D12 high temp.. or false sensor reading

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hkikis

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Hello,

I bought a Squadron 55 D12 715hp with 1100hr. Perfect boat and I have problem free trips with very good performance as a fairline!!

Max rpm 2300 33.5knots
Cruise 1900 25knots

I bought it and I did 250miles to bring it my city. Everything perfect except the temp meter. Port engine 92c-200f starboard 98c! Volvo dealer when I did sea trial told me maybe are the heat exchangers... Ok I thought that I can arrive in my city (250nm). And I did it very easy.

Same temp either 900rpm or 1900 or 2300rpm... Exactly the same... 92 and 98..

The seller told me that last year put off heat exchangers and they dont need. He told me that just after last service (oil, thermostats) has this problem so he told me that hw believe the thermostats is the problem.

Summer time and very difficult to find volvo mechanics. So first of all I asked a company to make a full heat exchangers cleaning by pump and chemicals that they use. They are veey popular and they are professional at this work. They told me that they was ok... Nothing blocked but they are like new now... I did a trip 50miles... The same...

Volvo visited me and they told me don't change thermostats... The previous owner gave me the boxes of the new thermostats. Original volvo and by part number they are right. While they check my engines was at 78C as I returned from trip. With laser they saw 64... Aaa the sensor is the problen they told me!!! They measured ohms and they was way different each other.. So they was 100% sure about it! Also they told me if I had real 98C I would hear the crazy alarm.. Also the green water would be out.. I was always full of water. I was so happy.. They changed them... I did another 50nm trip but the same temps!!!!

Any idea whats is going on?? My lovely Squadron works perfect but I don't want make any damage!!

Even if I start with cold engines and go only with 900rpm I will see the same temps 92-98!! Full wot for 3min the same temps!!

Hot shower water is at port engine if you will think something about it.
 
Wiring loom .
I had a similar issue with Volvo in the Med , Laser said normal ,
like you Volvo guy changed the sensor and a gauge .Also cleaned up the ver d gris on the connectors in the dash .Checked all the pins in the engine room connections were good etc .
Even swapped umbilicals to confirm the diagnosis.As one side was worse then the other .....problem swapped over with them .

He told me he see this often the insulation over the years due to heat soak breaks down and the resistance changes , which sends false readings from a new sensor to new gauges .


This was is August mid season ( my 8/9 th ) with it .
I cheated , or used my initiative depending on your point of view ?
Removed the thermostats and listed the boat with a broker who did 20 min sea trails with a punter , who bought it within a month.....yup sold the dam thing ......gone by the end of September . The issue did not show properly with the thermostats removed in a short period of time , and his engineer missed it .

I did send the new owner about a month after the sale a box of spares , new elbow s , belts filters , trim pump relays , impellers etc ....the box had the stats in too btw .......out of the goodness of my heart .


Sounds like your seller has also gone down the same well trodden path .....offload the thing .
 
Interestingly the broker an experienced S/Skr guy who took it out ( in my absence) for the sea trail and to the yard for the lift for the survey did notice it took longer than he would expect to get up to temps .It was windy and big seas so they just went round the bay and to the yard .
Surveyor / engineer missed it , but broker I suspected noticed .
 
So finally you sold the boat without to fix it? So you don't know exactly the solution? I was thinking too about wiring but it is very difficult to find which wire and where to check...

Also I hadn't said that when they came with laser one engine was 63 and the other 64... at the gouges they was 72 and 80... So with k
laser they see the same temp in both engines.. So if it is false reading it is just more false in starboard engine.. But i fear to traveling without to watching the real temp. And i don't know how to fix it..
 
Have you tried swapping the temperature senders between the engines, then put them back and try swapping the temperature guages between the engines. That will tell you whether the issue is in the sender, the guage or the wiring.
 
find the temp sender should be by the thermostat housing, unplug the wires (if they are two) and get two brand new wires (not telephone something thickish!) and run them to the instrument (I guess the only instrument is on the lower helm, or do you have two instruments one low and one on the flybridge?). See what you get, then you know it's the wiring..
But before you do all that remove cables on either side and measure resistance and clean contacts (or if the cable is long enough, cut 5cm off it, re fit NEW terminal, get decent heatshrink insulation on it and test.

V.
 
This is very good idea! I think that the sensor has 2 cables. One 5V and one signal. Right? So I cannot run both cables untill the gauge. I need to drive only the signal wire from sensor to fly...

I have 2 instruments.. One low helm and one fly. That's why i don't believe that the problem is the gauges. I have exactly the same reading there.
 
vas said:
find the temp sender should be by the thermostat housing, unplug the wires (if they are two) and get two brand new wires (not telephone something thickish!) and run them to the instrument (I guess the only instrument is on the lower helm, or do you have two instruments one low and one on the flybridge?). See what you get, then you know it's the wiring..
But before you do all that remove cables on either side and measure resistance and clean contacts (or if the cable is long enough, cut 5cm off it, re fit NEW terminal, get decent heatshrink insulation on it and test.

V.
Click to expand...

I dont think that will work, as on the volvo EVC engines the senders do not 'drive' the guages directly like in an old analogue engine, the sender is connected to the ECU, which works out what the temperature is and send a digital signal to the guages. Hence the suggestion to swap senders round between engines and see if the problem moves.
 
The senders are brand new. I change them to fix the problem. So it will not do something if I will swap them.

