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D4 260 starboard overheating

W

WESTFORD

New member
Am having sudden temperature increase on one engine, showing both on digital display (EVC) and temp gauge from normal 85 deg to 91-93deg when at 3000rpm. Within seconds this temperature drops straight back to normal 85 deg. Have exchanged the temp gauges to eliminate any fault with them When running at 2500rpm no increase shows.

Have noticed that member g karamalis of Greece (December 2009) has also had this problem and wondered how it was eventually solved.
 
I am also having the same problem.

Have a Jeanneau Prestige 32 with twin D4-260's.

At my normal cruising speed of 3000-3200 rpm 22-24 knots temperatures hold a constant 85 degrees, on the odd occasion when just having a blast taking the revs over 3200 rpm to max 3600rpm the port engine starts to overheat 92 degrees plus and alarm sounds, slow revs back down to 3000rpm and temp returnes back to normal within seconds.

Have checked all the obvious things, intake ok, pump/impeller ok, coolent level ok?

As above with Westwood, would appreciate any info/advise
 
Dear Ian172,
Thanks for the reply. We are going through an elimination process at the moment. Previously have had the black plastic elbows on sterndrives
changed as one was cracked,( you need to have the boat on dry land for this job) this done in May and all seemed OK. However have recently been having the old problem again and local engineers
have found that the heat exchanger was badly clogged with salt crystals and the release valve was broken.
They have today fitted new valves to both cleaned out heat exchangers and we are hoping tomorrow when we test that it will solve the problem.
Are you in salt or fresh water, consider the frequency of use, hardness of water etc. We are in Cyprus and use our boat approx 3-4 times per week, but it had been laid up for some 6 months when we bought it. Another chap on our jetty has exactly the same problem, but his boat is only used 2 - 3 times per year.
Will let you know the outcome in the next few days.
 
Hi Westford, thanks for your reply.

Yes had a feeling the problem could lie with the heat exchanger, may remove the end cap and have a look and try to clear in sit you rather than removing the whole unit.

I am running shafts so no probs with cracked elbows.

I am in salt water in the uk and use the boat every couple of weeks or so.

Look forward to hearing your outcome with the cleared heat exchangers.
 
Hi Ian Done sea test and still have same problem,ours was done in situ, now going to test thermostats will let you know results Westford
 
Surprising. If I was a betting man I would have bet that clearing the heat exchangers was going to solve the problem.

Did you just poke the heat exchangers out or did you use some sort of solution to break down the salt?

Again I await your findings.

Ian
 
OK, your engine will almost never overheat at 2500rpm no matter how long it runs like that and no matter how bad the cooling system is. As soon as you reach 3000rpm engine starts to make heat. Have you tried to keep the RPMs over 3000 for a while and see what happens with temperature? Also, please buy InfraRed handheld laser thermometer, you can just point it into any component on the engine and get instant temperature reading. This is the best tool when trying to hunt down the problem.

Aftercooler or oil cooler can get clogged as well, they both need to be checked and resealed just like you checked heat exchanger.

Also in your case transmission cooler, that is where all water initially passes thru as soon as its picked up.

You need to verify that raw water volume and flow is strong at the exhaust elbow. Shafts or outdrives, you still have EXHAUST ELBOW, which is consumable part and can also get clogged with metal scales.
 
Thanks for your input stringer bell. Will locate infrared handheld laser thermometer and ask local engineers to check the things you have suggested.
Things which have already been checked are: impellor, cleaned out heat exchanger, sea water filter baskets regularly, have checked and exchanged thermostats and dashboard gauges to eliminate possible fault with these. two and half months ago the black plastic shoes/elbows on the sea water inlets were changed as one was cracked and we thought this had solved the problem, but now its back.
 
For Volvo stern drives heat issues (the ones I have experienced so far) can come from:

- Growth inside the water pickups in the legs (can be very hard to find and may need the lower gearbox removed from the leg to check properly)
- Pinched or damaged O rings in the water pickup tubes in the legs
- Blocked heat exchanger, oil cooler, after cooler, transmission cooler (if fitted)
- Blocked exhaust mixer (elbow)
- Thermostats
- Incorrect coolant mix
- Blown head gaskets (usually obvious)
- Blocked strainers
- Bad impeller
- Leaky water pump seals
- Worn water pump housing
- Dirty hull

Other issues like low boost, dirty air side on the after coolers, and bad injectors can also affect temps, but usually only by a degree or two.

