Community Forums

fletch460 · 10-11-2020, 01:11 PM

I have read through several genny oil questions. My question is what would make make the oil turn to a tar like consistance? After hurricane running genny okay Shut down and gave low oil code. Checked and black goo on stick. Have cleaned out to best of ability and added fresh oil and filter. Running good nowws, but still worried about the jello oil

FatChance · 10-11-2020, 08:13 PM

The obvious question would be how long since the last oil change?

ky bob · 10-11-2020, 08:27 PM

it sounds like there was a long time between oil changes and when it got low on oil, the engine heats up more than it is supposed to. This makes the oil sludge up. If it were mine, I would clean it out like in this article,

https://www.zoniv.com/how-to-remove-engine-sludge/

Xmcdog · 10-11-2020, 08:37 PM

Oil thickening is usually caused by long change intervals as suggested or very high temperatures. A combination of both will of course accelerate the effect.

If it were mine I would be checking the operating temperature and changing the oil inc filter again after an hour or two. Might even be worth doing it a couple of times.

windsorbill · 10-11-2020, 08:39 PM

You changed the oil and filter once, but unfortunately I'd flush it out and do it again. Use a new oil filter again.

fletch460 · 10-12-2020, 08:38 AM

To all that answered, thank you. As I bought this MH last year with 9500 miles and 105 hrs on genny, it was probably original oil. I WILL CHANGE IT AGAIN after an hr or so.

aldave · 10-12-2020, 05:00 PM

I once took a shop class at a local high school mainly to use their equipment. One of the first classes we were required to disassemble some engines the instructor had obtained from various junk yards, etc. One of the engines was from a school teacher that he said had to have her engine replaced. The engine looked brand new on the outside.

The engine was almost pure sludge inside. Had to take a hammer just to loosen the valve covers. Had to use a hammer and chisel to chip away the sludge to get to the head bolts.

The instructor said that this particular owner lived about a mile from school. She drove the car to work in the morning and home in the afternoon. The engine never heated up and allowed the moisture in the oil to cook off due to the moisture in the oil that was absorbed through the humidity. He said allowing the engine to come up to temperature to boil off the moisture in the crankcase was key. And the moisture in the oil will combine with other stuff in the oil to form sludge.

It made an impression on me. Wouldn't have believed it could be that bad if I hadn't seen it.

Frequent startups and shutdowns and not allowing the engine to run at temperature will contribute to heave sludge buildup.

Howard Burger · 10-12-2020, 06:28 PM

aldave, welcome to the forum! And thank you for responding to fletch460. I have wondered over the years if the mantra to run an engine to burn off water was valid; you've put my doubts to rest. Thanks for the post.

**Spdracr39** · 10-12-2020, 07:03 PM

Quote:

Originally Posted by aldave

I once took a shop class at a local high school mainly to use their equipment. One of the first classes we were required to disassemble some engines the instructor had obtained from various junk yards, etc. One of the engines was from a school teacher that he said had to have her engine replaced. The engine looked brand new on the outside.

The engine was almost pure sludge inside. Had to take a hammer just to loosen the valve covers. Had to use a hammer and chisel to chip away the sludge to get to the head bolts.

The instructor said that this particular owner lived about a mile from school. She drove the car to work in the morning and home in the afternoon. The engine never heated up and allowed the moisture in the oil to cook off due to the moisture in the oil that was absorbed through the humidity. He said allowing the engine to come up to temperature to boil off the moisture in the crankcase was key. And the moisture in the oil will combine with other stuff in the oil to form sludge.

It made an impression on me. Wouldn't have believed it could be that bad if I hadn't seen it.

Frequent startups and shutdowns and not allowing the engine to run at temperature will contribute to heave sludge buildup.

I have seen this same thing in a Ford 302 and when we got the valve covers off the oil sludge remained in the shape of the covers. After chiselling it away we decide to tear down the whole motor, clean everything, and reassemble. we never figured out what caused it. My sisters Volvo did the same thing but it ruined the motor before they caught it.

