I have been searching for a while now and have not been able to determine where I need to add seafoam to the engine to give it the treatment. Can anyone direct me to the correct location.

Thanks,
John

 

What year do you have? The n14 has a PVC valve located on the passenger rear of the valve cover. That is where I have done it. The n18 does not have that valve. Do a search for sea foam treatment on the forum. There is a lot out there .

 

In the trashcan....along with BG44 and all the others. It's a worthless gimmick, get the media blast and do it right.

Just my .02

 

I actually already had the walnut blast and it did nothing. I am really grasping at straws here. I have all the classic signs of carbon buildup but nothing seems to work so far. I am open to any suggestions for other solutions.

I did try the Seafoam treatment today and there was no noticeable improvement.

 

The carbon build-up symptoms are very similiar to several other problems. Maybe if you share what symptoms you have and under what circumstances we can brainstorm some other possible solutions.

 

The main symptom is that the car hesitates and stumbles under load. This usually results in some combination of P0300, P0301, P0303 codes being thrown and in some extreme cases on of the cylinders turns off until the next restart. The first time I noticed the problem was doing some slightly spirited driving up a hill on a very hot day (105 F) The hesitation happens in all gears and all speeds if the car in under load. I have had the walnut treatment and it was noted that my compression was a little out of spec.

I do appreciate any help you can offer,
John

 

That's the first time I've heard that walnut blasting didn't work...how could it not though? It physically removes the build-up? Unless the place that did it didn't do it correctly...

 

Compression a little out of spec? Should be about 165psi. I had a similar problem that pointed to cylinder #1 and it turned out that one of the intake valve seats was burned and the cylinder lost compression. It was a faulty install at the factory but it didn't happen until I was out of warranty...lucky I bought a third party extended warranty so it cost zero to fix (would have been nearly 3k). Get those compression numbers checked again and see how far down they are....the only other possibility would be the HPFP.

 

The walnut blast will have done what it is supposed to. The OP has another problem most likely not related to the walnut carbon cleaning.

 

I had it done at South Atlanta Mini. I will say that for the first couple of days it didn't seem as bad but it didn't last.

The other thing that made me think it was carbon was that I don;t drive many highway miles. The car has 57,000 and most were surface street.

 

Another possibility is plugs and coils. Coils usually don't fail three at a time. I changed my plugs when I had the media blast done since they take out the plugs when the do the blast...so an extra $60 and new plugs!

Did you clear the codes and then they came back...or are they left over before the blast?

 

The dealer says the compression is 175 cyl#1 and 180 at cyl 2 thru 4
Cylinder leak down is cyl #1:10% cyl #2: 16% cyl #3: 12% and cyl #4: 9%

 

The static value is good...the 165 is what it should be after leak down, so 1 and 4 are good with 2 and 3 a little below 165....but nothing earth shattering for a 6ish year old car with 57K.....still thinking HPFP but normally hard starting accompanies your other symptoms....anyone else with thoughts?

BTW...I'm always suspicious of dealer performed maintenance or repairs, but that's me with my own experiences.

 

I have not changed the plugs but I suppose I should pull them out and see what they look like. I have reset the codes many times and they always come back. I did get a P1497 after doing the seafoam but it quickly cleared itself

 

Go for the plugs.....it's the easiest and the lest expensive. Make sure you buy the NGK Iridiums....and have the slim and deep socket.

 

I definitely agree with you on this one. We have two Dealerships here and they both are thieves

 

Double check the intake hose to the turbo (air box to turbo inlet hose) - on my '12 MCS the dealership failed to attach it correctly, and when it came loose, the effect was to screw up the mass air flow calculations. End result was fouled plugs and in my case P0300, P0301, P0302 and P0304 codes. My hose came off completely, so I could also hear the turbo and the diverter valve... It's easy to check, and easy to install incorrectly... Make sure the doughnut that fits under the hose is installed on the turbo inlet flange first, then slide the inlet hose over both and secure them with the clamp. Clean off any lube they may have used in the install too...
Cheers,
E

 

Well I seem to have an answer. It was the sparkplugs. Plug #3 was good and burned. I posted a photo in this thread. I am curious what could have caused this. There is some discussion in the other thread.