How many hours have these engines done, and how old are they?
 
Aliboy, thanks for all your suggestions, a lot of which we have already tried, but have noted the others.
Have now checked, at 85 deg, with laser thermometer places indicated on both engines and they read approx the same. So far unable to check temp at high revs as the sea is currently too rough to go out.
Have located the coolant temperature sensor on the engine block that is connected to the EVC , (when the wire is disconnected the temp gauge and EVC digital readout do not register, so know we have the right one) have disconnected these and swopped from starboard to port.

Boat is less than 3 years old with approx 300 hours use.
 
Have now taken the boat out for sea trial. Took laser thermometer to check. Ran boat at just over 3000 revs and temperature immediately shot up to 91 then increased to 94-95. Throttled back, raised engine hatch and checked immediately with thermometer both engines and there was no significant difference in the readouts.
Am now awaiting delivery of new rear hose connections (elbows) and then hope to take boat out and check if this problem has re-occurred.
 
Hi.

An update on my overheating trouble.

Inspected heat exchangers and inter cooler and both were clogged with salt and scale.
Cleared both using hydrochloride acid (brick cleaner) which dissolves the salt and scale without damaging the metal etc.

Took boat out for a sea trial and is now absolutely perfect, flat out at 3700 rpm no temperature increase at all, gauge does not move and holds 85 perfect.
 
great news Ian172
I replaced the elbo today took out for sea trial still the same ok till we get to 3000 revs then goes from 85 to 93 degrees Did you take the heatexchanger off the boat or did you do it in situ and if you have taken it off how difficult is this to do Look forward to hearing from you. Westford
 
Westford - do you have stern legs, and if so, have you checked the water passages for growth? We had a similar problem on a pair of earlier KAD32's and after overhauling the cooling system we finally found a rogue oyster way up inside the water passages. You couldn't easily see it without dropping the gearbox off the mid unit. Also found a slightly distorted O ring on the water pickup tube from where the previous service guy hadn't been careful enough with his reassembly. The oyster was the main issue, but the O ring wasn't helping either. If you have already done the water pump, elbow, and heatexchanger, either this or the intercooler is where I would be looking next.
 
Hi Westford.

I done it all in situ was no need to remove.

I removed the pulley off of the water pump to expose the end of the heat exchanger easily (the oil cooler is also on the end of the heat exchanger so is gets cleaned aswell), dropped the anode out and removed the end plate of the heat exchanger. Poked out the heat exchanger with a metal rod best I could and then refitted the end cap upside down so anode hole now facing upwards(note you can only fit 2 of the 4 bolts in)

I then removed the anode from the intercooler and then removed the end plate of the intercooler And again cleared it best I could with a metal rod and again put the end cap back on upside down with anode hole facing upwards.

I then filled the intercooler and heat exchanger up with hydrochloride acid (aka brick/patio cleaner) and screwed in the anodes while the acid done its stuff, foams and fizzes, dissolves all the salt and scale without damaging anything else. Once the acid had finished, removed both end caps exposing the now immaculate heat exchangers, refit end caps, pulleys, anodes etc and then run engine to flush through, repeated on other engine and sea trial.

Mine now absolutely perfect at full revs 3700 temp stays at constant 85.

Hope this helps.

Ian
 
Hi Ian, our model number for the engines is D4 260 A-C and they are approx 3 years old.
What model number and age are your engines?? I think your heat exchanger must be in a different position to ours, perhaps the difference is to do with you having shafts
 
Hi Ian, Thanks for the link. Have now discovered why mine is different to the heat exchangers that I had previously been looking at on this site It is called 'charge air cooler' and precisely matches what is fitted to our engines although I don't know what the difference is between the two. The drawing number seems to be 24363.
Will let you know what happenbs next
Thanks
 
Westford, the Charge Air Cooler or Intercooler/Aftercooler is the boxy looking object at the port side rear of your engine. You can confirm this by checking that it has a pipe (~40mm?) that goes from that unit to the Turbo. The compressed air from the turbo flows through the intercooler and into your inlet manifold. Your heat exchanger is a more round/oblong unit that has water pipes going to it. The Volvo's I know have it on the opposite side of the engine, but not sure about the D4. If you are still having any sort of cooling problems and haven't yet cleaned your Heat Exchanger, that is the next thing you should do. The raw cooling water does flow through both units, but the Heat Exchanger is the one that is most critical for engine cooling.
 
