Do I need the engine replaced?
Since Toyota has started the Special Policy Adjustment for model years between 1997 - 2001 this page will pertain to owners of earlier engines with the problem.
If you have an engine with the sludge problem and it's one of the models covered by the Special Policy Adjustment for "gel" then contact the dealer for assistance.
Automotive News article 4/3/02 & 2/8/02
I get a lot of questions about owners being told that because of engine sludge build-up they now need an new engine. In some cases that is true so lets offer some examples and see where you fit in.
Engine sludged and the motor will not turn over. You need a motor, the cost of repairing that one will exceed the cost of a new short block assembly. When the engine is torn down for removal they will check the cylinder head assemblies for damage and you may need to have more work done.
Engine sludged and the motor makes fairly loud noises when its running. You need to replace the short block and maybe the cylinder heads. Once the engine is torn down for removal will they know for sure if the cylinder heads and associated parts are good or bad.
Engine smokes and runs but does not have any noise. You probably have a good engine and all that needs to be done is cleaning the engine. It sounds easy but its labor intensive to do a good job. It really is not all that difficult (again if the engine is quiet when running). NOTE: Before starting the repair make sure you have all the parts you need or a way to get them once the engine is apart. The best way to clean the engine of sludge is to follow this formula:
1) Get the engine hot.
2) Take off the valve covers and using Diesel fuel in a spray bottle, spray the cylinder heads and other sludged parts. The Diesel fuel, when applied to a hot or very warm surface, will actually make the sludge flow off the parts and then using a scrub brush of some type start brushing the area and it will make it look new.
3) Now that Diesel fuel and sludge will wind up in the oil pan and that needs to come off also and be cleaned.
4) You then need to replace the oil pump pick-up screen (cleaning may work if you are careful), the valve cover (Covers if V-6) will normally need to be replaced. Cleaning the valve covers is difficult since the vented area toward the top of the cover can't be cleaned.
5) Clean the intake as well as you can, change the oil and filter, PCV valve and once together run the engine for a short time, then replace the oil and filter again to be safe. You will probably need to clean the throttle body to allow the engine to idle, the sludge will build up a varnish that may prevent base idle.
If things were not to bad to begin with you can probably get it done for as little as a couple of hundred dollars if you "repair" some parts instead of replacing them.
Some dealers take the cylinder head off others do not. Taking them off does a better job but adds to the cost, cleaning on the engine should be good for the repair.
Some are saying that the piston rings should be replaced. Since the problem is a sludge problem which is results in oil laying on metal surfaces the piston rings are not affected and do not need to be replaced.