Glow Plugs ... "Do they get WeaK"?

[tmajor]

Since I got my M/F 1529, last fall, it has always seemed to cold start kind of dirty to me. I recently pulled the glow plugs and checked them for visual performance. They did have some carbon deposits, which led me to believe, that they weren't getting hot enough in 15 seconds. They all measured about the same resistance and all glowed. In the initial test, the center G/P didn't appear to me, to be quite as strong. After about 15 seconds. FYI: These NGK G/Ps are $70.00 ea. from a dealer, but can be gotten for less that $15.00 ea. on the Internet



I got 3 new G/Ps and did the same test.



I believe, the new G/Ps allow cleaner cold starting, but it's been a little warmer, so haven't really come to a final conclusion.

 

[MultiMow]

It's not necessarily the GPs heat rise. Heat is only part of the equation. Type of catalytic material and reactivity, is the other. Some OEM and aftermarket GPs use thin layer catalysts instead of solid material. If the catalyst becomes depleted, you could have the same temps and still suffer poor performance.

 

[tmajor]

It's not necessarily the GPs heat rise. Heat is only part of the equation. Type of catalytic material and reactivity, is the other. Some OEM and aftermarket GPs use thin layer catalysts instead of solid material. If the catalyst becomes depleted, you could have the same temps and still suffer poor performance.

I don't quite know, how to interpret that information. It would seem, that you might be saying, "they get weak".

These NGK G/Ps are supposed to be "QGS" (QuickGlowSystem) with a time factor of 6-10 seconds. With 3 of them in parallel, and using an 8 second average time, it would seem that a 24 second "G/P on period" should bring them to optimum performance. (Only 1/3rd of the total current would pass through each.) ??

 

[jaxs]

Comparing $70 each to what some cost would lead me to believe they were never intended to do much work. $15 is dirt cheap but I bet adding a heater to intake air rather than replaceing plugs will do more good.

 

[Steave]

The current induced through the G/P depends on Voltage and Resistance of G/P. As in you set up showing the G/P wired in parallel the current will depend on the individual G/P resistance. (Example: Voltage applied = 12 volt, resistance of G/P = ~2 ohms, current would be voltage X resistance = 24 amps through each G/P and 72 amps total for the circuit.) I'm not sure what your G/P resistance is so I just used 2 ohms for the math layout. Each G/P is going to pull a certain amount of current no matter if you have 3 in the circuit or 4 in the circuit and even more. What will change will be the total current of the circuit.

Increasing the "G/P on period" is not going to get them any hotter. You said the time factor is 6-10 seconds so they should be at their maximum during this time. Of course leaving them on longer will heat the chamber more but not increase the heat of each G/P.

 

[Steave]

As far as your question "Do they get weak?". I would think they'd be like any type of heater element and eventually will wear to a point then short out or burn itself open. Not sure but they do go bad.

 

[tmajor]

(Example: Voltage applied = 12 volt, resistance of G/P = ~2 ohms, current would be voltage X resistance = 24 amps through each G/P and 72 amps total for the circuit.)

Sorry, your calculations are not correct I=E/R for 1 G/P, the current would be 6 amps in your example. And in the parallel circuit the total resistance would be 0.6667 ohms. Which would make the current = about 18 amps.

 

[Steave]

Absolutely correct. For some reason I had power calculations on my mine instead of current. Well I know the reason too many years on one brain. Sorry for the misinformation. I studied electronics once upon a time, back when..........transistors were a coming thing.

That's a good price on the G/P. On Jaxs comment about the intake heater, they work pretty good on my International backhoe and my Belarus tractor but I was thinking that was kinda old school. Look out here I go thinking again.

 

[fried1765]

Comparing $70 each to what some cost would lead me to believe they were never intended to do much work. $15 is dirt cheap but I bet adding a heater to intake air rather than replaceing plugs will do more good.

I have always been afraid of the physical integrity of "cheap" glow plugs.
If the tip of one should break off, what have you got?
Engine tear down ???

 

[TractorGuy]

Have you verified voltage to them? I have read where the relay goes bad on some machines and the indicator still worked but the plugs were not getting voltage.

 

[tmajor]

I have always been afraid of the physical integrity of "cheap" glow plugs.
If the tip of one should break off, what have you got?
Engine tear down ???

The $15.00 plugs are the exact same brand and number, as the original plugs. .. NGK Y-510R

SparkPlugs.com $10.20
clubplug.net $11.81
Massey Ferguson $70.00

 

[tmajor]

No relay on this beast.

