340 Cummins Overheating and Slowing Down

[wildebill308]

5 hours ago, jleamont said:

Figured it out. Auto meter makes a gauge #3344 with a required extension module #5257 (specifically for Marine or Diesel Pushers so the gauge remains accurate through all of that extended wire) so the probe gets inserted in the turbo outlet pipe, module gets mounted back in the engine bay area (10' lead on probe) then you run 18 gauge wire up to the dash and install your gauge. Total out the door just shy of $300.00. The gauge is very similar to my factory gauges, I had to ask for a chrome custom bezel so it matches the rest of them.

The probe should go just before the turbo. It is important to know the temp going into the turbo to prevent damage. 

"On a computer controlled engine and transmission it would be hard to push it hard enough to run the EGT's up with an OEM tune." I have run mine with no tune dialed in and seen 1400+ briefly before I took steps to drop the temperatures. I guess it all depends on what you think is excessive.  

Five, EGT Exhaust Gas Temperature. The reason this is important is EGT temps can go up to the point you are melting piston tops before water temps move.

Bill

[jleamont]

Five, well I'm not so sure it's actually needed but would be a good instrument to have. Prior to shutting down a turbo diesel your Exhaust Gas Temperatures need to be below a specific number or you can/will damage the turbocharger. Newer engines can be a little more forgiving, but none the less a good instrument to have just to be safe, kinda like an insurance policy.

modified turbo diesels or manual transmission equipped can also over heat the turbocharger depending on how it's driven. So in those cases you would need it for driving and shutting it down.

older semi trucks had them from the factory, the were called Pyrometers. 

hope this helps and I have explained it well.

[jleamont]

11 hours ago, WILDEBILL308 said:

The probe should go just before the turbo. It is important to know the temp going into the turbo to prevent damage. 

"On a computer controlled engine and transmission it would be hard to push it hard enough to run the EGT's up with an OEM tune." I have run mine with no tune dialed in and seen 1400+ briefly before I took steps to drop the temperatures. I guess it all depends on what you think is excessive.  

Five, EGT Exhaust Gas Temperature. The reason this is important is EGT temps can go up to the point you are melting piston tops before water temps move.

Bill

Bill they make two versions, a before and after turbo version, supposedly the after compensates and adjusts the difference. 

[wildebill308]

2 hours ago, jleamont said:

Bill they make two versions, a before and after turbo version, supposedly the after compensates and adjusts the difference. 

When I was doing my research on what I wanted to install the majority were before the turbo and Banks said to put it before the turbo. I would consider Banks as a pretty good expert on how to set things up. Hear is a link to some explanations on what they did to make this Freightliner run better. You might pick up some tips on how to drive up hills.

http://banksinsider.news/2015/08/banks-super-turbo-dd60-freightliner-pikes-peak-outrage/

Bill

[five]

Thanks, I know what the acronym stands for...as for your before or after discussion, on turbine aircraft, as I said earlier, they have either and EGT or TOT (turbine outlet temp) or PTIT (power turbine inlet temp).  Our turbo diesels and all turbines require a cool down prior to shutting down.  On MHs, idling while checking in or idling while finding your camp site is normally enough.  On a fixed wing aircraft, taxiing to the ramp is the cool down, with the engines virtually at idle.  On a rotary wing aircraft, that has to hover to parking, the cool down (at least on a Huey) is two minutes at idle.  IMHO, some times it appears we over think some of these issues.  If we needed gauges other than those that are OEM, and there were problems, the engine manufacturers would be putting out new information and more gauges.  I'm on diesel number four and never had any problems...if it ain't broke, don't fix it.

[jleamont]

Bill, great video and very interesting! You need to have the first DP running pikes peak with that set up!!!!

Five, I do (and I sincerely hope most do it as well) idle when I pull into a CG and usually unhook the jeep check in etc. Where most people would have a problem is pulling off a road into a fuel stop, rest area etc etc and shutting it down prematurely. I'd bet most average people have no idea that they need to idle for a few minutes before shutting it down, the gauge in that normal environment could be the difference from leaving on its own or towing your coach away and tossing a few thousand dollars out the window. Since each engine/turbo combination, coach weight, ones driving habits etc play a crutial role on how long you need to idle the gauge would take the guess work out. I have often wondered on a few occasions if I idled it long enough, I try to error on the longer side just to be safe.

