TC29D glow plugs

[Mtsoxfan]

Is there a way to test if glow plugs working? On cold mornings, 20s, sometimes warmer, tractor has trouble starting. The glow plug light only goes on when cranking. I set throttle to where I believe 1500 rpm will be. Cranks good, but puffs black smoke and won't start. I tried putting in gear and turning key to crank so glow plug light goes on for 10 seconds. Then put in neutral and try starting. Very hard time starting. Today, when it finally started, it struggled to maintain 1000 rpm and after a minute, rpm shot up to 1600 on its own, and even with throttle returned to lowest, it took a few minutes to settle in at 1100.
My Yanmar used to make noise which I thought was glow plugs. Any help pointing me in right direction would be appreciated. BTW, cranks strong.

 

[keony]

Well, on mine the glow plug indicator light comes on with the key and goes out after 4 seconds and then is ready to start. Either your glow plugs or the relay are not working. I'm not sure how to diagnose it.

 

[Roadworthy]

Black smoke and difficult starting can be attributed to a dirty air filter. Don't ask. If you put a voltmeter on your glow plugs you will get a reading (nominal ten volts or so) on the meter. If they are getting power they can get quite hot. You can check each glow plug with an ohmmeter to see if it's good. Each individual glow plug will read about half an ohm if good. With many tractors turning the key to the left activates the glow plugs. Check your owner's manual.

 

[RickB]

The most common failure in this preheat system is the glow plug lamp timer relay. Your symptoms seem to indicate that with erratic/abnormal indicator lamp function.
Test the plug buss bar for power, ohm the individual plugs then go from there.

 

[dlctcg]

I'm not sure but I believe all the TCxxD tractors have the same concept for the Glow Plug Timer... It should energize & illuminate the glow plug dash light for 4 -5 sec's when the ignition switch is turned to the ACC/RUN position...

I can not confirm this is the correct testing procedure because it is for the TC35 - 45 series... but maybe it will help...

 

[rScotty]

SNIP....
My Yanmar used to make noise which I thought was glow plugs. Any help pointing me in right direction would be appreciated. BTW, cranks strong.

Glow plugs may or may not be powered while cranking - but usually they are not. In fact, the typical starting sequence is to turn the key to "on" and watch the glow plug indicatior light. Once the indicator turns "off", you can crank the engine.

It sounds like your glow plugs, or relay, or timer, or the wires from relay to the glow plugs are bad. It could be any of those things or all of them. Cranking while the glow plugs are being powered will drastically shorten the life of all those parts I just mentioned.
I've done a number of glow plug repairs. Old Fords were notorious for that.

You can test those parts by looking to see if the wires are burnt, turning the glow plug circuit on and feeling if the glow plugs get hot, and listening to the solenoid and timer. But best is to use a "clamp on ammeter".

The good news is that even if all those parts are bad, none of the above is harmful to the engine. You just have to replace the bad parts and they are fairly inexpensive and easy to do. Your next set will last longer as you learn more about them.

BTW, glow plugs are silent. The noise that your Yanmar made is because they alone use a different type of pre-heating system instead of glow plugs. Yanmar's "Thermostart" system is located in the intake manifold instead of within the head like glow plugs. And Yanmar's system makes a sizzling noise when it is working - just as you've heard.
good luck,
rScotty

 

[Mtsoxfan]

Thank you all for the replies. I have something to work with, now to figure out how to remove the dash out of way. Looks like 6+/- bolts inside engine area and 2 below steering column.
Snow coming to upper Vermont mountains this Friday where I live, want to make sure I can clear end of driveway.

Happy Thanksgiving

 

[Mtsoxfan]

A related question, where are you finding these pdf s? Can someone supply a link?
Thanks to all who help on here. Starting very late in life using a tractor and the support is awesome.

 

[RickB]

Take the black panels off below the instrument cowl. Two bolts below the steering column and two rearward facing bolts on each side under the hood.

 

[Mtsoxfan]

Thank you. Just waiting on temps to get into the 30s

 

[ruffdog]

My 1999 TC33D did not have a switch position for the GPs to work. Instead, when the key was turned ALMOST to cranking the engine is when the GP light would come on and I would then hold the key there and count to ten. Then, I would turn the key further and crank the engine.

 

[Mtsoxfan]

Thanks, I'll give it a try today. Was wondering why I only saw it during cranking.

 

[keony]

My 1999 TC33D did not have a switch position for the GPs to work. Instead, when the key was turned ALMOST to cranking the engine is when the GP light would come on and I would then hold the key there and count to ten. Then, I would turn the key further and crank the engine.

Good point Ruffdog. Sometimes I have to wiggle the key before the indicator light will come on in the "run" key position, and then the timer will function.

 

[dlctcg]

@Mtsoxfan - The PDF Pages I posted are from an a digital (PDF) version of a repair manual I purchased on-line for our TC40D... That's why I don't have the exact procedure for your machine. You can purchase one online fairly inexpensively from multiple locations... I have purchased a couple different ones for here, The Repair Manual, just type in TC29D in the search on the top left... they are fairly complete & pretty inexpensive.

​

 

[ruffdog]

Thanks, I'll give it a try today. Was wondering why I only saw it during cranking.

Yep, slowly turn key until GP light comes on then stop and wait 10+ seconds. Then, keep turning key to crank engine.

 

[Mtsoxfan]

I tried the slow turn, and I heard a relay cycle, but no light. Started much easier, but it was warmer. 35 degrees. A second time I did the slow key turn, the light came on dimly after about 5 seconds, and bright when I actually cranked. I will try again when temps drop. It seems to be the right direction.
This is also the first time I started tractor and hydraulic pump wasn't whining loud. Fluid is just over min Mark.

 

[ruffdog]

Two items that other people have had problems with is ignitions switches and the glow plug controller.

Hmmm...maybe a GP relay?

 

[McTowner]

The dash glow plug indicator light on my TC29D was hit or miss to work. But the glow plugs seemed to work regardless.
When I slowly rotated the key I could see the battery light get slightly dimmer, I assume from the electrical draw of the glow plugs.
I recently sold my NH, but it was a great tractor for 20 years.

 

[Mtsoxfan]

Woke up to 10" of snow. Slow turn didn't work at 20*. I have yet to try the wiggle. I will also look at battery light for dimming. Are NH known for loud hydraulic whine when cold? Moat cold days it is loud, like an issue loud. As it warms it diminishes.

 

[RickB]

They are loud when cold. Fresh oil and filters might help. Kubota Super UDT2 or Deere Low-vis HyGard will definitely help.