kad 32 getting hot ....STILL !!!!!

STEVEDUNSTABLE

STEVEDUNSTABLE

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Hi All..... some of you about these parts might remember my post about TM getting hot under load or above 19/20kts.... this all started last year, so the heat exchanger was removed in the autumn and found to be spotless as is intercooler. During all this bent doubleness in the bilge, both raw water and antifreeze systems were thourghly flushed through backwards and forwards and full flow was easily achieved with no effort or problem... also the impellor was changed at easter and AGAIN this wknd !!!....all to no avail ..my pi*sed off rating is now getting to "chuck stuff about setting"...the only thing left that I can do (myself) now is to change the thermostats...... so .. QUESTION TIME........looking at the exploded view of the housing,.. (http://www.marinepartseurope.com/en/volvo-penta-explodedview-7738870-26-3059.aspx it APPEARS to be a relative easy job BUT IS IT ???.....boat afloat at mercury, problem?, any special tools needed?, is it a repair kit job?........ comments, criticisms, advice, abuse FEEL FREE .......THANKS IN ADVANCE PEOPLE... ......
 
Did you ever get your mits on an infrared thermostat Steve? If this were me, I'd be asking Gary (that's me), to join up with me (that's you) to use his (mine) infrared thermstat on both Bizzy Bee and Thanks Mum in all the pertinent places until you find a component in the system where something is hot on Thanks Mum and not on Bizzy Bee.

clear as mud?
 
Agree with Garyo.

IR temp gun. Read temp of water exiting engine at exhaust elbow in particular when overheat occurs.

Sounds like it might be drawing in air through leg when on plane. Look over back of boat and you will most likely see at that speed upper drive is exposed.
 
oGaryo said:
Did you ever get your mits on an infrared thermostat Steve? If this were me, I'd be asking Gary (that's me), to join up with me (that's you) to use his (mine) infrared thermstat on both Bizzy Bee and Thanks Mum in all the pertinent places until you find a component in the system where something is hot on Thanks Mum and not on Bizzy Bee.

clear as mud?
Click to expand...

Hi G...are you floating at the mo ??
 
STEVEDUNSTABLE said:
Hi All..... some of you about these parts might remember my post about TM getting hot under load or above 19/20kts.... this all started last year, so the heat exchanger was removed in the autumn and found to be spotless as is intercooler. During all this bent doubleness in the bilge, both raw water and antifreeze systems were thourghly flushed through backwards and forwards and full flow was easily achieved with no effort or problem... also the impellor was changed at easter and AGAIN this wknd !!!....all to no avail ..my pi*sed off rating is now getting to "chuck stuff about setting"...the only thing left that I can do (myself) now is to change the thermostats...... so .. QUESTION TIME........looking at the exploded view of the housing,.. (http://www.marinepartseurope.com/en/volvo-penta-explodedview-7738870-26-3059.aspx it APPEARS to be a relative easy job BUT IS IT ???.....boat afloat at mercury, problem?, any special tools needed?, is it a repair kit job?........ comments, criticisms, advice, abuse FEEL FREE .......THANKS IN ADVANCE PEOPLE... ......
Click to expand...
Its quite easy and you can take the thermostats out and put them in water that you heat up to check if they open ok. I've personally not come across them not opening though, they tend to not close properly which keeps the engines and a lower temp with little load.

Did you clean/check the oil cooler and exhaust bend?
 
STEVEDUNSTABLE said:
Hi All..... some of you about these parts might remember my post about TM getting hot under load or above 19/20kts.... this all started last year, so the heat exchanger was removed in the autumn and found to be spotless as is intercooler. During all this bent doubleness in the bilge, both raw water and antifreeze systems were thourghly flushed through backwards and forwards and full flow was easily achieved with no effort or problem... also the impellor was changed at easter and AGAIN this wknd !!!....all to no avail ..my pi*sed off rating is now getting to "chuck stuff about setting"...the only thing left that I can do (myself) now is to change the thermostats...... so .. QUESTION TIME........looking at the exploded view of the housing,.. (http://www.marinepartseurope.com/en/volvo-penta-explodedview-7738870-26-3059.aspx it APPEARS to be a relative easy job BUT IS IT ???.....boat afloat at mercury, problem?, any special tools needed?, is it a repair kit job?........ comments, criticisms, advice, abuse FEEL FREE .......THANKS IN ADVANCE PEOPLE... ......
Click to expand...

I don't know if it's applicable with your set up but have you thought about the water intake being bung up with marine growth ?

