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Topic: Glow Plug Replacement for Isuzu 3LB1 Engine on Generator (Read 3390 times) previous topic - next topic

Glow Plug Replacement for Isuzu 3LB1 Engine on Generator

We have an Isuzu 3LB1 diesel engine on our generator.  During cooler weather, it has been harder to start than during the summertime.  We replaced the supply and return hoses in the summer of 2011. This made the engine run very smoothly with no drop outs of any kind.  However, this winter it has still been harder to start.

Last summer someone suggested that possibly the glow plugs might need to be replaced. 

I am seriously thinking about replacing the glow plugs, but I do not know for sure where they are or what is involved in replacing them.  Based on the research I have done so far, it appears the correct Isuzu part number is:  8971065494
It also sound like the equivalent Kubota part number might be 15521-65512-Y-106V

1. Can anyone confirm either of these part numbers as being the correct glow plug part number?
2. Where are the glow plugs located on the engine?
3. What are the steps required to properly replace the glow plugs in the engine?

Thank you very much.

Morris
Morris and Janice
1997 U270 36'

Re: Glow Plug Replacement for Isuzu 3LB1 Engine on Generator

Reply #1 –
This is not a direct answer to your question, but an experience that might influence your plan. Our generator has a Kubota engine, so it is a bit different from yours.

We took our 1997 U295 to FOT in January, 2011, for service. Included in the service specifications were to align the steering, check for an air leak, and fix the autostart function of the generator. Wayne Musser handled those tasks, and he also replaced the wheel seals that he found were bad. He found that the autostart module had been removed, causing a failure of the autostart function. (Duh! No wonder I couldn't locate the module.) He also replaced parts on the generator to fix the priming/starting functionality of the generator.

On a visit to FOT in December, 2011, he also replaced the steering gear, repaired the water heater, and repaired a furnace on our coach. I had tried and failed to fix the water heater and the furnace.

The point of my story is that Wayne knows the equipment, will diagnose the problems properly, and repair them if you choose to allow him to do the work. You may wish to consider a trip to NAC.
J D Stevens
1997 U295 CAI 36' Build #5085
2002 Subaru Outback
Motorcade 16869
Bellville, TX

Re: Glow Plug Replacement for Isuzu 3LB1 Engine on Generator

Reply #2 –
We have changed our Isuzu 3 cylinder Power Tech glow plugs several times and we carry 3 spares with us.

We usually buy your Kubota 15521-65512-Y-106V glow plugs as they can be purchased at Kubota stores.

Each of the three cylinders have a glow plug near the top front of engine. They are powered from the pre-heat switch that also runs the electric lift fuel pump located center bottom front. One glow plug has a pre-heat powered wire and all three glow plugs are connected together with a flat narrow metal power connector that is shaped to fit all three glow plugs.

To replace them, remove the top nut, metal 12-volt metal power connector, glow plugs. Use a deep socket to remove and install glow plugs.

Your detailed topic subject clearly shows your need.

Re: Glow Plug Replacement for Isuzu 3LB1 Engine on Generator

Reply #3 –
I had to change mine a while back. Same symptoms, hard to start in cold weather. Also have the 3 cylinder isuzu but 10 KW. Ordered from MOT. Brand was NGK and part # 6926        Y-106V. May or may not be same as yours. Used 12mm deep socket.
Felix and Gail Mathieu
99 U320
Jeep Liberty CRD
Build number 5522

Re: Glow Plug Replacement for Isuzu 3LB1 Engine on Generator

Reply #4 –
This topic reminded me to order spares. Amazon.com has them for $6.78 each.
Part # NGK Y106V
Felix and Gail Mathieu
99 U320
Jeep Liberty CRD
Build number 5522

Re: Glow Plug Replacement for Isuzu 3LB1 Engine on Generator

Reply #5 –
You may also remove one and go to your local NAPA store, they may have them as well. Champion spark plugs also makes them. Any parts store that sells them will have an application book to lookup the right part number.
Bruce, Linda, and Macy
Zoey RIP 1/20/19
1999 U295 40' build #5400
2017 silver Jeep Wrangler, 1260 watts of solar on top
Moving around the country

Re: Glow Plug Replacement for Isuzu 3LB1 Engine on Generator

Reply #6 –
I wanted to update everyone.  On Tuesday, we went out to the coach to exercise it and the genset.  Prior to starting the coach, I connected the spring clamp on my 6/12V circuit tester to the ground cable for the generator engine.  I then placed the point of the probe on the top of the first glow plug and pressed the fuel lift pump/glow plug switch.  The light in my circuit tester illuminated. I repeated this for the two remaining glow plugs and got the same result. So it looks like we have 12V power to the glow plugs. 

