Oil and carbon causing excessive pinging

[BlueOvalFitter]

2007 F150,4.2V6,17K miles
Just recently my truck started pinging very badly,esp. between the speeds of 55-75 mph.I took it to my local Ford dealer.The tech pulled the upper plenum and found the lower intake runners coated/lined with oil and carbon.Also,he pulled a few plugs and found them to be oily and carboned too.The pcv valve was very oily too!He had to call Ford to get further instructions on what to do next,which won't be until Monday.He thinks it might be a faulty baffle in the valve cover causing the problem.Anyone else have any ideas what the problem might be?

 

[Gary Allan]

Sounds like he's on the right track. If this was beyond warranty you would be installing a catch can of some type ..or lengthening or enlarging the hose.

 

[jorton]

Try to find out if the oil/carbon coating could have come after damage from the pinging. Ford should instruct the mechanic to do a compression test.

 

[bdcardinal]

i bet he already did one via the scan tool. the factory scan tool can perform a relative compression test based off of variations in cranking RPM, it is extremely accurate.

 

[BlueOvalFitter]

Originally Posted By: jorton
Try to find out if the oil/carbon coating could have come after damage from the pinging. Ford should instruct the mechanic to do a compression test.

Are you thinking the rings in one or more of the cylinders could be bad?

 

[mechtech2]

When you get the vehicle back, strongly consider a catch can system of appropriate size in the PCV line to the intake.

Whatever Fords fix is, this will keep oil and raunchy blow by liquids out of your manifold. It keeps you TB and idle motor cclean as well.
A great thing to do fort he long term.

 

[BlueOvalFitter]

Originally Posted By: mechtech2
When you get the vehicle back, strongly consider a catch can system of appropriate size in the PCV line to the intake.

Whatever Fords fix is, this will keep oil and raunchy blow by liquids out of your manifold. It keeps you TB and idle motor cclean as well.
A great thing to do fort he long term.

What is a catch can? I have never heard of this before.Who sells them?

 

[eljefino]

you make them, there are instructions all over the net.

Popular thing is to get an air compressor moisture seperator and some barb fittings, and plumb it into the PCV system.

 

[BlueOvalFitter]

Originally Posted By: eljefino
you make them, there are instructions all over the net.

Popular thing is to get an air compressor moisture seperator and some barb fittings, and plumb it into the PCV system.

Well,i'm a pipefitter by trade so it should not be a problem for me!

 

[Drew99GT]

I essentially have the same problem as you BlueOvalFitter, so I made a catch can using a Husky air compressor oil/water separator.

Unfortunetally, engine heat warped it and it made a vacuum leak. One day, my idle started going up and up and then all of a sudden it was staying at 2,000 rpms or so.

So today, I took Gary Allan's advice and simply made an extended PCV line that goes around the brake booster nipple (you can see it on the end of the intake manifold.) It makes the hose gain about 5 inches of height above the level of the PCV valve - hopefully making it harder for vacuum to suck the oil uphill.

You can buy real PCV catch cans made of aluminum, or make one that's more durable than the compressor separators.

 

[mechtech2]

I use a common air/oil separator like in the picture above.
No heat problems. Under $20
You do have to drain it. Maybe every 2 weeks, maybe more.
It takes too long to drain from the Schraeder valve on the bottom - I just unscrew the bowl and use teflon tape to ensure a good seal.

My throttle body stays CLEAN. There is no more oil puddling in the intake manifold.
If you have a large engine, get a larger air/oil separator [$40].
This also keeps gunk off of the valves, and keeps them clean.

 

[BlueOvalFitter]

Originally Posted By: mechtech2
I use a common air/oil separator like in the picture above.
No heat problems. Under $20
You do have to drain it. Maybe every 2 weeks, maybe more.
It takes too long to drain from the Schraeder valve on the bottom - I just unscrew the bowl and use teflon tape to ensure a good seal.

My throttle body stays CLEAN. There is no more oil puddling in the intake manifold.
If you have a large engine, get a larger air/oil separator [$40].
This also keeps gunk off of the valves, and keeps them clean.

So,basically,you buy a air/water seperator and install it inline of the pcv valve hose?

 

[Drew99GT]

Here's my new setup. The stock PCV hose drops from the PCV valve to the intake. That can't be good for oil consumption. The newer Corolla engines have the PCV hose nipple at the top pf the intake manifold.

 

[Drew99GT]

Originally Posted By: BlueOvalFitter
Originally Posted By: mechtech2
I use a common air/oil separator like in the picture above.
No heat problems. Under $20
You do have to drain it. Maybe every 2 weeks, maybe more.
It takes too long to drain from the Schraeder valve on the bottom - I just unscrew the bowl and use teflon tape to ensure a good seal.

My throttle body stays CLEAN. There is no more oil puddling in the intake manifold.
If you have a large engine, get a larger air/oil separator [$40].
This also keeps gunk off of the valves, and keeps them clean.

So,basically,you buy a air/water seperator and install it inline of the pcv valve hose?


Exactly. I'd personally bite the bullet and make a real one, or buy one on ebay.

 

[mechtech2]

Yes. It simply goes in line. Make sure the flow arrows are correct.
Spend a few minutes to find a nice location. You don't want it next to the exhaust manifold, and you will have to get to it to empty it. You may need a longer piece of 3/8" vacuum line here or there.

 

[Brett Miller]

My Freestar 3.9L did the same thing. I'm glad I unloaded it. It would ping like mad unless I ran premium gas.

 

[mechtech2]

One more thing.
Installing a catch can will not clean out the manifold, backs of teh valves, or combustion chamber. It greatly attenuates deposits in the future.
A quality in tank cleaner may have to be used to get back to normal.

 

[Drew99GT]

Or a full top end cleaning with Seafoam or another cleaner, run through the PCV line or brake booster.

 

[Turk]

Wow - and this is a 2007!

Good luck...