Gauge question new truck to me

[MarkCooley]

Recently upgraded to a new fifth wheels, about 1500 pounds heaver than the last one, and that required the purchase of a newer truck, oh darn, a 07 5.9 3500 and it does a nice job. On my 99 2500 I installed a boost, EGT, Trans Temp, and fuel pressure gauge that saved me on one occasion. So I know I need the first three but do I need the fuel pressure, the truck is stock? Also thinking about the Edge Insight, any thoughts on this as well. One final question the transmission pan looks to be as large as the aftermarket one I installed on my 47RE, do I need to go bigger on the 48?

 

[Jim W]

I would suggest a Mag-Hytec transmission oil pan to go along with the three main gauges that you are choosing. Some nice features on the Mag-Hytec pan would be the drain plug, port for transmission probe, extra oil capacity and the AL fins and pan.

My total weight when towing is 20,300 LBS that's a fully load truck with DW and me plus our Cedar creek 34RL. When I cross through Colorado on I70 this fall at the Eisenhower Tunnel altitude of 11,000 + Feet my transmission temps was only 190F at the sump. I am using a Mag-Hytec oil pan on my 68RFE.

Jim

 

[Killgore]

I'm with Jim. As far as the fuel pressure gauge, I think of it as more of a diagnostic tool, and you can see from my signature that I do remain concerned about the condition of my fuel filters and the lift pump. Granted, I'm a little consumed.

- Ed

 

[SnoKing]

With the 47/48RE monitoring transmission temp at the output line gives you a much better view of what you are doing with the transmission. I had two probes on my 2001.5. Output reacted very quickly while pan hardly ever moved. I became convinced that one could smoke the oil and not see it monitoring the pan temps. SNOKING

 

[lpennock]

Fuel pressure was critical on a VP2 as it would destroy the pump if input pressure was low. CP3 will work fine at negative input pressure. In fact a Duriamax doesn't even use a lift pump with the CP3.

 

[cerberusiam]

The same gauges apply to the 07 as it did your 2nd gen. While the in-tank pump is more reliable they do quit and get weak. Low LP pressure will hurt the CP-3 and you are buying an 8 yr old used truck.

You would be better off taking the money spent on a pan and putting it towards some transmission mods to keep it healthy if you tow a lot. A shift kit plus a few small pieces will go a lot further towards keeping the trans happy than a deeper pan. Pretty easy to put a drain in stock one fro fluid exchanges and such.

The danger of the CTS is where a lot of the parameters are read from, especially trans temp. It doesn't have an aux for usable trans temp, fuel pressure, etc, so you are still buying gauges. For the cost a Smarty touch would be a better investment plus giving you ability optimize power. Once you tow with the Smarty as opposed to stock there is no going back.

 

[Mathes308]

Not sure if I buy the theory that a CP3 is damaged when forced to pull fuel.
The Duramax guys CP3's have a different primary gear that allows dump to pump and create a self priming condition and therefore can be run without a lift pump, cummins on the other hand dumps to line and doesn't self prime as well and requires the lift pump for assistance and after filter changes.
As for damage, I think it's more a myth than actual fact, if the CP3 has fuel to libricate, it will be fine. No fuel or really low fuel to keep it cool may be damaging but by that time you wouldn't be able to hold min rail pressures and the truck would shut off anyhow.
Bosch doesn't state damage will occur from no back pressure it they said repriming after a filter change would be hard.
Again, mostly theories.
If it was that damaging the duramax guys would be eating pumps weekly.
Although they claim the life is longer with a lift pump, but we're talking 10% or so gain.
Sorry cerb, seemed like a good chance for discussion.
Been looking at a TON of CP3 info, looks like their typical fail reason is ULSD lack of lube. Supposedly it was built from day one to be a million mile pump, the new gens are even more wicked.

 

[BigPapa]

With the 47/48RE monitoring transmission temp at the output line gives you a much better view of what you are doing with the transmission. I had two probes on my 2001.5. Output reacted very quickly while pan hardly ever moved. I became convinced that one could smoke the oil and not see it monitoring the pan temps. SNOKING

This ^^^ on the trans temps. Put your sensor in line before the cooler to see what your transmission temps really are. I still say deep pans are harder on transmission temps than standard depth. Yes, it takes longer to get more fluid up to temp, but it takes proportionately longer to cool more fluid.

 

[cerberusiam]

The Duramax guys CP3's have a different primary gear that allows dump to pump and create a self priming condition and therefore can be run without a lift pump, cummins on the other hand dumps to line and doesn't self prime as well and requires the lift pump for assistance and after filter changes.

The D-max has a different pump, both in the gear rotor and other design pieces. It was built to draw fuel, unlike the Cummins version. The line size and location of fuel tank play a large part in the design also.

That pump has also gone thru multiple updates because the original version was garbage. A lot of those early design never went 10k before the complete shelled the fuel systems on them. The first 3 years or so of the Duramax engine GM warrantied the crap out of stuff because it just would not stay together, CP-3, injectors (largely due to FOD from the CP-3), and problems with the fuel control system that cracked injectors an dumped fuel directly into the oil. As long as the manufacturer steps up there is no hue and cry about problems so no publicity. My cousin had one of those nightmares, 3 times in less than 50k the fuel system ate itself up requiring complete replacement. Had is the operative word, he finally dumped that turd for a newer one. Didn't kill the fuel systems all the time so that was a step up. I just laughed at him, less than 50k and all the problems he had while mine was over 100k with a tuner for most of that and all I did was change the oil and filters. GM guys have no sense of humor. I personally know of 3 of those early ones that were nothing but a headache and it ALL due to the CP-3 killing itself. Why do you think LP's were such a benefit to those trucks? Aside from the 20 hp gain that is.

Low\no fuel to a CP-3 is just bad news.

The Cummins CP-3 version was NEVER intended to be operated without at least 3 psi of head pressure, that is straight from the Bosch shops on that. Lines too small, route too long and steep to draw fuel adequately. The generic CP-3 is rated from -5 to +20 psi operating range, but, that is totally dependent on platform. Yeah, you can run -5 psi on a gravity feed 1/2 line on a 6 ft drop but don't expect it to live in Dodge truck too long.

The design of the CP-3 prioritizes fuel to the rail, so no you would not see problems when the pump loses lube. The ECU will stretch duration to compensate and unless you have gauges and\or are using it hard there is no indication of problems.

The bulk of failures, contamination aside, is going to be from cavitation in the gear rotor pump. MUCH higher percentage of the D-max pumps suffer that failure. Basic hydraulics tells you that 5-6 psi is way low for gear pump head pressures. Head pressure should be at least 20% of output pressure (closer to 30% is better) if you want it to live a long happy life. I leave it to you to figure out what that should be with a case pressure of 75 psi.

The CP-3 is far from fragile like the VP pump was but it ain't bullet proof. It will take longer but it will not like lack of attention and when it destructs it likely takes injectors and rail with it. A $6000 repair for lack of a $120 gauge is pushing the odds.

 

[Mathes308]

I remember those days, poor guys took a beating in repairs. Like being a ford owner.
A good stout mechanical lift pump would of been awesome behind the CP3.

 

[Mathes308]

I remember those days, poor guys took a beating in repairs. Like being a ford owner.
A good stout mechanical lift pump would of been awesome behind the CP3.

 

[Mathes308]

I remember those days, poor guys took a beating in repairs. Like being a ford owner.
A good stout mechanical lift pump would of been awesome behind the CP3.