5.3L engine block heater

ArcticJ · January 18, 2006

Not a problem in the world. Everything seems to be functioning as usual except I can hear that block heater run when I plug it in...however, I'm running the timer so the only time I hear it is when I go out to start it in the morning. And I've been using the block heater nightly - with the timer - since I cut the thermo plug off and replaced it.

Would I do this again - you bet as it hasn't seemed to affect anything. I've gone through roughly 15 start/shut down cycles and no light, nothing. And the temp gauge has worked consistently.

By the way, I did get a message back from the Municipality of Anchorage I/M Program Administrator...it read -

Thank you for sharing this information. I will have our office research this issue and we will pass our findings on to all of our I/M licensed mechanics and facilities.

Who knows, perhaps the Muni will be recommended everyone in Anchorage driving an 05 or new GM truck cut the plug off and use a timer....we'll see. But it worked fine for me!

Thats great!!!

GM TECH...what do you think...is it the timer thats doing it...using it 3-4 hours before the engine is started and not letting the heater run for hours and hours??

didnt someone else snip the plug? Any problems?

Redbugdave....whats goin on with you? Did you fix the temp gauge? How about the codes?

I like the thougt of leaving enough lead to reattach the plug if need be

GMCStepSide · January 18, 2006

Yeah, follow the plug up as it goes by the fuse box...there is where I cut is so that I had plenty of tail under the hood to resplice if there was an issue. It worked for me and I'm a happy camper again. Go for it!

redbugdave · January 18, 2006

Hello ArticJ...I have not used my block heater since taking it into the dealer to figure out what was wrong and fix it, (clear the code). It has not been cold enough down here, lately. I have a 2006 6.0L HD. I still think the temperature guage thing is related in some way and have had no problems since, (the temp guage acted up only when I used the block heater). I think I will get one of those code readers for the truck, since inquiring minds need to know. That was a good idea of cutting off the old plug and leaving a tail to splice back on, just in case. I wish I had thought of that.

When the weather gets cold enough, (teens), I will plug it in and try it for a couple cycles and report in. By the way, a couple of my plum trees are in full bloom down here, and the daffodiles are poking up with this weather. Has the groundhog seen his shadow...or is it too soon?

ArcticJ · January 19, 2006

Hello ArticJ...I have not used my block heater since taking it into the dealer to figure out what was wrong and fix it, (clear the code). It has not been cold enough down here, lately. I have a 2006 6.0L HD. I still think the temperature guage thing is related in some way and have had no problems since, (the temp guage acted up only when I used the block heater). I think I will get one of those code readers for the truck, since inquiring minds need to know. That was a good idea of cutting off the old plug and leaving a tail to splice back on, just in case. I wish I had thought of that.

When the weather gets cold enough, (teens), I will plug it in and try it for a couple cycles and report in. By the way, a couple of my plum trees are in full bloom down here, and the daffodiles are poking up with this weather. Has the groundhog seen his shadow...or is it too soon?

<{POST_SNAPBACK}>

Hey redbugdave...

I really appreciate your info and everyone else on this page...it's been extremely helpful.

I'm just about ready to get that plug off and I will definitely leave enough to re-attach...

No flowers here in chicago...were on our way to the great white north in a couple of days and it would be great if i could get this plug on and do a little test up there...the temps at night have been around 5-15 degrees...we'll see

Thanks again to everyone for the info...keep it coming please

ArcticJ · January 25, 2006

OK...new plug is on, but it hasn't been cold enough to run it...its only getting in the mid to high 20's...

Whats the update with the other cutters

problems...codes?

MS3DALE · January 25, 2006

I still haven't gotten my new cord back yet,and like you said it hasn't been very cold here anyway (High 20s-Low 30s)

GMCStepSide · January 26, 2006

Currently -21 degrees outside at 6:30 p.m.

When I got up this morning it was -24 and we never saw it go above -8. I had it plugged in ALL NIGHT LONG and never got a code, light or even a whimper. I started it this morning and everything performed as normal. Granted, I'm on the other end of the spectrum in that the thermo plug is supposed to pass electricity to the block heater when it's below zero thus it should be functioning as GM intended at this point. However, the real test will be when it's 10 degrees out and I use the timer for four hours. I was doing this before the cold snap hit, and had it working between 5 degree nights and 20 degree nights, and never had a problem.