[obedb]

Don't know about silver leaf. I now have the hardware and will hopefully have it useable before leaving this summer, but EGT gauges have been around for 40 years or more on diesel powered trucks. Had one on my 400hp big cam Cummins in my first Peterbilt . Depends on where the probe is installed  as to temp redline. My exhaust manifold had removable plugs before and after the turbo. Mine came with the sender installed down stream of the turbo, but Hewitt EGT gauge  had a guarantee and suggested a more accurate temp would be achieved by installing the probe  upstream of the turbo. I moved it upstream. I downshifted at 1200 degrees. The short of it is that if you stay on the throttle too long without down shifting the combustion temp could rise above the point of piston damage. They are aluminum and depending on the alloy could start a shape change (melt). Kinda thought our electronic engines would power back in that situation, but I am not sure. Time for a Brett comment.

[racoleman]

I had the slow up hills/overheating problem, shortly after I bought the unit, as I live in a mountainous area.  I thought I had done my home work, buying one of the highest peak torque to empty weight ratios.  There was several problems with that logic.  Two were huge.  First I did not know then how easy it is to overload a front engine unit, as the manufactures play games with dry weight like not including the weight of "options" that most of us would consider standard.  Second I assumed that since I was buying a 2011 unit that the Cummins engine was a 2011.  It turned out to be a 2009 that was programmed with a lot less torque and hp  So my torque/weight calculations was invalid.

The people at Cummins were great.  For less than $400, they reprogrammed the engine to the most Torque that block and turbo can take and still have a warranty.  Most of that cost was to extend the engine warranty for the higher output.  Apparent Winnebago could not afford to do that to begin with.  I also did some other small things like shorten the exhaust, wrap the exhaust, turbo and inter-cooler hoses, and changed the air intake so I could use a far less restrictive filter and take in cooler air,  All the above added 20 miles per hour to the nearest grade to me (34mph to 54mph)

One major bad result was engine overheating due to a too small radiator.  And I learned that once the fan clutch fully engaged I lost 15hp.  So I hand built a cowl so that all of the air entering the front grill goes through the radiator, which helped greatly.  As a further precaution I built a system that used the fresh water system to mist the radiator when engine temp reaches 195.   Since  doing all this my worse experience has been a grade that I had to slow to 45mph as I was fully loaded (half ton over GVW) and ambient temp was 105.

I considered all of the above a band aide.  Thinking that hem the engine and/or tranny let go  I would pay what ever it takes to install bigger ones (including radiator).  But I now have  65k miles and no signs of wear.  I also installed a egt gauge as well as a tyranny temp gauges  to help detect such signs .

In case some of you may want to comment on the overloading.  I've spent about 10k beefing the suspension and brakes.  Freightliner was way less than helpful on this.  But I now have about 90% of the chassis that Winnebago should have used to begin with.

If I ever buy a motor home again, which is unlikely.  I am going try to buy from a manufacture that is willing to custom install on a chassis and engine combo that is the next step up to what ever they are offering.  If I can not do that I am going to build my own.               

[obedb]

I am hearing stuff that I can identify with, but ours was gas powered in 1988. Spent a lot of time, effort, and dollars. It all worked . Pass anything but a gas pump. Love the way our current diesel unit pulls and the noise is in the back. Being a trucker, I don't expect heavy units to perform that way anymore. Got a little jealous of the diesel powered rigs. I went from terrible to overdoing the gas unit performance.  You will probably buy another unit before you give up the RV lifestyle. We did and love it.

[wildebill308]

There are a number of places that will build whatever you want. Here are a couple.

http://www.texascustomcoach.com/

http://www.newellcoach.com/

http://www.marathoncoach.com/

Bill

[five]

16 hours ago, WILDEBILL308 said:

There are a number of places that will build whatever you want. Here are a couple.

http://www.texascustomcoach.com/

http://www.newellcoach.com/

http://www.marathoncoach.com/

Bill

Yes, these manufacturers will be happy to build you one mighty fine coach.  Be sure to bring your check book, all your credit cards and your first born son.

[manholt]

FIVE.  Your coach is a 14' and your fine with what you have...we both run the same computer.  The EGT is built in, I go by exhaust temperature, when it reads below 300 I shut of engine.