Skip to main content ↑ ↓
Topic: 2006 Cummins 525 ISX (Read 1887 times) previous topic - next topic

2006 Cummins 525 ISX

I am having an issue with my engine.  There is something that happens that sounds like an acceleration or loud running of either a cooling fan or something that just occurs.  No increase in RPM but very loud and there is air as well as noise.  If in a dusty environment when it happens it blows up a lot of dust.  Any ideas as to what this could be?
Thx
Gerard
Gerard Caswell
Eunice, LA
2006 Phenix
2011 GMC Sierra P/U 4x4

Re: 2006 Cummins 525 ISX

Reply #1 –
It sounds like you radiator fans are going to high speed to try to keep the engine cool
previous 1984 35 ft ORED 250 HP 3208 Cat       
previous 1998 40 ft U295 CAI 325 hp Cummins
previous 2003 40 Ft u320 build #6140 450 Cummins M11.                                                         
1999 Mazda Miata
Ron, Nancy, Tipper the cat, Max The dog
1997 U 270 36 ft build number 5174 8.3 Cummins

Re: 2006 Cummins 525 ISX

Reply #2 –
You have an ISX, you might want to see if your number 6 piston is going down the tubes. Our fan was running at high speed trying to keep our engine  cool while our #6 failed, taking the rest with them  I am now 30 Cb into repairs.  And have been coach less for 12 months.
Lynn and Linda Day and Harry the pug
RIP: Tank 01-2008 to 03-2020
2012 Nimbus 42' build 6555
ISX12-500hp
2015 Jeep Grand Cherokee
MC# 17723

Re: 2006 Cummins 525 ISX

Reply #3 –
Quote from: pugmom –
You have an ISX, you might want to see if your number 6 piston is going down the tubes. Our fan was running at high speed trying to keep our engine  cool while our #6 failed, taking the rest with them  I am now 30 Cb into repairs.  And have been coach less for 12 months.

So sorry Pugmom. Yikes.
1993 U300 40ft GV SE
Build # 4344

Re: 2006 Cummins 525 ISX

Reply #4 –
I thought about the radiator fans as well and it does sound like that.  However my engine temp has not moved above what it usually is and it does it sometimes when I first crank up so i know its not overheating.  Could it be a bad thermostat?
Gerard Caswell
Eunice, LA
2006 Phenix
2011 GMC Sierra P/U 4x4

Re: 2006 Cummins 525 ISX

Reply #5 –
Could it be the pop off for the air dryer that is hanging open and the check valve is leaking/bad? When it does it what are your air pressures.

I had on an older coach that the check valve went bad. When the air compressor would unload with the bad check valve it would blow all of the air out of the tank and the compressor would kick in again.

Does it do it all the time or every once in a while? 
If once in a while, at a certain speed, accelerating, coasting?

If you have a boost gauge is it showing the same boost as before?
Same power as before?
Any check engine codes or lights?
2014 ih45  (4th Foretravel owned)
 1997 36' U295 Sold in 2020, owned for 19 years
  U240 36' Sold to insurance company after melting in garage fire
    33' Foretravel on Dodge Chassis  Sold very long time ago

Re: 2006 Cummins 525 ISX

Reply #6 –
Having owned a 2006 ISX, What I believe you are hearing is the high speed fan staying on even when you are not at a high temp.  I had that same problem with mine. It turns out that a valve in the hydraulic pump system get dirty and stay stuck in the on position.  If that happens the default is high speed.  The replacement valve is really expensive, but at that time they had a o-ring kit to fix it.  James Trianno actually helped fix mine at the company's home repair facilities.  I highly suggest that you put in a request to talk with James.  Once the valve was serviced helicopter roar and dust clouds were never to be seen again.  By the way I drove the coach over 7000 miles before I had it taken care of.

Re: 2006 Cummins 525 ISX

Reply #7 –
Yes what you are hearing is most likely the radiator fan. I have an ISX and in the summer months when I first start it, the fan will run at high speed sometimes. It will then move to slow speed after a little while. I have found that the dash A/C will kick it in to high speed more frequently too. So unless it is staying at high speed all the time, this is normal operation.
Previous coach - 2007 Phenix 45'

Re: 2006 Cummins 525 ISX

Reply #8 –
It is staying at high speed.
Gerard Caswell
Eunice, LA
2006 Phenix
2011 GMC Sierra P/U 4x4

Re: 2006 Cummins 525 ISX

Reply #9 –
According to James Triana my coach has the Sauer Danfoss controller for my radiator fan and it either failed or has a broken wire and it defaults to high.
Gerard Caswell
Eunice, LA
2006 Phenix
2011 GMC Sierra P/U 4x4

Re: 2006 Cummins 525 ISX

Reply #10 –
Gerald,
Does your engine still feel like it has the same power as when you first bought her? Our engine NEVER showed any change in temperature the whole time it was self destructing.  ISX Cummins engines have #6 piston/cylinder problems.  I hope it is only a fan, but I would be suspicious of the engine too.
Lynn and Linda Day and Harry the pug
RIP: Tank 01-2008 to 03-2020
2012 Nimbus 42' build 6555
ISX12-500hp
2015 Jeep Grand Cherokee
MC# 17723

Re: 2006 Cummins 525 ISX

Reply #11 –
While Cummins cylinder #6 can drop a valve, etc., it's not common to do so. So, unless you hear mechanical noises and a rough idle, it's probably just the fan controller. Pretty easy to detect a lost cylinder. Cold start should see the engine turning over evenly on the starter. Easy to check for broken wire or a photo tach to check fan speeds. 99% it's the controller is my call.

