right up.

Re: muffler.  Review the raw water flow on your engine, and you'll see why you don't have to.
Title: Re: Just overheated the engine
Post by: mregan on August 02, 2020, 11:52:54 AM
Will go down tomorrow after work and play around with it.  Will go through the water flow and see if I can figure out what the issue is.  Other than the lack of water coming out, it seemed to be running fine back to port.

I usually close all the seacocks when we go home for the weekend.  Just on the odd chance a hose breaks during the week.  That's why I keep the key on the intake valve.  So I don't forget to open it when I grab the key.  For some reason I had left the valve open last weekend but put the key on it.  Wasn't even thinking and grabbed the key and twisted the value, unfortunately into the closed position.  First time in 11 years. 
Title: Re: Just overheated the engine
Post by: KWKloeber on August 02, 2020, 01:07:08 PM
Quote

open it when I grab the key. 


Great plan, poor execution. LOL

Don't worry about that engine, it's tough to kill it unless it's abused continually.

Pull the cap on the Hx to see if there is anything blocking any tubes.

You can pull the supply hose to the Hx (for a short period) to make sure it's producing full flow.
Or at the injection wye.
Or at the vented loop.

This explains the cooling water flow directions (that you should study/remain familiar with as Stu laments re: the muffler water.)
https://groups.io/g/Catalina30/wiki/9626
Title: Re: Just overheated the engine
Post by: Ron Hill on August 02, 2020, 05:03:06 PM
Guys : I've said this a number of times, but if you overheat and MUST run the engine - turn on the hot water faucets in the galley and head

It will help keep the engine temp somewhat down.  The Water Heater is a heat exchanger!!   :thumb:

A thought
Title: Re: Just overheated the engine
Post by: Ed Shankle on August 03, 2020, 05:21:35 AM
MR,
In the off chance that your exhaust water had already reduced prior to your incident without being noticed, pull the HX input end of the hose from the RW pump. Verify you don't have a calcium/salt buildup just inside nipple. I've had that happen a few times, now it's the 1st thing I check when I notice a reduced exhaust flow. Just break it up with a screwdriver if you do see it. You may need a flashlight.

Regards,
Ed
Title: Re: Just overheated the engine
Post by: scgunner on August 03, 2020, 07:27:30 AM
That's a great idea Ron,

Under the heading of learning something new everyday. Similar to your car, if it overheats you can turn on the heater to increase cooling capacity, although that's not really popular with passengers.
Title: Re: Just overheated the engine
Post by: Ron Hill on August 03, 2020, 02:18:39 PM
mre : You asked about possible damage from running the engine with no raw water?
Depending on how long there was no water mixing with the hot engine exhaust to cool it; I'll guess those HOT dry gasses may have warped the fiberglass intake pipe to the muffler!?!   :donno:

A thought
Title: Re: Just overheated the engine
Post by: mregan on August 08, 2020, 05:24:41 PM
Finally got down to the boat today.  Took off the hose from the pump to the heat x.  There were impeller parts stuck in the hose.  Cleaned that out.  Then took the pump off again and found another impeller fin in the discharge fitting.  Got everything back together then cleaned the bilge which was full of dirty water.   Started the engine, water discharging out.  Wanted it to warm up to see where the temp would land. 
Went back in the cabin and noticed the bilge was filling with water.  Figured one of the hoses had cracked.  Engine hoses seemed fine so looked at the muffler.  The hose from the engine that attached to the muffler was leaking pretty bad.  Was thinking Ron was correct.  Unscrewed the hose.  Felt the fiberglass and it felt solid.  Looked like the hose had loosened and risen up.  Pushed it back down tight to the muffler and tightened the clamp. 
Started the engine back up and no leaks. After 10-15 min the engine had kept steady at 160* so things appear back to normal.

Thanks for everyone's help.
Title: Re: Just overheated the engine
Post by: scgunner on August 09, 2020, 08:09:03 AM
Wow, that sounds like a lot of impeller vanes floating around in your cooling system, no wonder it was overheating. I've had problems after losing one vane. That's the thing, if you pull an impeller missing a vane, the vane itself doesn't flush out of the system, you'll have to track it down and remove it.
Title: Re: Just overheated the engine
Post by: britinusa on August 09, 2020, 09:07:12 AM
Just a thought, when I rebuilt the engine exhaust system I had to repair the fiberglass muffler where the engine exhaust connects to it. So I also added the silicone hose with a bump in it to reduce the vibration at the connection.
Title: Re: Just overheated the engine
Post by: Ron Hill on August 09, 2020, 02:22:36 PM
Paul : Like I've mentioned before, besides changing to a hump hose change out the old stiff wire reinforced hose from the anti syphon valve to the nipple on the exhaust riser.  Make sure that hose is a nimble nylon reinforced hose!!

