Rough Idle/apparant misfire during high alternator load

[DavidC]

I read where the coil types have a tendency to swell which makes sense heating and cooling over a period of time. It stated it is quite the ordeal to try to remove them after that happens.

 

[AH64ID]

Might locate the heaters in the horn on the "up-hill" side, which should mitigate FOD concerns. Also, these are easy to pull and inspect, which can be periodic maintenance, something not so easy to do with a grid.

Not sure mods that increase maintenance for little benefit are really worth the time.

 

[MichaelOverfield]

I read where the coil types have a tendency to swell which makes sense heating and cooling over a period of time. It stated it is quite the ordeal to try to remove them after that happens.

Interesting. Well I have one set up for my testing that has been cycled a bit already, of course many more cycles would be needed to see such a thing happen, I can say expansion and contraction will for sure be a factor, if engineered correctly, they should come back, but I can see possible creep over time making them expand a bit. As a Mechanical Engineer, I like to get into the details! . I one other thing thinking about this, I could install a switch or electrical disconnect, and just leave them disconnected most of the time, and only connect them electrically when needed. That could be a solution with no downside.

 

[DavidC]

Michael, I believe I read it on the Duramax threads. I have heard it long ago on Fords also. The Dmax just jogged some cobwebs.

 

[MichaelOverfield]

Not sure mods that increase maintenance for little benefit are really worth the time.

Well, given the demonstrated Grid heater failures and subsequent engine damage.. keeping that thing makes me tend to want to inspect it to prevent such a disaster, and to do that you have to take apart many intake and EGR parts just to get there, then new gaskets etc. Not something quick or easy, thus likely just not getting done. In contrast, these plug type heaters can be located where they are accessible (in theory, as I have yet to do it), and it's a simple pull the wire terminal nut, then the plug, inspect, put back in. Of course that may be not needed at all since I have not seen a history of these coming apart, though certainly possible. Now if I just leave them electrically off most of the time, well then it seems the inspection would not be needed at all.

 

[MichaelOverfield]

Michael, I believe I read it on the Duramax threads. I have heard it long ago on Fords also. The Dmax just jogged some cobwebs.

Interesting, that is where these were used, so if they had issues, that is where it would be seen for sure. Thinking the switch/disconnect option makes sense.

 

[MichaelOverfield]

Michael, I believe I read it on the Duramax threads. I have heard it long ago on Fords also. The Dmax just jogged some cobwebs.

Found this, looks like for this guy he had trouble with the nut on the electrical connector, and that led to his twisted the heater element that led to it expanding and his breaking off a piece of the insulator. Looking at his engine very dirty, that is a common issue with corrosion in general. I don't always wash the outside of my vehicles, because appearances are not that important to me, but the engine compartment, that is important, and usually the cleanest part for my vehicles... for this kind of reason.

Also, he should have used a second wrench to hold the other nut while removing that upper nut, his disaster was avoidable.
I would bet this is the cause of the "expansion" that was seen on the threads.

 

[AH64ID]

Well, given the demonstrated Grid heater failures and subsequent engine damage.. keeping that thing makes me tend to want to inspect it to prevent such a disaster, and to do that you have to take apart many intake and EGR parts just to get there, then new gaskets etc. Not something quick or easy, thus likely just not getting done. In contrast, these plug type heaters can be located where they are accessible (in theory, as I have yet to do it), and it's a simple pull the wire terminal nut, then the plug, inspect, put back in. Of course that may be not needed at all since I have not seen a history of these coming apart, though certainly possible. Now if I just leave them electrically off most of the time, well then it seems the inspection would not be needed at all.

I guess I am not aware of 6.7 grid heater failures aside from excessive soot buildup on the 07.5-12's, which doesn't seem like it will be an issue with your setup.

 

[MichaelOverfield]

I guess I am not aware of 6.7 grid heater failures aside from excessive soot buildup on the 07.5-12's, which doesn't seem like it will be an issue with your setup.

Understandable, I wasn't aware either, but it was posted earlier from the 4th Gen section, this post:
https://www.turbodieselregister.com/threads/grid-heater-bolt-came-loose.265513/

 

[AH64ID]

Understandable, I wasn't aware either, but it was posted earlier from the 4th Gen section, this post:
https://www.turbodieselregister.com/threads/grid-heater-bolt-came-loose.265513/

It certainly is a bummer deal, but I still don't think it's a systemic issue. That thread is 2 years old and I don't recall another one.

I would still call the grid heater a safer option, but that's my 0.02.

The internet is full of random failures and we can now find out about all of them, even if its just small handful. It's impossible to engineer all of them out, one would go crazy trying.

 

[MichaelOverfield]

It's impossible to engineer all of them out, one would go crazy trying.

