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black sludge/deposits in head and intake manifolds
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go hereXJ (84-01)
All OEM related XJ specific tech. Examples, no start, general maintenance or anything that's stock.
That's how my jeep was when I went to replace freeze plugs, not sure if its bad or good, but it still runs decent. My dad got a new focus awhile ago and he was getting worse mpg then normal, he pulled his intake apart and what not and it was covered in the same type of stuff, shop said it was normal, just dirt and build up. So just clean it out with some cleaner is what I would say.
you can clean it a little while it's off, but the best thing you can do when it's back together is to drop some water in your throttle body (small drops, not pouring water) so it cleans it properly.
search on the forum you'll find threads about the process and how to do it properly
I had some sludge build up in my head too. I filled up the tank with 93 octane and frequently changed the oil for a whole summer. I also put Lucas injector cleaner (octane booster) in the tank after every oil change. That cleaned it up pretty good. Made the valves a lot quieter and I'm back using regular gas now. I considered using Seafoam but was afraid of hurting the engine so decided against it.
I had some sludge build up in my head too. I filled up the tank with 93 octane and frequently changed the oil for a whole summer. I also put Lucas injector cleaner (octane booster) in the tank after every oil change. That cleaned it up pretty good. Made the valves a lot quieter and I'm back using regular gas now. I considered using Seafoam but was afraid of hurting the engine so decided against it.
save your money and forget the whole "high octane gas cleans the engine", it's a myth. my dad used to tell me that too and someone on the forum told me what i just said so i looked into it and since then it's nothing but regular 87
like i said above, look into steam cleaning your intake. it only takes water and 15-20 minutes of your time.
save your money and forget the whole "high octane gas cleans the engine", it's a myth. my dad used to tell me that too and someone on the forum told me what i just said so i looked into it and since then it's nothing but regular 87
like i said above, look into steam cleaning your intake. it only takes water and 15-20 minutes of your time.
My dad swears by higher octane as well. It was tripping his o2 sensor in the Corolla so I finally convinced him to use the manufacturer's recommended octane rating and the check engine light was gone. hehe...
93 tends to have more detergents added than 87, though if your goal is to clean out an engine that's designed to run on 87, you're better off adding a bottle of Techron and giving it an Italian tuneup.
you can clean it a little while it's off, but the best thing you can do when it's back together is to drop some water in your throttle body (small drops, not pouring water) so it cleans it properly.
search on the forum you'll find threads about the process and how to do it properly
Drips? Heck no!!
Pretty easy.
Get a cup of water, preferably something like a 24 to 32 oz. cup.
With the air cleaner off, hold the engine RPM at 2000 RPM or higher and dribble the water from the cup, which you've pinched to look like a spout on top, into the carb or throttle body. Go slowly and the engine will bog a bit. Stop and let it recover. Repeat until the cup is empty.
The water is great for combustion chamber buildup since it flashes to steam, but it won't touch the gunk in the intake. Good ol' fashioned elbow grease or an actual solvent while you have it apart is the best way to take care of this.
(And yes it's normal, it's from oil vapours in the CCV system. You should see an EGR engine, or worse yet, an EGR diesel...)
Originally Posted by IJM
93 tends to have more detergents added than 87, though if your goal is to clean out an engine that's designed to run on 87, you're better off adding a bottle of Techron and giving it an Italian tuneup.
Depends on the brand. So-called TOP TIER gas is high on detergents. But again won't help with buildup where the injectors don't reach. Remember in a stock 4.0L the injectors shoot a stream right into the head.
10-20-2016, 07:06 PM
black sludge/deposits in head and intake manifolds
