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Low Engine (Cat 3176) Power problems and solutions

May 08, 2015, 09:32:44 am

We bought our 95 U320-SE (Cat 3176) a few weeks ago knowing it was down on power but didn't realize just how bad it was until a trip to Arkansas.  I now have a permanent "Williams Control" imprint on the bottom of my right foot...

Troubleshooting found a crack in the intercooler 12" long at the seam between the core and end cap.  I replaced the CAC with a piece of 4" exhaust pipe with 2 90's as a temporary solution.  Thinking I had found the solution, I took off up the road and still had no power...

Fortunately I have some connections with diesel mechanics and got  to use the Cat Electronic Technician software to run diagnostics and found the boost pressure sensor in the intake was bad.  $147 from Holt Cat in Longview and I now have 32lbs of boost instead of 0!  Unfortunately without the CAC, my Intake Air Temp (IAT) got as high as 246 F on a full throttle acceleration to 70 mph, not hot enough to be damaging but too hot to use regularly.

And now for the question, does anyone have a part number for the Atlas CAC?  I can make an excuse to go to Corpus to save on shipping, just need to get one ordered.

Thanks



(edited title for clarificaton of engine, not shore/electrical, power issue  - Michelle)

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Re: Low Engine (Cat 3176) Power problems and solutions

Reply #1 – May 08, 2015, 11:12:40 am

LD, first I would call them and give them your year etc as they where able to give me a # and price a few years ago when I called without any real info. I was told it would be at least 6 weeks before they had one made. It was around $1300 then and FT was $3300.
Now a suggestion. I had 3 holes in my CAC (big ones) and repaired them very successfully myself even though everyone said do not do it! If yours is just a long crack this is what I would do. Using a small Dremel or similar grinder open up very slightly the crack to a "V" shape without going to inside wall. Wash the CAC out very well with a hose and running water and let dry. Buy the 2 part Aluminum mix called  DEVCON and mix as reqd. Carefully press it into the crack without forcing it into chamber and let set overnight. Sand the outside smooth then clean again the CAC with copiuos amounts of water then dry. This repair is very good and WILL fix the crack.  When I did ours I blanked off the ends and fitted an air gauge one end and a airline to other and pressured the CAC to 45lbs and left for a night. It was still at 45 the next morning. # yrs later my Boost is still good and with the Banks I have up to 34lbs while driving. If your crack is close to the end of elbow you will be able to see if any of the Devcon has come thru the crack and to make sure none will ever come apart and get into engine.
This repair will work and save you time and lots of money, but doubt if anyone will agree on you fixing it except me. I have first hand knowledge now and would do it again if needed, but, at the same time you have to be very cautious while doing it.
JohnH

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Re: Low Engine (Cat 3176) Power problems and solutions

Reply #2 – May 08, 2015, 11:35:58 am

That sounds VERY repairable to me.
Mine was impossible as it was several tube welds (93 U280) I should be able to dig up info on mine from Atlas - its a standard design for all Unicoaches - much beefier thant the wimpy CAC in my 93 with CAST end caps - about 60% more surface area. And about 80 pounds heavier.

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Re: Low Engine (Cat 3176) Power problems and solutions

Reply #3 – May 08, 2015, 11:50:44 am

Search in the Yahoo section the PN from Atlas is 910113 (search: Atlas Radiator or Foretravel CAC)

I dealt with Larry Frederick - of course, that was 9 years ago.

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Re: Low Engine (Cat 3176) Power problems and solutions

Reply #4 – May 09, 2015, 09:33:52 am

It would be good to drill a (small) hole at both ends of the crack (relieves stress) and weld rather than epoxy, unless getting to the repair is an issue.  Surface prep (getting the repair material to stay in place) is the main issue when dealing with (Devcon is GREAT, just use the right kind) epoxy. 
Also consider welding an additional piece over the area to reduce stress.
If you can find someone that can sew beer cans together, you've found your welder BTW.  pc

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Re: Low Engine (Cat 3176) Power problems and solutions

Reply #5 – May 09, 2015, 10:19:06 am

Like John says, an epoxy type material will fix it for almost everything. I have made radiator tube repairs on the road with JB Weld when the fan cut off several radiator tubes and even damaged the tank. On the other hand, the intercooler may have either a design problem or the type of installation may put stress on areas not designed for it. A good aluminum welder can not only weld beer cans but for just a little more $$, reinforce it so you won't have to worry again.

Almost any idiot can use a wire feed for steel welding but aluminum takes more experience, careful cleaning, planning for expansion during the weld, etc.

