I'm posting this in a new thread with a better title so anyone searching the forum for cold start issues may hopefully find this one pretty easily. I also posted below my last entry in my original thread here: https://www.ford-trucks.com/forums/1...s-working.html

In short: My GP's, GPR, harnesses, batteries, etc. were working but I still had cold start issues. Changing over to synthetic oil was the cure.

Thanks to the members here for the help and support!!!

Rex
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Just wanted to let everyone know my last test regarding changing my oil to synthetic to help with cold starts. If you remember, I could only start my truck after having the block heater plugged in for at least an hour when the temps were below 40 degs. I checked all of my GP's, GPR, harnesses, etc. but couldn't find any issues with them. Two days ago I changed my dino 15W-30 oil to 5W-30 synthetic because I was having a really tough time starting the truck in the morning. Lots of cranking and loping before she would even out after a minute or two. But I also replaced my GPR at the same time so I really made two changes to the truck when it started right up the next morning without using the block heater. I just wanted to know if the GPR was part of the issue or if changing the oil had really helped with the cold starts.

Well, this morning in Austin, the temp was below freezing. Not sure the exact temp but the water sitting in the upside down trash can lid out by the garage was frozen solid. The block heater wasn't used and truck sat over 12 hours in the cold so definitely no residual heat to assist. I turned the key and immediatelty tried to start it- didn't wait at all for the GP's to get warm. And the truck started right up with only a sec or two of cranking!!! It sounded like a couple cylinders weren't firing but it was definitely running. The dino oil was definitely the reason why I was having cold start issues. After only 4-5 secs of running her, I turned the key off and then back on- this time waiting for the WTS to extinguish (maybe 10-15 secs??) before I tried to start her. And she fired right up and purred perfectly with only a second of cranking!!!

So bottom line: If you're having cold start issues and you believe your electronics (batteries, GP's, GPR, etc.) are fine, definitely change your oil to a low viscosity (low W) synthetic as a possible solution.

 

Just changed to rotella t6 tonight. Thanks for your post

 

Yep this has become a normal process for many. Run different oils with the seasons, although many just keep the 5w-20 year round.

 

Not to be a Debbie Downer, but...

While I agree a lower-viscosity oil can help startup, given the above how can you jump to the conclusion that changing the oil solved your issue?

Also, how many miles on your injectors? Your note that it "sounded like a couple cylinders weren't firing", coupled to lower viscosity, leads me to believe that your injectors may be getting long in the tooth.

Bottom line, I'm not clear you can definitively declare that changing the oil was your savior. Or that you're even fully saved.

- GA

 

Just caught your other thread on oil change. Sorry, dude, but I think you're due for injectors and the oil change is only masking the root cause.

A properly running engine should have no dead cylinders on startup; any existence of that means issues with the glow plugs (and they'll clear immediately after startup) or injectors (takes some amount of time or hard running to clear up). I had the same exact issue last winter (dead cylinders on startup, 290k miles) and worked the whole troubleshooting system. No luck. Got so bad over the next year that smooth startup even in 50+ degrees with the blocker heater plugged in was hit-or-miss.

Changed the injectors with remans and WHOOM! Beautiful start, smoother running.

Here's a thread from "another board" that describes the whole process I went through: http://tinyurl.com/madsqkt

Start putting some pennies aside, you're due.

- GA