Cleaning manifold and EGR, effect before and after

One aid you might have in making that "how often" judgment is that you can pull up the car's most recent EGR flow test results.

There seems to be some variability in how severely and how soon cars are getting clogged.



Another very useful contribution you could make toward the next person who has the same question is: whenever you do decide to tackle the EGR system cleaning, if you could collect the flow test numbers from before and after, and post them on the valve blockage data thread along with before/after photos from your physical cleaning, to build up our knowledge of how the numbers correspond to conditions on physical inspection.

 

Hi I installed oil catch can.
And no more oil under throttle body.
I assume that it will not eliminate oil consumption. But it eliminates burning oil ,hence it will save my egr from clogging , the same to catalitic converter

 

Looking forward to the future data on those points.

 

Don’t assume too many absolutes. Any oil catch can will reduce the oil delivered to the intake manifold via the PCV circuit. Highly effective ones more so. Two highly effective ones in series even better.

But it won’t get 100% of the PCV flow. And even if it did, you’ll also get a small amount of oil “spit back” into the manifold, from the intake ports (due to Atkinson cycle engine).

And, I don’t think your Exhaust Gas Recirculation cooler/valve/pipe is going to remain carbon-free, even with a goodly reduction in the intake manifold oil. Combustion engines inherently put out carbon.

it’ll help, but I’d still be prepared to clean everything periodically, maybe just not as frequently. And anyways, after the first time you’ll be a lot smoother at it, especially if you’ve left off the bottom bracket nut and stud of the cooler.

And, draining a couple of quarts of coolant first (into clean container), you don’t need to clamp coolant hoses, and won’t spill a drop.

 

So I finally got around to working on my car last weekend and found oil in the intake manifold just like everyone else. I also found quite a bit of carbon in the EGR cooler, valve and pipe and ended up using 3 cans of Brakleen and some degreaser to clean them out. I only remembered to take a picture of the EGR cooler while it was dirty though.

@ChapmanF I did however get screenshots of the EGR flow before and after as requested.

While in there I noticed that I had a pending DTC for P0303. I am attaching screenshots with details of the misfire and would like someone's input if they can provide some insight or see any values that stand out. @Patrick Wong

Is there still a TSB for this code? I have reset it as I didn't see any active misfires and wanted to know if it resurfaces after cleaning. Any recommendations or advise would be appreciated.

I also currently see the misfire margin drop as low as 22% while the engine is running. What values are considered normal?

While there I also checked the spark plugs and they looked good with correct gap, no oil just a little carbon buildup that I gently brushed off. The car only has 51,500 miles on it and there doesn't seem to be any coolant or engine oil consumption. The oil still looks clean/yellow after about 2500 miles. Oil has been changed every 6 months between 3-4k miles.

 

DTC P0303 means that cylinder 3 has a misfire. I would say that your odometer reading is sufficiently low so that I would not expect the EGR system to be the cause. I would also expect the misfire count to be zero for an engine that is operating normally.

You say that the car does not have an active misfire, so it may not be that easy to trace the problem.

However, you might start by swapping the cylinder 3 ignition coil with another cylinder's coil to see if the misfire moves around, after you've driven the car enough for the misfire to reappear.

If you find the coil is not the problem, then swap the cylinder 3 spark plug with another cylinder's spark plug and repeat the process of driving around enough for the misfire to appear.

If you find the coil and the spark plug are not the problem, maybe the cylinder 3 fuel injector has a problem, or maybe the intake manifold EGR port for that cylinder actually has developed a clog.