6.2 Diesel Block Heater Time

[KSSB]

Quick question for those who have 6.2 diesels. Say it's upper 20's, to maybe freezing, how long do you run your block heater, before starting? Or, do you even have to run the block heater at those temps?

I had this pickup once before, but it was always inside, and that was quite awhile ago. So, I don't remember specifics about the block heater, and I'm not real familiar with diesels overall. I'm basically trying to get some sort of a baseline to determine if I have an issue, or if I just need to run the block heater longer.

Yesterday, it failed to start after 2 hours plugged in, with a battery charger boosting batteries. It was mid 20's, with upper teens "feels like" temp.

Today, I had the block heater plugged in 4.5 hours, battery charger on boost, and it finally started, but took a bit. It was 32, with "feels like" temp at 28.

Fuel is treated down to 0 degrees. Batteries are 2 years old and do test good, both voltage wise and load tested.

Would you folks say there's an issue? Or, is it par for the course, and I just need to plug it in longer?

Thanks!

 

[squaredeal91]

Only need about 3ish hours or so to make a big difference. I used to use a timer to turn it on 3 hours before leaving for work. Might experiment with different amounts of time to dial it in.

 

[KSSB]

Only need about 3ish hours or so to make a big difference. I used to use a timer to turn it on 3 hours before leaving for work. Might experiment with different amounts of time to dial it in.

Maybe I should plug it in for 8 hours and try to start it in the morning and see what happens, and work backwards time wise, if it starts. If everyone else's start in those temps after 3 ish hours, and mine takes almost 5, there may be another issue. Or, at least that is what I'm trying to rule out.

I will probably replace glow plugs regardless. So, I reckon that'll help some.

Case in point........I tried to start it today after being plugged in 3.5 hours (probably upper 20's at that point), and it wouldn't start and the batteries went down a good bit, and fairly quick for being decent batteries. Starter was moving slow at that point. Another hour, and the batteries on the charger, and then boost, it started.

Thank you for your help!

 

[squaredeal91]

Possibly your injection pump is getting weak. How does it restart after its fully warm and say you go into a store and come out to start it. Slow cranking should be looked into.

 

[KSSB]

Possibly your injection pump is getting weak. How does it restart after its fully warm and say you go into a store and come out to start it. Slow cranking should be looked into.

When it's cold like this morning, I'm not sure. I just got it going good enough to be driving it somewhat regular, and yesterday was the coldest day I've tried to start it. I usually drive my gas C10. One sec..........

So, it's 38 degrees, with a "feels like" of 30 degrees, and I just went out and cycled the glow plugs, and it fired up immediately. Not as cold as earlier, but not warm either. It's been 3 hours since it ran. I ran it for an hour after I got it started earlier. So, it did run a good bit. Temp gauge was back at the bottom just now, but I'm sure there was residual heat in things yet.

It also starts quick when the temps are warm, if that maybe helps rule out a weak pump.

Edit: It didn't crank slow just now, and doesn't when the temp is warm either. Only yesterday, after it pulled down the batteries. In case that helps some.

 

[squaredeal91]

Sounds like you're on the right road lol. Id say you're pump is good as well

 

[Blue Ox]

My first suspicion would be bad glowplugs. Does it start quickly after sitting for a long time when the weather is warmer? If not, it may be losing prime. Are you using the throttle when you're cranking?

A worn injection pump starts manifesting itself by being hard to start hot.

As a rule of thumb, I plug the block heater in when it's near or below freezing. It's not mandatory at those temps, but it does make life easier on everything. As @squaredeal91 said, three hours is enough. Naturally as the temps drop it becomes more mandatory and needs to bake longer.

 

[KSSB]

My first suspicion would be bad glowplugs. Does it start quickly after sitting for a long time when the weather is warmer? If not, it may be losing prime. Are you using the throttle when you're cranking?

A worn injection pump starts manifesting itself by being hard to start hot.

As a rule of thumb, I plug the block heater in when it's near or below freezing. It's not mandatory at those temps, but it does make life easier on everything. As @squaredeal91 said, three hours is enough. Naturally as the temps drop it becomes more mandatory and needs to bake longer.

I'm going to get a set headed this direction, just in case. I read somewhere a guy can test glow plugs, but for no more expensive than they are, I'd rather just replace them. I have no idea if, or when, they were changed last.

If it sits for a few days, or longer, it takes maybe 4, or 5 seconds to start, in warm weather. I do use the throttle a couple pumps when cranking. I wonder if it is losing prime a bit. I'll have to look into the causes of that. It has a new mechanical fuel pump on it. Other than that, everything fuel related has been on there awhile.

Hmmmm........yesterday and today were the first times it's been a bear to start. I bought it back from my cousin after it sat without running for 5 years, and it started easier than today, and all I did was throw batteries and fresh fuel in it. That was in March '24.

Ok, if that's the consensus on the block heater, then I have other stuff happening it seems.

Thanks for your help, Derek!

 

[KSSB]

Sounds like you're on the right road lol. Id say you're pump is good as well

I thank you for your help! It's appreciated!

 

[Turbo4whl]

You can check the block heater too. If you check it with an ohm meter there will be almost no resistance. This is good. As you hold the meter on the block heater a little while, you should see a little more resistance. This is also good. If the meter shows an open circuit, the block heater has burnt out and needs to be replaced.

 

[KSSB]

You can check the block heater too. If you check it with an ohm meter there will be almost no resistance. This is good. As you hold the meter on the block heater a little while, you should see a little more resistance. This is also good. If the meter shows an open circuit, the block heater has burnt out and needs to be replaced.

Thank you for the advice! I'll check that, too.

 

[Blue Ox]

You can test the glowplugs with a meter or test light too. Pull the wire off and check for continuity. Burned out plugs will show open. I don't know that I would just automatically replace them all, but if it floats you boat...

 

[KSSB]

You can test the glowplugs with a meter or test light too. Pull the wire off and check for continuity. Burned out plugs will show open. I don't know that I would just automatically replace them all, but if it floats you boat...

Thank you.

Looks like I have several things to check out.

 

[KSSB]

I forgot to plug it in last night and test the block heater time, but I decided to try to start it just a few minutes ago to see what happened. It's 36, with a feels like of 48. Not bad at all.

Cycled glow plugs, turned it over, I pumped the pedal twice and it wasn't spinning very fast, but fired for a second. I turned the key again, held the pedal down a little bit, it cranked slow, but fired and ran.

I'm going to check the glow plugs this week while things are nice, and start there. I might talk to my Napa guy and see if there's something I can do about these batteries warranty wise. With as fast as they pulled down yesterday and the day before, I'd really like to upgrade them. They're Napa Lengends in there now. I'd like to get some Optimas.

I'll report back after testing the glow plugs.

 

[77Dmax]

Check your battery cables. Old ****** cables will bog a starter big time.