An important lesson in intercooler maintenance.

[Tree]

Been putting off pulling the cooler for ages now due to time constraints and not wanting the boat out of commission, but since the fishing is poor and so is the weather I cracked on with it this week.....


Two days it took to get the core out after soaking in diesel. As you can see why.

Small leak on the core - no idea how long but that is salt build up on the outside on the exit end.

This is the first time I’ve had it apart in just over six years ownership - I suspect it’s never been done since new, 20 years ago.

Hopefully I can save the core - it’s away for ultrasonic cleaning and acid dip, pressure test and repair and another pressure test once the damage has been repaired.

[RobS]

Do you do period oil sampling? Might have been enough to should high Na ...
Looks like you had some zinc chunks bouncing around a bit - a couple tube ends are banged up, but I have definitely seen worse.

[Tree]

Oil sampling isn’t something that’s really big over here - I probably wouldn’t show very high levels of anything as I swap the oil out every 50 hours anyway as I’ve constantly got gallon cans being given to me by the local Volvo and Cummins mechanics.

I’d agree with you about the zincs but that is the downstream end to where the zincs are fitted where the tubes are bent over in a few places.

Rydlyme run through the engine every two years seems to have worked well though - no blockages!

[RobS]

Rydlyme can attack aluminum so that would have accelerated that housing corrosion once the core/housing seal was breached.

[Tree]

The housing isn’t in bad condition to be honest. What you are seeing in the core is salt. Obviously had a minor water leak for a very long time - not had a chance to confirm if it’s leaking past the seal or if it’s the core that is damaged. Pressure test will show that. Now I’ve pulled it and realised it’s not that bigger deal - I’ll probably pull it every two to three years for peace of mind.

[Carl]

How long and how hard was it to remove, mine has not been done in 4 years and thinking about pulling it myself this time. Did you pull all coolers or just the inter cooler?

[Tree]

Just the intercooler. I’ve got new gaskets for the oil cooler as that showing signs of some corrosion on the anode end - not sure if it was the intercooler leaking on it or that’s getting a little raw water past the seal. I’ll do the oil cooler when the weather gets better again - currently blowing a gale and rain!

[mhanna]

My friend has been reminding me for a few years to pull my intercooler apart, after seeing your post on it I said it was time to do it so over the weekend I pulled it out but lucky it came apart with only a minor tap. I have owned the boat for 12 years and I never have done so I think it is original to the boat a 2001. I will be cleaning it and pressure testing it after reassembly before putting back on. Thanks for your post on it.

[Pitou]

Well Tree, this must be the year of AC maintenance! It's been six years since I've had all of my coolers off and I just pulled them all again last weekend. The seawater side looks really good on my aftercooler (AC), combo gear and fuel cooler and a little restriction on heat exchanger. I'll get the bundles out of the AC and HC this week to inspect airside of the AC and the coolant side of the HX. I always feel better when these sevices are complete.

BTW .. Matt, you have a really good friend!

1.18.2020 Service Removal.jpg

1.18.2020 Aftercooler.jpg

1.18.2020 HX SeaWater Side.jpg

1.18.2020 HX Coolant Side.jpg

[mhanna]

Hello there Kevin, hope you are well ! and yes a very good friend

During this summer I had the hose right after the water pump blow, at first I thought it was just a bad hose. Replaced it and when checking for leaks found that when revving the engine ~ over 3,000 RPM, the second hose from the fuel cooler to the intercooler started ballooning. I put a pressure gauge in where the intercooler zinc goes and found that when bring the engine above 3,000 RPM found the water pressure went to just under 40PSI. Yikes...

Took off some hoses to find the heat exchanges were clogged up some, it has been many years ( 8+ or so) since the last Rydlyme. I used Barnacle Buster this time and after the wash with it, it now only hit about 18 PSI at 3,000. I am considering that a big win.

2019-09-28 14.02.57.jpg

Here is a picture of a piece of hose that I let sit in the Barnacle Buster solution and it cleaned it up nice, I have to think it did that throughout the whole saltwater system.

2019-09-30 18.59.26.jpg

I am now a believer that it is something that needs to be done every 3-5 years or so.

[Pitou]

Our diesel engines are happier when they're taken care of with routine preventative maintenance and the seawater side of the cooling system along with the airside (aftercooler/intercooler) is probably the most neglected system by boat owners.

As seen and described in this thread, over time not only is water flow restricted which cools the air intake in the aftercooler for engine combustion, but coolant temperatures will rise when the HX is restricted and the same can happen wth the gear oil and fuel return to your tank. Routine inspections and servicing can catch seawater leaking into the air side of the aftercooler as seen in Tree's pictures. A dirty airside of the aftercooler from exhaust leaks or sea water mist in the engine room being drawn into the airside are also a concern and reason for routine maintenance. Just like the aftercooler, there is also potential for the coolant side of the HX having seawater penetrate a bad o-ring or if the bundles are compromised causing seawater to leak in. The same for the gear cooler / gear oil or the fuel.

Lots can go wrong because of the lack of service to this most important system that is bolted on to marine diesel engines. with the coolant drained, I'm also taking advantage of repalcing the 13 year old coolant hoses going to and returning from the hot water tank .. it's time. Happy wrenching everyone!

When I bought my 31TE it had 7 years snced new and no service. I negotiated $3,000.00 for the unknown that could be ahead when I serviced the seawater side upon ownership. Thankfully at servicing there were no expensive surprises beyond the normal disassembly, cleaning and reassembly.

Here is a picture of the seawater intake side of my HX at first ownership after those first 7 seasons - more than 50% blocked and coolant temperature was not elevated at sea trial:

5.10.2014 HE intake blockage 2.JPG

[RobS]

As the saying goes .... perform the PM before your engine takes a BM

[Tree]

So I've been through all the bills and receipts before I got FP2 and cannot find any evidence of an inter cooler service.

Quite possibly this has been like it from day one 20 years ago!

On the plus side, repairs have been made and it was a failed soldered joint that had a tiny leak on it. It was only showing the odd drip every couple of mins while under pressure test. I've not asked what pressure it was taken up to but it would have been significantly higher than operating pressure.

Not had a chance to collect it and to be honest it wont be until next week i get a chance to fit it due to the vile weather we are expecting this weekend - winds in excess of 90 mph and rain doesn't work for me!

[tdsull]

I took mine off today and had a small seawater breach as well. Tree do you have pics of what the core looked like after being ultrasonically cleaned? I am debating if it's work being sent out?

[Tree]

Afraid I don’t. The radiator company that did the repair rebuilt the intercooler assembly leaving just for me to install - what I will say is it made a difference to performance.