Good morning,
I purchased my MC just this past fall. I know it had sat for sometime and found a few gremlins on our first trip. I had immediately replaced both the starting batteries and the coach batteries. Even with the new batteries and warm weather the motor turned over slow and was a hard start.
Fast forward to winter and trying to start the coach periodically when the temps would jump up (50's) it will not start. I have recently charged up the batteries again and still just barely turns over. So I went bath to the compartment to check connections and the battery cables were HOT, especially the ground.
Does anyone have any pointers? I have am trying to get the coach ready for a spring break trip with the family.
Any help is greatly appreciated!!
Some work involved in this. I'm assuming you know how to safety block your coach, you must do this before crawling under. You will most likely have to raise the coach with an auxiliary air source.
Check all battery connections between battery terminals and starter. They must be tight and clean. Before checking terminals at starter, disconnect battery terminals! Also be sure boost switch is off.
If, after these steps, it doesn't spin over good....you probably need a starter. If it does spin over good but doesn't start, crank up your aquahot, switch on engine heat for a couple hours then try to start engine.
Doing keyword searches on this site for "slow crank, starter, battery terminals, start batteries" etc. will provide details.
A good mobile mechanic might be worth considering.
Issue with slow turning over should be taken care of first, posible starter motor?
Bought my coach 2 years ago. I had same problem with hard start, however none with speed of starter. Spent way too much money with shop diag, over $1,000. First shop replaced lift pump, and solenoid shutoff. Then shop recommended, incorrectly, replacing injection pump. Lucky, I chose to take it off and send it to a known pump shop by me in Portland. They said it was fine.
Then I checked this forum. Found issues with old *fuel lines. Found cracks in lines (air leaks), replaced, issue solved.
Cracks were small, but could be seen near fuel filters, also found fuel smell, fuel dampness, in center conduit in basement bays, and found dampness at curves in hose over fuel tank.
It might well be starved for fuel. Then check fuel lines. But you say slow turn over. Start with the basics, batteries and cables. Assuming connections at the batteries are good and all the way to the starter then hot cables, connectors or batteries mean a lot of load is getting pulled through them. It is possible that you have a bad battery. They need to be fully charged, sit for a day with no connections and tested with a carbon pile load tester. If any are bad the best plan is to replace all of them. O'Reilly's has great group 31 batteries for about $225 each https://www.oreillyauto.com/detail/b/fleet---heavy-duty-5000/battery-accessories-16452/battery---automotive-16864/battery---best-fit-16245/ec27e4e51018/super-start-fleet-heavy-duty-group-size-31-battery/agm31t/4742641?q=31+agm+battery&pos=0
If they are OK then the starter might be bad or going bad. A new gear reduction starter turns the engine over a bit slower but with more power (torque) from the starter will less battery load. I replace mine last summer. Found a genuine, brand new Delco starter on Ebay shipped for about $300. Genuine Heavy Truck Delco Remy 8200308 Starter 39MT 12V 11T CW See... Delco Remy 39mt Starter 8200308 CW 12v for sale online | eBay (https://www.ebay.com/p/25017005023?iid=303033954279)
Totally concur with above trouble shooting ideas. Loose and corroded starter and battery cables are not uncommon. See the thread linked below for a few examples, along with the now famous photo of the John Morales fireworks show.
It Took Me Two Months to Tighten a Nut! (https://www.foreforums.com/index.php?topic=36124)
One thing to consider is what you said about temperature. When temperatures jump up to the 50's, says a lot. The engine block and oil will still be cold. My engine is slower to turn over when it is cold. I run the Aquahot pump for a few hours before I am going to start in cool/cold weather. I find the starting much faster and easier. I check the engine temp gauge for the temps to hit around 70 and it fires right up. It is worth a try.
