8v92 ddec 2 engine operating temps

[encantotom]

Hi all, i just picked up my new to me 1990 38' newell this weekend. we drove it home 550 miles and it is really a joy to drive. the frame has 122k miles and the engine has 17kmiles since majory overhaul. i have a question about what temps you guys see on your engine during normal and steep grade driving. during night at 70mph it was 180-190. during the day as high as 200, but typically lower. but going up a 6% long grade it seemed to get around 220 or so. to be honest, the graduations on the vdo temp gauge are not linear, so i think it was around 220. it cools down quickly once off the grade.i slowed way down to 45 and drove in the power band in lower gears to be sure. no engine lites came on. what is normal for you guys? i am headed off on a 2 week 4kmile trip on tuesday, so would like some comments from you pros. thanks.

[tuga]

encantotom,

180 to 190 is normal on flat ground in the summer. In the hills and mountains you want to watch your boost gauge and keep it around 15 to 20 psi. You control the boost with the accelerator; if you let off of the accelerator the boost will drop and if you press the accelerator down the boost will increase. The gauge measures the boost going to the turbo.

Climbing a grade is best accomplished by using the gears; climb at a smooth steady rate, let the transmission select the correct gear and hold the boost to 15 or 20 psi and your engine should not over heat. Using the correct gears and boost should keep your engine temperatures down around 200 to 210. Pulling a vehicle may kick up the temps 5 degrees or so. Remember that the antifreeze is under pressure so the operating temps can be higher.

I agree with you about the markings on the VDO gauge not being linear. Mine has markings between the 180 and 230 = 50 degrees. I assume the first mark is 190, the second is 200, the third is 210, and the fourth is 220. What makes it confusing is they are not equidistant apart!

A yellow warning light will come on when the engine is approaching a dangerous overheating situation. A red shut down light will come on before the engine shuts down completely. So as long as no light come on you should be go to.

I think that if you just use the boost gauge and the temperature guage together and don't try to climb the hill too quickly everything will be fine.
I climb most grades at about 30 to 35 miles per hour.

One more tip: when you stop for lunch or at a scenic overlook check your oil. An engine that has been running hot WILL BURN OIL. Remember the coach should be level when checking it, and keep it right on the full mark.

Good Luck

[fulltiming]

Congratulations on your new acquisition. My temperature gauge typically runs between 180 and 190 degrees at about 70 mph on reasonably level roads. I use VMSpc to monitor the engine on my laptop computer display. That way I can see the engine temperature, oil pressure, boost, etc in a digital display rather than trying to interpret the non-linear gauges. I find that VMSpc shows I am running between 178 and 185 degrees most of the time. When the gauge shows 200, VMSpc is showing 195. That is good since Detroit Diesel considers the normal operating range to be 170-195 degrees and recommends not running the engine over 210 degrees. The hottest I have seen climbing a 6%+ grade per VMSpc was 207 degrees (which looked closer to 220 on the dash 'guess what this number is' gauge) at which point I backed out of the throttle and slowed down to let the engine temperature drop back down to 203 degrees. Detroits do NOT like to be overheated. In lieu of a Manifold Temperature Gauge, using the boost gauge to keep the boost down on long grades as Tuga suggests is the best way to protect your engine. Pulling a steep hill at 25 pounds of boost will really run the temperature up quickly.

By the way, my VDO temperature gauge is marked at 120, 180, 210, 250 and 300 with no marks in between.

[tuga]

Micheal,

The VMSpc sounds neat. Where can I get the software for my laptop?

[fulltiming]

The information page on VMSpc is here (http://www.silverleafelectronics.com/?q=node/6). I purchased the unit here (http://www.rvupgradestore.com/index.asp?PageAction=VIEWPROD&ProdID=332).

I recommend it anyone that doesn't have Detroit Diesel's EDM/AIM (http://www.detroitdiesel.com/products/electronics/Info_Management_Products/EDM_AIM/index.asp) or Silverleaf already. You can download the software free. The cost is in the controller box that connects your PC (serial port, requires a serial to USB adapter if your PC doesn't have a serial port) to the coaches engine diagnostic port.

Note: Click on 'here', 'here' or 'EDM/AIM' which are hyperlinks.

[encantotom]

i want to buy the cable set and need to know if it is a 6 pin or 9 pin.

i have had my coach one week now and have put on 2800 miles so far. it is great and i love it.

thanks

[fulltiming]

Actually, you will need the pigtail adapter rather than the 6 or 9 pin connector. The DDEC II connector uses a proprietary "ALDL" connector which is not available in the open market. This is a twelve-pin rectangular connector. You will have to hard-wire the JIB to the wires in the rear of the twelve-pin connector. The pigtail only has four wires. They are connected with the power wires to lugs A and H and the data wires to J and K.

A good source for the JIB and cable sets is RVUpgradeStore.com Click Here (http://www.rvupgradestore.com/index.asp?PageAction=VIEWPROD&ProdID=332).

