locked Engine Room Exhaust Fan / Blower - lessons learnt #lessons


David Vogel
 
Edited

One thing to keep an eye on, is the 220VAC engine room exhaust fan.

This unit sits in series with a 24VDC exhaust fan, which runs when the service (12V) alternator for the main engine is creating output.

The 220VAC exhaust fan runs when the ONAN GenSet is outputting 220V AC.

I recently discovered a failing capacitor on the 220V exhaust fan, revealed by intermittent running – the worst kind of fault, as it is not always obvious you have a problem. Sometimes the fan would run, sometimes not. I only recognised that I first had an issue when I walked past the deck-level exhaust outlet one day while the genset was running, and I didn’t have the usual plume of warm air blowing past my leg. With the genset running and the fan not, the fan could usually be encouraged to spin up if hand-started – useful to know, as I wasn’t anywhere near any kind of shop at the time, didn’t have a spare capacitor on-board, and with no other cruisers either within an island to two to check whether they had a spare on board.

Back in civilisation, capacitor quickly sourced at less than USD15- equivalent, and 10 minutes to wire it in. Problem solved.

But now I wonder about a few other failures I have experienced over recent years. And whether they might be related to the intermittent exhaust fan, which may have been failing for some time longer than I suspected. For example, the prolonged heat-soak of elevated temperatures in the engine room (measured up to and occasionally exceeding 50ºC whilst in the tropics), may have been a contributory factor to …

+ failure of the nitrile seals on the fuel-tank inspection hatches – portably due for replacement anyway, in light of other’s experiences with these at ~ 15 years of age, but is there something more going on here than simple chemical or age-related deterioration;

+ failure of some of the adhesive for the engine room foam sound insulation (top only, not sides);

+ premature failure (3 yrs) of ceramic water-maker membranes – one was cracked; these membranes are rated to 40ºC, but what happens if they are hot-hot-hot, and colder sea-water is pushed through them, perhaps resulting in thermal-shock-cooling;

+ early failure of the water-maker membrane pressure-vessel end-caps: this was due to erosion of the black delrin material around the stainless-steel bobbin (inter-connector). I wonder if differential heating/cooling of the delrin end-caps versus stainless steel, allowed a seeping of the HP-water past the O-rings, which then compromised the seal, creating leakage, leading to corrosion/erosion. Thinking along the lines of the space-shuttle Solid-Rocket-Boosters here, less violent, and over a greater time-frame, but the result is kind of the same. Perhaps not usually a problem when the engine-room temperature is held within normal range, but excessive temperature differentials creates a problem. Anyway, no–one wants HP salt-water spraying over the inverter, battery-chargers, switch-boxes, or other electronic or electrical components situated nearby. (Note: Dessalator is no longer issuing INOX interconnectors; replacements are now plastic.)

+ premature failure of water-maker HP hoses, running near-by to the genset, and showing signs of early degradation at the highest point they run in the engine room (external sheath falling apart, weeping) - after only 18-months installed;

+ early failure in the manual bulge-pump diaphragm – I could never could understand why this should fail after only 18-months, but maybe this too now makes sense;

+ failing seals on the salt-water supply pumps for the heads – portably age-relater, but … ;

+ failure of the ONAN Genset Main Control Board, a component known to fail, but was elevated engine-room temperature over a prolonged period a contributory factor?

There is no confirmed cause-and-effect relationship for any of these, but there does appear to be a pattern here, so food for thought.

In any event, I now mindfully check that there is warm air blowing out of the engine-room fresh-air exhaust outlet. Not every start, but whenever I happen to be on-deck when the genset (or engine) is running. I now also routinely check that the engine room blower is providing a healthy quantity of fresh air.

I am also considering:

+ installing an engine room temperature sensor & alarm (relatively easy to put onto the N2K bus, I hope); and

+ installing a timer circuit for the DC exhaust fan, to maintain air movement through the engine room immediately after machinery shut-down, in order to reduce residual temperatures and consequent heat-soak.

David
SM#396, Perigee
Savusavu, Fiji


Jose Venegas
 

David, you may have something here.  I have noticed randomly occurring increases of engine temperature up to 220F when running the engine above 2000 RPM.  However the temperature does not seem to drop after opening the engine-room  door  and have not been able to measure any temp in the engine higher the 176F with an infrared thermometer.  

Any thoughts?

Jose Venegas
Ipanema SM 278 

currently in Shelterbay PANAMA 


 

Jose,

80C or 176 is the normal operating temperature and if the cooling system is working correctly, the temperature should not increase more than 5-8% even at the highest RPM. When you measure 80C on the oil filter, you should measure 50C at the exhaust elbow immediately after the water inlet to the elbow. If it is higher, there is a problem that may be one of the following.