Glen
So the heated cable ground or hot is a indication of hi draw, resistance, undersized cables. The 450ISM will draw a lot of power and if you have charged 990 CCA batteries they are maxed out. If there state of charge is low they won't be enough. I would be choosing three good start batteries preferably group 31. A diesel starts by rotational speed and after 5 seconds it will be at near max speed. Has to have fuel to start, already covered
Scott
As others have said, make sure your cables are shiney clean along with the battery terminals. If some of your terminals are hot after trying to crank it could indicate a poor connection. To check that use volt meter, check between the terminal and wire under a load ( starting) the voltage you read is the loss at that connection. For a better explanation goggle check voltage drop. Be sore and check the ground connection as well.
Thank you everyone!
I have recently purchased the aqua hot filter and nozzle so I can preheat the motor in the future. I did have this problem when the weather was good last fall.
I will follow the cables to the starter and check connections today. I currently have all batteries disconnected and will be charging the third today. I had not thought about the starter yet but that has been I problem for me on another vehicle. I have had diesel odor in the mid bay and my generator will not stay running so it looks like I better start inspecting fuel lines too.
I do know a place that rebuilds starters so I might consider taking it to them. Any thoughts on that?
I would first check out your cables. Even with a bad starter they shouldn't get hot. What does your voltage drop to while starting it at the batteries. If the drop is less than at your dash gauge, it's the cables. Running your generator with the boost switch on will help if
your batteries are weak but with hot cables I don't think your batteries are the problem. I have no problem starting my engine when
its freezing.
This is what your battery connections should look like. Use a file to flatten both sides. I replaced all the washers and nuts with stainless.
When you say your ground cable is hot, is that at the battery or the whole cable? If it's the entire cable, your starter may have gone south. If it's hot just at the battery lugs, then cleaning may do the trick.
With a good starter, batteries, and clean terminals, your engine should spin like a top hot or cold.
Pierce
"Rebuilt" is only as good as the shop/tech that does the work, and the parts they use in the rebuild process.
In some cases, "rebuilt" is as good as new.
Manufacturer rebuilt air dryers, for instance, provide excellent service on our coaches.
In other cases, buying a new item is preferable because you receive the benefit of improved design or technology.
If it was me, and I was going to do the (sweaty & dirty) job of swapping out my starter, I would buy the new one suggested by Roger (above).
But that's just me.
It's your coach, and your decision. DWMYH
The new starters like Roger posted are gear reduction with much more torque. I had the hard start, but would start, issue until I put one in before the Q. Now it starts quickly.
Just a note here, check the cabling and connections first including the tie cables from battery to battery. Mine looked good but I had to make 2 new cables due to voltage drop.
Craneman, which starter did you use and why?
How long did you attempt to start?
Fuel smell in bay is screaming leak of fuel out or air leaking in.
Gear reduction starters are definitely preferred.
Diesel engine rotational speed represents starting or just turning over the engine. Read somewhere that if stuck and unable to start one can close off the air intake to produce a vacuum in the intake to reduce engine starter load and increase rotational speed then uncover to get that one faster stroke to fire. Sounds interesting, who knows
Scott
Delco 39MT 8200308
When I determined my 3 start batteries were putting out more than enough amps to start by themselves and I was having to use the boost switch to not have to grind away at the starter, I bought the gear reduction newer technology starter. Solved the problem. The old starter is much heavier and designed different. I use the same technology on the race car.
What did you do to your coach today IX (https://www.foreforums.com/index.php?topic=38604.msg376763#msg376763)
I had the same problem with my coach. It had two red top batteries less than a year old, but I was having to use the boost switch because the voltage was dropping to 9-10 volts and lugging with out the boost. I added another red top battery to the bank and kept the original leads as is but added another new battery cable straight to the starter and another new cable to the ground (frame). Ever since I have done this set up on my coach it winds up fast and starts fast, no lugging. I am sure there is corrosion on some of the old cable connections and I will have to deal with that in the future. I hope this helps
Just my two cents
Ron
If your Aqua Hot id mid bay it might be responsible for the odor. I had that issue with a weeping diesel fitting and it caused a faint smell of diesel.
