Contour Enthusiasts Group Archives
Posted By: Auto-X Fil UIM/LIM cleaning tips and tricks - 03/11/06 01:05 AM
With all the problems people have been having, I started looking around for the things that you need to watch for. They're very spread out, so I figured it might be useful to get them all together and get it stickied, or maybe put into the official How-to.

This is a great resource as well:http://www.contour.org/ubbthreads/showflat.php?Cat=&Board=v6maint&Number=931756

  • You've got to clean the heads. The restriction increases towards the engine, and my heads/valves were caked with junk. I ended up spraying cleaner into valves that were closed (4 out of the 6 cylinders should be closed) and scrubbing with an angled brush. I couldn't get up above the valve, but I got the rest of it spotless. I periodically sucked the cleaner and crud out with a turkey baster: I taped a piece of a plastic drinking straw on the end to help me get in there. Then I stuck a paper towel down there to suck up the rest. To get the other two, make sure everything is clean and nothing is in the heads, and crank the engine momentarily.
  • Get more cleaner than you think you'll need. I'd say 6-8 cans of the Wal-mart stuff would be good. Two cans of liquid for the UIM would probaly be enough, but I'd get three to be safe. Seafoam sucks!!! Use Berrymans B12 or another carb/choke cleaner. They eat the stuff right off, Seafoam barely touches it.
  • UIM without a big container and gallons of cleaner: I didn't do this (exactly this way) either time, but if I want to do it again I'd plug up the vacuum taps, bolt a piece of wood over the TB opening, and fill the inside of the UIM with cleaner through the openings in the bottom. A piece of plastic over the openings would keep it from evaporating. Just leave it sitting upside down, and I bet it would be nearly clean after sitting like that overnight.
  • Have a magnetic part retriever on hand. Even with no airbox and no battery, my engine bay is unbearably cramped.
  • If the car doesn't fire right away, you might have washed down the cylinder walls. If the car seems to crank a little faster/louder than normal, but doesn't fire, you might have lost compression due to the loss of the oil film. Squirting a little bit (teaspoon or so) of oil into each spark plug hole will get it to fire: and then run smokey for a bit.
  • BE CAREFUL! People have had problems with this, but there's really nothing to fear. Three big things:
  • Watch your wiring sequence! Put the plug wires back on right.
  • Don't get cleaner into the cylinders. If you run a lot of cleaner through the engine you could have issues. To get it out if you accidentally get it in, pull the plugs and crank, then let them air out before replacing the plugs.
  • Be gentle with wiring harnesses and vacuum hoses. They may be old and brittle.


Between the excellent how-to and these tips, it should be a painless job!

Anyone else have anything?
Posted By: Goonz SVT Re: UIM/LIM cleaning tips and tricks - 03/11/06 04:20 AM
ALWAYS CHECK YOUR WIRING SEQUENCE!!!!

I learned the hard way
Posted By: Big Jim_dup1 Re: UIM/LIM cleaning tips and tricks - 03/11/06 06:43 AM
Originally posted by Auto-X Fil:
With all the problems people have been having, I started looking around for the things that you need to watch for. They're very spread out, so I figured it might be useful to get them all together and get it stickied, or maybe put into the official How-to.

This is a great resource as well:http://www.contour.org/ubbthreads/showflat.php?Cat=&Board=v6maint&Number=931756

  • You've got to clean the heads. The restriction increases towards the engine, and my heads/valves were caked with junk. I ended up spraying cleaner into valves that were closed (4 out of the 6 cylinders should be closed) and scrubbing with an angled brush. I couldn't get up above the valve, but I got the rest of it spotless. I periodically sucked the cleaner and crud out with a turkey baster: I taped a piece of a plastic drinking straw on the end to help me get in there. Then I stuck a paper towel down there to suck up the rest. To get the other two, make sure everything is clean and nothing is in the heads, and crank the engine momentarily.
  • Get more cleaner than you think you'll need. I'd say 6-8 cans of the Wal-mart stuff would be good. Two cans of liquid for the UIM would probaly be enough, but I'd get three to be safe. Seafoam sucks!!! Use Berrymans B12 or another carb/choke cleaner. They eat the stuff right off, Seafoam barely touches it.
  • UIM without a big container and gallons of cleaner: I didn't do this (exactly this way) either time, but if I want to do it again I'd plug up the vacuum taps, bolt a piece of wood over the TB opening, and fill the inside of the UIM with cleaner through the openings in the bottom. A piece of plastic over the openings would keep it from evaporating. Just leave it sitting upside down, and I bet it would be nearly clean after sitting like that overnight.
  • Have a magnetic part retriever on hand. Even with no airbox and no battery, my engine bay is unbearably cramped.
  • If the car doesn't fire right away, you might have washed down the cylinder walls. If the car seems to crank a little faster/louder than normal, but doesn't fire, you might have lost compression due to the loss of the oil film. Squirting a little bit (teaspoon or so) of oil into each spark plug hole will get it to fire: and then run smokey for a bit.
  • BE CAREFUL! People have had problems with this, but there's really nothing to fear. Three big things:
  • Watch your wiring sequence! Put the plug wires back on right.
  • Don't get cleaner into the cylinders. If you run a lot of cleaner through the engine you could have issues. To get it out if you accidentally get it in, pull the plugs and crank, then let them air out before replacing the plugs.
  • Be gentle with wiring harnesses and vacuum hoses. They may be old and brittle.


Between the excellent how-to and these tips, it should be a painless job!

Anyone else have anything?






Nicely done. I would like to add that if you lost compression from washing down the cylinder walls, you may be able to get the engine to start by cranking with the throttle held wide open. Holding the throttle wide open while cranking shuts off the injectors and sometimes that's enough to get it to start.

Also, if you do need to squirt a little oil in the cylinders to restore compression enough to get it started, usually it is enough to just do the three front cylinders. It will run rough for a moment until compression comes back in the other three cylinders, but it smooths out pretty quickly.
Posted By: benkill15 Re: UIM/LIM cleaning tips and tricks - 03/11/06 06:45 AM
Excellent, simply stunning!

Thanks Auto X-Fil
Posted By: ToasterOven Re: UIM/LIM cleaning tips and tricks - 03/11/06 03:19 PM
that should be stickied or something in the how to or something. thats wonderful help.
Posted By: csvt_33 Re: UIM/LIM cleaning tips and tricks - 03/13/06 01:54 AM
I'm considering doing the cleaning. On a scale of 1 to 10, how difficult would you consider it(10 most)? How long did it take you?
Posted By: Auto-X Fil Re: UIM/LIM cleaning tips and tricks - 03/13/06 03:20 AM
Maybe a 5. There is nothing hard about it, but it takes some time. Removing the manifolds and replacing them takes maybe an hour or a little more the first time. Scrubbing and wiping the crud off is a long process, and a pain, but not really tricky at all. Just take your time, read a lot first, and follow the tips: get TONS of cheapo Wal-Mart cleaner, and let the cleaner do the work.
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