Harder To Start Than Normal.

[HDdave]

Well guys, I just switched from Penzoil 5w-30 conventional to Mobile 1 10w-30 synthetic, and my truck has been harder to start. Could it be because its 10w instead of 5w? I mean its not abnoxiously hard, but instead of holding the key to start for a fraction of a second, I haveto hold it there a little bit longer. I don't really think its a problem, but I figured it was worth checking on.

[Haulin' 8.1]

It's probably just as you suspect, the oil is thicker so it takes a bit more starter to fire up. I don't think it's a problem either. You might try using Shell Rotella sythetic 5W-40 next time. It's what I use. Works great at low and high temperatures.

 

Vernon

[HDdave]

Yeah, I know I will not go back to conventional, but I might try out a few different synthetics. I hear a lot about Royal Purple.

[BlackSilver]

Well guys, I just switched from Penzoil 5w-30 conventional to Mobile 1 10w-30 synthetic, and my truck has been harder to start. Could it be because its 10w instead of 5w?

 

If it were the middle of the winter in the middle of the Klondike I'd say "Well maybe, but not likely."

 

But it's not the middle of the winter and you're not in the middle of the Klondike, the switch from 5W to 10W is un-noticable, and some other issue is in play here.

[HDdave]

I have no clue what it could be then.. Possibly spark plugs. They have 100k on them too...

[Haulin' 8.1]

Do a complete tune-up and have a good shop perform a Crankshaft Sensor Varience Relearn procedure and you will be better off.

 

Vernon

[HDdave]

Do a complete tune-up and have a good shop perform a Crankshaft Sensor Varience Relearn procedure and you will be better off.

 

Vernon

 

 

What is the crankshaft sensor varience relearn? I actually think my crankshaft sensor is bad. My serveice engine light randomly comes on and blinks right around 63 mph. Someone else on this site had the exact same problem and it ended up being his crank sensor.

[Haulin' 8.1]

During the test the PCM samples the signal profile generated by the CKS under specific conditions then uses the new sample as reference for all future CKS input to determine current cranks position and movement. As these sensors age the signal it generates changes usually to the point that it causes the ECM to make mistakes thereby generating poor operation. By doing a relearn procedure it recalibrates the sample to current CKS output so that future judgements are more accurate. Sometimes I wonder if there is ever one done on the assembly line as I've fixed rough idles on brand new trucks doing this. It will often solve a rough idle, hard start, and or cutting out under WOT acelleration that a tune-up doesn't help. If it was me I'd get a new sensor in then do the relearn for it.

 

Vernon