Engine Sludge: Any Updated Fix?

[ljsommar]

Only on this forum will you find someone that would use the correct plural for formula, well done. The expertise on this forum constantly amazes me.

[SuperHerman]

How far you want to go depends on how bad the sludge is in your car and your budget.

Look up VW Engine Sludge and look at the images of severe cases of sludge. Volvos don't suffer the sludge issue like certain other cars.

Check out this video on flushing with a machine via the oil filter:

and this one that shows the stuff the flush pulled out (at the 2:30 minute mark):

Cleaning with diesel fuel rather than oil works, only what damage to the engine bearings and rings, is unknown. I have heard many stories from my older certified auto tech friends of success using diesel fuel rather than oil, but I have never seen a before and after oil analysis showing what if any added wear the engine suffered. When pressed, the response was similar from all of them. They all knew very well that diesel engine fuel didn't lubricate as well as engine oil. But the options were limited due to the vehicle's age and customer's budget. What did the customer have to lose? The engine was old and without tearing into it - the cheapest solution was a diesel fuel cleaning. If the engine made it only another 15-20k miles that is all the customer wanted. In other words the downside was minimal - so why not. They would drain the oil and change the filter, fill with diesel fuel, idle for 15-20 minutes and then do 2-4 oil and filter changes until the oil when checked was not dirty after idling for an hour or so. The numbers back then - for about $200 the customer would usually get 15-20k miles of additional use, at least. One tech told me he had put 50k problem free miles on his own truck (he picked up from a customer for "virtually free" as the customer didn't want to risk it) after he did a diesel cleaning before he sold it a few years later, still running strong.

Today they have specific flush machines and the price is not that bad. My pal was charged by my VW tech friend around $500.00 for the machine flush. The dealer told him he needed a new engine, but my friend's shop believed the flush would work. The flushing process was performed and last I heard he put on over 40k miles on the Passat post flush - and the Passat is still running strong last I heard. I would guess that the new machines have replaced the old school diesel flush - factoring inflation the price gap is not that large.

I would say if you have minimal signs of sludge, and have done mostly routine oil changes and normal driving, start by using a synthetic oil with additional detergent (or an additive detergent) and change your oil and filter more often. One can always check the engine oil every fueling after an oil change to see how quickly the oil gets dirty - this is a good gauge on your engine's condition. If it gets black fast - you have a dirty engine (but your oil is doing some cleaning).

My old 2001 XC70 took about 2500 miles until the oil showed signs of getting dirty - I changed it every 5000 miles or so with synthetic. From time to time I would use SeaFoam or Mystery Oil - generally every other oil change. I owned it from about 130k to almost 200k when it was sold. I believe I took pretty good care of it. But when the head gasket blew while loaned to a friend (another story) at around 190k I did the top end rebuild. Upon inspection the cams showed clear build up of semi hard sludge only on cylinder lobes 4 and 5 and certain areas of the head had slight sludge build up. The oil pan which I dropped showed slight sludge but plenty of hardened deposits. At some point the sludge would have caused an issue.

[MDK]

Wow...MDK here... thanks for the input on the diesel treatment. I was listening to certified Volvo techs here in Cincinnati. I suppose they didn't have my best interest in mind. So a retraction is due on my part.. broke my breaker bar today but not my knuckles... ciao

[abscate]

Only on this forum will you find someone that would use the correct plural for formula, well done. The expertise on this forum constantly amazes me.

There is even more expertise in these Fora.

[reverend]

I'm late to the game here, but in my 2006 V70 2.5t, I use Mobil 1, full synthetic. I change the oil every 10000-12000 miles and usually drive the car fully hot with as little stop & go as possible. That's what the Prius is for.

Oil analysis with TBN shows that I have plenty of more margin in the oil, no wear, no coolant, no exhaust or any other contaminants are present.
The color of the oil is academic, it'll be pretty dark within a few thousand miles no matter what you do (short of changing the oil every 3000 miles).

Speaking of which. Costco has $10 off a case of Mobil 1 starting tomorrow, and Mobil themselves have a $12 discount if you purchase 5+ quarts. Good time to stack discounts again.

[abscate]

Oil analysis with TBN shows that I have plenty of more margin in the oil, no wear, no coolant, no exhaust or any other contaminants are present.

The right oil change interval for you is one determined by oil analysis, well done.

Im amazed at the number of people who change oil based on appearance.

[oragex]

Looking back at the pictures in the first post of this thread, man that looks like the car was badly neglected at some point in its early life? I read that the car came with full maintenance at the Volvo dealer but I simply cannot get that. That car looks like it was run for long time without an oil change, possibly by the very first owner (rental with no oil change?) Also may look like the top of the engine is running a little bit too hot (just a theory here, but mixing tap water with coolant may cause lime deposits and prevent the engine head from being properly cooled)

These engines are tough, very tough. They can take some huge neglect not to mention when the PCV goes bad they still keep going (until some seal is blown).

That said, I'd try the Seafoam thing. Really far from being a fan of all the 'snake oil' market, but the Seafoam worked for me. I did the treatment 1 year ago, then replaced the oil. I'm 12 months later (and not many miles, perhaps some 8-10000) and my oil is still 'half way' clear on the dipstick. Before the treatment the oil would have gotten dark in a few months. Two lifters that were ticking (on cylinder #4 and 5) also got silent now. Worth mentioning I did replace the PCV during this interval.

[Rattnalle]

I personally wouldn't touch anything that can go I either the engine or the fuel. Seems a bit too universal for me.

I did flush my engine with flushing oil when I bought the car though. A ready made cleaning mixture that replaced the entire oil content of the engine. Idled for 15 min then proper oil in again. Not sure exactly what's in it but it came out black and the oil has stayed pretty clean since..

[mrbrian200]

Would "sludge guru" be considered a specialized degree apart from grease monkey, or is it more like the difference between one doctor that quacks like a duck and another one that doesn't?

[erikv11]

Yes, that's a very neglectful dealer if the car was actually serviced at one with any regularity. Anyway, it will be interesting to know how cn90 treats this one and how such a bad case of sludge comes out long term. Grab the popcorn and sit back, that will only take a few years to find out. : )