Cleaning Volvo Penta D4 heat exchanger

[kennyh]

Hi all

I'm about to perform a service on my D4-260 and I'm considering cleaning the Heat Exchanger while I'm at it to hopefully resolve a rise in temperature when running at max throttle (which may be due to the exchanger being clogged partially).

I've read a variety of threads on this forum and others, talking about rodding the exchanger to remove any debris in the exchanger matrix.

Now I have some concerns over this method, as I may just dislodge detritus and block the cooling system somewhere down the line (fuel cooler / after cooler).

What do you think, can I just remove one cap from the heat exchanger and pick a rod into the exchanger to clear any blockages or am I best removing the internal and doing a thorough clean with acid etc?

Thanks.

 

[Simon391088]

Hi,

I had one of my d4s cleaned.
Apparently the engineers flushed it with something called RedLyme.
Don't ask me what the process to do this is, but hopefully this helps!

Thanks
Simon

 

[spannerman]

The heat exchanger has the oil cooler tacked onto the aft end of it so there are two coolers inline, if you rod the heat exchanger from the front you risk pushing the crud into the space between the heat exchanger matrix and the oil cooler matrix, to do it properly you need to split the coolers so you get everything out but that is a lot of work involving removal of oilfilter mounting. Have you tried one of the chemical cleaners first that dissolve deposits.

 

[jimmy_the_builder]

Hi,

I had one of my d4s cleaned.
Apparently the engineers flushed it with something called RedLyme.
Don't ask me what the process to do this is, but hopefully this helps!

Thanks
Simon

Yep, Rydlyme is what we used when cleaning the heat exchangers on my D6's (although in my case we removed them from the boat).

 

[frothblower]

Hydrochloric Acid, also known as brick or patio cleaner (must contain Hydrochloric Acid)

-Remove anode from heat exchanger and intercooler.
-Remove the end cap of each and you can see how badly clogged they are
-Turn end caps upside down and refit lightly so anode holes facing upwards (you can only refit with 2 bolts)
-Fill with Hydrochloric acid down anode holes
-let it fizz away and do its stuff
-when the acid has stopped working remove end caps and any remaining acid.
-stand back in amazement at look at your gleaming immaculate heat exchanger and intercooler.
-Refit end caps and run engine to flush out any remaining acid
-Enjoy the full revs that you can now once again achieve :encouragement:

Obviously take the relevant safety precautions when working with the acid.

 

[Bandit]

Rydlyme is the business and much milder than brick cleaner, with brick cleaner you risk damaging the copper alloy that the cooler is made of.

You can either flush your engine through with Rydlyme or dismantle the cooler stack and clean it in baths of Rydlyme. Plastic window sill pLant trough planters work well.

 

[jimmy_the_builder]

Plastic window sill pant planters work well.

Growing your own Y-fronts again?

 

[volvopaul]

Hydrochloric Acid, also known as brick or patio cleaner (must contain Hydrochloric Acid)

-Remove anode from heat exchanger and intercooler.
-Remove the end cap of each and you can see how badly clogged they are
-Turn end caps upside down and refit lightly so anode holes facing upwards (you can only refit with 2 bolts)
-Fill with Hydrochloric acid down anode holes
-let it fizz away and do its stuff
-when the acid has stopped working remove end caps and any remaining acid.
-stand back in amazement at look at your gleaming immaculate heat exchanger and intercooler.
-Refit end caps and run engine to flush out any remaining acid
-Enjoy the full revs that you can now once again achieve :encouragement:

Obviously take the relevant safety precautions when working with the acid.

Brick cleaner can damage the solder in the tube stack , use it at your own peril. Rydelime is the correct chemical for heat exchangers.
Just doing some D 4 coolers now, I'd advise you remove and strip them down as it's the o rings that fail causing leaks that can ruin the starter motor . The price of the o rings are stupid and there are 8 inside the whole unit you will need to renew to do a proper job.

 

[Anders_P42]

As preventative maintenance on a new motor, should I ask Volvo to flush raw water circuit with Rydlyme every two years, or how often should full strip down take place? Boat used in Solent waters circa 125 hours pa.

Anders

 

[volvopaul]

As preventative maintenance on a new motor, should I ask Volvo to flush raw water circuit with Rydlyme every two years, or how often should full strip down take place? Boat used in Solent waters circa 125 hours pa.

Anders

Big debate in my head over the D range engines, I ask myself why at 6 years old and sometime way before these intercooler and heat exchangers require a full strip, clean and reveal, why I don't know.
Look at the earlier generation engines, KAD series, TAMD 63/74/75 series motor, they didn't require this level of we will call it expense at that age. Something wrong in my view with its design and location on the block, low down compared to earlier motors, sea water sits inside them 100% of the time, where sea water drains out of the earlier series motors, especially the gear cooler. I've just done two D4 inter and heat ex, full strip clean and rebuild, parts alone which is bag full of o rings £450, plain stupid , behind heat ex engine block rusting and corroded away quite nicely, you don't find this with the old motors. D base unit great, it's the rest that's bolted to it that lets it down .

 

[Anders_P42]

Appreciate your comments, not the best design by all accounts. But should I fork out for the Rydlyme preventative maintenace or just accept engine will start to overheat 3-5 years down the line as indication of blocked tubes? It sounds like Rydlyme will just delay the inevitable.

