Why do intercoolers on my MAN engines need cleaning every 2 years?

[Deleted User YDKXO]

According to the service schedule for the MAN D2842 LE443 engines in my boat, the intercoolers need 'cleaning' every 2 years. I've never seen this requirement in the service schedule for any other engines on boats I've owned. Does anyone know why this should be a requirement for MAN engines and what is meant by 'cleaning'?

 

[volvopaul]

If there sea water cooled the tube stack may need cleaning , the air side can become blocked with oily deposits from the turbos , but I'd guess your manual is referring to an engine that does many hundreds of hours a year , I'd speak to a dealer about this before you start ripping it apart.

 

[MYAG]

According to the service schedule for the MAN D2842 LE443 engines in my boat, the intercoolers need 'cleaning' every 2 years. I've never seen this requirement in the service schedule for any other engines on boats I've owned. Does anyone know why this should be a requirement for MAN engines and what is meant by 'cleaning'?

Mike, I have the LE 433 engines (2011) and I don't remember that service element as a requirement. I'm off to the boat tomorrow and will check my service manual.....

 

[superheat6k]

On my VP TAMD60C the intercoolers partially drain down on the seawater side when the engine is off, because the water is above the sea water level outside the boat, and I guess the pump does not make a perfect seal, as whenever I remove the top cover there is no water inside, and I suspect some of the crud is due to this effect.

I find B&Q descaler removes the crud layer within about 30 minutes, and seems to need this every two years or so.

I have now made a simple flush pump with an old oil change pump and pump this in through a small plug fitting on the side of the water pump housing. I remove the pipe connecting to the injection bend, and close the seacock inlet, then pump away until the fluid reaches the injection hose (about 3 or 4 plastic jugs worth). Leave for an hour, then re-connect and use the engine to pump the system clear. I do remove the zinc anodes first.

 

[Deleted User YDKXO]

If there sea water cooled the tube stack may need cleaning , the air side can become blocked with oily deposits from the turbos , but I'd guess your manual is referring to an engine that does many hundreds of hours a year , I'd speak to a dealer about this before you start ripping it apart.

VP, the manual definitely states every 2 years without reference to hours and yes, the intercooler is raw water cooled

 

[Deleted User YDKXO]

Mike, I have the LE 433 engines (2011) and I don't remember that service element as a requirement. I'm off to the boat tomorrow and will check my service manual.....

Hi MYAG, it's listed in my manual under the A1 service schedule required every 2 years and btw it includes the heat exchanger too

 

[Deleted User YDKXO]

I have now made a simple flush pump with an old oil change pump and pump this in through a small plug fitting on the side of the water pump housing. I remove the pipe connecting to the injection bend, and close the seacock inlet, then pump away until the fluid reaches the injection hose (about 3 or 4 plastic jugs worth). Leave for an hour, then re-connect and use the engine to pump the system clear. I do remove the zinc anodes first.

Thanks superheat6k, neat system

 

[jfm]

Deleted User, it is quite easy to go the whol ehog on freshwater flushing, and this would stretch the need to clean the intercoolers almost indefinitely

See pics. First one is engine flushers. I connect hosepipe ( it's right there in the first pic above the engine seawater strainers, though you could use a dock hosepipe too) to the sticky up fitting at top of seawater strainer, shut the raw water intake seacock, start the engine (in e/room), and open the valve (blue handle in first pic), and run for 5 mins. Second pic is identical set up on genset raw water strainer. I also have one exactly the same on the airco raw water circuit and the hydraulic oil cooler, so that's 6 in all. When leaving boat for a while I do this routine 6 times, takes 30mins or so, and all the machinery has the seawater flushed out replaced by nice fresh water. (There might be a mod I could do to put some kind of corrosion inhibitor in (like auto antifreeze) but I haven't figured that out yet).

 

[Latestarter1]

Deleted User,

The MAN service schedules are drawn up based on historical experience much of it from U.S market where in certain geographical locations the seawater side becomes fouled in a relatively short period.

All SWAC engines tend to see levels of oil carryover and gunk on the air side however MAN tend to suffer air side fouling quite heavily, possibly due to the design of their closed crankcase breathing system and it takes very little fouling before performance is impacted.

Whilst I would suggest MAN are being over cautious at two years I would suggest Cat and Cummins are too lax in this area. Bi annual servicing of heat exchanger and SWAC adds significantly maintenance costs, and whilst I think that three yearly cycle would be perfectly adequate MAN can be a little anal if you ever come looking for a policy claim in the future.

 

[MapisM]

Deleted User, it is quite easy to go the whol ehog on freshwater flushing, and this would stretch the need to clean the intercoolers almost indefinitely

Well, if as I understand from the last LS post the problem is mostly on the air side, I'm afraid there's not a lot the freshwater flushing can do to reduce the need for cleaning...

