5.3L engine block heater

beasleyiv · December 6, 2005

I have found 12497459 as the possible part number for an engine block heater. The description is:

5.3 liter MFI 8 cyl engine, 6.0 liter MFI, HO, V8, iron engine (6.0N), 4.8 liter MFI 8 cyl engine, 8.1 liter MFI 8 cyl engine (496 CID), 5.3 liter flexible fuel (gas/alc) 8 cyl engine with MFI.

Notes: t/w gasket 12560438 for vehicles w/LQ4 or LQ9)

Can you verify this would work on my 2003 5.3L 1500 4x4?

Will I need the gasket?

Thanks!!

ArcticJ · December 14, 2006

WOW that was fast...thats it...

now I know it does us no good...if im reading it right, the recommendation to eliminate the codes is to swap the cord for a thermostat cord, disallowing the use above 0....

Im not looking forward to the upcoming 2-10 degree day and nights

GMCStepSide · November 29, 2007

I'm telling ya, cut that tumor plug off and let the CEL do it's job. Every now and then I get a CEL light but with enough start/stop cycles, it would go out unless we were having a long stretch of 5 or 10 degree weather. When I asked one of the GM Service Managers about the CEL light, he checked and said doing so will not hurt the engine, tranny, or anything...it will just be a minor annoyance for the driver. Heck, that's what they make black electrical tape for - to cover that minor annoyance.

Plus, I'm protecting my engine versus cold startups at 5 degrees day in and day out.

dewfpo · January 14, 2008

I modified my plug 3 years ago so that the thermostat is inoperative (heater comes on when plugged in) and I have never set a code. The only other thing to be aware of is the '05 and up block heaters are only 400 watts.

DEWFPO

norsemanberg · January 31, 2008

where is this tumor? I looked at the plug an i dont see it. Is it at the block heater connection?

GMCStepSide · January 31, 2008

Yes, it's a round black cap that is located on the plug in end of the block heater cord. When you go to plug it into an extension cord, you'll see it has a black cap on the top of the plug. That is the thermostat - assuming you have a 2006 model year and beyond. Your sig shows a 2003 1500...if you have a 2003, you don't have ther thermostat plug. Yours will operate any any temp...

Edited January 31, 2008 by GMCStepSide

norsemanberg · February 2, 2008

Yes, it's a round black cap that is located on the plug in end of the block heater cord. When you go to plug it into an extension cord, you'll see it has a black cap on the top of the plug. That is the thermostat - assuming you have a 2006 model year and beyond. Your sig shows a 2003 1500...if you have a 2003, you don't have ther thermostat plug. Yours will operate any any temp...

Thanks for the info I guess the heater is just burnt out.

9r9r9r · February 2, 2008

I just spent about $450 to have my local GM dealer install a "genuine GM part" K05 block heater in my 6.0L Sierra. It didn't come with one new. Checked it this morning when it was +2F and couldn't tell if it was working. Thanks for all your posts---now I know it probably wasn't. Nice heater. Anyway, I think the dealers up here do know about all the idiosyncracies with them as my guy warned me not to buy a cheap aftermarket one or the computer would get upset. So I have instead an expensive block ornament. Do all the manufacturers do this or just GM? Seems nuts.

dewfpo · February 2, 2008

I just spent about $450 to have my local GM dealer install a "genuine GM part" K05 block heater in my 6.0L Sierra. It didn't come with one new. Checked it this morning when it was +2F and couldn't tell if it was working. Thanks for all your posts---now I know it probably wasn't. Nice heater. Anyway, I think the dealers up here do know about all the idiosyncracies with them as my guy warned me not to buy a cheap aftermarket one or the computer would get upset. So I have instead an expensive block ornament. Do all the manufacturers do this or just GM? Seems nuts.

I bought a 2007 Toyota FJ Cruiser and installed a factory block heater. No thermostat on it, and no warnings for its use. I use it all the time, have had it plugged in for 48 hours straight and it and it never sets a code. It's only a 400 watt heater like the on on my 05 2500HD 8.1L. So I can't say if Ford or Chrysler's block heaters are set up like the GM's, but the Toyota's are certainly not.

