Overheated my Perkins! What damages?

[skwanderer]

The muffler is fiberglass. I just replaced the exhaust hoses from engine to muffler. As I think further on the experience, there was steam as well as water spluttering out of the stern

[a64pilot]

Originally Posted by skwanderer

All excellent additions to my newly forming departure checklist.

Sounds like I should get my mech back in for that cooling system service. Not confident yet in my DIY abilities.

One thing additionally that I observed is that the oil pressure used to run consistently at 60, but at the overheating and after it dropped to ~50. Though I haven't checked fliud levels yet this morning, any ideas in the cause of drop in oil pressure?

Hopefully oil pressure drop was from overheating the oil and it losing viscosity.
I would change it soon.


Sent from my iPad Pro using Cruisers Sailing Forum

[PaulMarion]

Once again I agree with all the previous suggested posts. A few more items would be worth mentioning, as I also had an overheat on one of my Volvo/ Perkins D30's in wild weather one night. I found a restriction at the inlet cock, and having removed that, water flow was normal. After replacing the impeller, and checking as aforementioned, I also replaced the thermostat, retensioned the cylinder head and reset valve clearances. This is done to ensure any compression of head gasket material is taken up, and also expansion of valve seats or valves. Mostly you will find the exhaust side of the head will retension as its the hottest due to an overheat, and the valve clearances can change due to expansion or seats settling further into the head. Tight valves will cause rough running, loose will rattle. An easy check for head or gasket problems on any overheated motor is to notice if it starts and runs cleanly when cold. If it doesn't, head or gasket problems may be at hand. Before panicking though, you MUST tension head and set valve clearances, as this often allays the problem. Injectors can also be affected in extreme cases and if head removal is necessary, need to be serviced. As a senior mechanic of 50years with motors, I always run Wynns products in all my engines, gearboxes etc. My customers and I have proved their worth many times over, saving big $$$ on repairs when things go wrong! Your oil quality will definitely be compromised by the overheating and MUST be changed SAP. Once done the oil pressure will return to normal.

[boeing1]

good advice in the above threads, If you close you sea cocks place your key on the sea cock valve and you will not forget to turn them back on before you start your engine,

[Capt Gill]

I don't think this is mentioned in the thread: Given that a couple gallons of coolant was found in the bilge it would be a v. good idea to check for raw water intrusion in the eng. coolant jackets,i.e., remove the coolant pressure cap and do a taste test. This could happen where the end caps seal the heat exchanger raw water from the surrounding coolant. Realise that the pressure from the positive displacement raw water pump can easily be three times(esp. at start up) the pressure of the engine coolant system at normal eng. temp. So,in this case upon opening the raw water thru-hull there's going to be a large press. difference and temp. difference,fertile ground to exploit any weakness in the end cap seals for the heat exchanger and allow salt water into the coolant system.
Based on a true story - mine:biggrin

[Triton]

Hi guys a good trick I use if unsure of coolant pressure checks. Drain coolant, top fresh water and food colouring concentrate. Run up to temp, put a bucket at exhaust outlet water, check for colouring in water. A sensor can be fitted in the exhaust to alarm on Temp.
cheers
Tony

[Muckle Flugga]

Hi there,

I wouldn't worry too much. Generally agree with the good advice given above.

Sounds like you just boiled the coolant out of the pressure cap. Not really a big deal in itself. Change oil, filters, and check impeller, as well as monitoring gaskets and seals in general.

All advice given above… I post only to say that it is in fact possible (though seriously not recommended as a procedure!) that you in fact did more good than harm, since you caught it quickly: you may simply have cleaned the cylinders somewhat. Occasional near overheat can assist in this. Of course actual overheat is dangerous and should be avoided, but redlining a Perkins for a few minutes every few hours will help to keep it healthy.

[Sandero]

Engines.... you need to be regularly checking the exhaust to see that water is being ejected. If it looks less than "normal" something is up.... pay close attention. It may not overheat much... but it will run hotter than "normal" . When in port... figure out what the cause is and fix it. It could be a clogged strainer... or barnacles blocking... or a busted impeller... Find it and fix it!

[Mike OReilly]

We blew our belt which led to a serious overheating. I knew it was happening b/c we were dealing with a fouled anchor in a tight, windy anchorage at the time, so couldn't shut the engine off. Anyway, we managed to bring the temperature way over (forget the final temp). Shut her down, replaced belt and some coolant. Let her cool. Fired back up no problem. Replaced oil and filter soon after. Has ran for three years with no problem (except pressure pump, which I'm sure is unrelated).

These are tough engines.

BTW, part of our regular running procedure is to glance at the gauges every 1/2 hr or so. I watch oil pressure and temperature petty closely. This has allowed us to catch issues before they build. Helps that the gauges are easily viewable from the helm.