Possible Causes of Overheating:
1. Restricted seawater flow anywhere in the pathway beginning with the seawater entry into the sea chest to the seawater and exhaust exit through the hull. 
a. Sea Chest restriction
b. Hose restriction or kink
c. Restriction at the input to the in-line transmission oil cooler, if equipped
d. Failing seawater pump and/or failing seawater impeller
e. Restricted Exhaust Elbow
2. Restricted Coolant water flow
a. Failing coolant water pump
b. Failing Pressure Cap (should be replaced every 2 years)
c. Failing and/or clogged Heat Exchanger
3. Incorrect coolant ratio, but this is usually not a major contributor but will contribute somewhat.
4. Incorrect V-Belt tensioning with the V-Belt turning the coolant water pump
5. Failing Coolant Thermostat (not opening completely)
6. Other engine issues

Do not think that you can measure enough water flow by observing the seawater and exhaust exiting the boat. It will fool you.

Bill

CW Bill Rouse Amel Owners Yacht School
Address: 720 Winnie, Galveston Island, Texas 77550 
View My Training Calendar

On Thu, Sep 2, 2021 at 1:40 PM Jose Venegas via groups.io <josegvenegas=icloud.com@groups.io> wrote:

David, you may have something here.  I have noticed randomly occurring increases of engine temperature up to 220F when running the engine above 2000 RPM.  However the temperature does not seem to drop after opening the engine-room  door  and have not been able to measure any temp in the engine higher the 176F with an infrared thermometer.  

Any thoughts?

Jose Venegas
Ipanema SM 278 

currently in Shelterbay PANAMA 


Patrick McAneny
 

Jose, You seem to contradict yourself . You said you have notice engine temps to 220 when running above 2000 rpm., but then said you have not read temps above 176 with a infrared . What engine do you have? I have a Volvo TMD22a and have had overheating issues in the past and discovered a cause ,probably overlooked by many.
Pat
SM Shenanigans 


-----Original Message-----
From: CW Bill Rouse <brouse@...>
To: main@AmelYachtOwners.groups.io Notification <main@amelyachtowners.groups.io>
Sent: Thu, Sep 2, 2021 5:43 pm
Subject: [Special] Re: [AmelYachtOwners] Engine Room Exhaust Fan / Blower - lessons learnt #lessons

Jose,

80C or 176 is the normal operating temperature and if the cooling system is working correctly, the temperature should not increase more than 5-8% even at the highest RPM. When you measure 80C on the oil filter, you should measure 50C at the exhaust elbow immediately after the water inlet to the elbow. If it is higher, there is a problem that may be one of the following.

Possible Causes of Overheating:
1. Restricted seawater flow anywhere in the pathway beginning with the seawater entry into the sea chest to the seawater and exhaust exit through the hull. 
a. Sea Chest restriction
b. Hose restriction or kink
c. Restriction at the input to the in-line transmission oil cooler, if equipped
d. Failing seawater pump and/or failing seawater impeller
e. Restricted Exhaust Elbow
2. Restricted Coolant water flow
a. Failing coolant water pump
b. Failing Pressure Cap (should be replaced every 2 years)
c. Failing and/or clogged Heat Exchanger
3. Incorrect coolant ratio, but this is usually not a major contributor but will contribute somewhat.
4. Incorrect V-Belt tensioning with the V-Belt turning the coolant water pump
5. Failing Coolant Thermostat (not opening completely)
6. Other engine issues

Do not think that you can measure enough water flow by observing the seawater and exhaust exiting the boat. It will fool you.

Bill

CW Bill Rouse Amel Owners Yacht School
Address: 720 Winnie, Galveston Island, Texas 77550 
View My Training Calendar

On Thu, Sep 2, 2021 at 1:40 PM Jose Venegas via groups.io <josegvenegas=icloud.com@groups.io> wrote:
David, you may have something here.  I have noticed randomly occurring increases of engine temperature up to 220F when running the engine above 2000 RPM.  However the temperature does not seem to drop after opening the engine-room  door  and have not been able to measure any temp in the engine higher the 176F with an infrared thermometer.  
Any thoughts?
Jose Venegas
Ipanema SM 278 
currently in Shelterbay PANAMA 


ESTELLER
 

Hello Bill,

 

Are you sure this email is for me?

I do not encounter a temperature problem with my D3 110, and I do not believe I have asked any question on this subject on the sites.

 

Your answer concerning the engine temperature is as usual very relevant.

