Pez

So I have a list of about 5 things I'm doing over the next few weeks, one of which is to perform a valve adjustment, and refi the valve cover.

I removed the cover and it seems that this car has had some old/too hot oil at one point in it's life.



Not too worried about the gunk on the cam lobes as it all seems to be away from the ramps. I'm a bit worried about the bearings and the oil rail. The oil pressure in this car always reads low, not sure it's related to this or not. it would seem like if something was clogged or obstructed that the pressure would run higher.

I plan to drain the oil, drop the pan and clean it out, then reinstall the pan and leave the drain open. Then I will use something to scrub this up a bit and will use fresh oil to wash all the gunk down into the oil pan.

So a couple questions for the esteemed enthusiasts here:

1. How big a problem is this black gunk?
2. Is there a recommended way to see if the bearings are ok?
3. What sort of solvent can I use that will drain safely into the oil pan?
4. Is there a method to test the oil rail for any sort of obstructions?

Cheers!

PredatorZ

What did the oil look like when you drained it ? Was it a deep black like the sludge ? This is typical of an engine not well maintained, the PO probably did not change the oil very often. Most likely your PVC valve is clogged, typical in this situation, cheap part, I would replace it after a few oil changes. A good detergent oil will help maintain the cleanliness of the motor. Normally when I buy an older car I do an oil change and tune up, replace the typical things that wear out like pug wires. Then in a few months maybe 2k miles I do another oil change and upgrade to a synthetic, the 1st oil change will loosen up most of the sludge and it will come out when you change the oil. I would rather "waste" a few gallons of cheaper oil in a set of low mile oil changes to get that crap out of the motor. Then in your next few oil changes watch the color of the oil, does it maintain a nice honey color for many months or is it turning black fairly quickly, if so you are still in the cleaning cycle. My ZX has 360K on it, no idea what the previous PO's have done to it, but now the engine is nice and clean inside, my oil stays looking nice a long time.

Pez

Yea, it was pretty black. Will check on the PCV valve... seems like an easy fix when I have the intake manifold off. Thanks!

lumens

I have seen this before. Pull the pan. It will likely have a thick layer of sludge.
Clean and reinstall like you said. Start using one of the oils that are
labeled 'high mileage'. They will help clean out the rest over a period of time.
You may want to put a new oil pump on as well. It may be original.
Once cleaned up you should have a lot of miles left in that motor.

Pez

Will look into the oil pump.... got the replacement oil pan gasket in the mail yesterday. Will think about the oil pump, trying to get the car out of SWMBO's garage in 4 weeks, so I have to be mindful of scope creep.

I was thinking also that I would put some seafoam in a spray bottle and go after some of this gunk with a stiff nylon brush, then let it drain into the pan before dropping it again and cleaning it out.

thanks for the advice.

Turksspeedwerks

I have used motor flush before and it works surprisingly well but a old trick my grandad thought me is run it with a quart of kerosene but do not run the engine long with the kerosene because it will smear your rod main and other bearings but I've used this on a couple really sludgy ol small block Chevys.. I usually get the oil up to temp them add a quart of kerosene run it for ten to 15 minutes waalaa now don't go revving up the engine just let it idle then shut it down and change the oil I've even after running the motor just poured more kerosene and let it just run through the motor and straight out the oil drain plug just as added cleaning... I'd also look into a positive crank case filter it greatly helps oil from misting up and the gasses that cause sludge but if you change the oil like it should be it won't sludge up but trust me a positive crank case filter helps tremendously my grand father ed chandler tougher me this little trick when I was a boy he used the same set up on his asphalt circle track car he used to run out in Vegas and he also used this set up on his planes he built ... Hope this info helps