[ebsail]

I used to hang my engine keys on the engine intake seacock handle to remind me to open the seacock before starting.

[ericoh88]

FWIW

A nice boat was being delivered from Singapore to Australia. Half way, the volvo engine overheated. The boat sailed and towed back to Singapore for a new Volvo engine replacement.

After learning of this incident, I bought a high exhaust temp alarm and raw water flow alarm from aqualarm, hopefully to prevent an engine disaster .

The items arrived last year and the install is on my checklist for this month.

[Capt Gill]

Originally Posted by skwanderer

Like an idiot I forgot to open the seacocks to the salt water heat exchangers on my twin Perkins 4.236 when I headed out today.

Had only gone about a mile, no greater than 5 knots at any point, when I noticed the temp gauges exceeded the usual 180 degree steady temp. After acouple more minutes, I lifted the engine hatch to be greeted by a big plume of steam. (Not oil fortunately!) I jumped in and opened the seacocks but kept the engines running eventually increased above idle, thinking it would help circulate water quicker. Within a few minutes the temp did come back on both engines to 180 steady as ever. Steam did continue to come out of the exhaust hoses (as well as water as per usual) at the back of the stern

When I got back to the slip about an hour later and inspected the engine room, looks like green coolant sprayed out as I found drops all around. Also found a couple gallons of green coolant/water in the bilge.

So, before I call my mechanic$$$$$$, anyone think I did egregious damage to my engines? I'll check the coolant lines for splits or leaks (as soon as I learn which ones they are. Will check coolant level and oil level. And other ideas to see the health of things?

Many thanks for any thoughts of assistance on assessing the situation.

Some questionsid you add coolant at the time you went below,if no how much did you add after returning ? I'm wondering that if all that fluid in the bilge was coolant and did not add any until returning an hour later how the temp stayed normal ? I don't know your coolant capacity,but a couple gallon loss would seem close to empty.

[yachtcowboy]

One thing I would add is a "no water alarm" in the intake line after the sea strainer. Pretty cheap, about $100 installed with a unique sound so that you recognize that you have low or no sea water to your engine. West Marine has them in the catalog.

[meirriba]

Originally Posted by Triton

Hi im a marine engineer had this call out often. Advise the following 1. Oil and filter change. High temp has depleted oil additives, and possibly glazed bearing shells / Lacquers 2. Send in oil and filter sample for analysis to detect High lead in oil Pb. or copper, aluminium and coolant 3. Replace raw water pump impeller. check water lock / mufflers, exhaust hose, header /expansion tank, coolant hose / clamps for split damage. Master oil pressure check idle and full must be in spec. coolant pressure checks to determine heat exchange seals and leaks. Half interval oil / filter change and resample analysis.
Cheers
Tony

All the above and:
Install temperature alarm.
Simple installation that will warn you before any damage starts.

[skwanderer]

Thanks everyone! Great help and advice. Love this forum.

I had the mechanic (since I'm still learning this) check and change the oil, add in coolant and replace the impellers. We could easily see the impellers were chewed up, and so also chased down the chunks that ended up in the cooling pipes and baffles.

(I definitely need to learn how to do... $700 later for a half day of oil change, coolant added and impeller changes. Not major stuff... I'm considering it as my education tuition to boat life school)

We also discovered that my overheating alarm sensors are faulty. Need to get those replaced.

I've since taken the boat out, and everything seems to run as before. I now watch the guages like a hawk.

I've creating a checklist for departure so I don't have to think:

Exterior
Remove dock fresh water hose connection, dock electricity lines and turn off dock breaker(s)
Visually inspect and clear or secure any other objects that may be tied to the outside of the boat (kayaks, tenders, waverunners, debris, etc)
Visually inspect and stow or secure any objects that may be loose on the decks (heaters, propane tanks, chairs, pop-up tables, awnings, etc)
Visually inspect to all sheets and lines are clear and clean laying, unobstructed or knotted their entire length
Remove window shades

Interior
Visually inspect and stow or secure any objects that may be loose in every room and cabin / interior (computer, tv screens, speakers, hanging wall pictures, countertop ornaments, dishes, groceries, etc)
Ensure source of fresh drinking water available (bottles or igloo)

Start up
Sniff test of engine compartment
Oil check
coolant check
Fuel check
SEACOCKS OPEN (I don't need keys to start engines, so may add something like "remove before start" banner/pin hanging on them)
bilge functioning check
Fire extinguishers handy
Visually inspect engine compartment and stow or secure any objects that may be loose
Once running, check stern exhaust for normalcy (no blue, white or black exhaust) and water displacement
VHF Radio on and functional
PFD Life vest on or at hand

Any other items to add?

Many thanks again to all the helpful replies!