Just a thought
 
IR thermometer first to read true temps @ various speeds / rpm,s - on both engines
Water pump impeller plate ,top of thermos stat house , both ends of HE ,and exhaust elbow
compare engines
Guage measures resistance - if you unplug the sender ( s) it shoots up the RHS straight to 250
Alarms / guard I suspect is separate circuit ? Hence it's silent
Doing this you will arrive at a diagnosis
Corroded spades at the back of the guage -increase resistance so it " falsely " moves to the RHS
Really cannot arrive at any definitive temp rising issue with VP without a IR thermometer test
Maplins
 
I had a kad 32 that used to sound the over heat alarm under load it turned out to be an over sensitive sender
I fitted a new one and it never had the problem again
It's the sender behind the supercharger
 
STEVEDUNSTABLE said:
Hi All..... some of you about these parts might remember my post about TM getting hot under load or above 19/20kts.... this all started last year, so the heat exchanger was removed in the autumn and found to be spotless as is intercooler. During all this bent doubleness in the bilge, both raw water and antifreeze systems were thourghly flushed through backwards and forwards and full flow was easily achieved with no effort or problem... also the impellor was changed at easter and AGAIN this wknd !!!....all to no avail ..my pi*sed off rating is now getting to "chuck stuff about setting"...the only thing left that I can do (myself) now is to change the thermostats...... so .. QUESTION TIME........looking at the exploded view of the housing,.. (http://www.marinepartseurope.com/en/volvo-penta-explodedview-7738870-26-3059.aspx it APPEARS to be a relative easy job BUT IS IT ???.....boat afloat at mercury, problem?, any special tools needed?, is it a repair kit job?........ comments, criticisms, advice, abuse FEEL FREE .......THANKS IN ADVANCE PEOPLE... ......
Click to expand...

I'm getting at lot of owners saying through boats are overheating, this isn't the case.
What the actually seeing is that there engine are running hotter than last year, no more no less. The simple reason is that the sea is now around 24 deg c last year it didn't get near 20 deg c.
A marine motor is reliant on what temp the sea water is thats going into it so if its hotter than previously then the net result will be that the engine runs hotter.

A Volvo is happy at 90 to 95 deg c and no more, any hotter you will get the alarm coming on.

Examples, this is my rule of thumb.

The AD 41 series run up to 90, any more and I'd be looking at coolers.

Tamd 63 p will run up to 95 deg c.

Kad 32 and 44/300 I see 90/95.

Tamd 74/75 seem to run in the mid 80s all day and touch 90 at full load, I've never seen them hit higher than this on sea trials.

Remember guys were at the mid season hull growth point now so your motors are working that bit harder.

So Steve, what temp are you actually seeing on the gauge where flat out.

If your getting the alarm on then there's a problem, unless of course the gauge shows a low reading and it's coming on, which does happen as these senders do faili
 
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Steve - I had exactly the same symptoms on a Volvo TAMD71B. It would only overheat under heavy load at high speed. Knackered inner bearings in the raw water pump which was NOT evident when checking or changing the impeller and the drive wheel was disengaging when loaded so effectively the pump stopped. As the engine/boat slowed it would re-engage. I had the same suggestions as you've had and none of them worked and exactly the same i.e. no evidence. I even had once suggestion to change the engine as was unrepairable. I'm not saying it is this but think outside the box. The IR thermometer was used when the engine was loaded out in the channel (never repeated itself in the marina as the engine was never loaded enough) and I managed to get a replacement direct from Jabsco although quite difficult to get to but I did manage with it in situ. It had been bugging me for weeks. I would suggest 90% of engine overheating problems are on the raw water side.
Dave
 
Hi Guys.... THANKS PLENTY MUCH for all the replies and theories ..to fill in a few of my own gaps, here is more detail.. boat had a major bum clean on trailer last Friday, flow through the oil cooler (both directions) clear, pick up pipe ok as far as we can tell,.. temp on gauge pre. supercharger coming on is 89/90, when hitting the loud n thirsty switch, the gauge can be literally seen rising to 96/7 at about 19/20 knts (2900/3000 rpm)where I chickin out on letting it go higher and this temp is arrived at in about 20/30 secs ..... if I drop the rpm to around 2650/2750 it stays at 95/6... but any quick dash needed is instantly shown on the temp gauge..... just for the record, the alarm does work as had it go off last yr following a ferry out of lymington on low springs and the filter was choked with weed..it came on at about 98/99.. hope all this stuff is a bit more helpful ......again thanks all for your replies....
 
If the raw water feed from the leg is by flexible hoses as I believe mine are (kad32 with DPE), it could be that they are soft and effectively collapsing when the pump is pulling more water as revs increase.
 
Volvo outdrives have an o-ring below the H frame that has been known to allow air to be drawn into the salt water flow. Especially if there is any movement up and down between the h-frame and the outdrive body.

It is possible that you are experiencing this. As the boat goes onto the plane and increases speed the water level behind the transom drops away to expose this part of the drive. This causes a loss of salt water flow.

Of course, you then throttle back and the problem disappears as the water level rises. Take a look over the back at high speed and you will see what I mean.

Have had numerous situations over the years where this problem has caused money spent in the wrong direction.

The same thing can happen if your pick up elbow is cracked or your hose is perished.

The FlushSok that I have designed and am currently marketing can prove this problem ashore as it simulates the water level on the drive when the vessel is planing. But only with the vessel ashore.
 
volvopaul said:
The simple reason is that the sea is now around 24 deg c last year it didn't get near 20 deg c.
A marine motor is reliant on what temp the sea water is thats going into it so if its hotter than previously then the net result will be that the engine runs hotter.
Click to expand...