A thought
Title: Re: Just overheated the engine
Post by: mregan on August 11, 2020, 10:19:26 AM
Might have spoken too soon.  Went out for a sail Sunday. Motored about 20 min. Temp steady at 160. On thr return trip, also 20 min motor.  Was running at 160 then creeped up to 180.  When got close to the marina throttled down and temp dropped to 160.
I did notice thr was a bit of water in the bilge so something is still leaking. Will have to explore more next weekend.
Title: Re: Just overheated the engine
Post by: glennd3 on August 11, 2020, 04:43:29 PM
The main thing is that your engine seems fine, not effected from the initial overheating.
Title: Re: Just overheated the engine
Post by: KWKloeber on August 11, 2020, 11:20:07 PM
Quote from: mregan on August 11, 2020, 10:19:26 AM

I did notice thr was a bit of water in the bilge so something is still leaking. Will have to explore more next weekend.


It's seawater and not coolant in the bilge?
Check the Hx hose clamps and that the cap ends are tight, rubber gaskets not leaking.
Stuffing box checked lately?
Title: Re: Just overheated the engine
Post by: mregan on August 12, 2020, 08:51:15 AM
It's clear water. A little dirty but clean. No anti freeze in it.  When I noticed the hose to the muffler was leaking and I loosened the clamp. I was able to raise up the hose and The exhaust pipe it was attached to would hinge up an inch or so. Didn't think anything of it but looking at Stu's exhaust replacement article I'm wondering if that exhaust section is supposed to be rigid with no movement.
Title: Re: Just overheated the engine
Post by: Stu Jackson on August 12, 2020, 11:06:48 AM
Quote from: mregan on August 12, 2020, 08:51:15 AM
......but looking at Stu's exhaust replacement article I'm wondering if that exhaust section is supposed to be rigid with no movement.

The exhaust RISER should be rigid, because it is supposed to be firmly screwed into the flange at the manifold end.
Title: Re: Just overheated the engine
Post by: Noah on August 12, 2020, 11:46:34 AM
You should be able to run engine, in gear at the dock, with all compartments/doors open and aft bunk removed, and spot any water leaks from raw water systems. Just make sure you are very careful to not get caught up in any spinning parts or burned. May be a bit scarry but doable.
Title: Re: Just overheated the engine
Post by: Ron Hill on August 12, 2020, 02:04:09 PM
mre : Which hose to the muffler?? ("I noticed the hose to the muffler was leaking")

The inlet hose into the muffler from the stainless riser "should be a "blue hump hose" and flex; while the black exhaust hose is ridged.

A few thoughts
Title: Re: Just overheated the engine
Post by: mregan on August 12, 2020, 06:17:38 PM
Inlet hose into the muffler. It's a black rigid hose. Definitely not the blue hump hose.

Like I had mentioned, I had unscrewed the clamp on the inlet hose where it attached to the muffler. I was trying to get it off the muffler stub to see if the overheating had cracked or deformed the fiberglass stub. It was sitting about an inch up on the stub. As I lifted the hose up to try to get it off the stub, the riser moved up about an inch which I wasn't sure it should be doing.

I'm going to do what Noah said and look over everything. Do I have to be in gear or can I leave the boat in neutral.
Title: Re: Just overheated the engine
Post by: Noah on August 12, 2020, 06:46:28 PM
Not absolutely necessary to be in gear, but it will heat the engine faster and you can see if stuffing box is dripping appropriately to cool shaft when it is turning.
Title: Re: Just overheated the engine
Post by: Ron Hill on August 13, 2020, 03:32:08 PM
mre : The whole idea of the flexible blue Hump hose is so that all of the engine vibrations are NOT transmitted to that inlet hose going into the muffler and crack that inlet seal. 
That is what is happening with your black stiff hose from the riser into that inlet of the muffler!!
 
Of course, if you move that stiff hose on the muffler it will lift the riser slightly because it is connected (bolted) to the engine and the engine mounts will give!

The same idea of the nimble nylon hose from the anti syphon valve to the nipple going into the riser. If there is a stiff wire reinforced hose from the factory, the engine vibs will stress that nipples weld cracking it and it will break and leak!!

Get a hump hose and change that raw water hose from the anti syphon valve.  :thumb:

A few thoughts
Title: Re: Just overheated the engine
Post by: Roland Gendreau on August 22, 2020, 11:31:33 AM
MRE

If the riser moved up an inch, that is more than I would expect the whole engine to move on the mounts.  Look over the condition of your riser carefully; mine failed 2 years ago , and it broke right where the water injection connection is made.   

Roland