 

[GrahamHR]

Big debate in my head over the D range engines, I ask myself why at 6 years old and sometime way before these intercooler and heat exchangers require a full strip, clean and reveal, why I don't know.
Look at the earlier generation engines, KAD series, TAMD 63/74/75 series motor, they didn't require this level of we will call it expense at that age. Something wrong in my view with its design and location on the block, low down compared to earlier motors, sea water sits inside them 100% of the time, where sea water drains out of the earlier series motors, especially the gear cooler. I've just done two D4 inter and heat ex, full strip clean and rebuild, parts alone which is bag full of o rings £450, plain stupid , behind heat ex engine block rusting and corroded away quite nicely, you don't find this with the old motors. D base unit great, it's the rest that's bolted to it that lets it down .

I just fitted a home made fresh water flush to my D4 (2009, but with very, very, very low engine hours, less than 1 hour in saltwater). Hopefully I caught it early enough to preclude such blockages. After having American VP V8 engines with fresh water flush as standard, I'm astounded that these very much more expensive, supposedly more sophisticated European diesel VPs don't even have it as an option.

(the cost of the parts for the flushing system was well less than £100; I did have to make a bracket up though from bits I had lying around in my garage, which I can't put a price on)

 

[beejay190]

I keep my boat in a Dry Stack and flush the D4 engine through with fresh water every time after use - so hopefully there is no sea water sitting inside and corrosion and a clogged up heat exchanger will be less of a problem

 

[frothblower]

Brick cleaner can damage the solder in the tube stack , use it at your own peril. Rydelime is the correct chemical for heat exchangers.
Just doing some D 4 coolers now, I'd advise you remove and strip them down as it's the o rings that fail causing leaks that can ruin the starter motor . The price of the o rings are stupid and there are 8 inside the whole unit you will need to renew to do a proper job.

Out of interest, If the o rings are not leaking and are not disturbed what is the need to completely strip down the heat exchanger when acid or Rydelime can do the job with minimal stripping down required?

 

[volvopaul]

Out of interest, If the o rings are not leaking and are not disturbed what is the need to completely strip down the heat exchanger when acid or Rydelime can do the job with minimal stripping down required?

The reason the o rings need to be renewed is because they always leak on the end cap and between the main housing and end cap, there are two o rings on each end cap to seal the tube stack to the main body housing, white salt crystals form on the outside. I have not yet had a blocked heat exchanger that hasn't had leaking end cap o rings, the white powder crystals is the sign the coolers are getting blocked. If I could put pics on here I could fill the forum with pics of Volvo engines repair faults. Rydelime alone will not cure leaks, if anything they make a partially leaking heat exchanger worse, as Spannerman said the centre housing between heat exchanger and oil cooler collects the salt deposits blocking the water flow in and out the cooler.

 

[kennyh]

Thanks Volvopaul

So if I need to disassemble to clean, do I need to fully remove the heat exchanger assembly / oil cooler or can I just remove the end caps and extract the matrix for heat exchanger / oil cooler and clean then up?

And I take it I'll need to drain down oil and coolant first (I'm planning on doing a change of both anyway)?

But before I do any of that - I'd like to check again the need to do the clean in the first place. The symptom I'm getting is that the temperature (reported) rises from circa 85C when I'm cruising at 3000rpm, and rises to circa 92 when at max throttle, 3420rpm. If I drop back to 3000rpm the temperature likewise drops.

So is that normal, or should I expect to run at circa 85C at all RPM?

Update with additional info: I discovered a specification sheet from Galeon yachts that covers the D4-260. It states that the thermostat starts to open at 82C and is fully open at 92C. So this makes me think that running at 92C is normal (at full RPM).

Spec sheet is here: http://www.galeonyacht.hu/hun/pdf/t_d4-260a_b.pdf

Any thoughts folks?

 

[julians]

It should be 85c at all revs.mine had the same symptoms, a temp rise above 3000 rpm removing and cleaning the heat exchanger and oil cooler fix it for me

 

[Bandit]

Kenny

How old are your engines?

 

[kennyh]

Engine is D4-260A-B circa 2008 with 290hrs and the last 2.5 yrs in Fresh water.

 

[spannerman]

The problem with the D4 is that there isn't much room between the back of the oil cooler and the HP pump, so its very cramped, also the end cap on the oil cooler is held on by a mixture of bolts and pin bolts with nuts which don't give you enough room to pull the oil cooler housing off the back off the heat exchanger. Its a while since I last did a D4 and I ended up taking the whole oil filter table off which then gives more room to work. That requires quite a few assorted O rings in itself. Maybe Volvopaul knows of a short cut but its definitely easier on a D6 as its a longer block so more room between oil cooler and other engine components.

Thanks Volvopaul

So if I need to disassemble to clean, do I need to fully remove the heat exchanger assembly / oil cooler or can I just remove the end caps and extract the matrix for heat exchanger / oil cooler and clean then up?

And I take it I'll need to drain down oil and coolant first (I'm planning on doing a change of both anyway)?

But before I do any of that - I'd like to check again the need to do the clean in the first place. The symptom I'm getting is that the temperature (reported) rises from circa 85C when I'm cruising at 3000rpm, and rises to circa 92 when at max throttle, 3420rpm. If I drop back to 3000rpm the temperature likewise drops.

So is that normal, or should I expect to run at circa 85C at all RPM?

Update with additional info: I discovered a specification sheet from Galeon yachts that covers the D4-260. It states that the thermostat starts to open at 82C and is fully open at 92C. So this makes me think that running at 92C is normal (at full RPM).

Spec sheet is here: http://www.galeonyacht.hu/hun/pdf/t_d4-260a_b.pdf

Any thoughts folks?