jor
So let me add my similar experience. September 2019 I have a 1999 40ft U320 M11 initial 1st and/or 2nd crank turns slow then pops around faster on 3rd rotation and fires up. MOT stated that is nature of the beast...common problem for 20 years due to high compression motor...? I respectfully requested some further diagnosis. I was informed staring batteries load test great and all connections are clean & tight. I was instructed to always use the boost switch to assist with .starting. 3 1/2 weeks later no start. Fast forward to a small area shop that agreed to assist me. Batteries did again show no issues under load test and this shop also stated to me all cables and connections look great shape. No Selinoid issue but starter appears very tired. I had a new starter installed. However, the mechanic had informed me that the initial draw on starting was in excess of 600 amps and he thought that to be excessive but that would take considerable time/money to figure out why it is such a high draw? I am not sure if my issue is truly a deep underlying problem or nature of the beast. I have religiously turned on boost switch and utilized my AH preheat or bed base switch for engine block heater and have successfully weathered the Wisconsin winter so far moving place to place every 2-3 weeks in some extreme cold temps but without using the boost switch and other engine warming aids the cranking is still the same on 1st & 2nd rotation. Note boost is used regardless of temp. After reading FarrarkC description I can't help but wonder is this a common issue with the 99/2000 U320 or am I/we heading for a future no start issues again??? Have others experienced this same starting issue on similar coaches?
TRy using jumper cables to add to the ground cabling. Maybe run the cables from the battery pos also to the starter.
When in doubt ,add ground cables.
ALL diesels are high compression. With the proper starter in good condition, the engine should turn over rapidly even if cold.b You should NEVER have to use the boost switch unless you have a problem somewhere in the starting system.
We have owned our coach for eleven years and never used the boost switch with the exception of the time I melted the start battery terminal because of poor maintenance right after we purchased it.
Our turbo 7.3 Ford/IH and our 300SD have higher compression ratios than your Cummins and never have to utilize a boost switch. The need for the use of a boost switch indicates a problem somewhere in your main starting system.
Cummins has a CCA requirement specification for all their engines. If your battery system meets or exceeds these specifications and you have the proper starter plus the manufacture installed the correct gauge cables for the length of the run when the coach was built, you won't have any problem starting W/O boost.
Ours spins like a top from the instant I hit the starter button. I know Craneman replaced his starter and has no trouble starting his engine.
Pierce
If the mechanics that checked out your starting system are correct, then the cables should be OK.
You don't say what size and number of starting batteries on your coach. What do you have?
What is the total (combined) CCA rating of your start battery bank? Chart below (copied from M11 Service Manual) says you need a
minimum of 1800 CCA at zero degrees (F). Does your battery bank satisfy this requirement? A little extra capacity never hurts.
If your batteries are up to snuff, and the cables are clean and tight, then that leaves a "weak starter" as the prime suspect.
Roger (Reply #3 above) has a similar size engine. He says a new gear reduction starter made a positive difference on his coach.
Craneman (Reply #16 above) also recommends the gear reduction starter. Something you might consider?
"Diagnosing" cables is easy. Voltmeter-- one probe at battery, the other at starter or for the negative on chassis ground.
Have someone engage the starter. See how many volts (or hopefully fractions of a volt) drop there is across the cables.
Wouldn't a dragging starter show the same excessive voltage drop?
I seem to remember that a m11 engines fuel system won't send fuel until the oil pressure comes up somewhat. That or it's driven by oil pressure. Something like that. So it takes a few turns to start.
I replaced everything and put a geared starter motor and it starts the same. Valves adjusted.
I will look at the shop manual again and see if I can find the section that talked about this
Only to a small degree. Excessive starter draw would bring down the battery as well. Yes, a little more voltage loss through the cable, but excessive starter draw would show as low voltage at the battery.
