Another block heater question [Archive] - Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum

: Another block heater question


xfyr2005
12-10-2009, 10:03 PM
Just got a 2008 TB and want to add a block heater. Several parts places state none avaliable for this year. Thier books stop at 2004 for applications of OEM part number. Questions are, has anyone added an OEM one to a 2008?

Second, has anyone ever installed a "Zerostart" block heater on a TB?

Thanks

Chickenhawk
12-11-2009, 08:05 AM
Zerostart is a brand-name of a block heater manufactured by Phillips/Temro. They make everything from the usual 750-watt coolant plug heaters to 1500-watt heaters for diesels, plus magnetic-mount heaters.

You do NOT want a 1500-watt heater because you will need an entire household circuit dedicated strictly to it. You also do not want the magnetic mount heaters. They may be easy to install on steel engines but they do not heat anywhere as good as the plain old frost-plug heaters.

The coolant plug heaters are a pain to install because: a) you need the vehicle on a lift, b) you need to drain most of the coolant, and c) in spite of a) and b), you will STILL get a face-full of coolant when you knock out the old frost plug.

But on the up side, they work reliably and will last for many years.

As for fitment, the books may not have them listed for that year but keep looking and you will find a listing. They are not engine-specific, but they will vary by size of the frost-plug and by length of the cord. This means that a good mechanic can get almost anything designed for that size of frost-plug to fit.

Take it from someone who relies on block heaters for 4 months of the year!

(When you are plugging in your vehicle, you only need it on for three hours at the most. Any more and you are simply wasting electricity. It will not heat the cabin any sooner if you leave it on all night. Three hours is just fine. I may occasionally go to four hours at minus 40 if the truck is outside but that is rare.)

vball61
12-11-2009, 12:00 PM
There is an OEM block heater listed in the GM parts catalog for the '08-'09 Trailvoys w/I6. It looks like the heater element and cord are purchased separately...

12586687 Heater Element (1)
15923709 Cord (includes 2, 3 & 4)

I believe the parts are supplied to GM by Phillips and Temro. The heater element is marked 400W @ 115V.

xfyr2005
12-11-2009, 03:17 PM
Thanks.........I appreciate the help.

MichEnvoyBoy
12-12-2009, 10:30 PM
The coolant plug heaters are a pain to install because: a) you need the vehicle on a lift, b) you need to drain most of the coolant, and c) in spite of a) and b), you will STILL get a face-full of coolant when you knock out the old frost plug.

But on the up side, they work reliably and will last for many years.


Take it from someone who relies on block heaters for 4 months of the year!


Whaaaaat?

I installed my Goodwrench Block Heater on my 2002 Envoy with the front driver side jacked up and the wheel removed. I installed it through the wheelwell in about 40 minutes from start to finish. Was one of the easier jobs Ive done on T360's over the years!!

For the record, the 'frost plug' is threaded. Dont need to knock anything out. I took out the plug, and quickly threaded in the block heater, thus only draining about 1.5 quarts of dex-cool. I refilled, started up, checked for leaks, and have been using my block heater for 3+ years now!

Chickenhawk
12-13-2009, 12:59 AM
Cool! Thanks for the update.

You can tell it's been many years since I had to install my own block heater!

One other thing to consider is that starting in about 2005, GM vehicles have a different block heater cord. The plug end actually senses the outside air temperature and won't put power to the heater until it is below a certain reading. (About 0 degrees F.) If this plug end is cut off and replaced with a regular end, the newer computers sense a wide temperature variation between the warm block and the cold outside air, and sets off the SES light and possibly the reduced engine power warning.

This could be one of the reasons for aftermarket parts suppliers not being up to date.

I think this is one of those 'green' ideas that was not well-thought-out. (Like most of them, I think ...) On the other hand, it does prevent owners from simply firing them on full blast all night long when it wasn't needed.

As I said before, 3 hours is plenty on even the coldest days on the planet. Any more is a waste of energy, and you risk setting off a trouble code on the newer vehicles if their temperature sensing plugs have ben replaced.

MichEnvoyBoy
12-13-2009, 06:21 PM
On other forums I frequent, there are a lot of writeups about that inline thermostat built into the block heaters you mention ... and a lot of talk about how to remove the inline t-stat on the block heater so it heats all of the time.

Ive got to say... I consider myself fortunate. Ive only had my CEL illuminate twice. Once when my 4wd switch went wacky and my "service 4wd" light came on, my CEL did too. And the other time was when my thermostat was stuck open. In 5 years of ownership and 60,000 miles (125,000 on the truck total), I think thats pretty comendable!