good thing to clean out engine

What makes you think there is sludge inside? If there has been any kind of responsible maintenance, there probably isn't. If there is and you try to flush it with chemicals, you are going to loosen all that crud and get it into your oil pump, clog your filter, make the bypass open, and then it goes straight to your bearings. If you're serious about cleaning out the inside of the engine, then you have to remove the oil pan and the valve cover to do it right.

Back in 1976 I had a Plymouth Valiant that would only take three quarts on an oil change. I guess you all know the reason. Things have gotten a little better in the lubrication business since then.

Earle

Sea Foam from NAPA.

Just follow the directions.

About once every two years I do the SeaFoam, then use a dealership $17 oil change coupon. Drive another week on that, then drain and refill with synthetic.

Add a little ATF (1/2 quart) and let it idle for 10 or so minutes. Don't rev the motor during this time. You can also buy 'motor flush' at any auto parts store. Both work well, but don't take the motor above idle while it's got the cleaning solution inside, you will ruin the bearings on an old motor.

Carl

When my son-in-law first tried Mobil Clean I was surprised when at 3k the oil was as black as coal.

I would first open the oil cap and have a close look at it and inside as far as I could see. If the engine has sludge, usually some is under the oil cap.

The second place to check, and this will show the slightest amount of sludge buildup, is the CCV tube. I unhook it from the intake and see if I can blow through it into the valve cover. If it still blows clear, there is no sludge. If it is plugged, then some carb cleaner sprayed into the tube with a ream from a wire or air blow to clear it is in order.

If this CCV tube plugs with sludge, then oil will start spitting into the air filter. At this point I would think on using a cleaner in the engine.

I prefer to use a pint of ATF into the oil about 100 miles before a change. This seems to clean them out without being to harsh on them.

Some folks actually remove the valve cover to make sure they get all the sludge out, but I wouldn't do this unless I couldn't keep that CCV tube clear and then I would want to pull the oil pan too.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's Canadian Off Road Trips Photos: Non members can still view! Jan/06 (More Off Road album links at bottom of the view page)

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I would worry that clearing out the varnish would loosen up all the oil leaks.

-- "We began to realize, as we plowed on with the destruction of New Jersey, that the extent of our American lunatic fringe had been underestimated." Orson Wells on the reaction to the _War Of The Worlds_ broadcast.

This engine has 225k on it and there is no line from the CCV tube to the air box, its gone.

That line is extremely important. It sucks off the engine fumes and condensation from cold starts.

Without it the engine will fast fill with sludge and water and up and die very soon.

You aren't talking using chemicals to clean sludge here, we are talking putty knife and pressure washer....

Our 88 has 315K on it and I keep that line working. My engine still only uses a liter of oil between changes...

Mike

abomb69 wrote:

I tried getting a piece of hose to connect it to the box, but every size I get is either too big or too small. What size is yours?

That sounds like a personal question.

*ducks and runs*

The hose is a non-standard hard-line in the ZJ. You can either get one from the dealership or use a slightly larger rubber hose and a couple of band clamps. A little electrical tape or duct tape to build up the connector might be required.

Is the line blocked off or have you been sucking raw air into the valve cover? In that case what Mike said won't happen, but you still need to get a line in place. Doug's idea to use tape is a pretty good one. I assume you are talking about the big CCV line to the air cleaner, not the small CCV line to the intake manifold.

Earle

As Earle mentions, it's the small one that is the really important one, the large one is the intake.

Here is a site with the part numbers and prices for the various tubes. They are not too expensive.

Mike

abomb69 wrote:

Nope just no tube there at all

IIRC, the small line for the ZJ was about eight bucks at the dealership.

You're talking about the bigger one though? In that case you're sucking raw air into the intake, for one, and you're sucking raw air into the valve cover if the small line to the intake manifold is still working, for two. This isn't the worst thing that could happen, but it's not real good either.

Earle

I am talking about both of the tubes, one going to the intake and the other going to the air box, I suppose I just need to take a visit to the local scrapyard and see if I cant find one that is still complete. If I can even find one at all!