I found a source on eBay for the glow plugs with the Isuzu part number for $12.00 each including shipping.  So I now have 3 of these glow plugs on order.

Members here provided some good trouble shooting suggestions for the above and how to check the resistance of the old glow plugs to see if any of them are good enough for spares.  I plan to do this as part of the glow plug replacement project in the near future.

Since Tuesday was a very warm day here, after cranking the diesel for the genset for a little bit, it started and ran very smoothly for around 1-1 12 hours while on our trip to exercise the coach.  I did run the house air conditioning in addition to charging the batteries to load the genset.

I will let you know the results after I have been able to change  the glow plugs in the near future.

I greatly appreciate the comments/assistance from everyone here.
Morris and Janice
1997 U270 36'

Re: Glow Plug Replacement for Isuzu 3LB1 Engine on Generator

Reply #7 –
An easy way to check the glow plugs is to disconnect the wires that feed juice to them (at the glow plug). Then connect the clip end of the tester to a known 12V source. Touch the pointy end to a ground to make sure the tester is working and then touch the end to the glow plug where you took the wire off. If the plug is good, the bulb will light. No light and the plug is bad. Only takes one bad plug to keep the generator from starting in really cold weather.

Direct chamber injection diesels usually don't have glow plugs while diesels with pre-combustion chambers almost always do. A pre-combustion chamber diesel makes a lot less noise so lend themselves to generators and cars. With modern common rail injection diesels with computers, direct chamber engines are much quieter than their predecessors but may not be cost effective in smaller applications.

Keeping the glow button down for 20 or 30 seconds after the generator has started may reduce the smoke at higher altitudes and keep neighbors happier. Automotive diesels have a timer that keeps the plugs glowing for up to 90 seconds after the engine starts.

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: Glow Plug Replacement for Isuzu 3LB1 Engine on Generator

Reply #8 –
Quote from: Pierce & Gaylie Stewart –
An easy way to check the glow plugs is to disconnect the wires that feed juice to them (at the glow plug). Then connect the clip end of the tester to a known 12V source. Touch the pointy end to a ground to make sure the tester is working and then touch the end to the glow plug where you took the wire off. If the plug is good, the bulb will light. No light and the plug is bad. Only takes one bad plug to keep the generator from starting in really cold weather.

Based on this, it sounds like I can disconnect the cable providing the 12Vdc to the "bus bar" and then clip the tester clip to that cable and hold the lift pump/glow plug switch to the ON position while touching the probe to the end of the glow plug while it is still in the engine block.  Am I right?

Thank you very much.
Morris and Janice
1997 U270 36'

Re: Glow Plug Replacement for Isuzu 3LB1 Engine on Generator

Reply #9 –
Yep, sounds like you're ready to go. Just make sure nothing is connected to the end of the glow plug and then touch it with the probe. You could use a multimeter but the test light is quick and easy and hard to make a mistake with.

If the light does not come on, touch the probe to the base of the glow plug or the engine block next to it to make sure you have 12V at the alligator clip end. You will catch on to the drill quickly.

Always good to carry a spare. At $10-15, they won't break the bank.

Let us know how it goes.

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: Glow Plug Replacement for Isuzu 3LB1 Engine on Generator

Reply #10 –
Just hook it up to a 12V source and hold it...
The selected media item is not currently available. Dave Head & Megan Westbrook
Titusville, FL - The Great Outdoors
'98 270 buying this month
Toad is a 2018 F150 XLT

Re: Glow Plug Replacement for Isuzu 3LB1 Engine on Generator

Reply #11 –
Another beautiful day here today. So I went to the coach to replace the glow plugs on the Isuzu diesel engine for the genset.

I did the troubleshooting outlined above and it appears that all 3 of the old glow plugs were inoperative.  So I replaced all 3 of them.  After installing the 3 new glow plugs, I checked them per the above and all 3 of them checked out functional.

As part of the trouble shooting, I was using the OFF/prime/glow plug switch so the pump had primed the engine.  So I pressed the start switch and it almost immediately tried to kick off and run, but it stumbled and died.  So I tried it again and it almost immediately tried to run but it stumbled and died again.  On the 3rd attempt, it almost immediately started running and continued to run. 

I turned on the air conditioner and ran the engine for over 1 1/2 hours. So it looks like the problem has now been corrected.

