60 Series Detroit Diesel problem

[Stretch]

Our coach has a 60 Series engine. When the engine has not been run for a couple of the days when cranking over, the engine it cranks rather slowly. but it does start and has never left us stranded. However when the engine is warm it cranks rather quickly and starts quickly. Not a big problem but need to know if anybody else has a similar experience.

To put a finer point on it. When I turn the key the starter goes "clunk", hesitation and then slow crank and start. When engine is hot I turn the key and the engine turns over immediatly and starts

[RoyM]

Are the batteries in good condition? Are the cable connections clean and tight? Any engine will turn a little harder after sitting, the oil is cooler and thicker.

[Robi.1014]

Ross,

I think Roy has gotten it right. Sounds like your starting battery (or battery bank) is failing. When "starting the engine hot", that tells us that the alternator has been recently charging the battery(s). But after sitting unused (even briefly)....oops.

If you have a way to use an analog DC volt-meter, you might be able to observe this condition. When your rig has "sat" for a while, measuring the DC voltage at the battery posts (while "grinding" on the starter) might read 6 or less volts (for a 12V battery or battery-bank). But a recently charged battery will probably read around 8 volts when the starter is cranking. This difference of 2 or 3 volts will explain why your starter sounds sluggish when "cold".

[Mike Thomas]

Better yet, have the battery test with a load tester. That will tell you quicker than anything else, whether you have a battery problem, connection problem or starter issue.

[slickest1]

I agree with the above posters and if all that checks out it will then be the starter.

[Stretch]

Thanks for all the help. I'll check out the cold starting voltage compared to the hot start........

[Mike Canter]

Ross I would take both starting batteries out and get them tested underload. You may or may not get what you want by a voltage reading. Do you have a factory installed dash voltag gauge? If so turn the key on and read the volages on the gauge.

[dieselbeaver]

And if the batteries test ok, have a "starter draw test" performed. Starters can drag on the bushings that support the armature. They are oilite bushings and they can wear and that can let the armature drag. Or the brushes/commutator can wear as well. Normally that are pretty bullet proof, but age takes its toll (on all of us!! :-)

[series60man]

My 06 Exec has the same engine. It has always had a slow sluggish starting motor but since it always fires in less than 2 seconds I have had no reason to check further.

[Mike Canter]

Mine always starts first time so it is hard to tell if it sounds sluggish. Maybe that is just a normal sound for that big motor and starter motor combination. I agree if it takes more than two seconds to start then there is a problem. Maybe I need to go back and stand by the motor and have my wife start it so I can hear what it sounds like.

[Stretch]

Mike Canter and Series 60 man:

Now I am getting the answers I needed. You two have the same engine that I have. As you know it is a big engine. I suspect the the slow crank is normal cause it always starts right away. Just sounds like it may not. We are going up to Seattle this December for Xmas holidays and not being in the cold weather much I just wanted to be sure. I think my Aquahot can preheat the engine anyway. Never tried it though............

[Mike Canter]

If it is below 65* or has been cooler overnight then I always preheat my motor with the AQ before I start it. I wait until I see 90-95* on the engine page. Comes from my racing habits./

[Stretch]

Thanks Mike Thats the answer I have been waiting for. Particularly since I'm heading north in December. BTW My coach averages 6 to 6.5 mpg and uses hardly any oil. Towing a 5500lb toad. how does that square with your coach?

