5.3L engine block heater

[GMCStepSide]

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.

[alwcurlz]

Some thoughts came to mind after reading this long discussion.

The error codes that come up are because it is getting temperature imbalances from different sensors. This seems to tell me one of two things. Either the block heater does not reach a high enough temperature to open the thermostat valve and circulate through the whole motor or, the thermostat requires a higher temperature to open and allow circulation. I would guess that the heating system still bypasses and will circulate through the motor but, not in all the same locations. A cleared windshield would prove that. To say the block heater would damage something is silly to me, unless there are some components that don't behave well with extreme cold/hot fluctuations because the whole motor is not the same temperature.

 

My feeling is this: That if you have a block heater that gets hot enough to open the thermostat, then the coolant will circulate/boil through the whole motor and create an acceptable recently been running condition. However, this is REALLY dependent on how cold it is outside, and how long the heater has been operating. If you don't get the whole motor warm, then problems will arise. On my old car I had, if I didn't have it plugged in long enough, it wouldn't heat it up enough to melt away frost/ice off the carb/linkages and the choke would goof it up too. I had to plug my car in when I got home and left it plugged in all night and then in the morning it was fine. I tried plugging it in a few hours before and that didn't cut it. It needed more than 2-3 hours to warm up with the block heater I had. I don't know what wattage it was. It was averaging -14°F to -20°F between day and night. I would only plug it in when under 10°F as it would fall below that at night. There is a major noticeable difference once the temp drops below 10°F. One time I had to park my car and start it in Karlsruhe, ND without being plugged in. You talk about an engine not liking that...all I remember is the sound the motor was making, it sounded awful, sounded like there was no oil in it and the oil pressure gauge pegged, past 90psi and the hood shook so much it was banging on either fender. And the air cleaner came loose and started rattling. That was the last time I did something like that. 20 min later it was warm and I drove home. The shocks didn't move either so the drive home was a bumpy one. Another thing that's funny now but not then...once on the road, the engine temp which would be at around 190° would drop down to about 150-155°. I had the entire radiator covered and realized the air coming out the vents was not very warm after a while. I found that although the air flow was blocked from the front radiator, it was still pumping coolant through my heater core and cooling the motor that way. The radiator hose was cold to my amazement. I had to pull over cause the windows were frosting up and wouldn't clear. I then proceeded to stuff rags into the air entry to block some of the windchill coming in. Ended up with a fist sized hole and then it was ok.

 

ANYWAY...I moved from there nearly 8 years ago and...I'm moving back there this fall/winter with a 99 Silverado with no block heater. I'm still looking for a set of frost/block heaters. I'd like to put two on it but not sure if it accepts that. Not easy to find one here in Texas.

 

Boy, I miss those Nordern Lights. The best silent light/fireworks show on earth.

 

Edited October 31, 2008 by alwcurlz

[Roger Sparrow]

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!!

[Roger Sparrow]

Since your on the heater subject. I pulled the 6 liter out of my o1 siverado to cure the ole piston slap problem (think rebuild time). As I was cleaning up parts I noticed that there was no gasket under the screw in block heater. I appears to me that there should be one but none of the local dealers can tell me if there should be a gasket for it or not. Do you know?

 

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!!

[rs250]

Sorry to bump this old thread up guys but I have a quick question!

 

When I ordered my 2003 I spec'd it with the block heater even though where I lived in did not get cold...hey it was cheap!

 

Now, seven years later I am using it for the first time since I am now somewhere it actaully snows and gets well below freezing!

 

I plugged it in and came back a couple hours later, stuck my hand down and felt the block and it was slight warm, no sounds but putting my hand over the top radiator hose I detected a slight vibration with a barely audible sound.

 

Is this normal, it seems to work as it gave heat very quickly and wamed up quick in 49 degree weather. As soon as I unplugged it the vibration stopped.

 

Is this warm water trying to make its way around, or just a normal by product of the heating element doing its thing?

[stefman722]

Hey guys! Old thread I know hehe. How's the trucks doing for the people that cut the cord ends with the thermostats? It's been -40 for two days overnight here and I can't take my truck sounding like a dying rabbit every time I start it after its been sitting for 12 hours in this cold. Seems like the block heater isn't working at all. Piece of crap.

[getgoosed]

I have had the end of my cord chopped off for about 2 years now and it is working perfectly. Temp here is constantly below -20c and have no issues. Nice to know that when the truck is plugged in, the block heater is on.

[Taz107]

To help others who come across this problem...there is an alternative out there to the $160-$180CDN that GM wants for it...

 

Phillips Temro p/n 3600082 is the replacment cord, most parts stores can get for around $50 CDN...

As an example...

http://www.oreillyauto.com/site/c/detail/ZRO0/3600082.oap?ck=Search_3600082_-1_1769&keyword=360008

 

I am going to cut the factory one off and splice the just the new plug end on, no way I'm crawling around under the truck in these temps trying to connect it to the block heater itself...

 

Hope this helps someone else out...it took me way too long to find this info...

[j-ten-ner]

To help others who come across this problem...there is an alternative out there to the $160-$180CDN that GM wants for it...

 

Phillips Temro p/n 3600082 is the replacment cord, most parts stores can get for around $50 CDN...

As an example...

http://www.oreillyauto.com/site/c/detail/ZRO0/3600082.oap?ck=Search_3600082_-1_1769&keyword=360008

 

I am going to cut the factory one off and splice the just the new plug end on, no way I'm crawling around under the truck in these temps trying to connect it to the block heater itself...

 

Hope this helps someone else out...it took me way too long to find this info...

I'm not sure if I understand correctly.

You wanna replace the factory cord with the thermostat by another cord with a thermostat?

 

Since English is not my native language I have sometimes trouble finding the "connections"... .

 

so long

j-ten-ner

[Taz107]

I am replacing it because the wires corroded and the plug broke off right at the end, leaving no wire to splice back together on the factory one.

 

Just wanted to let people know there is a cheaper aftermarket option available.

[j-ten-ner]

Thanks.

 

so long

j-ten-ner

[Peter Golden]

Would this part work on my 2000 GMC ukon xl?  What is the thread and size of thread? Zerostart 3500043 Engine Block Heater for Ford, Mercury, Lincoln, International, Caterpillar, Detroit Diesel, Hino, Mack, Nissan, 3/4" NPT Thread | CSA Approved | 120 Volts | 1000 Watts

[txab]

Don't think so. If you've got a 5.3 then you should use one that looks like this, according to charts. One of the block plugs unscrews and this replaces it