Blue smoke only on startup

Tiny
NHUNTER24
  • MEMBER
  • 2015 FORD F-150
  • 2.7L
  • V6
  • TURBO
  • 4WD
  • AUTOMATIC
  • 109,000 MILES
There is blue smoke coming from the exhaust, but this only occurs on startup and stops after about 5 to 10 seconds after starting the engine. I would say bad turbo if it was happening constantly but it only happens upon a cold start. Could it be PCV related? Or is it in fact the seals going bad? Can’t find anything concrete online.
Do you
have the same problem?
Yes
No
Tuesday, July 28th, 2020 AT 10:35 AM

11 Replies

Tiny
ASEMASTER6371
  • EXPERT
Good afternoon,

This is usually a result of worn valve seals. When the engine is turned off, oil goes past the seals and into the cylinders.

The oil is burned off when started.

The book pays 25 hours to replace the seals. The seals are around 10 for all of them.

I attached a picture of the seals for you to view.

Due to the age, I would call the dealer and see if there is any warranty for these seals. This is a huge job. How many miles are on the truck?

Roy
Was this
answer
helpful?
Yes
No
Tuesday, July 28th, 2020 AT 1:24 PM
Tiny
NHUNTER24
  • MEMBER
109,000 miles roughly.
Was this
answer
helpful?
Yes
No
Tuesday, July 28th, 2020 AT 1:38 PM
Tiny
KASEKENNY1
  • EXPERT
This could be a PCV, but it looks more like a valve stem seal. The reason I say that is you can see the engine starts but the smoke is delayed by about 2 seconds. Then the smoke is thick and dissipates. This indicates that the oil is already in the cylinders or on top of the head. Due to the engine cooling the valve seals constrict and then when you start the engine it pulls the oil in from the top of the head and it burns it off. So I suspect the oil is dripping into the cylinders when the engine is off and so it builds up for the next start.

I would start with pulling the PCV and checking it for oil then replace it just to be sure. The only reason I am not thinking it is the PCV is this seems like a lot of oil for a PCV.

If that is not the issue, then I would replace the valve stem seals and go from there. It is unlikely that it is oil rings due to this being a newer vehicle but clearly that could be the issue. It is just not likely which is why these other options are more likely.

The way to try and confirm this is to use a borescope and look in the cylinder before you start it after it sits to see if any oil has collected in the cylinder.

If not, run the engine in a high vacuum situations when it is cold. Meaning off throttle braking. This means you accelerate pretty hard and then coast with no accelerator and see if there is a buff of blue smoke. You may need someone to follow you for this.

Let me know what you find or what questions you have. Thanks
Was this
answer
helpful?
Yes
No
Tuesday, July 28th, 2020 AT 1:45 PM
Tiny
NHUNTER24
  • MEMBER
Awesome, I will give this a try and see what I find. I do have a bore camera so that should be a quick way to see if oil is in the cylinders.
Was this
answer
helpful?
Yes
No
Tuesday, July 28th, 2020 AT 1:52 PM
Tiny
ASEMASTER6371
  • EXPERT
They will not cover it under warranty at all.

Sounds like you will need the seals replaced.

Do you have extended warranty?

Roy
Was this
answer
helpful?
Yes
No
Tuesday, July 28th, 2020 AT 1:54 PM
Tiny
NHUNTER24
  • MEMBER
I don't but I do all my own work and have another vehicle. Seems like a simple enough fix, just really time consuming.
Was this
answer
helpful?
Yes
No
Tuesday, July 28th, 2020 AT 2:09 PM
Tiny
ASEMASTER6371
  • EXPERT
Okay, but if a shop pays 25 hours for the job, you can plan on almost doubling that time for the repair.

Roy
Was this
answer
helpful?
Yes
No
Tuesday, July 28th, 2020 AT 2:14 PM
Tiny
NHUNTER24
  • MEMBER
That's what I would expect. In these times I just don't have 3 to 4 thousand to spend on something like this so I picked up the books, so to speak, and taught myself. Been learning all I can for the past few years and I must say it has paid off.
Was this
answer
helpful?
Yes
No
Tuesday, July 28th, 2020 AT 2:18 PM
Tiny
ASEMASTER6371
  • EXPERT
Good for you.

I would get a subscription to Alldata DIY for your truck and you can get the procedure for the job. It is not a lot of money and worth it. It has all the pictures and procedures for you for the job.

Roy
Was this
answer
helpful?
Yes
No
Tuesday, July 28th, 2020 AT 2:27 PM
Tiny
NHUNTER24
  • MEMBER
That sounds right up my alley. Appreciate the tip.
Was this
answer
helpful?
Yes
No
Tuesday, July 28th, 2020 AT 2:39 PM
Tiny
ASEMASTER6371
  • EXPERT
You are welcome.

We are always glad to help.

Roy
Was this
answer
helpful?
Yes
No
Tuesday, July 28th, 2020 AT 3:00 PM

Please login or register to post a reply.

Sponsored links