Indeed! It might be too late for me on that number! I'm the kind of guy that if the failure is 1 in a million, I'll be that one guy.. like my thread on the odd TIPM/ECU DLC/OBD2 port issue. No one, I mean no one else seems to have that issue, and I've been trying to figure that one out of a while. I'd be the guy where that nut melted off and went in the engine.. At the minimum, I'm not putting power to that thing until I can verify it's not an issue, of course the plan is to do away with it completely, which reduces the flow restriction in that part of the intake.

 

[AH64ID]

Indeed! It might be too late for me on that number! I'm the kind of guy that if the failure is 1 in a million, I'll be that one guy.. like my thread on the odd TIPM/ECU DLC/OBD2 port issue. No one, I mean no one else seems to have that issue, and I've been trying to figure that one out of a while. I'd be the guy where that nut melted off and went in the engine.. At the minimum, I'm not putting power to that thing until I can verify it's not an issue, of course the plan is to do away with it completely, which reduces the flow restriction in that part of the intake.

I know the feeling. I had the front timing cover spacer break and split the oil pump on my 05.

It’s been mentioned, but I think that relocation kit from GDP is probably the best option. It uses a 5.9 heater and is high flow. GDP stuff is always top notch and Rich Martin is a great guy. It also will have minimal impact on airflow in that position.

https://www.glacierdieselpower.com/...0-high-flow-grid-heater.html?ref=category:185

 

[MichaelOverfield]

I know the feeling. I had the front timing cover spacer break and split the oil pump on my 05.

It’s been mentioned, but I think that relocation kit from GDP is probably the best option. It uses a 5.9 heater and is high flow. GDP stuff is always top notch and Rich Martin is a great guy. It also will have minimal impact on airflow in that position.

https://www.glacierdieselpower.com/...0-high-flow-grid-heater.html?ref=category:185

That does look like a nice unit, but pricey! I have just over $270 in parts for replacement of the intake horn, grid delete, and the other heaters.. though this is a good idea, it validates my thought about moving the heaters further away from the intake manifold. I do have some stainless sheet and tube I could use to do something similar, though I don't think that 5" will fit in there anywhere, I'll have to do some fabrication for sure.

 

[MichaelOverfield]

To the OP, I swaped ECUs again while still chasing a different network communication gremlin. I re-verifed this problem was corrected, since last time it was doing this this ECU was installed. The problem corrected.. At well over 120Amps, no rough running engine. I think the issue was the alternator field/sense connector plugs not staying fully seated. I have some aftermarket plugs that were used to do my dual alternator set-up, they appeared to vibrate loose enough to lose pin contact while still connected, both alternators were found to have this issue. I tightened them up with some liquid electrical tape as a quick fix, and problem is gone.. I think the sense line being loose was sending erronious data to the ECU causing this condition.. it's a theory, but seems to fit the pattern.

 

[MichaelOverfield]

Since it came up here, the Grid heater is gone, the new custom heater is installed in the cold side intercooler to intake pipe, it came out quite nicely. Easy to service if needed, and it draws about 150amps, vs whatever insane current the grid was pulling. Several drive cycles all seems well. Here is the tread on that final outcome on the grids:

https://www.turbodieselregister.com/threads/grid-heater-alternative-the-hard-way.270801/

The original issue here appears to have been the not fully connected alternator sense from that connector on the alternator.

 

[Yo Hoot]

Old thread but in line with electrical noise. Currently trying to get a GM big block 454 running decent. GM HEI ignition. It used to run perfect. Started backfiring and fouling plugs randomly. At the same time I was hearing what sounded like a bearing going internally in the motor. I didn't think it was the alternator cause it wasn't very high pitched. I notice the whine coincided with a change in the engine running. Popped the fan belt off and it seems like it runs great without the alternator turning. Spinning the alternator by hand it feels like there is something amuck. New one coming tomorrow.

 

[Alan Reagan]

Yo Hoot, turning the alternator, it should be smooth. If it’s not smooth when you turn it, the bearings are probably shot. You can go to a parts store and they will usually let you see what a new one feels like.

On the HEI, check inside the distributor cap for carbon trails, cracks and melting. Make sure the vacuum line is not cracked. From there, you will be looking at the module failing. I had to replace mine on my last Chevy truck.

 

[Yo Hoot]

Yo Hoot, turning the alternator, it should be smooth. If it’s not smooth when you turn it, the bearings are probably shot. You can go to a parts store and they will usually let you see what a new one feels like.

On the HEI, check inside the distributor cap for carbon trails, cracks and melting. Make sure the vacuum line is not cracked. From there, you will be looking at the module failing. I had to replace mine on my last Chevy truck.

,
New alternator fixed it. I had already replaced the distributer cap, wires, plugs and everything under the cap. I read that bad diodes can create havoc in the electrical system. Also bad bearings anywhere can generate EMI. I know that from flying model helicopters. A bad bearing spinning at 1000's of rpms messed with the radio and the receiver.

 

[Alan Reagan]

Glad you got it fixed.