I would like to know this answer too. I have a 300D, mine wont even start unless i hit the glow plugs first, you have to use the glow plugs even when its warm.
Diesels are compression engines, compress the air enough to raise the temperature high enough to ignite the atomized fuel. When its 30 degrees outside it will take a lot more to raise the temp of the air to ignite the fuel, hence the glow plugs. My truck has a grid, air flows over heated grid warming the air before it enters the cylinder, easier cold weather starting. Now, on the opposite end, when it 70 degrees out it will take less to heat this air to ignite the fuel. Again, my truck when its 30 outside the light stays on for 15-20 seconds or better. When its 60-70-80 it is barely on 5 seconds or usually less.
In my opinion your just peeing in the wind using them 60 and above, maybe 50. Get down below 50's and then I'd use them. For me in winter, gets down in the 40's and I start plugging the truck up...but that's just me.
If it is a pre chamber engine [probably is if it has glow plugs] it may need them even if it isn't cold out, or a cold engine. It all depends on how fast the engine cranks. As Shawn points out, the engine uses the heat of compression to ignite the fuel. An engine that cranks at a higher RPM raises the air temperature more than one that cranks slower due to the lesser time for ther air to transfer heat to the combustion chamber and greater time for air to leak away lowering compression pressure.
Pre chamber/glow plug engines that I have worked on spray the fuel right on the glow plug. These usually light off readily if the plugs are hot.
The Peugeot Indenor engine in My boat cranks slowly, and won't start without the glow plugs, but starts right up even in cold weather with them.
If Your engine lights right off without the glow plugs, You are OK not using them, but if it cranks several revolutions before firing, use the glow plugs.
I can say from years of experiance with deisel engines, that they all will have a personality of their own. If it starts without glow plugs, fine. If you need to heat them up a little, that's fine too. Overuse of glow plugs can cause them to fail, sometimes with the tip falling off and leading to mechanical damage. Think of the glow plug switch like an eher button and only use them when needed.
Diesel engines are compression ignition and they depned on the heat from the compression stroke to fire the fuel. The glow plugs warm the chamber to aid in combustion.
My boat engine had a Bosch glow plug controller when it was new. At some point, about 2K hours it failed. I don't know if it happened at the same time or not, but one of the glow plugs arced out through the side of it's casing. The debris from this pretty well trashed that cylinder liner & rings. I put another 8K hours on it, runs pretty well on 3 1/2 cylinders, but it has a lot of blowby...
Thanks for the replies... I have heard of glow plugs burning out and bad things happening so I didn't want to over use them..
So lets say its below 40 outside and you attempt to start it without glow plugs... Does that hurt the engine in any way..
I remember starting some old Detroit diesels that ran big conveyor belts at a Mine that I used to worked at when it was -15 -20.. If the fuel was not jelled up they would start.. We would have to hook a welder up to the battery half the time to keep them cranking long enough to start and one of them had a compression release that we would pull and that would help sometimes..
What I'm worried about or wondering is if these newer diesels have something I'm not aware of ( Electronic or otherwise ) that I could hurt by not using the glow plugs..
If I'm not hurting anything than I'm laying off that sucker till it gets cold..!! She fires up just fine without them so far..
Thanks
RC
As long as it lights right off, You won't hurt anything. Long cranking just puts more wear on the starter.
If you hit the start button and it doesn't start right away, hit the glow plugs. Each engine will have it's own personality, and you will get to know when you need them and when you don't. My Vantage 300 Kubotas like about two seconds on the glow plugs for the first start of the day, even in the summer. About five seconds will start them at zero.
If it starts right of it wont hurt it. Colder weather and warming the glow plugs will be better for sure. You start it up for the first time when its 30 outside and your gonna swear the engine is gonna come apart with all the noise it will make!
The guy talking about having to use glow plugs from 20-120 no matter what, sounds like a compression issue to me, worn rings, valve seats, just dont seem right a diesel needing glow plugs in 80 degree weather or 90's. Last diesel I worked on that started like that was flat wore out and ended up sleeving the block, new pistons, rings and the whole 9 yards.
I have had a Vantage 300,400 and now a 500. I have never used the glow plugs unless it was 40 degrees or below. I have never had a problem
Mine has to start the first time of the day with glow plugs no matter -40 to +118 but after that it usually fires right up
+118!!!...gasp, who even thinks of working at that temp. ho-leee!
hey johnny, how is that vantage 400??? are you happy with it????? i'm thinking bout getting one myself.... thanks
Dwayne,
Just able to take them out of the freeking blue machine this week, and hoping it works out.
But such is life, wife and the granddaughters love it here.
Hope this helps
Thank you for your time and consideration
Sincerely,
Kent
Heck I thought all you would have to do is point at it and snap your fingers to start it, after all, it is a Vantage.
Just funnin ya!
jrw159
No I didn't like the snap option...!! I got the clap ON clap OFF switch.. lol..!! If I had an I-phone I would get the phone remote app... It lets you start and stop your Vantage but they are still working on the Vantage turn things to gold app.. LOL
RC
LMAO!
jrw159
i have a 300 d with a kabota. i have never had to use that button on it nomater what the temp.
After years and years of just bumping the starter of my 71 SA200 (gas engine), I had to learn to keep the starter on a little bit longer to start my Kabota powered Pipe Pro. If I just released the start key the instance I heard ignition, it would die. At first I thought I needed to use the glow plug on even moderate days. But just keeping the start on long enough to help the engine spool up to idle speed seemed to solve my problem.
Look for the low oil pressure switch and check it too plus other connections. Those low pressure switches get off some and it won't start at all or have to really spin it over to get pressure up higher before it starts. Can bypass with a jumper wire to test and find out.