Yes, hard to separate bad batteries from excessive draw without doing a load test on the batteries.
Yes, it might be a LITTLE more voltage drop in the cable.
But excessive starter draw would also lower voltage at the battery-- far more than the drop between cable ends.
Yes, more difficult to diagnose excessive starter draw from bad batteries, as both will show low voltage at the batteries. That is where load testing them becomes a good diagnostic tool, as is checking SG if wet cell batteries.
On my M11 there is a short ground cable from the starter negative to the engine. Cleaning it improved starting quite a bit. It is in a particularly dirty place and not readily seen.
M11 should be an instant start. Faulty oil pressure sensor should only keep the engine from going above idle but not effecting starting time. ECU will trigger auto shutdown after 30 seconds. Delayed starting is usually because of loss of pressure in the system.
See these videos. Terry takes his time getting to the point but good information:
https://www.youtube.com/watch?v=oCxojfhkYBk
https://www.youtube.com/watch?v=HkUj8-2wZws
Pierce
Starter would be my first choice
May be, but diagnosing by "parts replacement" can get really expensive. Much less expensive to diagnose the root cause.
Thank you everyone for taking the time to chime in. Being I had the problem from day one and due to the age of the coach, I have taken Roger's suggestion and have ordered the new Delco 39MT 8200308 starter. I will keep everyone posted!
Again how long were you cranking when you found your hot cable. Heat is a direct indication of excessive load/resistance. Put your volt meter in parallel to your cable. Should read zero. Crank engine, should still read zero. If it shows voltage you have corrosion, undersized cables, excessive load, internal resistance. Costs nothing to do. Clean cables. Check voltage across all connections. Should be zero. Cable size should be correct. Verify battery state of charge is above 12.8 volts. If voltage drops excess battery's could be weak. Weak battery will reduce engine start rotation speed. If cranking slow will draw lots of power without reaching starting speed. All good? suspect excessive starter load, change starter. Great batteries will hide failing starter. Oh yes air if fuel will not reach higher needed fuel pressures and will start poorly or not at all. Cables may get hot if start cranking time is exceeded. Will also damage starters. Follow recommendations for starter crank limits and cool down times. Hope I don't sound too matter of fact, it's just what I would do to troubleshoot issue. If your cranking and cranking stop and resolve your problem. I've always preferred the gear reduction replacement starters. Less power draw and I believe faster rotational speed. IMO
Scott
When I first got my coach I phone Cummins and asked why the M11 turned over a few times before it started not like my old
8.3 which started immediately. They told me that the computer had to read the RPMs before the computer would give the engine
any fuel. I believe he said that the computer wanted to see the engine turning over at a certain RPM
That's interesting. I've had two M11s both of which did exactly that. My current coach has the 8.3 which, like yours, starts immediately.
jor
The geared Delco turns over my m11 at roughly the same speed as the original starter. Meaning my original was not bad I would think. Only way to know is to switch it out it seems after checking cabling and batteries of course.
My geared starter always starts with no boost now, but with the gear reduction I can't compare the speed as the sound isn't the same as the old starter. Same batteries and cabling so my old starter was the problem.
No one warned me about what a pain in the rear it would be to take out the starter!!! Here are a few pictures. I obviously have have/had a power draw at the starter. Should I now replace the entire power cable or can I replace the eyelet? Trying to trace everything is a total pain!!
I did not have the extension, with me, I needed to remove the 3rd bolt today so I hope to have the old starter out tomorrow. I do believe this is the original starter and I believe the installer used an impact and cross threaded one of the bolts!! I had to use a cheater bar to get the thing out!!
Any tips are greatly appreciated!
When working with recalcitrant bolts it doesn't hurt anything to try and work some penetrating oil into the threads as you go along.
You can replace the cable ends if you want to spend the money on the crimping tool for that size cable.
Assuming you are able to cut away the insulation and are able to get to clean shiny copper, not copper oxide.
Check the other end as well.