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: 2006 Cummins 525 ISX

Reply #12 –
Y'all might want to Google Cummins ISX 600 PROBLEMS and see what pops up. I am basing my comments on what we experienced a year ago. When we limped into Nac. The fan had just about burned it's bearings out, very little power, no overheating showing on the gauges, but a decrease in power. No odd, crunching noises coming from the engine. Bernd has been working on our engine for 10.5 months, Everytime he thinks it is ready for a road test, another problem connected to the original mess shows up. He is now trying to get the ERG system to work correctly. We are 30 CB's into the engine, have been with out our coach for over a year when coupled with the deer smack repair. If an ounce of prevention saves you 30 CB's, I think I would possibly have it checked.  If Lavocat, has the same fan we had, the bloody thing gets a trip to England, so it maybe gone for 8 weeks to be fixed.
Lynn and Linda Day and Harry the pug
RIP: Tank 01-2008 to 03-2020
2012 Nimbus 42' build 6555
ISX12-500hp
2015 Jeep Grand Cherokee
MC# 17723

Re: 2006 Cummins 525 ISX

Reply #13 –
I know you live near NAC but I would seriously consider researching a Cummins engine shop somewhere in Houston or in a nearby
city and talk to the service manager and think about going elsewhere.If he has actually had your coach in for engine problems that long he's on a fishing expedition and will never get it fixed no matter what he tells you.Would even consider paying the cost for a dyno test.Did'nt research the fan problem but would think somehow you could get the parts from England and have a shop rebuild
these pumps here.Unless for some reason he has extensive expertise and expierience on that particular engine your up the creek.
Find a shop that has worked on them and knows how to diagnose it,in many cases that is the hardest part of the equasion.When
you know exactly what the problem is it's very easy to fix.
96 U270 BUILD 4810
85 380SL
Drummonds TN.

Re: 2006 Cummins 525 ISX

Reply #14 –
10.5 months is insane. Too late now but other others, I would find a Cummins shop that does lots of overhauls and even if it took an exchange engine, I would want to be stuck no more that a couple of weeks. Does anyone think a big trucking company waits almost a year to get their rig back in service? What is unique to a Foretravel Cummins?

Im not super sure but I think another member took his Detroit in for an inspection. He was told it had "weak" valve springs and one bad and another "marginal" injector. Some new parts installed by an apprentice but when it started running badly a few hundred miles later, it turned out the wrong parts had been installed. Again, I'm not sure of the shop's name but...

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: 2006 Cummins 525 ISX

Reply #15 –
I have seen the guts that Bernd took out, the #6 cylinder sleeve had slipped, the result was increased pressure leading to extensive damage on All 6 pistons and sleeves. The head gasket was also involved. I have extended insurance that has been reluctant to pay and Bernd has been fighting with them to complete the job correctly. As he has torn the engine apart, he has found more damage that had to be renegotiated to be repaired. As I said it gets close to being fixed, goes out on the road to be tested and voila, another problem rears it's ugly head.
As far as I am concerned, Cummins is the biggest part of the problem, They had worked on the engine in the Spring of 17.  We were assured all was fine...brought it home and my husband went to go to Nac and had the oil light go on.  She was low a couple of gallons. When the fan started to run constantly, we stopped at two Cummins dealerships. Told at one they couldn't do anything. The other one said, they didn't work on "aftermarket" add-ons.  Neither offered to run any diagnostic checks to see "why " the fan was running. Our engine light came on yellow in Perry OK. We limped down to OKC Cummins. They told us to keep going home as long as the light didn't go red, it was safe to drive as they couldn't get to us for at least 4-5 weeks. Handed us a list of possible problems .So we continued to limp to Nac.
FOT reviewed the information, but not being sure recommended having Bernd look at it.
We have had to send the fan to England which turned out to be a bit longer than 8 weeks, then the fan had to have some customized brackets created. Some type of control board that was replaced via it's part number turned out to have been subdivided down into 6 or more boards under the same part number. That had to be worked out. Now the EGR is having to be worked on thanks to Cummins having improperly installing a sensor along with cracking it. So what should have been a simple fix has been a  very long night mare. When Bernd gets the job completed, I think he will have done an outstanding job. He has been patient, communicated every few weeks on progress or with each set back.
Lynn and Linda Day and Harry the pug
RIP: Tank 01-2008 to 03-2020
2012 Nimbus 42' build 6555
ISX12-500hp
2015 Jeep Grand Cherokee
MC# 17723

Re: 2006 Cummins 525 ISX

Reply #16 –
Glad I have a simple engine.
96 U270 BUILD 4810
85 380SL
Drummonds TN.