I still very much like the idea anyway - well worth considering regardless on any cleaning that the intercoolers might still require on the air side.
BTW, just in case Deleted User would consider to make such adaptation, I still think that when making it from scratch it would make sense to fit a 3-way valve, to facilitate also the strainer backflushing, as we discussed after your post #348 on Rob's build thread:
http://www.ybw.com/forums/showthread.php?374141-Fifty-Feet-of-Grey-(steel)&p=4664060#post4664060
But that's firmly in the hair splitting category...

 

[jfm]

Well, if as I understand from the last LS post the problem is mostly on the air side, I'm afraid there's not a lot the freshwater flushing can do to reduce the need for cleaning...

Yup, agreed, I was thinking only of the water side when suggesting the flusher installation.

Latestarter/anyone: what is SWAC please? Sea water charge air cooling? (SWCAC?)

 

[aquapower]

Latestarter/anyone: what is SWAC please? Sea water charge air cooling? (SWCAC?)

Sea Water After Cooler

 

[Deleted User YDKXO]

Deleted User, it is quite easy to go the whol ehog on freshwater flushing, and this would stretch the need to clean the intercoolers almost indefinitely

jfm, thats a really neat system and I've never seen anything like that before. Is that a Fairline original fit or was it one of your special mods during the build?

 

[Deleted User YDKXO]

All SWAC engines tend to see levels of oil carryover and gunk on the air side however MAN tend to suffer air side fouling quite heavily, possibly due to the design of their closed crankcase breathing system and it takes very little fouling before performance is impacted.

Whilst I would suggest MAN are being over cautious at two years I would suggest Cat and Cummins are too lax in this area. Bi annual servicing of heat exchanger and SWAC adds significantly maintenance costs, and whilst I think that three yearly cycle would be perfectly adequate MAN can be a little anal if you ever come looking for a policy claim in the future.

Thanks LS1. How does the air side fouling manifest itself in terms of the effect on engine performance? I recently had my boat moved by a skipper to the yard where routine winter maintenance is going to be carried out and the skipper reported that the s/b engine was running a few degrees hotter than the port engine. If this is correct it's something new as I didn't see it last season. The boat hasn't moved since Nov last year

Also how is the airside fouling supposed to be cleaned?

Yes I agree that the MAN 2yr service requirement does seem a bit over the top but since I can't be sure when the intercoolers and heat exchangers were last cleaned, I've asked the yard to clean both systems on both engines

 

[MapisM]

jfm, thats a really neat system and I've never seen anything like that before. Is that a Fairline original fit or was it one of your special mods during the build?

LOL, funny you should ask that M, 'cause not only I'm sure it isn't FL original fit (and neither I've ever seen that as standard fitting on any other boat, for that matter), but the idea was firstly debated, back in 2010, here in the forum: http://www.ybw.com/forums/showthread.php?237755
And as you can see if you just read my OP, it was inspired by something I discussed with Mr.A, the guy you are now in contact with at the yard.

That said, chapeaux to jfm for actually implementing the idea, and shame on my laziness for not having done anything yet!

 

[Portofino]

Thanks LS1. How does the air side fouling manifest itself in terms of the effect on engine performance? I recently had my boat moved by a skipper to the yard where routine winter maintenance is going to be carried out and the skipper reported that the s/b engine was running a few degrees hotter than the port engine. If this is correct it's something new as I didn't see it last season. The boat hasn't moved since Nov last year

Also how is the airside fouling supposed to be cleaned?

Yes I agree that the MAN 2yr service requirement does seem a bit over the top but since I can't be sure when the intercoolers and heat exchangers were last cleaned, I've asked the yard to clean both systems on both engines

Rise in exhaust gas temp ' check it out on the MAN gigital dash
Hope this helps ( from tinternet I,ll add )

Air Cooler Fouling and its Effect on the Engine
When the air cooler becomes fouled, less heat will be transferred from the air to the cooling water (usually fresh water). This is indicated by the changes in the air temperature and cooling water temperature and a pressure drop in the air passing through the air cooler. To measure this pressure drop, a manometer is connected between the charge air cooler inlet and outlet. The amount of pressure drop will depend upon the degree and nature of the fouling.

