D6 370 hp

Seastoke

Seastoke

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Hi guys i have couple of questions . temperatur,e we run at 85 degrees ,is that nornal for these engines .
Also we read so many posts of sea water geting into the engine via the exhaust . When do you determine to replace , ours are 2008 by the way , thanks for replies.
 
How many seasons has it been 85 ?
what’s a IR gun on the t sat housing say ?

Water gets into cylinders usually from the other side via a leaking charge air coolers ....into the inlet side .
Not sure on Volvos rep with corrosion on the CAC s , they supposed to be timely stripped , cleaned , and checked etc .
CAT recently have well documented problems with there CAC s ....infact they cover there arses these days saying the CACs are a throw away part ..every 6/7 years ouch £££ wise ! After loosing 2x huge class action lawsuits in the states from loadsa busted engine customers.

Your exhaust manifold should be cooled by the closed coolant circuit ( not sea water ) if the coolant been timely replenished , it’s additives will robustly resist corrosion.If the EGT s ( so sorry guys :) ) have been within spec ie not overloaded then the risk of a thermal stress incident , cracking it is negligible.Parking up the boat with a cracked manifold is asking for water ingress ,from the closed side though. Bit of rolling ,tilting etc with an open valve and in it goes .


With the actual exhaust pipe after the turbo it really depends on the particular design .
Need more info .Generally it’s pretty hostile even to S Steel some really nasty hydrochloric acids form when the sea water meets the gases and they all have a life corrode away .How ever water should not really get through the exhaust that far back in , it has to knacker the turbo first . The engine manufacturers usually sign off the instal in hull no #1 and maybe a few more ?


Small genys mostly single cylinder in theory can get water , seawater running back into a open exhaust valve filling a cylinder due to the closeness of the water in on the exhaust elbow and inclination ....boat rolling in a swell , just after shut down .Or corrosion of the valve if left open over the winter due to the sea air effect .Best mounted in the centre of a boat .
 
We have D6-330 engines and they sit at 85 day in day out. The charge air cooler and oil cooler are recommended to be cleaned ever 5 years according to the owners manual.

I’m on outdrives so can’t help with the exhaust elbows.
 
In terms of temperature we have 2xD6 370 on outdrives. Had them since new and always had 85 degrees as the working temperature- so would imagine you are ok on that part.
 
The owners manual specifies the correct operating temperature,so just have a look in there. RTFM.

I don't have the d6, I have the d4, but the correct temp for the d4 is 85c. So I'd guess from others answers above that the correct temp for the d6 is 85c also
 
The reason you are all seeing 85C is that VP programmed the EVC to show 85 even when the temps are a few degrees above or below. This was to alleviate the questions from owners with twin installations if for example one engine runs at say 82 and the other at 87 and thinking there is a serious problem. This I have been told by Volvo instructors on two different courses I attended on D series engines. As when you think about it, having a twin installation is like running two single installation boats in tight formation, they each have their own battery, charging system, harness and instruments so the chances of getting identical readings are not guaranteed.
 
Temp gauges in modern cars are the same ,algorithms set the temp gauge , once it’s in a range it moves to what ever preprogrammed position and stays there .
So the dealers are not inundated with OCD fuss pots .
 
seastoke said:
Also we read so many posts of sea water geting into the engine via the exhaust . When do you determine to replace , ours are 2008 by the way , thanks for replies.
Click to expand...

The above is different to standard running temp. I had a client who had an exhaust manifold failure on a D4a-260hp from 2006 engine. A problem which online seems reported to happen on some D4 and D6.
As reported online more common in the D4 then D6. But what he described it seems his first suspect-able symptoms started end last Summer when going at over 3k revs and engine would go to above 90 deg.
When first symptoms appeared he asked his mechanic about this and told him it was heat exchanger's which he cleaned. After he cleaned boat went perfect. One month down the line he had the manifold failure, which also resulted in a cracked valve sleeve, i.e new head + new manifold. etc etc a very expensive failure.
To make story short mechanic is saying he got a plastic bag and engine overheated and temp arrived to 110 according to Voda. There is some reports of manifold failures so I do not know what to say.
Is it a manifold failure or a plastic bag which resulted in the manifold failing. I am not sure Voda can answer that question, as it would not be convenient for the Swedes.
 
So my question is , what do you do to check the parts that can break down and allow sea water in the engine.
 
Take the heads off after every trip Roy.....check the bores ??

Stop worrying man! The forum is only used for issues....there are 1000’s of D6’s being used right now and running perfectly.

You could check your exhaust elbow by taking the big exhaust hose off and having a look if you’re really bored, however, if all well....just enjoy it mate
 
seastoke said:
Replaced the coolant 2 years ago and put genuine mix in .
Click to expand...

The D6-370 was a development of the D6-350, which I had in the T40. Used to run at 85C all the time, same as everyone else has said. I changed the coolant every two years, and ran coolant flush through as well on the last couple of coolant changes, made a big difference. The other big thing you can do with regard to cooling efficiency is to run rydlyme through the coolers as part of your annual service.
 
seastoke said:
Hi guys i have couple of questions . temperatur,e we run at 85 degrees ,is that nornal for these engines .
Click to expand...
The software for all D4 & D6 engines will make the gauges show 85C once up to temp, despite small fluctuations in the actual temperature. If the temperature goes over 92C then the gauges will jump to that reading & then show the true temperature if it continues to climb.

So yes, 85 is normal

If one engine has a calorifier fitted then it may well take slightly longer to get to 85 as essentially it has a second heat exchanger
 
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