[Mike Canter]

Ross, since we are talking about Detroit Series 60 motor and there is no specific forum for them then let me deviate a little and pass on some lessons learned from a small group of us that have this motor and stay in close contact. Yes, your MPG is right there. My last overall average on a 1200 mile trip was 6.2 mpg while driving at 62 mph. I always have a headwind (lol). At 55 mph on a flat road with no wind in 6th gear you can see 8.0 mpg and it will decrease 0.1 mpg for every 1.0 mph increase.
1. Before starting the motor turn on the ignition key and wait until the CHECK ENG and the STOP lights go out. If that STOP light comes back on after the Detroit starts then shut it down right away. The STOP light monitors about five important functions such as oil pressure, coolant level, coolant temps and a few others. If you are driving down the highway and that STOP light comes on the quickly glance at the gauges while pulling over and shut it down as soon as possible. The CHECK ENG light is not as serious. Only a laptop loaded with special Detroit software can fully check and clear the lights.
2. For climbing steep grades such as 6% and 7% keep the motor at 1750-1800 rpm which it develops peak horsepower. Do not exceed 2000 rpm. Watch that engine temp gauge if it starts climbing over 200* then downshift and match your speed to the 1800 rpm. For most 6%+ grades that 48 mph in 4th gear at 1800 rpm works best for me. If the ambient temps are 100+ and it is steep then maybe 1800 rpm in 3rd gear at 35 mph will have to be used to keep the engine temp down. Don’t be alarmed if the Engine Coolant Temp warning light comes on which will be around 210* it is an early warning that you need to downshift to cool it off. The first time it will scare you to death. That is a heavy MH even with the Detroit motor.
3. Your motor will momentarily exceed 2000 rpm if you hit the Jake brake going down a steep hill. Not to worry.
4. There has been two major recalls for the engine. One is by Detroit and is a free software update to the ECU to stop turbo failures and resultant engine fires. It is important and you need to get the serial number off the motor and call Detroit Engines or go to a Detroit certified engine shop and have it checked. Monaco Tech can also give you your engine serial number if you give them your VIN number. This is a major recall and I have attached the recall notice below.
5. Another important notice (attached below) is on the engine coolant level sensor. These sensors were initially made of plastic and cracked due to heat and leaked coolant. This coolant came through the sensor and wicked down inside the plu and wire until it gets to the engine ECU and shorts it out. The ECU cost $1800 plus towing fees and plus labor. It is easier to pay the $40 for the new brass sensor. To check the sensor is easy. On the right side (curb side) of the black coolant tank (radiator cap attached to it) about one third the distance up the curb side of the tank is the sensor with a wire attached to it. If it is black then it is plastic. If it is brass then you are good to go. I do have a part number somewhere for the brass one. It is easy to change.
6. The Racor primary fuel filter can be another problem. The original one has a white body and is located back of the engine between the engine and the bumper on the driver’s side. You can look right there and see it. The original RACOR one has a 12 volt solenoid to dump water out of the water separation unit on the bottom of the filter. So if you get a Water-In-Fuel warning light the solenoid became active and you can go to that small control box above the filter and push the button to dump the water. The problem is that the solenoid can open up without a warning and suck air into the fuel system and the motor stops. It has happened to me and two other people I know. I was doing 65mph on I-12 in Baton Rouge when a MH full of grandkids when my engine died. Had no power steering. Had to be towed and pay $700 to a diesel service to figure out the problem. This filter unit also has a primer pump for if you run out of fuel or you are changing the fuel filter so you don’t have to pour fuel into the filters. That pump freezes up. Test yours my turning on the ignition switch to the first position so dash lights are on and go back and push the Prime button on the control box above the filter unit. You should hear the pump start running. Regardless I would change this whole unit with a form fit replacement which is a RACOR 700 series part number 790R30 (see attchment). This unit has a replacement control box and plugs to connect into the Monaco harness for the Water-In-Fuel light. Costs $250 but is cheap if you compare it to what it cost me on the road.
7. At 60K miles the Detroit needs a “Tuneup” which adjusts the valves and the injectors.
8. If you boost gauge on the dash doesn’t work then we have an easy free fix.
9. Your Navigator also had a recall on the Aqua Hot system. You can get the serial number off the unit and call Aqua Hot and they will tell you if it was done. It is a free recall and important.

If you have any questions about your Detroit or your motorhome then please feel free to email me at mike.c@mindspring.com. Like I said we have a small group that have these motors in like motorhomes and we all have experienced almost the same problems and have worked them out.