Pierce

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Re: Low Engine (Cat 3176) Power problems and solutions

Reply #6 – May 09, 2015, 02:10:38 pm

Caution on the welding idea as the carbon build up inside will NOT allow you to weld the CAC. What happens is the carbon causes the material to break down with the weld and actually will "crumble" for want of a better word. My Aluminum welder friend who does this everyday (welds) would not touch mine as he told me about this condition. "Been there done that- never again" he said.
The Devcon is a perfect fix and you can actually use this to epoxy a back up piece for strength along crack area. I have used devcon for over 50 yrs ago on large Diesel engine blocks that had casting flaws and it never once came apart. It was common practice on the Deltic Diesel engine we built in England and they are VERY big.
I also talked to one of the Engineers at Devcon and she said as long as the area is clean and no water there it is good. As I said before this is an easy fix, but some people love throwing money away and buy new. If it is possible to put a couple of clamps around the pipe after fixing why not do that too?
JohnH

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Re: Low Engine (Cat 3176) Power problems and solutions

Reply #7 – May 09, 2015, 05:16:35 pm

Talked to Atlas and a new one is $1564 and lead time is 2-3 weeks.  Atlas recommended a product called Accu-Tech epoxy to repair the crack.  I did the drill holes at the end, clean it up with a Dremel and JB Weld Professional but it only held 25psi for 2 minutes before splitting back open.  Once I get the epoxy, I will remove all the JB Weld and then epoxy it to see if it will hold.



Thanks!

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Re: Low Engine (Cat 3176) Power problems and solutions

Reply #8 – May 09, 2015, 05:24:35 pm

That is one nasty crack! I agree with John H about the Devcon product. Have used it many times as a chief engineer on tuna boats and tug boats. Proper prepping of the material is most important in using epoxies.
  Good luck and keep us posted on your progress.
 
 Richard B

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Re: Low Engine (Cat 3176) Power problems and solutions

Reply #9 – May 09, 2015, 07:53:45 pm

Nice to see a picture so here is what I would do with this crack. Get a piece of 1/2" X 1/2" ALUM ANGLE  THE RIGHT LENGTH AND ABOUT 1" LONGER , then cut off a piece on one leg so you just have 1/4" on one side as this is the one edge you will put towards the cores. Clean the whole area up carefully and widen that crack about 1/16" on the outer face (making a vee down it). Then using some emery cloth roughen up the faces of both the CAC and angle. Clean both up and mix some of the Devcon or the other one ( I have no experience with that one) Mix enough to fill the alum' angle and gently force a bit into the crack then place the angle over the crack and press it onto the face of CAC. Put a heavy wieght on angle to keep it flush and down on CAC and let it set up. Once hard smear a bit more of the  filler to cover edges of angle and flow over to the rad. This will extend the support some. Important--- make sure that you do not force any thru the crack if possible. Leave it overnight and then pressure test. it should have no problem holding air but do not go over 40lbs as you will never have that much in CAC. The secret to this repair will be cleaning and roughing it up to hold the Epoxy.
JohnH

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Re: Low Engine (Cat 3176) Power problems and solutions

Reply #10 – May 10, 2015, 07:46:48 pm

Good advice, I hope to repair it this week.  I'll keep you posted with repair photos and results.

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Reply #11 – May 11, 2015, 12:41:46 pm

Looks like the cycle life of the tank has come and gone. 
What is the chance of having the cracked tank replaced?  pc

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Re: Low Engine (Cat 3176) Power problems and solutions

Reply #12 – May 11, 2015, 05:49:30 pm

Tell you what, if you can successfully fix this stress crack with epoxy, I'll be a believer.  Don't see any chance of tig welding it either, it would be, I think, a problem even for my Jedi Master tig guy.  Now if I was really desperate, might try epoxy and a couple of thru bolts to stop the zipper failure. 

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Re: Low Engine (Cat 3176) Power problems and solutions

Reply #13 – May 11, 2015, 06:23:42 pm

Chuck, if it is done right I can almost gaurantee it. Mine has been 3 yrs and I get 34lbs many times and my holes were in the cooling fins and the size of dimes. The secret I feel is the backing piece mated correctly to the main casting, then a healthy amount of Epoxy overlapping the angle..
JohnH

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Re: Low Engine (Cat 3176) Power problems and solutions

Reply #14 – May 11, 2015, 06:48:16 pm

Only local place that would even consider fixing it wanted to ship it to Alabama to have the core replaced.  $1400 and a week turn around.  If I'm spending that kind of $ I'll just have Atlas build one.  As soon as the Accu-Tech comes in I will give it a shot.  I'll waste $40 and a few hours to try and save $1500 any time. 

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Re: Low Engine (Cat 3176) Power problems and solutions

Reply #15 – May 11, 2015, 07:31:40 pm

LD, not so negative " I will waste a few hrs and $40----"
This will work if you clean it up right.
Positive thinking.
JohnH

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