I can not agree more about not pushing weak OTC dino oil past 3000 miles without UOA. The modern corvettes use gear drives right off the crank. Alot of vechiles use gear drive for ballance shafts right off the crank. Alot of oil pumps on modern engine designs also use gear drive from crank to avoid belts and chains. Straight cut gears generate alot more heat, and noise especialy at idle then helical cut gears. The engines in question have a pretty good history prior to 1997. I reliase that gears drives definately shear cheap VI's but I doubt that that is engines fault. Cheap VI's have no place in oil to begin with. The shearing should not be a huge factor in the sludge problem either but a minor player(opion only). I think that if anything the coolant system and emiision system would be primary contributors on top of owner neglect.
Their are many subtle indicators of sludge building up in an engine. First you see sludge bits in oil drain pan. Second you have the rancid/burnt smell of the oil. Third the oil fill cap usualy shows accumulation. Fourth your oil turns black within a few hundred miles of an oil change. Fith you might see sludge on the dipstick. Sixth oil consumption usualy goes up on engines that are sludgeing up quickly. I know that you do not always see these right away but surley you would see some of them before an engine was chocked with sludge.
I agree that all manufatures are pushing the extended drain issue a bit to much considering the oil they are recomending(5W30 dino). Toyota was stupid to recomend 5000 mile drain interval for sever schedule in hot running high reveing 4 cyl. engines with small sump capacity and cheap 5W30 dino oil. The old 3.0 V6 were almost bullet proof prior to 1997 when useing heavy oils and 3000 mile drain intervals.
I laughed when the dealership sales staff told me to use 5000 mile change interval with 5W30 for sever driveing and 7500 mile as non-sever schedule. They walk you through the owners manual right before you take possesion of your new car. Then I get into my car and what do I see in the corner of the window. I see a Valvoline oil change sticker with next oil change reading 3000 miles. You would think that sales and serive could get on the same page. I would hate to be a uninformed consumer!! Sorry so long!!!!
[ June 27, 2003, 07:57 PM: Message edited by: JohnBrowning ]
Their are many subtle indicators of sludge building up in an engine. First you see sludge bits in oil drain pan. Second you have the rancid/burnt smell of the oil. Third the oil fill cap usualy shows accumulation. Fourth your oil turns black within a few hundred miles of an oil change. Fith you might see sludge on the dipstick. Sixth oil consumption usualy goes up on engines that are sludgeing up quickly. I know that you do not always see these right away but surley you would see some of them before an engine was chocked with sludge.
I agree that all manufatures are pushing the extended drain issue a bit to much considering the oil they are recomending(5W30 dino). Toyota was stupid to recomend 5000 mile drain interval for sever schedule in hot running high reveing 4 cyl. engines with small sump capacity and cheap 5W30 dino oil. The old 3.0 V6 were almost bullet proof prior to 1997 when useing heavy oils and 3000 mile drain intervals.
I laughed when the dealership sales staff told me to use 5000 mile change interval with 5W30 for sever driveing and 7500 mile as non-sever schedule. They walk you through the owners manual right before you take possesion of your new car. Then I get into my car and what do I see in the corner of the window. I see a Valvoline oil change sticker with next oil change reading 3000 miles. You would think that sales and serive could get on the same page. I would hate to be a uninformed consumer!! Sorry so long!!!!
[ June 27, 2003, 07:57 PM: Message edited by: JohnBrowning ]
