Don't Run A Descaler...?

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Loopy

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Things I've been told that I'm somewhat skeptical of:

"Don't run a descaler (like Barnacle Buster) through a Volvo engine because they use a specific alloy in the heat exchanger that requires it to be removed and disassembled in a shop. Descalers will damage the engine."

:rolleyes:
 
Dunno what barnacle buster uses as ingredients but I've used brick cleaner ( HCl...hydrochloric acid) thro my Volvo after looking up as many opinions as I could cope with.
All went well and no overheating or bad side effects since - about 4 years
 
Yes, we do have an overheat problem with our 1991 Volvo 2003 engine (normally aspirated).

After about an hour of motoring under load the overheat light comes on. The audible alarm has long since failed with no replacement part available.

We do have a coolant leak (about a 1/2 cup an hour) off the front left side of the engine where the external circulating pipes meet the block. Discovered this after hooking up a cooling system pressure tester from the auto parts store and pumping the system up to 6 psi. The coolant dripped where we suspected. Over the course of about an hour and a half, the pressure slowly bled back down to zero.

Ordered the replacement gasket kit for freshwater cooled engines and a new thermostat.

Going to run the descaler on the raw water side, leave it in there for about 8 hours, and then flush it.

Got a compression gas test kit for the exhaust and will send the oil out for analysis to see if a head gasket leak exists.

If so, we'll have the rings and the head gasket replaced.

Any other thoughts? I think we're eventually heading for a repower, but if that eventually can happen 2-3 years from now rather than, say, December, I'll be happier.

My original post had more to do with the false advice given by the business office of a yard that apparently was more interested in the billable hours involved in removing bits and pieces and hauling them back and forth at $105 an hour than actually fixing the problem in a correct and efficient manner.
 
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Have you cleaned out the hole in the thermostat housing that acts as a breather from the head, small pipe going from the thermostat housing to the expansion chamber, I learnt this the hard way but it cured the problem instantly.
Mike
 
Pagetslady said:
Have you cleaned out the hole in the thermostat housing that acts as a breather from the head, small pipe going from the thermostat housing to the expansion chamber, I learnt this the hard way but it cured the problem instantly.
Mike
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Take the thermostat out and pickle it in warm white vinegar. Job done . Recirculating cooling water with dilute acid (to a bucket/from a bucket)for a short while - is very effective. Just don't let it get too hot!
 
So just to clarify, my installation is raw water/freshwater with both a seawater pump and a freshwater pump with coolant tank. This sort of install won't require an anode? Unfortunately my owners manual is in French.
 
Loopy said:
So just to clarify, my installation is raw water/freshwater with both a seawater pump and a freshwater pump with coolant tank. This sort of install won't require an anode? Unfortunately my owners manual is in French.
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No because the engine cooling circuit is protected by the corrosion inhibitors in the antifreeze mixture you use as coolant, just like your car engine , and the heat exchange, the only part in contact with sea water is made of corrosion resistant materials that don't need the protection of an anode.

(In some makes of engine the heat exchanges are protected by an anode )

Why don't you download an owners manual in English from VP's website. https://www.volvopenta.com/marineleisure/en-en/for-owners/your-engine/manuals---handbooks.html
 
With an engine of that age, its about time you removed the heat exchanger and checked it for corrosion. Do you leave the seawater side of the system flushed through with freshwater over winter. If not, then I would check over the heat exchanger and clean it physically as it really could be near its sell by date if it has not been looked after. A check like this will give you peace of mind as well as confirming that the fresh water leak does not come from corrosions pin holes.

The Volvo 2003 series uses many "push fit" connections on the cooling system. These are very good until you allow a crumby engineer on board who wrenches them off with a lever.:disgust:

And by the way, there is no reason that you need to re-engine because its 1991 vintage - if looked after and services and run for decent long periods rather than just to get out and out of harbour, there should be plenty of life left.

We have a similar aged 2003T now nearly 30 but still fine. The heat exchanger has been off twice - no corrosion - just needed decruding. The Oild cooler - which I did not know it had - until a warning from this forum - was completely pink when it came off, as it crushed between my fingers! - just moments from giving up the ghost - which would have finished off a perfectly good engine.
 
Chris_Robb said:
With an engine of that age, its about time you removed the heat exchanger and checked it for corrosion. Do you leave the seawater side of the system flushed through with freshwater over winter. If not, then I would check over the heat exchanger and clean it physically as it really could be near its sell by date if it has not been looked after. A check like this will give you peace of mind as well as confirming that the fresh water leak does not come from corrosions pin holes.

The Volvo 2003 series uses many "push fit" connections on the cooling system. These are very good until you allow a crumby engineer on board who wrenches them off with a lever.:disgust:

And by the way, there is no reason that you need to re-engine because its 1991 vintage - if looked after and services and run for decent long periods rather than just to get out and out of harbour, there should be plenty of life left.

We have a similar aged 2003T now nearly 30 but still fine. The heat exchanger has been off twice - no corrosion - just needed decruding. The Oild cooler - which I did not know it had - until a warning from this forum - was completely pink when it came off, as it crushed between my fingers! - just moments from giving up the ghost - which would have finished off a perfectly good engine.
Click to expand...

Appreciate the information. Replaced the heat exchanger and sea water pump last year.

The oil cooler will be something to look at.

I used a block test kit earlier today and got a negative result on a combustion gas leak...
 
Loopy said:
Appreciate the information. Replaced the heat exchanger and sea water pump last year.

The oil cooler will be something to look at.

I used a block test kit earlier today and got a negative result on a combustion gas leak...
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Only the Turbo version has an oil cooler - so you are spared that - £2400!

How bad was the heat exchanger - mine looked in very good condition. I have an engine flush teed into the boats fresh water so if I leave the boat for any time, it gets flushed, which looks like it might have paid off. I believe that most american powerboats have a docking flush which they use regularly - why o why do we leave these things out of site and out of mind!
 
Chris_Robb said:
The Oild cooler - which I did not know it had - until a warning from this forum - was completely pink when it came off, as it crushed between my fingers! - just moments from giving up the ghost - which would have finished off a perfectly good engine.
Click to expand...

My 2003T had a pinhole leak from the oil cooler. The wretched thing is hidden away under the heat exchanger and virtually impossible to check. I had a new one fitted. People grumble about Volvo spares, but you can still get off-the-shelf bits for 20+ year old engines.
 
pvb said:
My 2003T had a pinhole leak from the oil cooler. The wretched thing is hidden away under the heat exchanger and virtually impossible to check. I had a new one fitted. People grumble about Volvo spares, but you can still get off-the-shelf bits for 20+ year old engines.
Click to expand...

I managed to get a used oil cooler which the turkish engineer had taken off an abused engine. €450.
 
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