I have a 94 Camry with 150,000 miles. The engine was getting hot, but not overheating. Running very badly. Was going to replace the head gasket and found grooves in one cylinder. So I decidedto rebuild the engine. It ran great at first. After a couple of oil changes it started to develop sludge. At one point it was so thick that there was no oil on the dipstick. The oil seemed to be staying in the upper half of the engine. Ran engine cleaner through it and drained and repeated several times until the oil looked right. Was good for awhile and now it is sludging again. Idles ok. When put in gear it runs horribly. Any thoughts or suggestions?

 

What's the weather like where you're located? What are your driving habits, short run before engine heats up? Does engine heat to proper temp? What grade oil are you using?