I want to thank everyone for their assistance, the troubleshooting procedures and pictures to show me exactly where the glow plugs are located.  Without all this assistance, I would not have been able to correct the problem.

Due to replacing the 3 glow plugs today and replacing the fuel hoses (supply and return) last fall, I am now very confident the generator will start quickly and run smoothly when we need to charge the batteries or provide AC power to the coach systems.

Thank you very much everyone!!!  I greatly appreciate your support.

Oh, BTW, when I removed the old glow plugs, it looked like they had a NGK part number on them. After getting home and using a magnifying glass, it looks like they show NGK one one flat, Y720U10V on another flat and 9623 on a third flat.  (The flats are where the deep socket fits to remove/install the glow plug.)

Can anyone confirm this as being a NGK part number?  I will do some web searches for the Y720U10V number to see what I find.  I will let you know if I find anything.
Morris and Janice
1997 U270 36'

Re: Glow Plug Replacement for Isuzu 3LB1 Engine on Generator

Reply #12 –
I communicated with NGK to get the correct NGK part number information for the Isuzu 3LB1 glow plugs.  Here is the email communication with NGK concerning this:

Message flagged
Wednesday, March 28, 2012 3:12 PM

Hello,
 

The glow plug you need is a Y720U-1 #5392.


Best Regards,

Andrew Hauenstein

Technical & Training  Specialist

NGK Spark Plugs (USA), Inc

"Like" us on Facebook: http://www.facebook.com/NGKsparkplugs
 
---------------------------------------------------------------------------------------------------------------
From: Morris
Sent: Wednesday, March 28, 2012 1:43 PM
To: Info
Subject: Fw: NGK.com
 
Contact Us Form Submission

Hello,

The below form identifies the question I have concerning the correct NGK part number for 3 glow plugs I removed from my Isuzu 3LB1 diesel engine yesterday. The Isuzu part number for the glow plugs is:  8971065494

I would like to know the correct NGK part number and availability for the correct glow plug for my application.  The glow plugs are 12 Volt.

Thank you.

Morris


----- Forwarded Message -------------------------------------------------------------------------------------
From: Sparkplugs.com
 
<cust@website.sparkplugs.com>
To:
Sent: Wednesday, March 28, 2012 12:18 PM
Subject: RE: NGK.com Contact Us Form Submission
   


Customer Service
cust@sparkplugs.com
888-800-9629
951-672-8501
951-672-0759 fax

---------------------------------------------------------------------

I have an Isuzu 3LB1 diesel engine. It uses Isuzu 8971065494 glow plugs and they are 12Volts.

When I changed the 12V glow plugs today, the ones I removed have the following NGK number on one land where the socket fits:

Y720U
10V

On another land, they have the following number:

9623

What is the correct NGK part number for the 12V glow plugs that are the same as the Isuzu 8971065494? What is the per unit price for these glow plugs?

Thank you.

NGK Tech Information

NGK.com
 
is a distributor for NGK. Here is NGK's tech# 877-473-6767 or you can email the NGK tech team at Info@ngksparkplugs.com. For further information you may also try their official website NGK Spark Plugs USA
 
.

Thank you,
NGK.com

---------------------------------------------------------------------------------------------------------------

So based on this, the correct NGK glow plug for the Isuzu 3LB1 diesel engine is:  Y720U-1 #5392

From a post I saw on another forum, it appears this glow plug MIGHT be available through NAPA.
Morris and Janice
1997 U270 36'

Re: Glow Plug Replacement for Isuzu 3LB1 Engine on Generator

Reply #13 –
Morris,

It is very unusual to have all three glow plug fail. I have seen 2 out of 5 fail on a couple of Mercedes diesels but never all of them. I am not familiar with glow system on this particular generator but they can operate in several ways. First would be to only heat as you push the glow plug heater switch. Others will have a timer and temperature sensor on them with a light that goes out when the engine is ready to start. These typically will continue to supply voltage to the glow plugs for a number of seconds even after the engine starts. This is used to lower emissions and help the engine to run smoothly in the first 30 seconds after it starts. If this were to stick "on" or heat for too long, it could damage the glow plugs and cause premature failure. Might be a good question to ask the generator manufacturer. Make sure to have your generator model and serial number available when contacting them.

You did your homework well contacting NGK. These glow plugs are typically available somewhere around $10 ballpark online. If you order from the generator manufacturer, you can pay 5X this amount. Bosch may have the same plug available for this application. Either one normally excellent.

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)