Engine sludge (NOT Jeep related)

[Chocolate Thunder]

So my wife bought a used Nissan Versa Note (1.6l) from Carvana as a commuter. It looks as if some of the maintenance has been neglected. There’s sludge in the engine. The dipstick looks terrible. You can readily see it in the oil fill opening.

So far I’ve run some Seafoam in the tank, top end, and crank case for about 25 miles and changed the oil/filter. Ran great for a few miles then the RPMs started to bounce under acceleration. I plan to run it a few more miles then drop the oil pan and clean whatever I find in the pan and on the pickup/screen. A few more flushes/oil & filter changes until it runs smooth. Anyone else deal with this and have better or different advice?

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[jeepingib]

What are you seeing exactly? If you are seeing sludge then there's a good chance of it having some water in there. Is it dark or light colored?

 

[jeepingib]

I'd actually guess that you have a blown head gasket.

 

[Chocolate Thunder]

What are you seeing exactly? If you are seeing sludge then there's a good chance of it having some water in there. Is it dark or light colored?

Not water or coolant. That would show up easily in the oil. Sludge. Grime. Looks almost like coffee grounds in the oil fill hole. I scraped some off with a screwdriver tip but didn’t take a picture. No water. No coolant. No large particles in the one oil drain I’ve done so far.

More like this (not quite as bad) than the peanut butter you get from water contamination.

 

[jeepingib]

A bunch of varnish and carbon deposits. Try the sea foam and see how it goes. Another popular engine flush is made by liquid moly. I haven't used it myself, but I have heard decent things about it. Or the old school ATF in the engine. It has detergents that break down things better than standard oil. Whatever you do, change the oil very frequently for the next few months after. Once you get those deposits moving they will continue to break down and get caught by the oil filter. Also don't run any of the sea foam or engine flush stuff in your oil for very long. Just a single heat cycle or so before draining the oil. They don't have the same lubricity as engine oil, and can even damage seals in some cases.

 

[roaniecowpony]

CT, any follow up on this? Wondering if you had any success in cleaning.

 

[Chocolate Thunder]

Been down with health problems. I’ll update when I know more.

 

[Yawnie'sPapa]

Long time mechanic here - used to deal with sludged-up engines all the time in years past, usually because of short commuters or those who ran cold stats, never let engines get hot, etc.
Sludge happens from lack of getting the engine hot enough to burn out the moisture that naturally happens in the crankcase, which in turn, creates acids.
I've seen it so bad on some V8 engines that oil gathered up in the valve covers and couldn't drain back fast enough to the pan leading to valve cover leaks and low oil pressure.
Likely also oil change intervals were too far apart. Short drives means sludge and acids and that means you need to shorten times between oil changes.
If it's a tow vehicle, it can also mean the oil got too hot and the light parts evaporated off leaving only heavy parts behind.
Sludge can actually solidify and require using tools to break it away from the engine parts.

I picked up a 1994 Grand Cherokee to salvage the engine from for use in a car of mine - the Jeep had 100,000 miles on it and i'm not so sure the oil didn't have that many miles. Came out black and thick and the distributor drive gears were eaten badly.

Sludge isn't coolant in the oil - a tan emulsion that looks like an over-priced drink from Starbucks is coolant in the oil. It would be tan and thick, but not sludge.

My guess is short drives, perhaps coupled with extended oil change intervals.
If it's low miles for the years, that could support that thinking. (or could be like my wife's Jeep - 5,000 to 6,000 miles a year, tops -infrequent drives, maybe once a week)

 

[roaniecowpony]

Long time mechanic here - used to deal with sludged-up engines all the time in years past, usually because of short commuters or those who ran cold stats, never let engines get hot, etc.
Sludge happens from lack of getting the engine hot enough to burn out the moisture that naturally happens in the crankcase, which in turn, creates acids.
I've seen it so bad on some V8 engines that oil gathered up in the valve covers and couldn't drain back fast enough to the pan leading to valve cover leaks and low oil pressure.
Likely also oil change intervals were too far apart. Short drives means sludge and acids and that means you need to shorten times between oil changes.
If it's a tow vehicle, it can also mean the oil got too hot and the light parts evaporated off leaving only heavy parts behind.
Sludge can actually solidify and require using tools to break it away from the engine parts.

I picked up a 1994 Grand Cherokee to salvage the engine from for use in a car of mine - the Jeep had 100,000 miles on it and i'm not so sure the oil didn't have that many miles. Came out black and thick and the distributor drive gears were eaten badly.

Sludge isn't coolant in the oil - a tan emulsion that looks like an over-priced drink from Starbucks is coolant in the oil. It would be tan and thick, but not sludge.

My guess is short drives, perhaps coupled with extended oil change intervals.
If it's low miles for the years, that could support that thinking. (or could be like my wife's Jeep - 5,000 to 6,000 miles a year, tops -infrequent drives, maybe once a week)

Cheap oil and/or long change intervals can do it. I've been running M1 synthetics for about 24 years in everything now. Under the rocker covers of one with about 300K miles was clean as a newer car.

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