 

Kindly

 

José ORION A54

 

De : main@AmelYachtOwners.groups.io <main@AmelYachtOwners.groups.io> De la part de CW Bill Rouse
Envoyé : jeudi 2 septembre 2021 23:43
À : main@AmelYachtOwners.groups.io Notification <main@amelyachtowners.groups.io>
Objet : [Special] Re: [AmelYachtOwners] Engine Room Exhaust Fan / Blower - lessons learnt #lessons

 

Jose,

 

80C or 176 is the normal operating temperature and if the cooling system is working correctly, the temperature should not increase more than 5-8% even at the highest RPM. When you measure 80C on the oil filter, you should measure 50C at the exhaust elbow immediately after the water inlet to the elbow. If it is higher, there is a problem that may be one of the following.

 

Possible Causes of Overheating:
1. Restricted seawater flow anywhere in the pathway beginning with the seawater entry into the sea chest to the seawater and exhaust exit through the hull. 

a. Sea Chest restriction

b. Hose restriction or kink

c. Restriction at the input to the in-line transmission oil cooler, if equipped

d. Failing seawater pump and/or failing seawater impeller

e. Restricted Exhaust Elbow

2. Restricted Coolant water flow

a. Failing coolant water pump

b. Failing Pressure Cap (should be replaced every 2 years)

c. Failing and/or clogged Heat Exchanger

3. Incorrect coolant ratio, but this is usually not a major contributor but will contribute somewhat.
4. Incorrect V-Belt tensioning with the V-Belt turning the coolant water pump
5. Failing Coolant Thermostat (not opening completely)
6. Other engine issues

 

Do not think that you can measure enough water flow by observing the seawater and exhaust exiting the boat. It will fool you.

 

Bill


CW Bill Rouse Amel Owners Yacht School

Address: 720 Winnie, Galveston Island, Texas 77550 

 

View My Training Calendar

 

On Thu, Sep 2, 2021 at 1:40 PM Jose Venegas via groups.io <josegvenegas=icloud.com@groups.io> wrote:

David, you may have something here.  I have noticed randomly occurring increases of engine temperature up to 220F when running the engine above 2000 RPM.  However the temperature does not seem to drop after opening the engine-room  door  and have not been able to measure any temp in the engine higher the 176F with an infrared thermometer.  

Any thoughts?

Jose Venegas
Ipanema SM 278 

currently in Shelterbay PANAMA 


andrew parker
 

Hi Bill 
I received the email below but I think you meant to send it to Jose 


On 2 Sep 2021, at 23:43, CW Bill Rouse <brouse@...> wrote:


Jose,

80C or 176 is the normal operating temperature and if the cooling system is working correctly, the temperature should not increase more than 5-8% even at the highest RPM. When you measure 80C on the oil filter, you should measure 50C at the exhaust elbow immediately after the water inlet to the elbow. If it is higher, there is a problem that may be one of the following.

Possible Causes of Overheating:
1. Restricted seawater flow anywhere in the pathway beginning with the seawater entry into the sea chest to the seawater and exhaust exit through the hull. 
a. Sea Chest restriction
b. Hose restriction or kink
c. Restriction at the input to the in-line transmission oil cooler, if equipped
d. Failing seawater pump and/or failing seawater impeller
e. Restricted Exhaust Elbow
2. Restricted Coolant water flow
a. Failing coolant water pump
b. Failing Pressure Cap (should be replaced every 2 years)
c. Failing and/or clogged Heat Exchanger
3. Incorrect coolant ratio, but this is usually not a major contributor but will contribute somewhat.
4. Incorrect V-Belt tensioning with the V-Belt turning the coolant water pump
5. Failing Coolant Thermostat (not opening completely)
6. Other engine issues

Do not think that you can measure enough water flow by observing the seawater and exhaust exiting the boat. It will fool you.

Bill

CW Bill Rouse Amel Owners Yacht School
Address: 720 Winnie, Galveston Island, Texas 77550 
View My Training Calendar

On Thu, Sep 2, 2021 at 1:40 PM Jose Venegas via groups.io <josegvenegas=icloud.com@groups.io> wrote:

David, you may have something here.  I have noticed randomly occurring increases of engine temperature up to 220F when running the engine above 2000 RPM.  However the temperature does not seem to drop after opening the engine-room  door  and have not been able to measure any temp in the engine higher the 176F with an infrared thermometer.  

Any thoughts?

Jose Venegas
Ipanema SM 278 

currently in Shelterbay PANAMA 


 

I was answering Jose Venegas, Ipanema SM 278. Jose was the original poster of the question regarding higher engine temperture at higher RPM.

Bill

CW Bill Rouse Amel Owners Yacht School
Address: 720 Winnie, Galveston Island, Texas 77550 
View My Training Calendar

On Fri, Sep 3, 2021 at 7:02 AM andrew parker <apwarwick@...> wrote:
Hi Bill 
I received the email below but I think you meant to send it to Jose 


On 2 Sep 2021, at 23:43, CW Bill Rouse <brouse@...> wrote:


Jose,

80C or 176 is the normal operating temperature and if the cooling system is working correctly, the temperature should not increase more than 5-8% even at the highest RPM. When you measure 80C on the oil filter, you should measure 50C at the exhaust elbow immediately after the water inlet to the elbow. If it is higher, there is a problem that may be one of the following.