But, smart $$ is to replace it.
Check ground cable as well.
You have invested time and money in a new starter. Reusing old cables that are probably worn our or damaged is not a good idea. Alan at Bay Marine Supply will make any size tinned marine grade cable with any lugs you need for a fair price and send them to you pretty quickly. Buying a crimper, lugs and cable to do it yourself works if you are making a lot of cables. Otherwise check with a farm tractor (John Deer or like that) dealer. They almost always can make cables to order. Never cheap.
I've always used large welding cables to replace OEM cables that were damaged or too small for the job. Welding cables are more flexible as they need to move with the welding application. They do have many times the copper strands that automotive cables do and may need to be supported if traveling long distances where they hang down. Good practice is to make up an extra ground cable from the battery to the closest frame member. Not a bad idea to make another from the frame to the engine or transmission to insure a good electrical path. Poor grounds are responsible for more than dim headlights.
Copper lugs may be crimped on or soldered. While we have a crimping tool at the shop (hammer type), I usually solder (electrical solder) them on at home with either a propane/mapp gas torch or with welding torch. If you slide shrink tubing down the cable first, you can slide it back over the new lug, heat it and a moisture proof seal is made. Shrink tubing comes in different colors so you can buy red for the positive. Either way works quickly and securely.
When I turn the key, our engine instantly spins like a top. I remember a factory Gates tensioner video where they went to start the big diesel after installing the new tensioner. It slowly hesitated before bringing the starter revs up to speed. No adequate starting system should do this.
Anyone remember the aluminum cables GM used on a couple of years on Corvettes? What a terrible idea.
Pierce
Looks as though your cable end was the problem. Starter bin on awhile also. You have the new starter and a good match would be new cables. Your local welding shop may actually be able to crimp properly. Shrink tubing with the inside glue has been a favorite of mine for years and you can get red or black. Keeps the air, moisture, corrosion under control. I do solder some but a strain relief need to be installed to prevent breakage were soldered.
Scott
I would recommend using marine cabling. UL1427. Welding may or may not have a pvc compound cover on it. Battery cabling uses rubber.
Why the difference? Rubber melts off and leaves bare metal.
PVC turns to ash and stays on the wire preventing shorting to adjoining cables.
All boats are required to use UL 1427 cabling as far as I am aware.
Just safety,...
The starter is out! The top bolt ended up being the easiest. I am confident in saying this is the original starter and it seems the installer used an impact with little regard to not cross threading one of the lower bolts!!
I also was able to remove the positive cable. I do think it a welding type cable. It has a mid cable eyelet, should I keep that design or can two cables be used? I will need new terminal connectors (lugs) being both positive and negative bolts sheered when I tried to remove them.
As far as the new starter, is there something I am overlooking when it comes to the end connection inlet? The old starter does not have this and I am not sure if it should be sealed and ignored or if there is something else I need to add.
As always, your time and knowledge is appreciated!
Tom
Change all of the cables. Clean those mulit point connections .
So you have/will come across the same problem with your coach in regards to corrosion. You will need to learn how to remove corroded fasteners. Brute force will always break fasteners. Open end wrenches are not to be used till it's loose. Good tools are a must. Learn to slow down and size sockets to fit tight. This means that they may reduce in size corroding. Metric can be used. Okay to tap sockets on with hammer. Six point sockets on six point fasteners. Valve grinding compounds will help lock tool and part together to prevent slipping. Get your propane torch (and using safeguards) heat fasteners and cool with Aero-Kroil or mouse milk. They are both expensive but well worth it. IMO.Reattempt removal and repeat heat cool cycles till it releases. A variety of impact tools will greatly assist. Cordless 1/2 impacters IMO are difficult to regulate. 1/2 air is more user friendly. Pre soak days before with either. The mouse milk is my preferred fluid. Splitting nuts will also sometimes be required. Sometimes attempting to tighten the fastener helps. Also since you live in a very humid area using anti-seize is a must. Get in the habit using on everything in the elements. Striking the head of the fastener with hammer and or punch helps wake it up. Any one thing may work but may require all the above in multiple cycles till it comes loose or fails. Clean removed threads with tap and die set, wirewheel. All good fun. Well maybe not.
