Burning oil on start up

[Brandon96]

After my Ex sits over night or has time to cool down upon start up it blows out a decent and increasing amount of smoke. It only burns off at start up, never at idle or under acceleration and it appears to be oil to me. But now I'm hearing that it can be a fuel backup with bad injectors?

What causes a vehicle to burn fuel and or oil on start up? Any thoughts? I'd like to get this fixed

 

[Brandon96]

I'm going to bump it one time as I have a ton of free time today

 

[my98nnj]

A large puff of blue smoke (oil burn) at start up indicates leaking valve guides.

 

[Brandon96]

A large puff of blue smoke (oil burn) at start up indicates leaking valve guides.

Alright I'll look into that, thanks. A coworker today told me it could have something to do with the PCV valve? Is that feasible?

 

[chapsdeva]

A large puff of blue smoke (oil burn) at start up indicates leaking valve guides.

+1....Yep....sounds like you will need to replace your valve guides eventually.

 

[Hunz]

I think what your co-worker meant is that your crankcasse will leak oil out of every whole it can find if you PCV valve is clogged. If its stuck or clogged up, your engine can't regulate its crankcase pressure(usually causing too much) So you drive your truck, its leak oil and makes its way down to your exhaust when it sits overnight and when you crank it up; heat and oil equal oil burning. I've dealt with this problem for two years. It is my front main seal leaking though and I have already replaced the PCV and front main seal and it still leaks like a sieve.

 

[jlsparky7]

Definitely valve seals.

 

[ranger7ltr]

X 2....

Definitely valve seals.

But I would ask if the last oil change showed really dirty oil? If so, you COULD have a lot of top end sludge keeping oil around the valve guide tops and/or valve stem seals which are probably not in the greatest shape...

Did this just start happening? And yes a clogged PCV system can cause problems like this too...

How long have you owned or driven this vehicle before this started???

 

[Brandon96]

But I would ask if the last oil change showed really dirty oil? If so, you COULD have a lot of top end sludge keeping oil around the valve guide tops and/or valve stem seals which are probably not in the greatest shape...

Did this just start happening? And yes a clogged PCV system can cause problems like this too...

How long have you owned or driven this vehicle before this started???

It's been family owned since day 1. But I've been driving it for the past +/- 16,000 miles. I don't know eaxaaactly when it started but I'd say around 2k miles ago.

The oil was changed right before I got it with Valvoline high mileage. I replaced it 5k later with the same. Then another 5k but I switched to a lower grade Pennzoil synthetic and replaced it again 2k after that with a Castrol Synthetic. Every time I've changed the oil it's been dark, but still had a brown tone to it, Never black.

NOW, about 3k - 4k miles ago I started to notice a terrible idle and a misfiring problem with Cylinder 4. Never fully figured it out, but cleaned all the sensors, checked for vacuum leaks and replaced the Spark plus with Champion Iridium plugs. Since then I've run a few cans of Seafoam through it and put some Lucas injector cleaner through her. I did pick up a few MPGs but never could shake off that rough idle. It will only do it while in park, but it will run fine for 2 or 3 seconds then the RPMs drop barely noticeable, like it doesn't register on the RPM guage.. and it starts to lope like it's cammed or something for a couple seconds.. then picks back up to normal idle. I just said whatever, that's kinda cool, I quit with you.

About that time or shortly after it began to smoke on start up.

Can that idle have something to do with the PCV?

 

[Brandon96]

Okay, nevermind. A new PCV valve, Lucas Oil system treatment and a new sway bar link seemed to fix the problem! hahah, thanks guys!