DEWFPO

9r9r9r · February 3, 2008

It's -14 degrees F here right now and I got up early to see if the digital power meter I placed on the heater cord would show it's working. It's not, and the KW/hr meter shows it hasn't worked all night. The heater P/N that the dealer put in is 12586687 ($37.25) and the cord is P/N 15801284. The end of this cord doesn't have a "tumor" like the pictures posted earlier, but it costs $129.27 so it must have some type of control in it. These aren't the part numbers mentioned earlier in the discussion so maybe these parts are wrong, or it's faulty or it's not supposed to kick in till -50! Anyone know? It's hard to believe GM would make a block heater like this. Also, the owner's manual does state that the block heater will work below 0 degrees F, and you shouldn't need one above 32F but doesn't address what to do in between 0 and 32F. It would be considered negligent to start an airplane engine at +5F without preheating, synthetic oil or not.

Edited February 3, 2008 by Alaska06GMCSierra1500

dewfpo · February 3, 2008

It's -14 degrees F here right now and I got up early to see if the digital power meter I placed on the heater cord would show it's working. It's not, and the KW/hr meter shows it hasn't worked all night. The heater P/N that the dealer put in is 12586687 ($37.25) and the cord is P/N 15801284. The end of this cord doesn't have a "tumor" like the pictures posted earlier, but it costs $129.27 so it must have some type of control in it. These aren't the part numbers mentioned earlier in the discussion so maybe these parts are wrong, or it's faulty or it's not supposed to kick in till -50! Anyone know? It's hard to believe GM would make a block heater like this. Also, the owner's manual does state that the block heater will work below 0 degrees F, and you shouldn't need one above 32F but doesn't address what to do in between 0 and 32F. It would be considered negligent to start an airplane engine at +5F without preheating, synthetic oil or not.

It's hard to imagine the heating element itself being bad, there are no moving parts and it's a simple design. So, I would check to make sure the plug connector is firmly seated on the block heater itself. A PITA because of it's location, but if it's on, then you may have a plug with a bad thermostat in it.

If it is the blister kind of plug, then cut off the round part of the blister, pull out the little round, thin metallic thermostat and stick a small metal washer or a dime in there, make sure it is tight, put the rubber blister back on and tape it back together tight. Make sure the washer is making contact all the time. That will eliminate the thermostat in the plug and you should get current to the block heater regardless of temp.

Just use caution when cutting the blister, at those temperatures, that rubber is like hard plastic and difficult to cut. I first tried using a utility knife but that was useless, I wound up using a Dremel tool and that worked sweet. Good luck. BTDT.

DEWFPO

Edited February 3, 2008 by dewfpo

GMCStepSide · February 3, 2008

Welcome to the club Alaska 06! That's why the 06 Silverado gets parked in the garage at night and the 04 Malibu Maxx stays outside - I can plug the Maxx in at any temp and the block heater will work. The 06 with the tumor plug is a joke. You are right about starting a cold Cessna at 5 degrees but GM and the EPA must believe it's no big deal for our trucks. I too have an 06 Silverado, left it out for one night two nights ago and when I went out to start it up thought I was going to have heart failure as the truck sounded like it hadn't been plugged in at all. Granted, it only got down to 2 degrees that night so the block heater never even got a chance to do it's job. I've got it in the garage this morning and will be removing the tumor plug shortly after the Super Bowl or during if it becomes a blow out. You might check to ensure the other end of the cord is actually attached to the block heater...they may have forgotten to do it.

P.S. I had another 06 with the tumor plug, cut it off and other than a very rare CEL, everything was fine - and the truck ran much better on 2 degree or 15 degree mornings! Take that GM and EPA!

Edited February 3, 2008 by GMCStepSide

9r9r9r · February 4, 2008

Thanks for the info. I checked all the connections and now my ammeter says it's working. Good, as it's -10. Looks like when the ambient air gets to zero it will shut off. I guess if you use that block heater stock, you'd better have a garage. That plug is coming off.

