Tried to Seafoam my car...barely runs now...HELP

GToddyT5

Founding Member
Jan 14, 2002
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16
Hamilton, NJ
Yesterday I decided it would be a good time to Seafoam my car (Cobra) and then change the oil. So I pulled the hose off of the PCV (car would barely stay alive at this point), stuck a straw on there and sucked in a little Seafoam. The car died. Then I started it up again and sucked in a little more and it died again. In total, I didn't use more than 1/8 of the can. So then I drive it to Strauss and grab some oil after letting it sit for a little bit. It was fairly normal. So then I got a case of Mobil 1 10w-30 and a quart of synthetic Lucas as well as a filter. I changed my oil and the car was running OK. Then later in the day, it can't hold an idle without stalling. It's been like that ever since. I tried taking the batt cable off and resetting the computer. It hasn't helped, I've had to drive around revving it at stoplights to keep it from stalling. What happened????
 
you need to keep the revs high while sipping the seafoam or else it will kill the motor. i dont think seafoam will cause it to hydrolock though, but if the revs arent high enough and the motor tries to suck down a whole can at idle then yeah, thats alot of fluid at low rpm and its a possibility.
 
I always kept the RPM's high, and added seafoam kinda in drops. Takes me a long time, and even still I'd only use about half a can.

For what its worth simply because of the symptoms your having, I'd try just taking 5mins to pull your IAC off and clean it out with some carb cleaner and bolt it back up. Shouldnt take more than 10mins, and although unlikely, some amout of carbon could have worked its way into the IAC and causing it to stick a little. It's worth a try. I doubt seafoam wiped out your plugs.
 
What you need to do is crank the car up with the PCV line OFF....then the car will stay running. If you crank it up and then pull the PCV hose it will cause the car to stall. Thats how I did it the last time and it helped alot.

As for your current problem, some carbon probably broke loose somewhere and is causing the problem. Get someone to rev your car to around 2500RPMs and run the rest of the can through...just not TOO fast. That should help you.
 
I wish I woulda known this before...I just changed the plugs. O well, they're only a couple bucks.

Yeah, it doesn't happen all the time, but of the dozens of cars that I've Seafoamed over the years, I would say 1 in 10 times ends up killing a plug or two. No biggie on these motors as it only takes 30 mins max to change the plugs. LT1's are a nightmare.

For Seafoam to work correctly it relies on a solid ignition/combustion event in each cylinder. The Seafoam must be flashed to steam within the cylinder/combustion chamber to effectively get rid of the carbon deposits. If you have already killed a plug, the Seafoam will not work correctly in that cylinder without combustion. And there is no way you will hydraulically lock the motor with a little can of Seafoam, so no need at all to worry about that.;)

The trick is to hold the throttle open just enough to maintain good vacuum but to also sustain the RPM's to keep the engine running. And like mentioned above, when you first start the car to add the Seafoam, you will want the PCV hose already off the valve cover, then once the car starts you can dip the PCV hose into the solution.

I like the BG products way better than Seafoam.
 
Like Kevin said the Seafoam is pretty good... but it is known to occasionally hose plugs. We like to use the BG products....most of the gurus use BG stuff to clean fuel systems and top ends.
 
Remove and clean your front o2 sensors, and clean the MAF. Then get those codes cleared, and I bet its fixed. That seafoam can contaminate your o2 sensors pretty quickly, regardless of what it says on the bottle. I've just recently fried an o2 sensor on my ZJ from doing the seafoam too fast.
 
OK, I was revving the car with the hood up and it sounded like a leak. The problem was, I can't do it by myself because the car will stall. The question I have though is why would I develop a vacuum leak? The only thing I disconnected was the PCV tube and the PCV. Should it pop out of the grommet with ease? Because that's what it's doing.