CAT 3126 - Zincs and Aftercooler cleaning

markrinker

markrinker

New Member
Jul 19, 2011
325
Lake Union - Seattle, WA
Boat Info
2000 410DA
Engines
Caterpillar 3126
In another thread, it was stated that each engine has 11 zincs to replace. I am assuming that my aftercoolers will need to be pulled and cleaned, since I have no documentation of this service having been done before, and it appears that a multi-viscosity oil was used...

Question: How many zincs can be done 'on the bench', rather than in the engine room - by pulling the aftercoolers for cleaning first?

I understand turbocharged diesels with air-to-air intercooling, but admittedly until I really see one of these 3126s apart, its hard for me to visualize things.


Again - your experienced help is greatly appreciated!
 
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The 11 zincs will take maybe an hour or less to replace in place. There are 5 on each aftercooler.
 
Putting new zincs in the after coolers after they've been cleaned will take 5 min in the engine room.
 
Sounds like the right approach, John.


Question: Is there any practical way to inspect the aftercooler to determine if it needs cleaning, before pulling it?
 
Engine performance is the key method...........Cat 3116/3126's are very clean engines so you should have either very little or no soot on the transom after a decent run at cruise speeds. A fouled aftercoooler restricts intake air and a key symptom of that on marine engines is sooting. Both after coolers almost never clog at the same rate or at the same time, so you will usually see sooting more on one side that the other if you need to clean them.

If you concern is the cooling side, you heat exchangers are a good gauge of build-up in the after coolers. Remove the right (as you look at the crankshaft damper on the front of the engine) heat exchanger end cap and see what is inside. Be careful with the
o-rings ...............
 
The soot can also be a result of needing the top end adjustment too, right Frank?
 
I haven't see that, but the Cat powered boats around here are well cared for and the top end service is done on schedule.

The usual cause for sooting, other that the obvious....overloading, wrong pitch props, dirty bottom.......is an intake air restriction. I suppose if your valves were really out of adjustment or the injectors were set wrong, you could get some soot.
 
My observation after 600+ quick miles this late summer is there is zero sooting at the transom. At fall haulout, I took the swim platform off to have gelcoat repairs made this winter, so was up under it and the only gunk was organic and green, not sooty and black.

There was a very little bit of sooting around where cooling water pumps out port and starboard, but nothing that couldn't be wiped off in a few seconds.

Sounds to me like zinc inspection and replacement is all I am going to worry about at this time. Again, thanks for all the seasoned responses to these newbie questions.
 
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Cats are very forgiving, but no diesel tolerates overheating. Thankfully, Cat over specs the cooling systems so you have plenty of warning when a heat exchanger, transmission oil cooler or aftercooler gets fouled. Just watch your temp gauges and learn what is normal and how it fluctuates for cold vs. warm ambient water temps. When you see 200 degrees, start paying attention ad at 205, pull back the throttles and figure out what is wrong before using the boat again. Tip......pull the inlet hose off the transmission oil cooler first. Lots of small dia tubes that catch everything.
 
Will the ECM record high or highest temp occurrences? And if so, is there a high temp threshold that warrants a service call ?
 
On an electronic engine the ECM should record warning events; however, the 3116/3126 questions here are for mechanical engines so the answer is no. I don't know on your 3196's. The not to exceed temps are in my previous post. If you see engine temps rise with power application or rpms or see temps over 205, its time to find out what's going on.
 
Yeah I followed the 3116/3126 part. The subject just made me think for second. I forgot to re-open a seacock after cleaning the strainers once this summer. Once I got out of the marina, I was more concentrating on the different sound I was hearing (like an impeller was ready to go TU) than shutting things down. When the alarms did go, I did shut down. Thought it was the impeller before I realized my idiot mistake. No apparent repercussions that I could tell. Since the impeller was fairly new, was on the port side of course, And I had no more long trips planned I decided to wait until spring to change it. As I said the temp discussion just got me to thinking. Have a cat equipment (mining eq) service business owner as a neighbor, was thinking about asking him to hook his laptop Into the ECM and checking the codes and what-not...

Apologies to the Op for the hijack...
 
I just ordered new engine zincs from Boatzincs.com. Mine should be fine but I am changing them anyway...
 
searay40dad said:
Yeah I followed the 3116/3126 part. The subject just made me think for second. I forgot to re-open a seacock after cleaning the strainers once this summer. Once I got out of the marina, I was more concentrating on the different sound I was hearing (like an impeller was ready to go TU) than shutting things down. When the alarms did go, I did shut down. Thought it was the impeller before I realized my idiot mistake. No apparent repercussions that I could tell. Since the impeller was fairly new, was on the port side of course, And I had no more long trips planned I decided to wait until spring to change it. As I said the temp discussion just got me to thinking. Have a cat equipment (mining eq) service business owner as a neighbor, was thinking about asking him to hook his laptop Into the ECM and checking the codes and what-not...

Apologies to the Op for the hijack...
Click to expand...



Boating is a never ending learning experience. Having done it, and had the marina service guys do it, you learn to recognize "that sound" of the engines running with no cooling water in the exhaust. This is now one of the items on my check list for as soon as I fire up my engines......"IDIOT, do they sound right?

I learned that the impellers may be resilient but after they are over heated from no water in the pump, their effective life is really shortened. I'd replace the ones you ran without water pretty soon. What happens if you don't is that the vanes begin to fragment and break apart in little pieces. If that happens, you are going on a scavenger hunt in every cooler on the engine to retreive the little hunks of rubber

One key piece of data to request from the Cat guy is load history. A lot of the intervals on Cat maintenance is driven by % time at load and a load summary will let you know if your use is at, above or below the mean for your engines and that will guide you on future maintenance that is time or load driven.
 
markrinker said:
My observation after 600+ quick miles this late summer is there is zero sooting at the transom. At fall haulout, I took the swim platform off to have gelcoat repairs made this winter, so was up under it and the only gunk was organic and green, not sooty and black.

There was a very little bit of sooting around where cooling water pumps out port and starboard, but nothing that couldn't be wiped off in a few seconds.

Sounds to me like zinc inspection and replacement is all I am going to worry about at this time. Again, thanks for all the seasoned responses to these newbie questions.
Click to expand...

Here is the information I received from the Service Manager at my marina/storage today regarding zincs:

Randy did inspect all the zincs on the mains and generator. He found 6 per main engine for a total of 12 and with 1 on the generator. He is confident he did not miss any. He inspected them all and all were in great condition with the exception of one that was broken off. This broken one he replace, cleaned all the others and reinstalled them. With Randy's 26 yrs. of experience at this marina alone, I would highly recommend his advise on not needing to replace them.
 
Yep....there are 5 in each aftercooler, 3 in each main heat exchanger, 2 in each transmission cooler and 1 in the exhaust elbow.
 
I'd suggest you pull the Cat manual and see for yourself. After 26 years of experience he should know to follow manufacture's recommended service procedures and check behind himself becuase if he doesn't someone else will. Nothing pisses me off more than "someone say's" and this is taking for fact. Anyone working for me should be able to back up his knowledge by showing the facts. In this case he has failed the test and would rasie more questions no less.
 
not to mention a zinc's low cost compared to the alternative (damage done from lack of zinc replacement), why take the time to pull them and not put something new in?
 
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