[Jacky Campbell]

I have a 99 Suburban that won't start when the outside temperature is too cold, like below 40. The engine turns, acts like it wants to start, but won't fire. I end up having to jump start it. It has a brand new Interstate 5 year battery, that's been tested twice in the 2 months I've had it. This last time, the guy put a voltmeter on it and had me start it. He told me to get my starter checked and that it was pulling it down too far.

It starts fine when it's warm outside, or when it's already been running for a while. Before I take it in yet again, does this sound valid? Thanks.

 

[RayVoy]

I'm in Canada and we can have cold mornings, I am not able to plug in my truck (block heater) if my driveway is filled, as it is right now, with snow.

For that reason, I started to use synthetic oil many, many, years ago (there are a number of other advantages as well).

On the coldest of mornings, my truck starts like it is a summer morning.

 

[Aquila99Sub]

RayVoy makes a very valid point. With mineral or regular oil, in cold weather it can thicken due to the cold. Synthetic oil is less likely to do this which would make the engine turn over a lot easier on first start up.

Jacky - if you are using mineral oil and possible a decent weight, that would be creating a heavy load on the starter first thing in the morning which would cause a heavy draw on the starter and battery. Does it crank slowly on first start up? If so, that would be a first clue. You probably already know this, in cold weather best to use a light weight oil, possibly synthetic and also make sure you have the right coolant mixture for your temperature, you probably want a higher percentage of anti-freeze if you are in freezing conditions.

 

[RayVoy]

@Aquila99Sub, I agree with what you said, just want to clarify that the best antifreeze mix is a 50/50 mix.

 

[the phantom]

If your having the problem around 40 degrees your oil and antifreeze should not prevent it from starting regardless of what kind your using. Now if you were just having the problem when its 0 degrees or below zero (Fahrenhiet) I could see this being a possibility. I have had a starter do exactly what your describing though. Has a hard time when its cold but if its warm out or the vehicle has been running it has no problems. But usually you can hear the strain from the starter most of the time if/when the problem occurs. If your battery is good and it starts only when you jump it then the extra power from the jump is the difference in getting it to turn over fast enough. I would tend to agree with the guy you had put the voltmeter on and would say your starter is on its way out. I had this happen to a fuel pump. Brand new battery, turned over fast and perfect but wouldnt start. Put jumper cables on and would start right up every time. sounds weird but just the extra amp/voltage to the worn out fuel pump gave enough pressure to start.(this was on a 99 jimmy). Anyways good luck and hope you find your gremlin

 

[RayVoy]

If your having the problem around 40 degrees

I had to go back and re-read the first post. He said below 40, I thought he said 40 below.................haha, that's not cold, that's a summer morning in Canada.
I think @Aquila99Sub read it the same way.

 

[Family Force 6]

Agree w/ phantom. Pull the starter and have it bench tested. I had a bad starter solenoid that acted up when it got cold and sounds like that could be your problem.

 

[MrShorty]

Perhaps I am not reading this correctly, but this

The engine turns, acts like it wants to start, but won't fire.

does not sound like a bad starter. I could be wrong, but when my starter was dying, one of the symptoms was very slow, hard cranking. It would often start, but you could tell that the starter was turning the engine really slow.

I might suggest you double check your description of the problem. If the starter is doing its part to turn the motor, and the motor is not starting, then I would suspect something else is causing the no start. Low fuel pressure, no spark, or something like that.

 

[Aquila99Sub]

I live in a place where 50 dergees is considered cold - sorry if my information was wrong. I did read it to mean like it was freezing. Could just be something as simple as fuel supply.