I recently put seafoam in my engine through the brake booster. Followed all of the directions and took that car for a hard drive to flush all that crap out. I initially noticed that when i really punched it, the engine kinda kicked back, or lost power for an instant. That night on the highway, it started to happen more frequently and eventually the engine started shaking and the Check engine light flashed. Ever since the car has been undriveable. I cleaned the MAF sensor as this seemed to be the issue, but as of now the problem has not been resolved. I am planning on getting a scanner today to pull the codes but has anyone else had a similar issue with the seafoam? Everything i read about it claims its perfectly harmless but it clearly did something bad to my car here. Its a 1.8T by the way. Hope someone knows what's going on here cuz I'm in the dark.

 

I'm assuming you killed a check valve or two. Check for vacuum leaks.

 

i had this same thing happen... i swapped plugs and corresponding coils that went bad ironically at the same time as doing the seafoam... flashing cell means misfire... yes pull the codes, probably 1 or 2 cylinders, swap coil packs see if it follows those, if not swap plugs.... might have got carbon on one and it can't pass the fire

 

im pretty positive there are no vacuum leaks. I only disconnected the brake booster and i know that it is fully reconnected. where are these check valves located? how many could be affected by the seafoam? is it just a cleaning that would do it or would the valves need to be replaced

 

turbo, I am by no means a qualified mechanic. is this something i should have my mechanic do or is it something i can do. I replaced the coolant temperature sensor because I know the one in there was faulty, regardless of if it affected the misfiring, and now it's leaking coolant, which i think i can attribute to the faulty o-ring. regardless, im at a point where i dont wanna touch the car anymore myself. it seems everything i touch is turning to ashes.

 

Seafoam through the brake booster? That just doesn't sound right to me. Am I missing something?

But, yeah, you sound like you have bad coil packs. Get the codes and follow the steps listed above. It's easy. Pretty much, if it says misfire, cylinder 1, then swap cylinder 1 coil pack with cylinder 4 and the cyl 1 spark plug with cyl 3. Reset the CEL and go for a little drive. If the code follows to cyl 4, you need a coil pack, if it goes to cyl 3, you need a spark plug, if it stays on cyl 1, then you have other issues.

Just be careful not to break anything else

 

well, you will need a code reader either vag com or just a basic reader, and like i said if it says cyl 1 then swap that coil, i would actually not go to cyl 4 unless you know which is which, go to cyl 2 or 3.... then if it stays, try swapping the other one you think is 1... but i think it goes front to back 1-4....

check valves are the little space ship looking things, but i doubt your check valve is causing a flashing cel.... lately i have felt the same way about touching my car.... lol

 

well good news all around. thanks for your posts guys. i got the reader and the biggest issue was cylinders 3 and 4 were misfiring. i pulled the spark plugs, which looked horrible, and ended up replacing all of them. right away the car was idling waaay better than before. took it for a drive and it pretty much feels back to normal. huge relief. as for the coolant sensor, i realized i put the black clip that holds the sensor in place on incorrectly, so i fixed it and no more coolant is leaking out. before i replaced the plugs, i was getting 5 codes, after replacing them i only had 1 about the MAF having low circuit input or something, but i cleared it and ill see if it comes back. Thanks!

 

Glad to hear its all better. For future reference seafoam is known to **** up sparkplugs. A wire wheel can be your friend tho instead of buying new ones. And I would seafoam elsewhere in the vacuum system, cuz it can trash check valves.

 

Elsewhere meaning the ports on the intake manifold. I prefer to use some small clear tubing. I disconnect the vacuum line closest to the bumper on the manifold and put my tubing on. Then I start the car and let it suck up the foam little by little. It usually takes ten minutes to drink the 1/3 can seafoam. I might rev it a little, but not so much that the turbo is spooling or anywhere near that. The line I remove goes to the diverter valve and it less important it seems than the vacuum line that is nearest to the cabin. That line is for the fuel pressure regulator. After all the seafoam has been ingested, as you know, you shut the car off for five minutes or so, then start her up and give it some revs. I dont drive the car with seafoam in it, I just rev it in the driveway. 4k or lower, no need to hit super high RPMs.

I think seafoam is also bad for catalytic converters...