Scott
Read the instructions that came with that starter to locate where the cables are attached. If you don't have them PM me and I will get mine out of the coach and read it to you.
Have you cut off the ends and pealed backed the insulation on your cable. If the wire is nice and shiny it's OK to reuse it. Someone
mention using marine cable and one of the advantages the marine cable is usually tinned and that stops the corrosion. As dsd said
anti or never seize is a must.
After reading this thread, I got to thinking that my starter was pretty anemic, and I usually use the boost switch to give a little more juice. So I cleaned and sanded down all the battery terminals until I had nice clean cooper and then went to the other end and took the terminals off the starter to clean them and noticed that the positive stud on the starter was really lose and would wiggle side to side easily. Tightened up the nut on the stud and then cleaned and reinstalled wire onto positive starter stud and tightened down the nut that holds the terminal and then went back to the battery and reinstalled all the battery terminals. Tested it out and now it spins like a top without boost switch. So make sure to check the positive stud on starter is tight, and if not tighten the nut that holds the stud tight. Thanks to everyone in the forum.
That's why the boost switch is such a crutch, masking problems in the primary starting system. Big rigs don't have a second set of batteries.
Pierce
But we do, so why not use it?
I've got reasonably new starting batteries and my system works fine on them alone, but I figure it's less strain on them if I include the house batteries when cranking. Every tenth time I don't use the boost switch, just for reassurance.
I don't think there is any strain on the starting batteries whether you use the boost switch or not. I never do and the last batteries lasted over 10 years with one having low voltage. Car batteries last the same with no backup. Why do you think it strains them? That's their job. I have three 31 series start batteries that are 1000 CCA more than I need. If I used the boost switch and added the 6 house batteries, the start batteries would not last a day longer in my opinion.
If the boost switch had not been used in the case above, the starter problem would have been found a lot earlier. Imagine the starter totally failing in a remote winter location and when the boost switch was used, it still would not start.
When the CCA matches the engine requirement, any problems starting require a repair, not covering it up by jamming more CCA at it. If I used the boost switch, I would have never found that one of my start batteries was low on voltage.
Pierce
We hooked up our blue sea auto combiner auto disconnect for the banks when the engine start relay is energized.
Other wise, as posted, always connecting the banks can mask battery problems
Thanks guys.
I see both sides of this "use/don't use the boost switch for starting the engine":
Don't use it because it will mask issues with starting batteries and/or battery cables and connections.
Do use it to provide more amps/less voltage drop to the starter.
So, let me offer a "compromise":
Use boost switch for most starts.
Once a month/every 10 starts or so, start without boost switch to prove all is working as it should.
I'll keep doing it that way Brett.
Update>>>
The coach is purring like a kitten again! Today I finalized the connection points to the battery bank and torqued all of the bolts to spec. With fingers crossed I went up front and turned the key. With 3 cranks of the motor she took off like she is supposed to!!
I did get nervous because after running just a few minutes the motor died. Being cautious not to turn it over to much, I made a few attempts to restart the coach and it failed. Knowing it was likely a fuel issue I opened the back and stared at the motor and then decided to try one more time to start her. SUCCESS, I guess my stare down worked!!
Thank you to all that took the time to read my hassle and to those that lent a helping hand!! Time to chase another gremlin!!
Can you summarize the solution? s.
Simple!
I followed the above recommendations and ordered a new starter and then I ordered new positive 4/0 battery cables. Both replacements went pretty seamless. I did find one of the starter bolts were cross threaded which made it difficult to remove. I then tapped out the threads and sent to cummins and bought a new bolt for that hole. I also changed the positive and negative power posts.
Approximate cost $430