Possible Causes of Overheating:
1. Restricted seawater flow anywhere in the pathway beginning with the seawater entry into the sea chest to the seawater and exhaust exit through the hull. 
a. Sea Chest restriction
b. Hose restriction or kink
c. Restriction at the input to the in-line transmission oil cooler, if equipped
d. Failing seawater pump and/or failing seawater impeller
e. Restricted Exhaust Elbow
2. Restricted Coolant water flow
a. Failing coolant water pump
b. Failing Pressure Cap (should be replaced every 2 years)
c. Failing and/or clogged Heat Exchanger
3. Incorrect coolant ratio, but this is usually not a major contributor but will contribute somewhat.
4. Incorrect V-Belt tensioning with the V-Belt turning the coolant water pump
5. Failing Coolant Thermostat (not opening completely)
6. Other engine issues

Do not think that you can measure enough water flow by observing the seawater and exhaust exiting the boat. It will fool you.

Bill

CW Bill Rouse Amel Owners Yacht School
Address: 720 Winnie, Galveston Island, Texas 77550 
View My Training Calendar

On Thu, Sep 2, 2021 at 1:40 PM Jose Venegas via groups.io <josegvenegas=icloud.com@groups.io> wrote:

David, you may have something here.  I have noticed randomly occurring increases of engine temperature up to 220F when running the engine above 2000 RPM.  However the temperature does not seem to drop after opening the engine-room  door  and have not been able to measure any temp in the engine higher the 176F with an infrared thermometer.  

Any thoughts?

Jose Venegas
Ipanema SM 278 

currently in Shelterbay PANAMA 


ESTELLER
 

ok Bill!



Envoyé depuis mon appareil Galaxy


-------- Message d'origine --------
De : CW Bill Rouse <brouse@...>
Date : 03/09/2021 14:17 (GMT+01:00)
À : "main@AmelYachtOwners.groups.io Notification" <main@amelyachtowners.groups.io>
Objet : [Special] Re: [AmelYachtOwners] Engine Room Exhaust Fan / Blower - lessons learnt #lessons

I was answering Jose Venegas, Ipanema SM 278. Jose was the original poster of the question regarding higher engine temperture at higher RPM.

Bill

CW Bill Rouse Amel Owners Yacht School
Address: 720 Winnie, Galveston Island, Texas 77550 
View My Training Calendar

On Fri, Sep 3, 2021 at 7:02 AM andrew parker <apwarwick@...> wrote:
Hi Bill 
I received the email below but I think you meant to send it to Jose 


On 2 Sep 2021, at 23:43, CW Bill Rouse <brouse@...> wrote:


Jose,

80C or 176 is the normal operating temperature and if the cooling system is working correctly, the temperature should not increase more than 5-8% even at the highest RPM. When you measure 80C on the oil filter, you should measure 50C at the exhaust elbow immediately after the water inlet to the elbow. If it is higher, there is a problem that may be one of the following.

Possible Causes of Overheating:
1. Restricted seawater flow anywhere in the pathway beginning with the seawater entry into the sea chest to the seawater and exhaust exit through the hull. 
a. Sea Chest restriction
b. Hose restriction or kink
c. Restriction at the input to the in-line transmission oil cooler, if equipped
d. Failing seawater pump and/or failing seawater impeller
e. Restricted Exhaust Elbow
2. Restricted Coolant water flow
a. Failing coolant water pump
b. Failing Pressure Cap (should be replaced every 2 years)
c. Failing and/or clogged Heat Exchanger
3. Incorrect coolant ratio, but this is usually not a major contributor but will contribute somewhat.
4. Incorrect V-Belt tensioning with the V-Belt turning the coolant water pump
5. Failing Coolant Thermostat (not opening completely)
6. Other engine issues

Do not think that you can measure enough water flow by observing the seawater and exhaust exiting the boat. It will fool you.

Bill

CW Bill Rouse Amel Owners Yacht School
Address: 720 Winnie, Galveston Island, Texas 77550 
View My Training Calendar

On Thu, Sep 2, 2021 at 1:40 PM Jose Venegas via groups.io <josegvenegas=icloud.com@groups.io> wrote:

David, you may have something here.  I have noticed randomly occurring increases of engine temperature up to 220F when running the engine above 2000 RPM.  However the temperature does not seem to drop after opening the engine-room  door  and have not been able to measure any temp in the engine higher the 176F with an infrared thermometer.  

Any thoughts?

Jose Venegas
Ipanema SM 278 

currently in Shelterbay PANAMA