And yes you are right. The signal goes direct to the ecu. It reads the temp the ecu. And then it send signal to the gauge. Theese engines has electronic diagnosis with vodia and you can see water temp. So sure isn't going directly to the gauge.

Any other ideas?

Can this temp be real? For example blocked exhausts? But I think that even if they are block they will not have same temp at all rpms.
 
I have exactly the same engines but with around 650 hours, and exactly the same temperatures that you are getting. I’ve had everything checked by the VP service engineers and they say that there is no problem with overheating. We’ve never had the overheating alarm go off so the thought is that it’s a faulty temperature gauge. We’re going to change the gauges to be sure.
 
Illetas
Exactly the same temps? Haha
What boat do you have? 1 or 2 stations? Low helm and fly?
I have the same reading in both stations so I don't believe that all gauges have problem.

Maybe wiring but how to find the problem... It is quite difficult.
 
You say the engineers measured with IR gun the temps were different to gauges.

"Also I hadn't said that when they came with laser one engine was 63 and the other 64... at the gouges they was 72 and 80. "

and all gauges read the same values.

Are your gauges original Volvo and compatible with the system? If the difference as you say is consistent between helms I doubt it is wiring or connections but rather an incompatibility between gauge and ECU as the likelihood of both ECU's sharing a same fault seems improbable.
 
sounds like this needs to be put in the dont worry about it category - make a note of what is normal on the guages, and if it goes above this then you have a problem, doesnt matter what the absolute values are, just the relative values.

A lot of cars these day have a bit of 'intelligence' built into the gauges where the gauges points to say 80C regardless of whether the actual temperature is 75 or 85, its only when the temp goes to 90c+ that the gauge shows a different value - apparently it stops all these questions from the car owner to the dealership about varying temperatures/gauge accuracies etc. I dont think this is what is happening on your boat, but if the IR thermometer says everything is fine and the ECU isnt throwing warning/errors then just ignore the discrepancy
 
hkikis said:
Illetas
Exactly the same temps? Haha
What boat do you have? 1 or 2 stations? Low helm and fly?
I have the same reading in both stations so I don't believe that all gauges have problem.

Maybe wiring but how to find the problem... It is quite difficult.
Click to expand...

If its the wiring it will be in the analogue section of the wiring between the temperature sender and the ECU,or between the sender and the earth. the digital section of the wiring between the ecu and the gauge wont be affected in this way.
 
BruceK
Everything is original yes!
Low helm gauges and fly shows the same temp.
With laser at the sensors they read 63 and 64 and the gauges show something like 72 and 80.

julians
The truth is that the only laser measure was after around 1hour of a trip and at sensor body. I haven't done a sea trial with vp engineers with me to check exactly IR rearing when I will travel to be sure 100%. Ofcourse as I have full of water and the alarm doesn't hit probably I am ok. But I cannot live with that. These engines works at 82! Now I see 98! When the gauge will show me 108 I will have 90 or I will get crazy? haha
Theeese engiens aren't cheap I think so haha
 
First think Hikis is to establish the actual real temperature temperature. Finding out why an electronic gauge is a bit off can be time consuming and may not be necessary to fix but you do need to KNOW the engines are basically fine.
Buy yourself an Infra Red thermometer - they are about 20 euros -and useful for lots of boat engine tests in future.
Take the boat for a good run and while some one else is driving measure the temperature using the infra red gun at the following points (sunject to access) Stick a square of black insulation tape on the relevant parts first in the same place on both engines

1) top of the thermostat housing
2) the main cooling heat exchanger - anywhere that you can check it easily
3) top or side of the exhaust housing on the turbo charger
4) somewhere on the cylinder head

make sure you measure in the same location on both engoines and record teh readings - they should be within a few degrees of each other.
 
julians said:
I dont think that will work, as on the volvo EVC engines the senders do not 'drive' the guages directly like in an old analogue engine, the sender is connected to the ECU, which works out what the temperature is and send a digital signal to the guages. Hence the suggestion to swap senders round between engines and see if the problem moves.
Click to expand...
I pass, was talking about analogue gauges obviously, sorry!

V
 
hkikis said:
Do you know at what temp is the warning alarm?
Click to expand...
94 if it’s real .
But as said the real signals get lost with the insulation breakdown due to heat soak of the loom ,changes the resistance values Two areas the wires from the sender to the ECU and the wires from the ECU ,s to the gauges ....or both !

Changing , renewing , swapping , sender or gauges changes nothing .
The only diagnostic help is swapping the umbilicals, and the same numbers move .
eg ...if the port gauges ( new sender + gauge ) say 93 and the Stb says 89 , if you swap the umbilicals the 93 moves to the stb and the 89 to port .When you return to OEM the numbers follow

Amazed at the posts after my #2 tbh ....thought I laid it all out logically.

Theres no get around .
Live with it .
Sell it .....and either remove the t sats which delays the warm up and keeps them below 82/84 on the gauges for the surveyor for a about 30 mins to do a sea trial, or come up with a cock and bull story to hood wink the buyer .....which seems to have occurred here .

Why buy a boat showing 90 odd ( 98 says the OP ) jacket temps ? Huh ! ......even though the laser says 82/84 .

Then come on here for a fix after filling a VP engines pocket with € .

To the OP why did you not enquire about the 98 + gauge temps before closing on the deal ?
 
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