 

[Phillip w]

I have a mf 1531. I'm going to catch some flack, but I think it is the tractor. If it gets colder than 15-20 degrees, the tractor won't start. Talk to dealer/agco about this and the said I need to install a block heater. I said "do what?" The said "yeah you need to install a block heater". Need less to say I have a allis Chalmers 185 from the 1970's that starts better in the cold than my little mf. I have had my allis Chalmers running when it gas been 10 below. Kind of defeats the purpose of using the mf for snow removal. Not to proud of my little massey ferguson 1531.

 

[Phillip w]

I have a mf 1531. I'm going to catch some flack, but I think it is the tractor. If it gets colder than 15-20 degrees, the tractor won't start. Talk to dealer/agco about this and the said I need to install a block heater. I said "do what?" The said "yeah you need to install a block heater". Need less to say I have a allis Chalmers 185 from the 1970's that starts better in the cold than my little mf. I have had my allis Chalmers running when it gas been 10 below. Kind of defeats the purpose of using the mf for snow removal. Not to proud of my little massey ferguson 1531.

Don't know how the word "gas" got in the post. The allis Chalmers 185 is a diesel.

 

[tmajor]

Not to proud of my little massey ferguson 1531.

I hear you! I've watched New Holland and Kubota's start without a puff of smoke and not even waiting for glow plugs to heat. All diesels, seem to be different, for some reason. A friend of mine is a diesel mechanic and he has some make, which he has reworked, which takes 3 minutes to clear it's throat. ... but, it's probably 40 hp more than original.

 

[Dave M7040]

Since I got my M/F 1529, last fall, it has always seemed to cold start kind of dirty to me. I recently pulled the glow plugs and checked them for visual performance. They did have some carbon deposits, which led me to believe, that they weren't getting hot enough in 15 seconds. They all measured about the same resistance and all glowed. In the initial test, the center G/P didn't appear to me, to be quite as strong. After about 15 seconds. FYI: These NGK G/Ps are $70.00 ea. from a dealer, but can be gotten for less that $15.00 ea. on the Internet

View attachment 529277

I got 3 new G/Ps and did the same test.

View attachment 529278

I believe, the new G/Ps allow cleaner cold starting, but it's been a little warmer, so haven't really come to a final conclusion.

Do you have a wiring diagram for your tractor. If so could you please post it.

There have been many cases where the circuit wiring for glow plugs has been wrong for years. Wired in parallel when they were designed to be wired in series is one example.

This marked up wiring diagram is for different machines than yours but I provide it to illustrate the difference in GP wiring and how easy it is for someone to do it wrong and then, ever after, the next owners just copy what the first wrong did.

Below is a caution from the NGK Horticultural, Agricultural and Industrial Catalogue.

Testing Sheathed Type Glow Plugs
In order to check the heating coil, measure its
resistance as shown in the diagram (excluding
double insulated, YD, CX type part numbers). Some
resistance values are extremely low (such as some
QGS types) and should only be tested with an
Ohmmeter capable of recording values down to
0.1Ω. Testing glow plugs by connecting directly
across a battery is NOT recommended as, apart
from risk to personal injury, damage can occur to
the internal construction of the glow plug if it is not
designed to have continuous voltage applied (e.g.
QGS types).
Resistance value ∞: The heating coil is broken
Resistance value less than 5 Ω : The heating coil is in
good condition


Dave M7040

 

[tmajor]

I do have some diagrams, which were emailed to me. ... they aren't much good, as they get so big for the monitor, when I enlarge them, so that i can make anything out, it's quite a chore to get from point A to point B, following the wires. With that said, it shows 4 glow plugs, which I know is NOT correct, but they are in parallel. I'm sure they are to be in parallel, as they have a buss bar running between all three.

As I think of it, I don't know of any way to wire them in series.

 

[Dave M7040]

I do have some diagrams, which were emailed to me. ... they aren't much good, as they get so big for the monitor, when I enlarge them, so that i can make anything out, it's quite a chore to get from point A to point B, following the wires. With that said, it shows 4 glow plugs, which I know is NOT correct, but they are in parallel. I'm sure they are to be in parallel, as they have a buss bar running between all three.

If you want to email me what you do have, I will look them over.

david.petepiece@sympatico.ca

Dave M7040

 

[tmajor]

If you want to email me what you do have, I will look them over.
Dave M7040

They don't have any means to wired in series, as they screw into the head and have only 1 terminal on top.

 

[Dave M7040]

They don't have any means to wired in series, as they screw into the head and have only 1 terminal on top.

I am not trying to argue with you but rather just show you other situations were owners believed one thing and upon further investigation wiring was wrong.

I will leave you alone as I may be making matters worse for you.

Sorry

Dave M7040