Rough Cold, Smooth Hot
Thread Starter
|
Senior User
Joined: Sep 2007
Posts: 335
Likes: 1
From: Richmond, Texas
Rough Cold, Smooth Hot
My truck runs very rough and lacks power when cold, even during the Texas summer. Once it warms-up, everything is fine. It's almost like turning on a light switch. If it's plugged in for a couple/few hours, it's smooth as soon as it starts. I'm assuming it likes the oil once it reaches a specific temperature. Any ideas on what my problem is?
Thread Starter
|
Senior User
Joined: Sep 2007
Posts: 335
Likes: 1
From: Richmond, Texas
I'm running T6 and changing it every 6k. Prior to my most recent oil change, I had used Hotshot's Secret 3 or 4 times. I'm not using it now, and nothing seems to be any different. Fresh oil or tired oil, additive or no additive, nothing seems to make a difference except oil temp.
Postmaster
Joined: Nov 2015
Posts: 4,807
Likes: 125
From: Colorado Springs
Try using Archoil 9100 in your oil. It made a huge difference in my cold start and idle! I convinced a buddy to try it in his 6.0 an he's sold on it now too.
AR9100-16 Archoil 16oz Friction Modifier https://www.amazon.com/dp/B005UO6EWE..._ehVzwbR2SDQX0
AR9100-16 Archoil 16oz Friction Modifier https://www.amazon.com/dp/B005UO6EWE..._ehVzwbR2SDQX0
Junior User
Joined: Apr 2012
Posts: 60
Likes: 0
From: Romeoville
My truck runs very rough and lacks power when cold, even during the Texas summer. Once it warms-up, everything is fine. It's almost like turning on a light switch. If it's plugged in for a couple/few hours, it's smooth as soon as it starts. I'm assuming it likes the oil once it reaches a specific temperature. Any ideas on what my problem is?
Trending Topics
Lead Driver
Joined: Jun 2004
Posts: 6,303
Likes: 575
From: Amarillo, TEXAS!
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
Ford Super Duty: 5 Things Owners LOVE, 5 Things They LOATHE!
Joe Kucinski
Every 2026 Ford Truck Engine RANKED from WORST to FIRST!
Michael S. Palmer
The Best F-150 Deal of Every Trim Level (XL through Raptor)
Joe Kucinski
Lead Driver
Joined: Jun 2004
Posts: 6,303
Likes: 575
From: Amarillo, TEXAS!
It's relatively easy to confirm it or rule it out with a set of feeler gauges. When the armature plate to poppet body clearance is less than 0.0015", that's when they usually start showing the signs of wear, in the form of running rough when cold.
Tuned
Joined: Jan 2014
Posts: 441
Likes: 5
I'm dealing with the same issue. On cold start under 43 degrees my Excursion runs really rough, but after it heats up, smooth as can be. It has 143,000 miles, and no codes for glow plugs, so I am thinking injectors are worn out.
Lead Driver
Joined: Jun 2007
Posts: 7,760
Likes: 27
From: Hampton, Maryland.
You won't necessarily get any glow plug codes. I would check the GP system and make sure it is working properly. I know you have the GP control module and I am not sure how to check it, but I am sure there is a procedure and a search will turn it up. You certainly can ohm out the connector and make sure the GP's themselves are in working order. 143,000 miles is a little soon, but mine started getting bad the winter I was around 150,000 miles, so it CAN happen. I just would hate to hear that you threw $1000+ at a problem that could be a bad module, or several bad GP's and then had to replace them on top of buying and installing new injectors.
Thread Starter
|
Senior User
Joined: Sep 2007
Posts: 335
Likes: 1
From: Richmond, Texas
I'm really thinking my issue is something other than injectors or oil temp. It's a "light switch" type of issue. When my motor gets warm, the "light switch" is turned on and everything is great. If I plug in my truck, everything is great. If I don't plug in my truck, it's really rough, similar to when my IDM went out and I was running on half the motor. When I leave in the morning with a stone-cold engine (whether it's 30* outside or 90* outside), the "light switch" comes on roughly at the same intersection about 3 miles from home. So, I'm leaning towards an electrical issue. Any ideas?
More Turbo
Joined: Nov 2012
Posts: 727
Likes: 1
From: Chariton, IA
You can check the UVCH and make sure it's not loose, ohm out the injectors and glow plugs, but it really sounds like injectors. I just replaced mint last year at 340k, and it was doing pretty much what your describing.
The reason it feels like a "light switch" could be because the injectors either work or don't, until the oil warms up enough to flow through the poppet valves.
Check the poppet valve clearance like was mentioned earlier, ohm the injectors, and do a compression test before replacing the injectors. Also if you have some kind of OBD2 tool to read live data see what your HPOP and IPR is doing just to rule those out. At 340k, things start to wear out. i'm hoping to get a t500 this year for mine.
The reason it feels like a "light switch" could be because the injectors either work or don't, until the oil warms up enough to flow through the poppet valves.
Check the poppet valve clearance like was mentioned earlier, ohm the injectors, and do a compression test before replacing the injectors. Also if you have some kind of OBD2 tool to read live data see what your HPOP and IPR is doing just to rule those out. At 340k, things start to wear out. i'm hoping to get a t500 this year for mine.