Discussion in 'Engines' started by Danvilletim, Apr 9, 2020.
Any recommendations for someone that does this? Have two 3412s that are running 200 at 2200.
Southshore diesel. They ve been doing the 3412s and C32s i run for 10 years. They recently descaled the C32s. I ll PM you the number.
I've used Overtemp Marine and was happy with them.
I second Overtemp. I couldn’t remember the name but he was a very nice guy and I thought his work was thorough and very neat. Came when he said and charged what he said he would charge.
I also have used Overtemp but James is out of town I’m told.
Booked him tomorrow @ 10:00.
Now circulating the acid for 2 hours:
It would be interesting to see your before and after temp numbers. I believe that this process also eliminates pieces of (pencil) zinc anodes that might be in your coolant system.
Zincs in the coolant system or raw water side?
Good catch Ralph! It's been such a long lockdown I'm putting zincs in the coolant side.
For the record, pencil zincs and descaling go on the raw water side!
I know that you know it. You know that I know it. I'm sure that most here know that we know it.
I got your back bro.
I'd rather point these lil & fun things out vs shopping for a new oven...
Just getting ansi, Got to fix some things and get off the dock again..
1) Engine has been running cool since I bought the boat 2.5 years ago.
2) Boat and engine is 19 years old, descaling has never been done before as per detailed maintenance records.
3) The above made me nervous and with 5 heat exchangers it was time and way too much work pulling each cooler/heat exchanger off and cart to a radiator shop for an acid bath.
4) Pleasant maintenance procedure: I sit in the shade with a cold beer while the descaling process is going on, running backwards to flush out any impeller piece or debris from the intake.
5) Preventive maintenance only, no problems noted before.
Descaling only does so much. I've seen many heat exchangers where the issue was on the coolant side and not the raw water side or impellor pieces in the H/E which descaling wouldn't help with. Pulling the heat exchangers allows you to visually inspect them and pressure test them. I like to pull the heat exchangers and have them professionally cleaned the majority of the time.
We went ahead and pulled the exchangers and took them to the shop. Cost was double but used to be triple or more. covid19 discount. Sea trial went perfect and we hit 18knts at 190f.
Curious as to which type HE and how long since last cleaning?
This guy runs the flow backwards to flush out any impeller pieces.
Yeah, I should pull all the H/Es to inspect them, but hell of a job, bad access on my boat. Happy with the descaling for now.
You can do some basic stuff to them , if you can get to them by pulling off the hose one end at a time. Each side of the heat exchanger has a perforated screen and I've pulled out old impellers, zincs, plastic wrapper, and junk at those point and that always makes a difference .
The back flow idea may not always work to get all the old rubber and stuff out because the screen holds it in place no matter the flow direction.
But, in your case it is still money well spent.
Pull some hose to the easy ones on your boat and see what's in there or not.
Forgot to mention that some if not all 3412s have the fuel cooler before the raw water pump. Any grass or debris that makes it past the strainers will get caught there. first thing to check. Pull the inlet hose and take a look
No screen on the Yanmars:
I have pulled the end-caps a few times and found some gunk:
Also found the raw-water strainer had a small hole in it, (in addition to many other smaller holes) new strainer installed a few weeks ago.
James from Overtemp said impeller pieces was unusual with Yanmars.
At any rate, should be good to go now.