Hi aliboy & Ian172,
Thanks for the additional info. Have now located the heat exchanger and will try Ians method for descaling it and the air cooler at the same time.
The mechanic has already partially cleaned the air cooler, but not with any type of fluid. We hope when it is carried out by Ian172's method it will solve our problem also.
Will keep you posted
 
Good luck Westford.

Im confident this will solve your problem as it is very difficult to get the heat exchanger and intercooler totally clear by just poking out the tubes, the acid actually reacts with the scale and salt and dissolves it all, literally they were immaculate and looked like brand new when I inspected them after the acid had done its stuff, just make sure what ever solution you are using that it has hydrochloric acid in it.

I have since discovered that after using the acid solution my flexible water pipes which used to feel very hard and brittle and that I was planning to replace in the near future because of this also feel like new and are no longer hard and brittle, must have been the build up of scale inside these to so it really has cleaned the whole system.

Look forward to your results, hopefully it's good news ;)
 
Hi

To ensure the gauges look the same & not cause undue alarm, the EVC system will keep both gauges at 85C, despite the thermostats opening & closing and the actual temperature being a few degrees above or below this figure. If the coolant temperature goes above 92C (I think) the gauge will then jump to the actual temperature, and alert you to the fact that there could be a problem. If you keep going at 3000+ RPM, does the temperature keep climbing or does it settle at the higher temperature? If it was a complete loss of cooling water I'd expect the temperature to keep going until the shutdown kicked in.

Definately check the heat exchanger cores out and get them cleaned - common problem on older boats & seen it quite a few times!

Andy
 
Andyroonot said:
Hi

To ensure the gauges look the same & not cause undue alarm, the EVC system will keep both gauges at 85C, despite the thermostats opening & closing and the actual temperature being a few degrees above or below this figure.

Andy
Click to expand...

Is this really correct Andy? I know Volvo are often stupid, but this is just criminal if correct. I start looking for cooling issues when my engines are running anything more than 2 or 3 deg above their normal temps. From what you are saying, I wouldn't even know this was happening if I was running these engines. I guess they get to sell more new engines this way!!!!!
 
Hi - yes, to the best of my knowledge that is true, although I personally don't think it's an issue - the engine shutdown system with kick in if the temperature gets higher than it should be, so although you won't necessarily see a change in the gauge reading until it gets over approx. 92C, the engine would reduce it's RPM automatically if it suddenly went dangerously high, and certainly would reduce the RPM quicker than you would be able to if you happened to notice the gauge was in the red and reached for the throttles to bring the speed (and temperature!) down yourself.

As I said, I'm fairly certain this is the case, as it would explain why the gauges are always both bang on 85C all of the time once up to temperature, and would also explain the scenario that this (http://www.marineengine.com/boat-forum/showthread.php?393302-D4-overheating-(or-not) forum member is experiencing when he says the temperature suddenly jumps to 92 - it isn't a gradual climb as you would perhaps see on a tradiational temperature gauge.

No word on whether the cleaning of the coolers has solved the problem though from the thread creator?!?

Andy
 
That set up would really annoy me if correct. I use close checking of my engine temp gauge and exhaust temps to monitor the state of my cooling system. If you keep good notes you can literally see the affect of the impeller deteriorating and the cooling system building scale etc over a few years period. You can time your maintenance of these items perfectly like this without throwing away perfectly good parts due to a 'manufacturers maintenance schedule', and without ever seeing even a 5deg rise in temps above normal. Diesels don't like running hot, so close attention to temps is one of the easiest ways to make your engines last longer. Since I often go away from base for 10 days at a time, often well away from any support or spares, I need to know what shape this most important part of my engines is in. If Volvo really are 'hiding' that information as you believe, it is another example of their arrogant culture towards their clients, and just another way to make sure that their engines generate lots of spare parts sales.
 
Hi everyone - Sorry for the delay in updating. A few days ago the starboard air cooler and heat exchanger were cleaned with acid as described by Ian 172. Managed to take the boat out for a test yesterday. Can now run at 3000rpm without any sudden increase in temperature, but as soon as I reach 3200 rpm the temperature shoots to 91 - 93 deg. As I did not push a metal rod or similar into the tubes I may now try this and using the acid treatment again on the heat exchanger.
 
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