Greetings,
I found this forum while trying to decide how to "clean out" my engine.
I read about many opinions and options, but thought first hand facts/pictures would be more helpful to someone else in my predicament.
The vehicle I have extreme sludge in is a Chevy pickup with a 305 V8, 77k miles.
Previous owner had only driven it about 1500 miles last year, but had 2nd owned it for the last 27 years.
Plenty of signs the vehicle had been maintained at a NAPA shop, but it used about a quart of oil every 500 miles.
There was a slight puff of smoke at start up, not so much at idle, but more under load/acceleration.
The first thing I did was change the oil to SuperTech full synthetic 10w30.
The oil coming out didn't look bad at all, and appeared to have been recently changed.
I drove it around for a while, changed the thermostat to a 180 degree one that worked, and hoped some of the oil consumption would improve over time/use.
It did not.
I began to investigate, and performed a compression test on all the cylinders.
They all were about 160psi, +/- 10 psi, with no jump seen with oil squirted into the cylinders.
This meant the rings were not letting oil blow by, but that the valves and or seals were NG.
I decided the valve seals could be the next logical step, theorizing the seals dried out, or broke.
I took off the valve cover and found this
When I removed the valve cover, there was an accumulation of oil still in the head, as it was trapped in there by the sludge, and couldnt easlily get to the pan.
The sludge was thick and sandy in nature.
When I removed the rocker/pushrods, they barely came out with interference, but were unclogged.
Whatever sludge I disturbed, I just tried to push out of the engine.
The return oil passages needed some help though.
I found this forum while trying to decide how to "clean out" my engine.
I read about many opinions and options, but thought first hand facts/pictures would be more helpful to someone else in my predicament.
The vehicle I have extreme sludge in is a Chevy pickup with a 305 V8, 77k miles.
Previous owner had only driven it about 1500 miles last year, but had 2nd owned it for the last 27 years.
Plenty of signs the vehicle had been maintained at a NAPA shop, but it used about a quart of oil every 500 miles.
There was a slight puff of smoke at start up, not so much at idle, but more under load/acceleration.
The first thing I did was change the oil to SuperTech full synthetic 10w30.
The oil coming out didn't look bad at all, and appeared to have been recently changed.
I drove it around for a while, changed the thermostat to a 180 degree one that worked, and hoped some of the oil consumption would improve over time/use.
It did not.
I began to investigate, and performed a compression test on all the cylinders.
They all were about 160psi, +/- 10 psi, with no jump seen with oil squirted into the cylinders.
This meant the rings were not letting oil blow by, but that the valves and or seals were NG.
I decided the valve seals could be the next logical step, theorizing the seals dried out, or broke.
I took off the valve cover and found this
When I removed the valve cover, there was an accumulation of oil still in the head, as it was trapped in there by the sludge, and couldnt easlily get to the pan.
The sludge was thick and sandy in nature.
When I removed the rocker/pushrods, they barely came out with interference, but were unclogged.
Whatever sludge I disturbed, I just tried to push out of the engine.
The return oil passages needed some help though.