LETMGROW · 10-12-2020, 07:26 PM

Quote:

Originally Posted by fletch460

To all that answered, thank you. As I bought this MH last year with 9500 miles and 105 hrs on genny, it was probably original oil. I WILL CHANGE IT AGAIN after an hr or so.

There are plenty of products available to add to oil to clean an engine. Most are overpriced or not effective. If I was you I'd warm the engine and drain the oil letting it drain overnight. Then I'd add 1/4 qt. of Dexron 111 auto transmission fluid and top it off with the recommended engine oil. Start the engine and let it run with no load on it until it has run at operating temperature for 10 to 15 minutes. Shut the engine off and drain the oil while it is hot. Let it drain overnight again if possible.
Replace the filter and oil and keep watch what happens.

Goodspike · 10-13-2020, 08:43 AM

I would use nothing but synthetic oil in an air cooled engine, particularly something like a generator that has long run times. Probably not as important on a lawn mower, but we're not talking big $$$ differences.

fletch460 · 10-13-2020, 11:06 AM

Plan to drain and run again. Think I will try the transmission oil as Let Me Grow suggested. I will add Mobil 1 upon completion of cleaning. Again Thanks to all contributors

Goodspike · 10-13-2020, 12:25 PM

Quote:

Originally Posted by fletch460

Plan to drain and run again. Think I will try the transmission oil as Let Me Grow suggested. I will add Mobil 1 upon completion of cleaning. Again Thanks to all contributors

They do make engine oil flush products. I'm not crazy about them, but this may be a good situation for it, and probably a better idea than transmission fluid. At least it's designed for the use intended.

sibe · 10-13-2020, 05:52 PM

Just change it after a couple hour run,, IMO a good synthetic is best ..

As far as the goo... with 100 hours,, that is not bad BUT.. depends on the oil that was in it, and how long hard you ran it..

I have test run engines, mostly motorcycle/atv in conditions to turn oils like rotella and royal purple etc into goo.. It takes alot of heat mostly to do that.. 300 degrees for a bit even 360 for a moment ot two LOL

As for my 460 powered RV, I lost a coolant hose on a entrance ramp to innerstate RT 80 in PA,, I noticed the temp climb and then fall right off.. and the motor ping.. My son was behind me a few cars, I called him he said I can smell coolant.. Shxt.. and a few others.. I am in one lane construction .. I see rest area 1.5 miles.. So I get to two lanes and peddle it.. I see the smoke.steam.. Hang in there... Junior catches up with 4 ways on.. I make it into rest area, STOP and shut off, Can not see a thing, I bail out, . A trucker runs over, with a fire extinguisher and another guy.. are you of,, well no flames, we here popping .. crackling..

I get to my door and open.as I bailed out of pass side becasue of steam hitting me blah blah.. I pop hood, Junior has a some gloved and old coat on backwards .. He gets hood up,, Truckers say no fire but wow is she hot..

I let it cool, we can hear and smeel oil popping as coolant is all gone, I un hook trailermm 5 of us lift tongue and swing it.. to get on Juniors van.. 600 tongue atleast.. LOL

We hang out, I had some food in fride, let it cool,, about 4 hours now and we look. AWE heater by pass blew, . I had a peice and we fixed.. I pulled dip stick, oild was BLACK.. but still hot..
We had water and filled it. slow, letting it snap and pop.. running etc.. I limped it back 97 miles.. ..

Next weekend,, I started started to patch it up, dumped oil and it was thick dark but not too bad, Amsoil 15/40 truck oil.. Changed radiator and all hoses,, then fount the water pump to block/timing cover warped.. small leak.. Did a had to trip and then tore it all down again..

long story but most good oils take a beating .. If I had regular auto 5w-30 it would have fried.. I am a goof and change it twice a year covering 7-9k of travels a year.. I also do trans every year or 2 years if i tow less.

roll the dice they say..

SORRY to get off point but oil is where i get nutz...