Engine Sludge: Any Updated Fix?

[sleddriver]

I've used BG109 engine flush twice on a hot motor with idle raised to about 1500 RPM and hood open for about 15min. Oil viscosity was reduced to zero, used oil was jet black as it flew out of the pan. Also drained engine oil cooler and line.

At this point you could fill with cheap oil + new filter and drive for a couple of hundred miles, then drain and refill with 100% synthetic + new filter.

Don't understand why engine flushes are verboten on turbo cars as some claim. No problems here.

[Rattnalle]

Since the turbo spins on the oil film it'll wear quickly if there isn't one or if it's too thin.

I did flush mine with flushing oil, that is i added new oil sold with added cleaners already in it, and it came out black after 15 min of idling at 650-ish rpm. The instructions were very clear on not running the engine at more than idle with the oil in.

[mrbrian200]

Don't understand why engine flushes are verboten on turbo cars as some claim. No problems here.

It's not just the turbo I'm worried about. I'm wary of flushes on any higher mileage engine that hasn't been flushed at least once in a while from new. If too much chunky crap thats built up come loose all at once you run a risk of plugging small oil passages and the pickup screen. On these you add turbo oil passages to the list.

If you buy a car new or well maintained-low mileage under 40k miles then go ahead and flush every so often.
But when you buy a used car with 100k+ on the odo that is obviously filthy be careful how you approach the matter.

One of my previous cars, a '90 Ford Taurus acquired from a relative, after a quickie lube recommended a flush on that higher mileage car (around 100k miles) the sump screen plugged solid within a couple days. My aunt was ready for a newer car anyway so she ran out and bought something else and offered it to me 'free if you can fix it'. She stopped driving it when the oil pressure light came on and it got noisy at idle. I wasn't sure how much damage was done. ~$12 for a new sump screen and an afternoon to drop the pan/clean it out was worth finding out. With some luck it turned out that the engine was ok and I took it.

[Rattnalle]

A well maintained high milage engine shouldn't develop any issues. On the other hand it shouldn't need it either.

Regardless just doing shorter intervals is the safer option.

[sleddriver]

Don't understand why engine flushes are verboten on turbo cars as some claim. No problems here.

It's not just the turbo I'm worried about. I'm wary of flushes on any higher mileage engine that hasn't been flushed at least once in a while from new. If too much chunky crap thats built up come loose all at once you run a risk of plugging small oil passages and the pickup screen. On these you add turbo oil passages to the list.

Where you live is very different weather-wise from here in the heat. Not just extended periods of extreme cold but salt as well.

To have that much goo and globs of it not only make it down to the pan, but clog up the oil pickup indicates a severely neglected engine. Like something run 30kmi on conventional oil without a change. Unfortunately there are 100,000's of people so clueless.

As long as the oil & filter has been changed regularly, flushing won't hurt a thing. Much better to use synthetic oil on any turbo motor. I would also expect doing so would prevent any PVC clogging issues as well.

[jamadams]

I recommend to remove the engine oil pan. this is where you will know the true condition of the oil and sludge.
Cleaning can be difficult, use ZEP industrial cleaner (Lowes) to remove most. or, take the oil pan to an auto/truck shop with a parts washer. not just a solvent based wash tank, but a parts washer machine. That includes hot, pressure with cleaner. 2-3 hours and the oil pan looks close to new.

[jamadams]

2.5L oil pan.pdf

(223.32 KiB) Downloaded 172 times

I recommend to remove the engine oil pan. this is where you will know the true condition of the oil and sludge.
Cleaning can be difficult, use ZEP industrial cleaner (Lowes) to remove most. or, take the oil pan to an auto/truck shop with a parts washer. not just a solvent based wash tank, but a parts washer machine. That includes hot, pressure with cleaner. 2-3 hours and the oil pan looks close to new.

[cn90]

I just had this theoretical idea of cleaning any engine with sludge...
Completely hypothetical...
Let's see what you guys/girls think:

- Drain old oil and dispose of properly.
- Reinstall the drain plug.
- Remove spark plugs.

- Pour some Berryman or equivalent (AC Delco fluid, info in BMW forum) down the spark plug holes.
With time, the fluid will dissolve the carbon build-up on the piston and on the rings.
This fluid will eventually end up in the crankcase.

- Now pour 2 gallons of diesel into the oil filler hole, it will end up in the crankcase anyway.
Let it sit in the crankcase for 1-2 days to dissolve any gunk.
Do NOT run the engine during this soaking period.

- After 1-2 days, suck out any remaining fluid inside the combustion chamber. Reinstall spark plugs.
Drain the diesel from the crank case.

- Do an oil change with new oil filter. Drive for about 300-400 miles. Do another oil/filter change.

---> Is this (completely soaking the crankcase with diesel fluid) a good idea?

[SuperHerman]

It is really hard to tell what the condition of the engine is without dropping the oil pan and removing the upper cam cover. At about 180k when the head gasket blew on my old XC70 the oil pan was dirty, but not bad. The head on the other hand was another story. While it did not have any sludge, the cams had serious build up on 3-5 cylinders. The bottom end was fine - pistons and rings. To be honest, I don't think any solvents would have cleaned the cams - they had to come out. I did buy the car at about 120 or 140k, but the prior owner had excellent service records.

One never knows - it has to do with miles, maintenance and driving environment. Every car is different as some go short runs while others go long runs - it is not about miles or even synthetic oil (although it is better).

If you know you have a problem, the best approach is to drop the pan and take off the upper cam cover and do a real clean.

If you are just worried, run a 1/2 can of SeaFoam with your synthetic and at the last 500 miles put the in the remainder of the can. Do this 4-5 times and change your oil every 3-5k. You should notice the oil color change improvement.

[MoVolvos]

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Run a quart of transmission fluid for a hundred miles or so before an oil change. Friend the mechanic use to pump in some diesel and drove it for about half an hour before doing an oil change.