rusf77

I have a 96 a4 with 120,000 miles, and was on the a4 forum, but since so many have the 1.8t there i decided to post this here as well.
I want to remove the sludge from the engine, and some swear that by draining oil, leaving old oil filter and flodding engine with diesel overnight, adding new oil filter and cheapo oil idle for 10 to 20 min and then adding "Good Stuff" works Miracles, i am inclined to try this but before i do, what does the forum think?
Thanks =)

20VT90q

far though.

bcs296

I would suggest a regular Seafoam treatment first - anyone have link to the guide?

bcs296

<ul><li><a href="https://forums.audiworld.com/a4/msgs/2514238.phtml">https://forums.audiworld.com/a4/msgs/2514238.phtml</a</li></ul>

moribundman

you'd run a serious risk of clogging the oil filter and oil passages, resulting in catastrophic lubrication failure. Diesel fuel is not a good lubricant (lack of protection from wear) and running it instead of engine oil is a bad idea. I'm against using any aggressive solvent in the crankcase. You risk damaging bearing seals, which are already old. Removing sludge will also very likely remove some false seals, causing oil leaks.

First of all, find out why your engine is sludged (Do you KNOW there is a sludge problem?):

- wrong oil (cheap mineral oil, wrong viscosity etc)
- oil change interval excessive in regard to driving conditions (short distance driving, cold/hot weather all the time)
- PCV system not working properly (sludge maker #1!). Check all breather hoses for clogs and tears, mesh filters in valve covers, plenum

Fix what needs fixing and change the oil and filter. You may want to use an engine oil with a large amount of detergents. That means a mixed fleet oil (rated for gas and diesel engines -- never use an oil that is rated for diesel engines only!) will work to your advantage. Do a few early oil changes. Since it can be presumed that the engine has been somewhat neglected for a long time (otherwise it wouldn't be a sludge monster), you may then want to switch to a high mileage oil, for example Valvoline Max Life 10W-40, which contains seal conditioners that may help with seal life and oil consumption issues.

rusf77

i use Mobil 1 , previous owner didnt use a lot of the proper fluids and proper coolant. Some guy's from europe swear by this technic, they claim that diesel is a really good cleaner; in fact they claim that you could technically put reg gas or even thinner, but they are highly volatile, they recomend then diesel and they swear by it, in fact they calim to do it all the time.
Maybe i'll try it and post some pictures, but im weary in trying this one.
Thanks forum<ul><li><a href="http://M">http://M</a</li></ul>

moribundman

Well, this European here thinks it's a bad idea due to the aforementioned reasons. Of course, do whatever you want.

PS: The use of conventional oil by itself, if used with an appropriate oil change interval, will not cause sludge in the 12v engine.

Luxus Panzer

I have been thinking of changing to this oil (Valvoline Max Life 10W-40) for some time now in both my 12v's. I have just had such a good track record with Castrol GTX 10W30/40 for so long that I am finding it hard to do the switch.

Old dog and new tricks syndrome.

ImQuattro®

And thinning the oil out that much when running the car... hard on bearings, let alone what you might now be circulating to and through the engine and bearings....
Bad...
Just change your oil when it's hot, and do this more often for a while.

rusf77

got a killer deal today. Autozone is running a special with Castrol Motor Oil when you buy a Fram Oil Filter; this includes syntetic oils.
Autozone sells a Castrol Syntec specially made for europeans 0-30 made in germany, i just tossed that fram filter but got the discount on the oil, and used a mobil 1 filter. Hope this helps and thanks to the forum...
Cheers =)