No problem since I cut it off - at all. And my service manager told me on Monday that he's been recommending it to those who will use a timer. However, he said he was waiting for the first truck to come in with a fella who cut it off and left it plugged in overnight at 30 degrees. At these temps, it will be a while before he sees him.....

fossil · January 29, 2006

Why not just leave the block heater cord the way it was intended. Put on an oil pan heater pad and tie it into the system. Now when you're plugged in your engine oil will be nice and warm and when it gets really cold your block heater will kick in and you wont set off any codes. One thing with a block heater is that the block stays warm but when it gets really cold the oil in the oil pan stays thick as the heat doesnt make it to the pan.

seneffna · February 10, 2006

Thanks to everyone for all the info and effort. I have figured out they way to bypass the thermostat in the end of the factory plug. This being my first post I don't know the best way to display pictures but I will try to describe the process as best I can. If interested I can email the pictures. [email protected]

In short I have found that removing the black hard plastic cap (tumor) reveals the temperature sensor. The cap comes off easily with a pair of plyers. The temp sensor is a silver disc that somehow expands at 0degrees to close the pair of contacts underneath it. At first glance it looks like a watch battery. The temp sensor comes out easily with plyers as well which reveals the two contacts which just need to be shorted together. Don't try to remove anything else as you will damage the rest of it in the process as my pictures prove. The tumor cap should go back on to keep things protected. This doesn't fix the fact that you may get diagnostic errors sometime but at least we can bypass the temp switch while leaving your factory plug looking stock. BTW replacement cords can be purchased from your dealer $45 (buying the heater kit is cheaper though $32) and the <04 replacement cord does not fit the heater connector for the 05 and up.

ArcticJ · March 4, 2006

Hey cold weather lovers...missed you for awhile...(been working nights)

I hate to revive what appears to be a dead post, but whats the deal with the heaters? Those that have cut, did you get any (additional) codes or problems (temp gauge? etc.) Are the heaters working? Are the codes coming on if the cut heater is used above...say 20?

I cut one of my trucks plugs, used it in N. WI. when the temps were in the single digits and ultimately -25 one morning. Obviously the stock plug would have worked on that particular day, but on the mornings above 0, I plugged the truck in for a couple of hours before driving on two occassions (once up, I rarely move around until leaving for IL.) I had no problems...truck started nicely, no warning lights came on and everyone was happy.

Those that have not cut, are you accepting the heater for what it is, useless unless in extreme temps? Has anyone tried that last mod? Problems?

again, I hate to reopen but I just gotta know whats happening out there...

Thank you

Thanks

GMCStepSide · March 4, 2006

Still no problems with mine and I've plugged it in at -25 as well as 15 degrees and never a problem. As you know, I cut the plug off and replaced it....everything still works fantastic.

redbugdave · March 5, 2006

Hello ArticJ and the block heater gang,

I have also been wondering about the block heater issue. For me, I have not used mine since I originally had the problem...2 or 3 months ago. It's been a really warm winter down here and the low temperatures have been in the 20s and 30s. A conspiracy theory...I suspect GM had this global warming thing in mind to keep us from using our block heaters... Seriously though, this issue is not dead for me, and I have been occasionally checking this topic for further developments, like you.

Also, a reply to Neil...about taking the tumor cap off and pulling the thermostat from inside, reconnecting and putting the cap back on. That's ingenious! I did not even think of doing that...I just wanted that durn cancerous thermostat plug off! I sure wished Neil would have posted before I cut mine off! Ohhh well.

If we don't get cold weather, then we need to revive this topic NEXT winter!

Jerther · March 10, 2006

Just a thought from another forum...the combination of metal (block heater) and aluminum (block) causes corrosion when electicity is introduced via the heater...therefore, GM lowered the operable temperature thus greatly reducing the use of the heater and as a result, greatly reduced the potential problems from the corrosion issue...

I have doubts about this... First, isn't the heater element insulated? I don't believe that there is current flowing from the heater to the block.

Here's the theory:

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The phenomena explained in the quote is called Electrolysis. It does happen when there is current flowing in an electrolyte (here, the coolant) between two electrods (heater and block).

Let's assume the heater is not insulated. Then, electrolysis should occure. The result of electrolysis of electrolytes depends on its nature. I don'T know for the coolant, but as for water... Electrolysis of water tipicaly generates O2 and H2 (Oxygene and hydrogene). On a DC circuit, the anode (+ electrod) gets oxidized because of the formation of O2 there, and because the metal is disolving. Add some salt to the water and Cl will be produced there, and Cl is VERY corrosive.

As for the cathode (- lead) Hydrogene is produced there.

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

So, IIIIFFFFF there is current flowing... we have a rusting block, a rusting heater (both because the heater is powered with AC) and a highly explosive gas produced inside the engine... Either H2 alone, or O2H2 which is the PERFECT match for perfect combustion.

And by the way, in electrolysis, whatever metal is used for the + lead, it WILL corode/disolve. Ever seen rusted stainless stell? I did. ;)

So I really don't believe in current flowing between the heater and block.

And another thing, it would really be stupid to allow the block to get voltage from the heater... You could touch your truck and get electrocuted... This is non sens.

different_seasons · October 23, 2006

bumping this thread for our snow dwellers.

ArcticJ · December 13, 2006

Hello once again my cold weather friends...

I too am curious about the cutters and thermostat modifiers out there...problems? codes?

I started to get a code this year p0116 for the first time. The plug was in for about 3 hours with the temp about 4 degrees F.

I mentioned on another post/reply that I can't find now that I read somewhere that GM issued a software update for diesels to eliminate/reduce the codes thrown from the heater being used above 0. The update was issued around march or april...this won't due most of any good with gassers I know, but hey...

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