Indications of Air Side Fouling:

Increase of air pressure drop across the charge air cooler.
Decrease of air temperature difference across air cooler.
Rise in scavenge air temperature.
Rise in exhaust gas temperature from all cylinders.
Indications of cooling water side fouling:

Rise in scavenge air temperature.
Decrease in the difference of the air temperature across the air cooler.
Decrease in the temperature of the cooling water across the cooler if fouling is on the tubes.
Increase in exhaust gas temperature from all cylinders.
Increase in the temperature of the cooling water due to fouling or chocking material in tubes that reduce the amount of cooling water flow.
Methods of air side cleaning:

Fins in the air side can be cleaned by using compressed air at Low pressure.
The air side can be cleaned by dipping the air cooler in a chemical bath for a certain period of time. This will remove all deposits on the air side.
Another method of cleaning the air side is by using the jet of water at Low pressure.
Note: Usage of very high pressure may lead to bending of fins and thus causing permanent damage to the air cooler.
Methods of Fresh water side cleaning:

For soft deposits on the water side, dip the cooler in a chemical bath. After a certain period of time, take the cooler out and then clean with water at some temperature higher than ambient. It is always preferred to circulate water using wilden pump and drums.
For hard deposits use a long drill bit to drill the hard deposits on the tubes. Note this requires a specialist to drill the hard deposits because small mistakes in drilling may damage the tubes.

 

[Latestarter1]

Thanks LS1. How does the air side fouling manifest itself in terms of the effect on engine performance? I recently had my boat moved by a skipper to the yard where routine winter maintenance is going to be carried out and the skipper reported that the s/b engine was running a few degrees hotter than the port engine. If this is correct it's something new as I didn't see it last season. The boat hasn't moved since Nov last year

Also how is the airside fouling supposed to be cleaned?


Yes I agree that the MAN 2yr service requirement does seem a bit over the top but since I can't be sure when the intercoolers and heat exchangers were last cleaned, I've asked the yard to clean both systems on both engines

Charge air cooler efficiency can drop through contamination of either sea water side, air side or both. Symptoms generally manifest themselves in previously smoke free engines exhibiting wee bit of white/grey smoke, however I was a convert to the fitment of EGT (Exhaust Gas Temperature) gauges years ago. Any increase in EGT is indicator that CAC is becoming fouled, you can pick up similar data if vessel is fitted to boost gauges, however these are pretty much consigned to history as any fall in charge cooler efficiency manifests itself in a small difference is boost pressure and hard to detect.

CAC is best stripped and cleaned with Rydlyme on the seawater side and air side can respond well to real hot steam cleaning if gunk not too baked on. For commercial vessels where where the CAC is a big tube stack to deal with and gets in a real sh***y state in CAT 35XX, Cummins K or Mitsubishi S motors UCS Ultrasonic Cleaning Services Brixham provides an efficient service certainly overkill in your situation.

Rydlyme is perfect to heat exchangers.

Pressure testing of CAC following assembly with new seals is vital, however all marine engineering outfits are aware of pitfall of failing to perform this step (tears before bedtime).

Going back to EGT gauges, have pal who is airline pilot and drives offshore power boats, being a pilot knows all about driving on the EGT's, Round Britain 2008 proved that you could pull 1,000 hp out of a QSB 5.9 425, provided you knew what is going on inside the motor, EGT is the link to the outside World.

Apologies for the shorthand SWAC already answered, JWAC (Jacket Water After Cooler).

 

[Portofino]

MAN ,do EGT and charge air temp with the MMDS -another abreaviation -Man ,Monitoring ,Diagnostic ,System.

My 2003 - 2876,s Diplay the above in groups of 4pages x from memory 4 parameters ,which you can scroll through .i understand most are alarmed and the man agent can plug a laptop in to see the history
Here,s a pic for those unfamiliar with MAN -its a2003 -recent ones will be more techi .
Suppose we are suppose to look for tends -movements of the various parameters -but I can not even remember how many ,never mind what the numbers are-exept Engine temp it's Allways 82 never budges both sides .But I will look at EGT and charge air temp next time out

 

[Deleted User YDKXO]

LOL, funny you should ask that M, 'cause not only I'm sure it isn't FL original fit (and neither I've ever seen that as standard fitting on any other boat, for that matter), but the idea was firstly debated, back in 2010, here in the forum: http://www.ybw.com/forums/showthread.php?237755
And as you can see if you just read my OP, it was inspired by something I discussed with Mr.A, the guy you are now in contact with at the yard.

That said, chapeaux to jfm for actually implementing the idea, and shame on my laziness for not having done anything yet!

Ah yes, Mr A seemed to be overjoyed when I emailed him to tell him to clean my intercoolers and heat exchangers! Now i know why. Yes, congratulations to jfm for implementing the forum discussions from 2010 and making such a tidy job of it

 

[Deleted User YDKXO]

Thanks LS1 and Portofino. Yup I do have EGT info buried in the MAN MMDS menu and fortunately I have the data from the engine survey carried out last year, before I bought the boat, to compare with temps this season. I have used Rydlyme in the past on Cat heat exchangers and it did an excellent job but I've asked the yard in Sardinia to do the job so I guess they have their own methods. Thanks for the tip on pressure testing the CAC; I will certainly enquire whether the yard has done that