Paul I don't buy that. The thermostat deals with that and will keep the engine at same jacket-water temperature across a very wide range of seawater temperatures, if everything is working ok. The difference between 20 and 24deg C is nowt. Basically, if everything is working, the engine jacket will the correct 85 or whatever degC whether the seawater is 1 degree C or some upper limit like 40 deg C. Obviously once you go above the upper limit the engine will overheat, but that is going to be something like 40degC of seawater temp. My motors ran in UK waters in winter and are now in the Med at ~30degC, and at all times the jacket temp is the same (low 80s)

The seawater temp WILL affect the exhaust temp downstream of the elbow but that is a different point
 
STEVEDUNSTABLE said:
Hi Guys.... THANKS PLENTY MUCH for all the replies and theories ..to fill in a few of my own gaps, here is more detail.. boat had a major bum clean on trailer last Friday, flow through the oil cooler (both directions) clear, pick up pipe ok as far as we can tell,.. temp on gauge pre. supercharger coming on is 89/90, when hitting the loud n thirsty switch, the gauge can be literally seen rising to 96/7 at about 19/20 knts (2900/3000 rpm)where I chickin out on letting it go higher and this temp is arrived at in about 20/30 secs ..... if I drop the rpm to around 2650/2750 it stays at 95/6... but any quick dash needed is instantly shown on the temp gauge..... just for the record, the alarm does work as had it go off last yr following a ferry out of lymington on low springs and the filter was choked with weed..it came on at about 98/99.. hope all this stuff is a bit more helpful ......again thanks all for your replies....
Click to expand...

Sounds like its running a bit hot throughout the rev range.

Below 1500rpm ours will eventually reach 80. It only goes to 90 on the plane really.

Have you checked the bearings in the raw water pump?

Friends of ours had a mussel growing in their water intake which restricted water flow. Took ages to find the problem. I think a mussel would be unlikely in your case mind as you keep it on a trailer but is it possible there is some other restriction on the water intake?
 
jfm said:
Paul I don't buy that. The thermostat deals with that and will keep the engine at same jacket-water temperature across a very wide range of seawater temperatures, if everything is working ok. The difference between 20 and 24deg C is nowt. Basically, if everything is working, the engine jacket will the correct 85 or whatever degC whether the seawater is 1 degree C or some upper limit like 40 deg C. Obviously once you go above the upper limit the engine will overheat, but that is going to be something like 40degC of seawater temp. My motors ran in UK waters in winter and are now in the Med at ~30degC, and at all times the jacket temp is the same (low 80s)

The seawater temp WILL affect the exhaust temp downstream of the elbow but that is a different point
Click to expand...

Hi john,
Over the last 2 months I've now lost count how many engines I have removed heat exchangers from, stripped, cleaned out and rebuilt with the result that there still running warmer than last year , most units I stripped were showing only small amount of marine growth and partial blockage. After rebuilds and sea trial testing various points on the engine with IR gun this is the only answer I can come up with as all of the engines I've repaired run fine in the winter. Most marine motors run on the limit of heat exchanger size and design where there is no built in leeway for blocked tubes etc , so they overheat or certainly run hotter than they should do. You have very modern engines that probably don't have any marine growth in the coolers at all. A 10 year old something in the same waters won't perform its cooling capabilities as well in the med as it would do over here. We all know boats are down on power in hotter climes compared to cooler ones, the air intake temp is particularly important as this is where power is generated on turbocharged engines, so in my view the water temp does play a big part in cooling capabilities.
 
The reason engines develop less power in hotter climes is because the air density reduces, so less air mass enters the cylinder, and engines are not equipped to adjust for this other than the boost pressure provided by the turbo, and this is not compensated for ambient temp.

On Marine Gas turbine engines we had adjustment factors to account for changes in the ambient air temperature entering the engine to factor the power / fuel consumption and outlet power turbine temperatures, which had to be kept under close scrutiny.

Whereas the seawater cooling wil have some affect due to the reduction in effective after cooling at higher sea temps, I feel this is driting somewhat from poor old Steve's problem.

I suggest, following on from Gary's advice, that he fits a rain catcher to assist his local water flows - not sure what he means though ! (I'll get my coat !)
 
Hi All..... a bit of a delayed update due to a certain "Bertha" ...took TM up Soton water this morning with a temp gauge on loan from a certain ogaryo (ta much geezer)...these are the readings I obtained (bearing in mind I wasn't to sure at which target was best)...turbo, before water injection elbow 87degs....after water injection 36/7 degs.... heat exchanger, side 38, end plate 40.... thermostat housing top half 87 .. bottom half 84/5.... calorifyor take off elbows (both checked)(comes out of the thermostat housing) 80... hot tank end 68 (seems a big drop in 24") top of engine between rocker covers 77... PROBLEM .. I have no idea how to interpret these !!!!......ps. temp gauge on dash still getting up to 96/7 before I chicken out........ so over to you guys for a direction to follow pretty PLEEEASE !!!!!
 
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