Grit in engine... What to do ?

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Mar 11, 2003
My neighbors son (16) just bought himself his 1st car.... A 1978 Z28.Decient looking car 350 4V TH350 and probably 3.08 gears.He proudly showed me his new ride.He open the hood and I took a look. The engine appears origional and the origional owner said it has turned over twice so around 217,000 miles on it.He saidd the timing chain had been replaced as well as the other normal stuff.

I pulled the dipstick and the oil was black.When I wiped the oil off the dip stick had a dark brown varnish stain on it....I took off the oil filler cap and ran my finger under the valve cover...It had a hard baked on grit all over them.Took a flashlight and could see a dark gritty feeling stain in the rocker arms.The engine pulls 17 in vac in gear at idle and 20 pounds of oil press at idle and 40 going down the road....Runs surprising decient and passed Calif smog.

He asked me what oil to run. No real cold here , normally 40F to 95F temp range....

Would this be a cantidate for a high detergent type oil... maybe that Delo 15W-40 or is it best to not try to clean out any of the grit since it does seem to run well and just run something with less detergents ?? Any other ideas ?
Without seeing the grit, I'd put in a fresh change of cheap 5W-30 (light stuff for a good flush) and a filter, give it a one day run, drain it, fill with 10W-30, new filter, and Auto-Rx. Do the two stage Auto-Rx procedure and he should have a better running engine, as well as add to the engine's life. He would also be served well if he added Auto-Rx to his transmission, either manual or automatic, and ran 1000-1500 miles, and did a complete trans lube change.

If the cost of the Auto-Rx is to high for the kid (needs money for his stereo) get Schaeffer's Neutra from Mills.

When I posted those oil viscosities above, I didn't have that engine's mileage in mind. With the wear from the 217k, the 15W-40 is probably a good viscosity for that engine. The 15W-40 diesel/gasoline lube oil will keep the engine clean once the Auto-Rx or Neutra has cleaned it up.

Thanks for the help. I asked him if he happened to know what brand and viscosity of oil the previous owner had used and he didnt know.

I just got home from work and took another look.The grit really doesnt seem like sand or dirt but more like a thin hard varnish or burnt oil or carbon deposits on everything.I took a clean rag with some solvent on it and was able to rub on one rocker arm and some of it would come off but it does seem to be a tough deposit.

I hate to seem ignorant but I'm not familiar with Auto-RX or Neutra.I take it that these are products that can help clean out a filthy engine such as this ? Anyone know if it is available in Calif ?

[ April 12, 2003, 08:39 PM: Message edited by: Calvin ]
I just found the website for Auto-Rx.I'll have my neighbor take a good look at it.

Thanks again !
Schaeffer Neutra:

Sold in 12 oz. bottles under product #131. Call the Mills 800# in the ad at the top of this page.

1 oz. per quart of engine oil, same for manual transmission & differential, (half that?) for automatic transmission, (how about 1/2 oz. for power steering?). 1 oz. per gallon in a tank of fuel at the same time. Don't be surprised if engine runs really rough for a short time while it's cleaning the heavy stuff.


A 1978 Z28.Decient looking car 350 4V TH350 and probably 3.08 gears.

That was my first car as well. Oh, the memories!

Although you didn't ask, I believe that car came with a 3.73 rearend, or at least mine did.

From the day I bought it (new), that thing did use a little oil; leked down around the valve seals when engine cold. The heavier weight oil mentioned is a good idea.

Ya I agree perhaps something with some viscosity would help with that many miles on it...And you know darn good and well how a 16 year old is going to treat it...I'm sure in the 4 or 5 days he has owned that car that his right foot has probably gained 20 pounds....Makes it kinda hard to leave a stop sign in a quiet and controlled mannor...LOL.
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