i decided to seafoam the engine thru the throttle, i also went and changed the map sensor, tps, and iac. got a new air filter as well. i got great results from the seafoam, alot of thick dark smoke and the engine runs smooth besides a slight shake at a light. but my gas dropped dramatically in the short time from my parents to my house(15 mins-20). maybe 1/8-1/4 tank. ive installed new cat, muffler, o2 sensor, filter and rebuilt tranny. all within a few months. my question is would seafoam hurt my mileage and will the mileage come back. i had normal mpg before this tonight. i was gonna clean the egr but damn pepboys didnt even have a gasket. i might have a small exhaust leak by the left side pipe past the exhuast man at the connection. there is also a small rattle by this area. so could maybe the leak opened more?. any one got any ideas.

 

Run some more miles on it. Might just be burning off the rest of the crap out (which would give poor MPG til it clears up).

Also might not be a bad idea to clear the ECM and let it recycle the system again.

Cleaning all the junk out also sends different signals to the ECM, so if clear the ECM this should help.

 

The seafoam/carbon may have coated the plugs so this might be a temporary thing, you could put the seafoam into the tank and it might help clean the plugs.

If the exhaust leak gets to bad then you are affecting the O2 sensor readings for that side of the system and it could be part of your mileage loss.

When you replaced the TPS and IAC did you readjust then back to factory? It might be that they are a little off?

 

yea i made sure the pintle was about an inch on the iac and the tps sat pretty well, seemed like everything lined up. i was thinknig that maybe just a temporary thing and and im still burning carbon.

 

Yeah, you can't judge mileage with such a short interval. Heck, I normally don't start getting concerned until I see at least 2 tanks at a low mileage... Not to mention that while you were doing the seafoam treatment, you were running the engine without going anywhere... Then you went out and gave her hell (or were supposed to).

I know that if I park with the nose down, it looks like I have 1/4 tank more when I start it back up... Could be influencing things right now as well.

Also, it is always a good idea to at least pull the plugs, clean them up, and check the gaps if you aren't replacing them.

 

good idea kyle, im gonna drive the s--t out of it today. im a hard driver anyway but lets see what happens. thanx

 

I had kinda the same experience when I worked on my Blazer recently. I replaced the spider with a newer 2003 spider from an Express Van that had the newer injectors in the manifold (no poppets), well I forgot to replace the o-rings (thinkin that they were still in there) and drove it home. The next morning I had a fuel leak. And when i checked the mileage it had dropped down for that tank full same thing happened when I flushed the Dexcool out of the motor and ran it for 30-40 mins to check for leaks and make sure the rad was full.

 

seeems to be improving but with a little engine shake. but thats my blazer.

 

I did the seafoam pourage and it dirtied most of my plugs. It fouled all (3) 02 sensors as well. I had to wipe everyting down. My only bad experience w/ it.

The exhuast leak you mentioned, hear it at light throttle? I hear something when start driving but do not smell any fumes. Even w/ the vents on high.

 

4lowlife had the same problem i did with Seafoam - you may have to change your plugs, hopefully not your o2 sensors.

Just as a Seafoam recommendation - Seafoam the gas tank right before a plug change. If you have long life plugs in there (such as iridiums), change the plugs to some cheap copper right before you seafoam, then once its all gone, switch them back to the iridiums.