We have been experiencing some cold temps here in CO. Between 20 and 30 degrees when I start my truck. Yesterday when I fired it up it went to its normal rpms and then dropped to around 600 rpms (kind of struggling to get going) and then it bounced back up to normal. This morning it did the same thing then died, 2nd try it didn't start (I do not hold the key long feering damage to starter), and third time it fired right up. It has only done this when it has been cold. I am not sure what it is. I just had the exhaust system put on a couple of weeks ago, any relation. I just rolled over 4200 miles on my 3 month old truck. Any ideas as to what is going on would be appreciated. Is it possible that it will start like that when it is cold? Thanks for any info, it is alway appreciated. Levi

02 F150 4x4 5.4 V8, auto, 3.55 limited slip, sport, 17" wheels, cat back duals with NO MUFFLER...

 

I would not be worried. If it is that cold you can't be expecting it starts at the first turn of the key. Combustion doesn't work too well in very cold conditions. You might want to crank it a bit longer instead of going in bursts of key turns. You progbably are just starting to build nice compression, having things start to seat nicely and then you stop cranking, starting at 0 again.

I would crank it at least for 5 seconds before stopping to crank. I bet you it will start within 5 seconds. You will not damage your starter by cranking longer, unless you go for minutes! You will wear your battery out before the starter suffers. Your battery can take 5-10 second cranks easy if you give it some time to come back up between.

Hope this helps.

George

 

You might consider a 0W oil for winter time there, too. A 0W-30 will start more easily than the 5W-20 that is now currently recommended and which I assume is what you're using.

Besides, if you still have the original factory fill, that oil at 4200 miles, is laden with metal chunks (relatively speaking) and all kinds of crud that are dragging on the engine when the oil is cold, in addition to the oil itself.

 

I'd try changing brands of gas. First of all, 20 degrees is NOT cold- it's already been 12 BELOW zero here, and no problem starting any of my vehicles. You're probably experiencing the problems that come from winter-formulated gas, and the problems can vary from brand to brand. See if a different brand doesn't help. These problems can also be caused by too HIGH an octane. Your engine is designed to run on 87. Go much higher and volatility problems can arise, which usually show up as a hard-start condition. 93-94 octane is just too high- 87 to 89 is what you should be using.

 

Thanks for the tips. I do believe it was a case of bad gas. I added a half a tank of other stuff and it seemed to fix it. I use the spec oil and changed it at 3000 miles, so that shouldn't have been the problem. I got the bad gas at a SAMS station, they only have regular and premium (87 is midgrade in my part of the country) so I had to use the higher octane. That is interesting about too high of an octane. Premium here is 92 ( I think). Thanks for the info. Levi

02 F150 4x4 5.4 V8, auto, 3.55 limited slip, sport, 17" wheels, cat back duals with NO MUFFLER...

 

I am not an expert but I have a 1997 version of your truck and there are three basic considerations. Fuel: Use high octane especially of your location (thin Air). Air filter: Was it changed at 30K? This is really not necessary unless you have been driving under excessively dusty or off road conditions. The third might be plugs that should and usually last 60-100k miles with only rough engine symptoms occurring.

One other consideration is do you use dry gas? If not you might have water in your fuel or filter which would be worse as it could eventually block the flow under these conditions. I would spend a couple of bucks and add it to every tank full during the winter months to protect against this. Also consider the gas station you frequent might have had a bad batch of water latent fuel. Ask frequent customers of this station to narrow down your equation.

I Live in Maine and experience similar weather conditions and threw out the winter months and have found adding "Heat", "Dry gas", to be a low cost insurance policy against this difficulty and being stranded and having to have my vehicle thawed out in a heated garage for a day.

Best of Luck!

 

Levi,

One other consideration if you still experience problems and you did not purchase your vehicle locally at a similar altitude you may want to take it to a dealer or repeatable repair shop and have them program your system for that altitude.

Peter