Cold starts and glow plugs

[jnjpream]

It's stinking cold here right now.. About -10 or so. I picked up my BX22 from the dealer after some minor repairs (that didn't work.. thread soon to come) and when I got it home I had a tough time getting it started..

Here's the setup: The ignition has got 4 positions. Off, Run, Glow, and Start (in that order). You have to hold it in glow to get the plugs to warm up, if you release the switch it will go to run. If you turn beyond glow, the plugs shut off and the starter starts cranking.

I tried several times holding the glows for ~20 seconds, then cranked until it fired. As soon as I released the switch it would die. The way I finally got it started was to warm for ~20 seconds, crank until it fired, then released the switch just to the glow position until the engine got going for a bit, then released it to the run position.

My question/concern is: Am I going to do damage to the engine or plugs by holding the glow plugs on while the engine is starting/running?

 

[PILOON]

I had wired my GMC 6.2 liter to be manual glow plugs (plug relay was very$$) and I often held plugs while starting (not very long) so it can stand a bit of over run I guess, but not very much as the plug is basically a filament (little wire coil) and at some point it will want to melt.

But then I thought the switch should read: glow-off-run-start as on my Mitsu and my buddies B7100!
What does your owners manual state as to positions?

I know that on my Mitsu I often heat, start-stop, reheat start-stop and occasionally 3-4 times until she kinda shakes to life (but that's when temps are way down below 0.)

Matter of fact I am tempted to add a manual glow over-ride switch like I had on the old chevy 6.2L

Your question:
Worst would be to burn out glow plug/s, starter if you prolong starting.

Install a block heater if you don't have one. Much easier starting!

 

[jnjpream]

The manual says glow for 5-10 seconds, crank/start, and release. No mention of holding the glow on while it shakes, coughs, and sputters.

Don't think it would have started if I hadn't held the glow on. So I guess I really didn't have much choice anyway.. I'll just be sure not to do it too long.

 

[DANOCHEESE]

I would look at holding the glow plugs on for about 60 seconds in -10. The issues you may have will be the battery. Aslo you may want to look at a block heater to aid in starting. A diesel likes warm combustion chambers.

I have a 2001 7.3 ford diesel and I let the glow plugs run for about 2 miniutes when it is cold soaked and it will fire un-aided.

 

[dirtworksequip]

I see no harm in glowing until the engine smoothes out. Several different manufacturers state to glow after starting until it runs smooth. Everyone is correct about getting a block heater installed. Your engine will thank you and you won't be as agrivated.

Sincerely, Dirt

 

[amashinga]

The duration that you can operate the glow plugs depends entirely on the make and model. Some marine glow plugs are almost impossible to burn out whereas some light truck glow plugs can burn out pretty much anywhere after 15-20 seconds.

One thing you want to avoid is when glow plugs burn out, sometimes they expand and curl. When you try to remove them, they can break off, leaving a tip floating around in the precombustion chamber just waiting to drop through. There is a classic thread on the ford 6.9 forums where the proverbial buddy advises someone that the tip is just carbon, and he can just "drive through it". The result was a pile of aluminum scrap mixed with oil and water. Yup, the cylinder wall was cracked by the rod

Anyway, back on topic, cold weather is a triple whammy for diesels, especially older diesels. The battery is not nearly as efficient, in fact it can be below 50%. The engine is not cranking as fast, the compression is not quite as high especially in older engines, the oil is thicker, the temperature of the steel is colder and it takes that much longer for the temperature in the combustion chamber to reach flashpoint.

The best solution is prevention. Block heaters have been mentioned, you can buy wrap around and stick on pad heaters for a sump and battery, park indoors. I have seen a home made sock that covered the front of the tractor and hung down to the ground with a heat source, probably a heat lamp inside.

Something that I do which works well is I keep my truck close to the tractor, and when I start it I attach booster cables. Three batteries turn the starter that much faster and make a big difference to the starting time.

Sorry about the rambling response

 

[smfcpacfp]

If you have below zero temperatures on a regular basis, you should have a block heater. I started mine the other day at about 28 degrees without using the block heater and it did start noticeably harder. It actually cranked a while before starting and ran rougher for a a few seconds.

Normally I plug it in for a half hour when it is at the freezing point and as the temperature gets lower, I plug it in longer, though normally for not more than 2 hours. It stars right up and runs smoothly right away.

This is not a substitution for letting the machine warm up before putting it under stress however.

 

[RalphVa]

Can you "trick" your Kubota like we have to do our 4000 series JDs? On these JDs (think it's also the older 2000 series), there IS a glow plug spot between "run" and "start", but there's no glow light on the dash board to tell when one's ignition switch is in that position. So, what we do is to either put the range selector in "H" or "L" or put the PTO on, then turn the key all the way to "start" and hold it there for a count. Then move the range selector to "N" or turn PTO off.

In cold weather, my JD starts instantly (about 1/2 turn of the crankshaft) after 4 to 6 seconds of glow. Even my 25 year old Benz (with probably near the same type of "newer" pencil glow plugs) will start instantly after glowing about 6 seconds in the coldest of weather.

HOWEVER, on both of these, we have to open the throttle up about 1/2 way. Otherwise, it'll probably start and die or start, shudder and die.

I once started my 1973 Benz with really old type glow plugs in -22 F weather. Had to glow it for 2 minutes with a heater hose heater in place. Started instantly though.

Ralph

 

[jnjpream]

Hi Ralph.

No Need to trick it. The glow position is between run and start on the BX22 and has a light to show you when it's warming.

Most of the time the tractor is in the garage and usually doesn't get below freezing. But on occasion, such as bringing it home from the shop, there is a need to start it in cold weather. And other times there may not be 110v handy to run the heater.

But it sounds like warming the plugs isn't too bad of a thing so long as I don't over do it.

Thanks.