9r9r9r · February 10, 2008

The power meter I've had attached to the block heater indicates that it ran exactly 21min 28sec over the past 24 hours. We've been below zero for most of that time and it was -18 at 6a.m. today. The thermostat in mine is pretty close to the engine (not on the exposed male part of the cord), and must turn the unit off after it senses something nearby getting above zero. That heater is a fraud and GM deserves criticism for sacrificing the engine to please the computer. I don't buy the EPA stuff--- nobody else does it. My guess is that it would have cost them a fortune to fix the computer software, so they opted to just jury-rig the heater cord to make it useless. Doesn't say much for Yankee ingenuity.

Then again, I guess they'll sell more engines.

Edited February 10, 2008 by Alaska06GMCSierra1500

dewfpo · February 10, 2008

The power meter I've had attached to the block heater indicates that it ran exactly 21min 28sec over the past 24 hours. We've been below zero for most of that time and it was -18 at 6a.m. today. The thermostat in mine is pretty close to the engine (not on the exposed male part of the cord), and must turn the unit off after it senses something nearby getting above zero. That heater is a fraud and GM deserves criticism for sacrificing the engine to please the computer. I don't buy the EPA stuff--- nobody else does it. My guess is that it would have cost them a fortune to fix the computer software, so they opted to just jury-rig the heater cord to make it useless. Doesn't say much for Yankee ingenuity.
Then again, I guess they'll sell more engines.

My understanding is that....... the OBDII systems on our vehicles need to be able to determine if the sensors are working properly. GM took the cheap route in determining if the temp sensors are within spec. The ECM checks the ECT (engine coolant temp) and compares it to the AIT (Air Intake Temp) and compares it to the ATT (Automatic Transmission Temp) and/or any other temp sensor on the vehicle and if one is not reading a comparable temp for a certain number of starts, then the OBDII systems sets a code for a bad sensor (whichever one it thinks is off).

When we plug in the block heater, the ECT will be higher than any other temp sensor, and after so many starts, it will set a code. I have removed my block heater thermostat a couple of years ago and plug my truck in whenever I want to and have never set a code. But I think that is because all my starts are not cold starts. So if the ECT is reading warm on my first start that morning, the sensors are in sync the rest of the day on all my other restarts. So I never have a series of starts where the ECT is off. At least that is my theory why I haven't set a code yet.

The reason I say I think GM cheaped out, is because the programming for what I stated above is super easy and virtually no cost to them. So few owners have or need a block heater, that GM basically left us out in the cold wind. Whereas I use a block heater on a newer vehicle and never have to worry about it causing a problem, so other manufacturers have taken a different approach that does'nt negatively affect the customer.

Just my 2 cents.

DEWFPO

GMCStepSide · February 10, 2008

The power meter I've had attached to the block heater indicates that it ran exactly 21min 28sec over the past 24 hours. We've been below zero for most of that time and it was -18 at 6a.m. today. The thermostat in mine is pretty close to the engine (not on the exposed male part of the cord), and must turn the unit off after it senses something nearby getting above zero. That heater is a fraud and GM deserves criticism for sacrificing the engine to please the computer. I don't buy the EPA stuff--- nobody else does it. My guess is that it would have cost them a fortune to fix the computer software, so they opted to just jury-rig the heater cord to make it useless. Doesn't say much for Yankee ingenuity.
Then again, I guess they'll sell more engines.

You need to either modify the thermostat on the cord so it is on constant or reroute the cord so it goes out one of the tow hook holes in the lower air dam. Make sure the thermostat is outside of the body so the cold minus zero air can get to it. I played around with mine a couple years ago and found that thermo to be very sensitive to the warm radiator as the plug was sitting just under it. I feel your frustration - don't you just love the television commercials on KTUU and KTVA saying "It's below 20 degrees, remember to plug in." It makes for a real false sense of comfort do so for those who own newer GM products but most folks don't even have a clue. I contacted KTUU and the Muni about it a year or two ago as the block heater program is part of their "keep the air clean by plugging in" program but they didn't care enough to contact me for the full story...oh well.