: Combustion Chamber Cleaning

DopeStar 156
11-05-04, 08:25 AM
I was advised by some members to take my Fleetwood out on the highway and open her up to clean out some possible carbon build up in the combustion chambers. I had been experiencing some preignition after shutting the engine down sometimes but other than that the car is idling correctly, running fine and performing as it should. I would think it's because the car doesn't get driven much since I'm at school for two weeks. I'm home this week so I'll take her out on Route 80 to clean some crap out. Any other suggestions on how to perform a good combustion chamber cleaning?

11-05-04, 10:12 AM
Run hotter plugs and run her hard for about 30 miles.

DopeStar 156
11-05-04, 10:51 AM
Yessir! *Salute*

11-05-04, 11:06 AM
The hotter plugs should Make better combustion, therefore it should knock more of the carbon loose. Be careful that you don't throw a rod while doing this, its not hard to kill your motor once you pass redline.

11-05-04, 04:31 PM
pull the plugs and spray some B12 in the combustion chamber and more down in the carb then put the plugs back and fire it up should do wonders for cleaning it out also now danger of machanical engine failure :thumbsup:

11-05-04, 06:14 PM
I know some people think they are a waste of money, but I like the engine fuel system treatments. More and more of the major manufacturers are using fuel system cleaners for the 15K and 30K services. The manufacturers would not be using them if they were a risk, and a lot of research has gone into their development. Nissan has started using the BG product to clean out engine carbon.

DopeStar 156
11-05-04, 08:22 PM
Well I drove it hard and it didn't do anything, I tried dropping the RPM's before shutting the car off and that betters the situation. The preignition knocks once if not at all. The car's about due for an oil change, could this have anything to do with it? I'll give the fuel cleaner a try.

11-05-04, 09:30 PM
someone's probably already said this, DopeStar, but...

have you checked the timing? Maybe something's up with that...

DopeStar 156
11-05-04, 09:44 PM
I'm not really equippied to check the timing. I don't have any of the necessary tools.

Night Wolf
11-05-04, 10:12 PM
highway driving is always good for an enigne... lets it run at a nice RPM for extended time, while under load... perfect....

...I have had good luck with the fuel system cleaners... my favorite is Lucas...

maybe try a better grade of fuel?

11-05-04, 10:22 PM
You can get an inductive pickup timing light and test it out. Shouldn't be too expensive and it's a good investment.

But be careful, if the motor is set improperly it can be very bad. The 307 is pretty tough though...

11-06-04, 01:04 AM
I agree about the timing. Either get a light and figure out how to do it yourself or get the shop to do it when you get the oil change done.

One of my cars has carbon problems. It got a bit better when I got a new carb for it and I had to change the intake gaskets in the spring so I'll have to see what it's like now. Usually for the cleaning stuff I use Wells that you can get in a can. I think you can get carburetor cleaner or something called tune up. You rev the engine a bit and slowly pour it down the carb or you can put it in the gas tank. I usually do a bit of both but it usually works better when you pour it right into the carb.

barge master
11-06-04, 05:01 AM
Those are all good ideas. You can also trickle water into the carb while you keep it running, that's an old trick. Another that I used to do is get GM combustion chamber cleaner. You trickle it into the carb as you rev it up, then dump the last of it in and stall the engine. Wait at least a few hours, and fire it up and take it for a ride. It works great, but it is a very smokey operation.

11-06-04, 10:00 AM
Barge Master: Water in the carb....man you take me way back. Your posting broke through some cobwebs in the attic. I remember my Dad using that trick too. Of course, that's getting more difficult to do with the proliferation of fuel injection.

DopeStar 156
11-06-04, 10:44 PM
Actually I put 89 Octane gasoline in her today and the engine performed like never before. Also no preignitioning at shutdown. I think I may have found my solution.

11-06-04, 11:36 PM
Im actually considering running 89 in my truck, only about 5 gallons worth, but I'm nervous because when my dad did this when it was brand new it knocked. maybe its the kick in the ass she needs. Any advice?

11-07-04, 07:35 PM
oh those higher ocataine fuels are great I only use 91+ also a couple of cans of fuel booster

DopeStar 156
11-07-04, 09:41 PM
Yeah, I'm prolly just gonna make the jump to 93 since it's like 3 cents more. The timing is prolly off because it idles a little rough, I'll have that looked at sometine soon.