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Re: CAT 3126 Mechanicals need new Aftercoolers

[ Edited ]


I have two in good condition aftercoolers for 3208.

You can reach me at 347.788.8063


Re: CAT 3126 need new Aftercoolers


I have 2003 3126b  900 hrs  aftercoolers checked and cleaned etc... And then with in 1 year they were in complete failure ,

Cat tech scoped out aftercooler and head unit , only to state that salt was there and heads need be removed, they approved both engines performance to be perfect running condition   1 year before the inspection.

The boat has now sat for 3 years. I Need Heads and aftercoolers ASAP


I hope to save turbo units

Cylinder's/ Pistons check out OK., 

could use input on any assistance



won't Cat Help?



Re: CAT 3126 need new Aftercoolers

Hello Again,


My last post back in 2010 describes cracking in both aftercoolers on my 3126 SN6MK01241 and -49 engines.  At the time of posting I didn't really understand the nature of the problem as I was going on what the CAT engineer was telling me and I hadn't seen the problem for myself.  


The actual problem was as follows.  At either end of the aftercoolers there is a small plenum chamber (the bit that holds the anodes). One end is the raw water intake and the other end is the exit.  At the point that these plenum chambers are welded to the main casing of the aftercooler, the welds had cracked, allowing a small amount of raw water to drip externally.  I'm virtually certain that the problem is caused by thermal stress between the hot aftercooler casing and the cold raw water.


I had both aftercoolers removed, cleaned, pressure checked and the welds ground out and repaired using high quality silver welding techniques. Incidentally, the units were found NOT to be leaking internally.


Since refitting back in 2010 the engines have been looked after extremely well and run for ~300hrs, mostly at 1600rpm and never more than 2400 rpm (max continuous).  They have been periodically load tested at full weight and pull around 2850-2875rpm. New CAT oil every year, new anodes every 9 months whether they needed it or not. Props and shafts balanced so they run silky smooth.


In short, the aftercooler problem has returned... The port side aftercooler has cracked again at the same seam... I'm not sure how to proceed except to repeat the repair process and check again in 200hrs or 2yrs; expensive...


Has anyone else experienced this particular failure with their 3126 engines? I'd be very interested in any opinions.







Re: CAT 3126 Mechanicals need new Aftercoolers

I have had the same problem yes with one at 510 hours starboard motor and now at 747 hours both are bad now and ring power of Riverview Florida replaced the star board head because of the aftercooler problem at 510 hours and never checked the port side well guess what the port side needs replaced not leaking inside but outside, as for the starboard motor that ring power did the valve job on 230 hours ago, which is bad again 230 hours later, because of a bad after cooler again, which Ring Power Of riverview installed under warranty, amazing ring power gets away with this they even billed warranty work on the port  engine, now after 230 hours I have to do the head and aftercooler again but now it includes the turbo also, I was told by the mechanic and turbo rebuilder that the turbo was bad when they did the valve job and after cooler replacement 230 hours ago,  And guess what the warranty is over and so is the cooperation and support from ring power thanks a lot ring power of Riverview Florida what am I suppose to do or were can I get the after coolers ring power says 5000 each and 10000 thousand for the valve job god know what they want for the turbo, what can I do looks like I have to do the valve job myself with a mechanic, can anyone steer me to the after coolers for a fair amount not ring powers inflated price of 5 grand each





 Upset 2001 2002 3126b cat owner

Cat Dealer

Re: CAT 3126 Mechanicals need new Aftercoolers

If they are 3126B engines I have not been able to find an alternative.  If they are 8NM  or 1ZJ engines there may be used ones around but I would not trust them and they are not as expensive as the 3126B and C7 aftercoolers


CAT 3126 Mechanicals need new Aftercoolers

Hi all,


I'm looking for two (yes that's right both have failed) new aftercoolers for the CAT 3126TA. They're 2001's with 450 hrs and both aftercoolers are cracked although only leaking externally (thankfully). Can anyone give me a lead on replacement parts? I should mention I'm in New Zealand and although I'm dealing with the NZ distributors I'd appreciate some other options.