I recently replaced the valley gasket and valve cover gaskets on my '95 with 223,000 miles on it. I have seen the photos of gunk-filled heads on the forum, and was prepared for the worst.
However, there was no sludge at all in heads. I removed the rocker shafts, and both of the rear oil holes (the rearmost pedestals) were filled with sludge, so I assume there was some crap in the heads at some time. The front pedestals where clean.
The valve covers haven't been removed since 60,000 miles or so, maybe more since the gaskets were cork and perhaps the mechanics who charged me to do the valve cover gaskets didn't really do the work?
Anyhow, I've owned the disco snce 40,000 miles, and have put in all kinds of oils, both name brand and no-name-bought-in-a-jug stuff. I change my oil every 3000-5000 miles, although there have been plenty of times I've gone to 7000 or even 10,000 miles between changes.
At 170,000 miles or so, I did a couple of changes with semi-synthetic (because it was on sale). Then I read the posts here about wasting money on semi-synth, so I moved up to full synth (conveniently on sale) in order to take advantage of the cleaning properties advertised, since I thought my heads were probably pretty sludgy, and didn't like the thought of big chunks breaking loose and clogging things up.
At about 200,000 miles or so I started dumping a quart of transmission fluid into the crankcase before the oil change (a tip picked up here on dweb). I would pour in the ATF, bring the engine up to operating temp, and then do the oil change. Oh, and a few times I drove to the parts place (5 min 1-way) to pick up some forgotten part, usually an oil filter.
At around the same time I started using diesel 15-40 oil (again on sale), both Rotella-T and Castrol Tection. I am still using these oils.
I don't know what has kept my engine top-end sludge-free for 223,000 miles, but I've listed what I've done above as a data (counter)point for the fans of certain oil brands/additives who swear their stuff is what "really" works. Cheap and indifferent seems to work for my '95.
However, there was no sludge at all in heads. I removed the rocker shafts, and both of the rear oil holes (the rearmost pedestals) were filled with sludge, so I assume there was some crap in the heads at some time. The front pedestals where clean.
The valve covers haven't been removed since 60,000 miles or so, maybe more since the gaskets were cork and perhaps the mechanics who charged me to do the valve cover gaskets didn't really do the work?
Anyhow, I've owned the disco snce 40,000 miles, and have put in all kinds of oils, both name brand and no-name-bought-in-a-jug stuff. I change my oil every 3000-5000 miles, although there have been plenty of times I've gone to 7000 or even 10,000 miles between changes.
At 170,000 miles or so, I did a couple of changes with semi-synthetic (because it was on sale). Then I read the posts here about wasting money on semi-synth, so I moved up to full synth (conveniently on sale) in order to take advantage of the cleaning properties advertised, since I thought my heads were probably pretty sludgy, and didn't like the thought of big chunks breaking loose and clogging things up.
At about 200,000 miles or so I started dumping a quart of transmission fluid into the crankcase before the oil change (a tip picked up here on dweb). I would pour in the ATF, bring the engine up to operating temp, and then do the oil change. Oh, and a few times I drove to the parts place (5 min 1-way) to pick up some forgotten part, usually an oil filter.
At around the same time I started using diesel 15-40 oil (again on sale), both Rotella-T and Castrol Tection. I am still using these oils.
I don't know what has kept my engine top-end sludge-free for 223,000 miles, but I've listed what I've done above as a data (counter)point for the fans of certain oil brands/additives who swear their stuff is what "really" works. Cheap and indifferent seems to work for my '95.
