Cold Weather Blues

[sondog]

When my truck is plugged in all day at work, even at -30C, It starts for 10 seconds, then sputters and dies. Have pending code P0300. When I leave unplugged at - 25C, starts and runs fine. I thought the -18C cord solved this problem? Anybody have a suggestion? Truck is booked in on the 21st, but like to go there informed. They installed the block heater last fall, and I had no problems last winter.

[dwhults]

This might help:

 

Causes

 

A code P0300 may mean that one or more of the following has happened:

 

* Faulty spark plugs or wires

* Faulty coil (pack)

* Faulty oxygen sensor(s)

* Faulty fuel injector(s)

* Burned exhaust valve

* Faulty catalytic converter(s)

* Stuck/blocked EGR valve / passages

* Faulty camshaft position sensor

* Defective computer

 

Possible Solutions

 

If there are no symptoms, the simplest thing to do is to reset the code and see if it comes back.

 

If there are symptoms such as the engine is stumbling or hesitating, check all wiring and connectors that lead to the cylinders (i.e. spark plugs). Depending on how long the ignition components have been in the car, it may be a good idea to replace them as part of your regular maintenance schedule. I would suggest spark plugs, spark plug wires, distributor cap, and rotor (if applicable). Otherwise, check the coils (a.k.a. coil packs). In some cases, the catalytic converter has gone bad. If you smell rotten eggs in the exhaust, your cat converter needs to be replaced. I've also heard in other cases the problems were faulty fuel injectors.

 

Random misfires that jump around from one cylinder to another (read: P030x codes) also will set a P0300 code. The underlying cause is often a lean fuel condition, which may be due to a vacuum leak in the intake manifold or unmetered air getting past the airflow sensor, or an EGR valve that is stuck open.

[T Loz]

I just had my 07 Silvie at the dealer yesterday and I asked about the block heater cord. Because it only works after -18c, they recommend using a timer for the block heater...Plugged in too long raises the engine temp so when you start it the computer senses ouside air and engine temp. if the engine temp is too warm the computer will generate a code ....You then have to go to the dealer for a reset...."That's what they told me" !!!.....

[d3athsong]

I just had my 07 Silvie at the dealer yesterday and I asked about the block heater cord. Because it only works after -18c, they recommend using a timer for the block heater...Plugged in too long raises the engine temp so when you start it the computer senses ouside air and engine temp. if the engine temp is too warm the computer will generate a code ....You then have to go to the dealer for a reset...."That's what they told me" !!!.....

 

So are they saying it will raise the engine temp to an unnacceptable level, or that the temp difference beteween air temp and engine temp is too great, or what? Becasue if it's the first one, you must have the worlds greatest block heater. On a side note, the older trucks don't have a problem with beign plugged in for long periods of time.

[T Loz]

I just had my 07 Silvie at the dealer yesterday and I asked about the block heater cord. Because it only works after -18c, they recommend using a timer for the block heater...Plugged in too long raises the engine temp so when you start it the computer senses ouside air and engine temp. if the engine temp is too warm the computer will generate a code ....You then have to go to the dealer for a reset...."That's what they told me" !!!.....

 

So are they saying it will raise the engine temp to an unnacceptable level, or that the temp difference beteween air temp and engine temp is too great, or what? Becasue if it's the first one, you must have the worlds greatest block heater. On a side note, the older trucks don't have a problem with beign plugged in for long periods of time.

 

I believe this applies(temp difference beteween air temp and engine temp is too great) to the nnbs. Their computers ,I guess, are setup differently..The dealer also said you can use a regular cord(no temp sensor) in the nnbs but to use a timer as well...

[sondog]

You would think the block heater at -30 C running all the time would not get some sensors too hot, but seeing that I had no problems last year in the winter, I guess a quick check of other things may be needed. Since the truck works fine once I pedal it through the missing for 20 seconds, the pvc probably is out of the question. Don't know if an intake leak would seal itself after 20 secs, same goes for the plug wires. Probably a bad sensor. I still can not believe GM doesn't want us to plug in our vehicles. My truck last night was on a timer for 2 hours before I started it at about -23 C and it would not run.

[rodram]

I'm going with the advice from LaCeS OuT ...

 

....which may be due to a vacuum leak in the intake manifold or unmetered air getting past the airflow sensor, or an EGR valve that is stuck open.

 

I think the so-called intelligent block heater cord is a red herring .... (and a potential big pain in the ass.... what if it fails to click on when it goes below -18 or whatever...)