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Cat 3126 engine failure

Posted: Fri Sep 25, 2020 8:34 am
by captfrank
Well Just got a knee replacement so I was not able to go but my buddy took the boat last Thursday and on the way back heard a loud bang and lots of noise from port engine so immediately shutdown.

Upon further investigation found the oil level way high and no antifreeze in the tank but some in expansion tank at normal level. Decide to remove the head. Found a huge hole in cylinder wall AFT bore. Only 2600Hrs on these engines and I bought the boat off a buddy that put these engines in so I have been on the boat most of these 2600 hrs and its been taken care of changing oil before the Cat 250 hr cycle (have always used Cat oil from day one) , cleaning coolers every couple years etc.

We where told by a rebuild shop this is normal failure of Cat 3126. The injector fails apparently open and puts a bunch of fuel in cylinder and thus can not compress and blows out the cylinder. We had no warning etc on this or any maintenance that injectors should maybe be changed at 2500hrs to avoid this (looked on net could not find anything). I'm really disappointed with CAT as my buddy bought this boat with the 3116 CATs that had the soft blocks and thus blew one up about same hrs back in 2003 and put these new engines in. They don't seem to be reliable and a lot of money for engines (he paid over 50K to install these in 2003) that only seem to last 2600hrs or so. They should last like 8k if taken care of or more.

In any case anyone know where might be the bets place to get a re-manufactured engine?

Re: Cat 3126 engine failure

Posted: Mon Sep 28, 2020 12:54 pm
by dougl33
Oh man, that sucks. Sorry.

Any thoughts on what you'll do? Repower or replace? I feel really bad for your buddy too. He must've shit his pants.

Re: Cat 3126 engine failure

Posted: Thu Oct 01, 2020 9:28 am
by captfrank
Likely do a long block. It's like $6800. But will likely costs 10K+ before done with us doing the work.

Re: Cat 3126 engine failure

Posted: Fri Oct 02, 2020 6:35 am
by dougl33
That plus the cost of changing all of the injectors in the other engine for good measure.

Re: Cat 3126 engine failure

Posted: Sat Apr 17, 2021 7:44 am
by captfrank
well got new engine in, more like $15k with new injectors, turbo and prices increased form CAT.

Have an alarm going off (took impeller out running on land) , tiring to trouble shoot not sure what it is all sensors seem to measure same as other engine.

Also Tach not working. Can't figure that one out either. Even swapped with other engine and gaped same way and nothing.

Re: Cat 3126 engine failure

Posted: Tue Apr 20, 2021 5:49 am
by dougl33
Good luck sorting it all out!

Re: Cat 3126 engine failure

Posted: Sun Oct 24, 2021 10:40 am
by captfrank
well it the rebuild blew again. This time the valve seat on #5 came out. Builder says he will make good on it.

Re: Cat 3126 engine failure

Posted: Mon Oct 25, 2021 5:04 am
by Capn Tony
Oh Geez,
Well at least they will make good on the repair. Sorry to hear the news.

Re: Cat 3126 engine failure

Posted: Wed Feb 23, 2022 11:18 am
by captfrank
Well the guy is backing out of it. Says the value seat came out due to aftercooler failure of some metal coming out of it. We had it cleaned and checked and no leaks etc so I think the guy is looking to get us for another $15K.

Re: Cat 3126 engine failure

Posted: Thu Feb 24, 2022 2:07 pm
by dougl33
Shit. That stinks.

Re: Cat 3126 engine failure

Posted: Sat Feb 26, 2022 4:14 pm
by captfrank
he says the aftercooler failed. We had it cleaned and checked by place CAT uses in Glenn Burnie MD area.

Re: Cat 3126 engine failure

Posted: Sun Aug 27, 2023 4:34 am
by Rick
Sad to hear Frank. What HP 3126 is it ?

Re: Cat 3126 engine failure

Posted: Sat Mar 09, 2024 12:47 pm
by captfrank
350hp