| Author |
Message |
Doug Dickinson (Dougd470)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, October 28, 2005 - 9:39 am: | |
Something has me wondering. I have a 83 MC9 with a DD 6V92T in it. When I start the bus in cooler weather - like around 50 degrees and below, I have to crank it - let it "soak" for a minute or so, and it usually catches immediately on the 2nd go-around. When it is below 40, it may take two pre-start cranks followed by a minute to soak and then she will go. With Ether, it just starts. I am not a fan of ether starts - not the best starting idea for normal use.
Now, I get NO smoke from the exhaust unless a cylinder or two hasn't caught when she started (usually for a few seconds and then they are running fine). When I do the crank and soak routine, I get a little blast of smoke that clears up in maybe 15 seconds (overfueling burn-off).
Oil pressure is good when cold and so-so when engine at full temp. I have the right oil in it.
I crank the coach about once a month. It sits in the garage the rest of the time.
Not being an old hand with diesels, does this sound like a "get ready" sign or does this sound about normal. In reading here, I hear about folks that "cranks right up in 30 degree weather" but that is just not what my coach is doing.
It runs great - solid and no misses ever - runs the coach at the requisite 70MPH mark and runs right at the limit temp wise (around 200 degrees indicated) in the summer only - winter it is around 180 degrees. I only drove it long distances trwice - the rest of the time is around town and the interstate to exercize the coach.
Thoughts? Things I should look for? |
Eagle 10
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, October 28, 2005 - 10:37 am: | |
Put in a 110 electric block heater and it will start in any weather without the cranking. Mine does the same thing without the heater on. With the heater on, it starts on the first turn. |
Buswarrior (Buswarrior)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, October 28, 2005 - 11:45 am: | |
Hello Doug.
I doubt you have any real problem here, just something irritating, as long as the coach does start, of course!
What is the interval between your attempts to start the engine cold?
How does it do the morning after a long drive, vs the longer time/more starts without a long drive?
Do you have a fuel pressure gauge to confirm you have fuel available close to the beginning of cranking?
Cranking speed of the starter? One of those handheld tachs are great for trouble shooting lazy starters.
My coach definitely runs better the day after a proper drive, as opposed to the repetitive start and move around the yard routine.
happy coaching!
buswarrior |
Craig (Ceieio)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, October 28, 2005 - 12:01 pm: | |
Doug - mv DD8V71 has 14,000 on a full out of frame. It might do marginally better than yours in the 50 plus weather, about the same as yours in the mid to upper 40's but in the low 40's and on down I don't even try. I flip on the Wabasto and heat the beastie up before I try. The downside is I don't get the few seconds of cold Detriot rolling idle when I fire it up off the Wabasto. :-) I don't think you have any reason to be concerned about the condition of your engine based upon the starting habits you describe here.
I have an electric block heater in mine as well and if it is going to be below freezing for a while I will plug it in. Otherwise, the Wabasto has it ready to go in fairly short order.
Craig - MC7 Oregon |
Richard Bowyer (Drivingmisslazy)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, October 28, 2005 - 4:06 pm: | |
Doug, there have been lots of posts regarding starting a DD and letting it sit and idle for a period of time and then turning it off. The consensus of opinion is that it it really better to put the batteries on a trickle charger and let the beast sit for a few months, rather than the start and idle once a month scenario.
Richard |
david anderson (Davidanderson)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, October 28, 2005 - 4:14 pm: | |
Doug,
My 6v92 does about the same as yours, so I use the Webasto for preheat the same as Craig described above. You say you crank it once a month. Do you take it out and drive it to get it to normal temps? or just idling? Every DD seminar I've been to says not to run it unless you can get everything up to proper temps. They recommend this for engines that will sit for less than 12 months. In other words just let it sit unless you will take it out and run it hard. If anyone has a different take on that, let us know.
David |
Dale L. Waller (Happycampersrus)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, October 28, 2005 - 4:46 pm: | |
Doug, Your engine is fine. Just about every operating manual I have read says that starting at air temps around 40 require a starting aid. Those are a block heater, oil heater, starting fluid, webasto etc.
The starting fluid is a last resort!!!
Your starter and related parts will last longer with a block heater.
Some of our low hour diesel equipment (bought new) is hard to start at lower temps.
My 6v92 has a 1500 watt block heater from NAPA and takes about 2 to 3 hours to heat the block to start it in freezing temps.
As for starting and idling once a month that is a bad idea. As David and Richard said you are NOT getting the engine hot enough at idle, That also will cause the engine to load up on unburnt fuel. If you HAVE to idle it you should run a block heater and fast idle the engine. |
Doug Dickinson (Dougd470)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, October 31, 2005 - 12:34 pm: | |
Thanks to all for the responses. I was beginning to wonder abotu some of the claims of "starts right up in freezing temps" or something like that. I don't have a lot of time with DD in winter temps (a little marine time though). Good to know mine is acting normally.
As for winter startups and bringing it to temp - I drive it a while - usually an hour or so including local and highway driving, so I don't idle it very long. I start it in the barn with a pre-air so I just crawl out of the garage at idle and let it run for a couple of minutes in the lot before moving, and then give it a workout with a cool-down before parking it. I do that about monthly or so.
Doug
St Louis MC9 |
busboy
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, October 31, 2005 - 7:56 pm: | |
A DD mechanic told me newer normally-aspirated DDs run 18.7:1 compression ratio but turbocharged and older normally-aspirated DDs run 17:1. The higher compression ratio makes more heat which burns the fuel better and makes cold starts easier. Turbo'd DDs run the same operating pressure as non-turbo'd because the blower boosts the pressure, but that doesn't help you at start when the turbo is not spinning.
So among other things "starts right up cold" will depend on the compression ratio. |