[encantotom]

hi all,

i got the software and cable/box from silverleaf and hard wired it in with splices behind the plug. it worked first try and it is really neat. i am experimenting with what gauges i want to have and what format. i inserted a picture of my coach as the background. i am looking forward to using it more. i took it for a short spin around town this past saturday and now i have to build or buy a stand to put my laptop on or something to hold it on the doghouse better. i experimented with forming some 1/2" lexan in the oven this weekend and i gotta come up with a better way to make a laptop stand...of course i could always buy one but that is the easy way out....

if you like to see real data and like geeky stuff, this is really cool.

tom

[folivier]

Okay, after looking at the VMSpc software I'm ready to buy. Looked under the dash and there is a gray rectangular plug with a cap that says "do not remove, diagnostics" and there are 9 pins used. This is under the dash just above the accelerator. Is this where the pigtail version is wired into? I didn't see any other round plugs resembling the 6 or 9 pins on the Silverleaf website.
Thanks,
Forest

[encantotom]

hi forest, the plug is usually mounted on the center console right by the carpeted panel that goes over the brake pedal and on the side at knee height.

so yes, that is it...

it is easy to install the wiring. you will spend much more time configuring the screen you want. you can do that now ahead of getting the hardware. just download it and start playing with it.

tom

[folivier]

Ok, just got the kit in. Looks like they upgraded it to USB!
Did yall hook up the power & ground at the diagnostic plug?
Also the pigtail has 2 sets of data wires, one set is for J1708/J1587, and the other is for J1939 or RV-C data links.
According to VMSpc my Allison tranny may be able to readout fluid temp. Is that what the other set of data wires is for? How do I know which is which? I'm confused:confused:

[fulltiming]

Interesting, according to their website the wiring should be configured this way (http://www.silverleafelectronics.com/files/J1708-J1939%20Diagnostic%20Connectors.pdf). My 1992 has the 12-pin rectangular two row plug. The one I used (ABCDEFGHJKLM) has 7 connected wires, with power from A and H and data from J and K.

My transmission does not have a connector as it is not electronic.

[folivier]

My transmission has the electronic controls. The thing that's confusing me is the pigtail having 2 sets of data cables. I'll try and call Silverleaf tomorrow and see what they say.
Thanks.

[fulltiming]

My pigtail is several years old and only has the one set of data cables plus the power cables. Does your coach have a separate data connector for the transmission? Mine doesn't.

[encantotom]

by "electronic controls" do you just mean the shifter pad? i think you still have the same ht740 tranny the rest of us have.

tom

[folivier]

I haven't been able to locate a data connector for the tranny, just the one for the engine. I do have a display with "gear selected and gear attained" and also the tranny check switch I posted about earlier. The "electronic controls" are in the passenger side bay behind the front wheel which is where the HWH leveling sensor and box is. It may just be electric shifters, there are a bunch of relays going into an Allison box.
Do your JMSpc display the transmission temperature? Wondering if this is passed through the DDEC?
I'll call Silverleaf today and see what they say.

[Richard and Rhonda]

Forrest, I am on a slightly different system, but I do get tranny temperature through the DDEC connection. I do not tap into a separate twisted pair for the transmission.

I had to hard wire mine, since none of the supplied pigtails matched the DDEC diagnostic plug. It wasn't hard using those wire splice connectors.

Since I had a DD ProDriver (no longer working) I used the hot, ground, and twisted pair leads going to it.

You are going to LOVE the VMSPc !!!!

[folivier]

Well, nothing is ever as easy as it should be!
I spoke with Silverleaf and was able to figure it out. My connector did not have a wire on J, so I had to use trial and error (mostly error) to get it to work. Right now with the engine idling I'm getting the following gauges: Tach, Engine temp, % load, oil press., boot press, and hours. I'm not getting transmission temp. or manifold temp. Do our 8v92's have a sensor for manifold temp?
I may try playing with the other set of data wires to see if I get trans. temp. Silverleaf said I shouldn't be able to burn anything up by doing this. Yeah, right, I've got way more confidence in myself than that, I've managed to let the smoke out of a few things!!

[fulltiming]

I would be somewhat surprised if you can get a digital readout of the transmission temp on the 8V92 and your Allison. Have you tried using the PID sniffer to see the choices that VMSpc is reading on your DDEC? According to my VMSpc manual, the gear selected and gear attained are only available on Allison transmissions built after 1998 but doesn't mention the tranny temp.

Here are the results of the PID sniffer on mine:

9 Rolling MPG
10 Acceleration
11 Braking
12 Peak Acceleration
84 Road Speed
85 Cruise Status
86 Cruise Set Speed
91 Accelerator Pedal Position
92 % Engine Load
93 Output Torque
100 Engine Oil Pressure
102 Boost
108 Barometric Pressure
110 Coolant Temp
111 Coolant Level
168 Battery Voltage
174 Fuel Temp
182 Trip Fuel
183 Fuel Rate
184 Inst. Fuel Economy
185 Ave Fuel Economy
190 Engine Speed
244 Trip Dist
247 Total Engine Hours
250 Total Fuel Consumed
509 HP
510 Torque

[encantotom]

here is a screen shot of my vmspc. of course we all have it set up differently.

tom

[Richard and Rhonda]

Forrest,

There is an easy way to see what you can get. There is a sniffer function in the software, if you activate it, it will tell you everything the computer sees.