[Timmay]

One of my plans for my car is to take off the valve cover, oil pan and sump and clean out what sludging mess I can. I've had a few people tell me that throwing in a quart of tranny fluid about 50 miles before I change my oil can possibly alot to loosen up the crud. Can anyone tell me if this could potentially hurt my motor, and if so should I just try one of those engine flushes. Although I've tried one, and it didn't do squat. I've also been informed of special engine flushing machines that certain shops might have. Any recommendations would be of help since I plan on doing my oil change this coming weekend.

'97 900S
2.3L Auto
sadly, I think I need a timing chain or more and I only hit 69k miles.

Thanks,
Tim

 

[Slaab4life]

I'm not sure about the tranny oil into the engine, but what makes you suspect you need a new timing chain? 69K sounds awefully low for that.

If your car is black I have the exact twin of yours, except with nearly twice the miles...

 

[DickinFallsChurch]

ATF is not an engine cleaner or flush.

Sounds like you might have some sludge problems, based on what my car had.
You'll know better after pulling the pan.

 

[TGA78]

ATF is not an engine cleaner or flush.

Sounds like you might have some sludge problems, based on what my car had.
You'll know better after pulling the pan.

That is true ATF was not designed as an oil additive to clean your engine. However ATF does have a lot of detergents in it to keep your automatic trans clean so it can operate smoothly.



For many years now shade tree mechanics and mechanics alike have used it to “clean” and to keep engines “clean”. I know many old gear heads who to this day ad one quart of ATF to there oil every other oil change. Some of these guys have cars that are more then 20 years old with well over 100k on them giving me no reason to believe the quart of ATF they use every other oil change is harming these cars. However many of these guys may as well be stuck in the stone ages. They know nothing about the computers that control today’s cars. Nor do they have any idea what a turbo 4 can really do. I guess what I am getting at is that they are all set in there ways.



I have personally used ATF one time on a old V8 with the hopes of removing a lifter tick. I drained out about 1 quart of oil from my truck. Toped it off with ATF and then let it sit and idle for an hour. When the engine cooled I changed out the oil and filter, The ATF did manage to clean out the lifters and remove my tick. However it also seemed to have cleaned out some sludge around the rear main seal because it began leaking a few days latter. But I can not blame the ATF for that.



I also had a fried with a 92 Dodge Stealth. Those cars had a somewhat faulty lifter design that wasn’t fixed until the final year they made the car (99). Anyway he use to put 1 quart of ATF in the oil every 4 oil changes and let it idle for about an hour like I did. This plus the combination of oil he used kept him from dealing with the lifter tick in those cars that everyone complains about. He also uses (Seafoam?) to keep the throttle body and such clean.



So it has been my experience that ATF can be used as a cheep solution to cleaning some of the gunk that build up in and around the moving parts or your engine safely. However there are many other options that are engineered to clean the gunk out of an engine. People only started experimenting with ATF because years ago they didn’t have any other options. However I also don’t believe ATF or any special oil additive is going to remove sludge build up from the oil pan. But hey I sure don’t know everything and I suppose all you have to lose is some money. However there would be no way to know if it worked with out pulling the pan when you are done and even then since we don’t know what it looked like first we still wouldn’t know. So yea if you are really concerned about sludge build up then pull the pan. Anything else is just going to give you a false sense of security.



BTW I pulled the engine from my 94 900se turbo about a year ago. The engine had about 145k on the odometer. To be honest I found very little sludge buildup in the pan. Defiantly no worse then the buildup I have found in other engines with similar mileage. Now keep in mind I still haven’t looked at this report that was released about sludge build up in the Saab engines so I know nothing about this specific :”problem” with the GM Saabs. To be honest it has been my experience working on cars that if someone changed the oil regularly there engine was quite clean on tear down. If the oil wasn’t changed regularly then there will be lots of sludge in the pan. No matter who built the engine! I guess what I am trying to say is that I have never seen anything that would lead me to believe that the engine design makes one bit of difference when it comes to sludge buildup. So for the life of me I can’t understand why people with less the 60k on there car are paranoid about sludge buildup.



**Disclaimer the above information is based on my personally experience with automotive repair. To keep this from getting any longer then it already has I may have left out key information. If you attempt something I mentioned and damage your automobile please do not come crying to me. If you have any question about my automotive repair experiences and observations that lead to the above comments please feel free to ask me in a PM. If you have any questions for me based on the original posters topic then feel free to ask here. I do not want to hijack this thread!!**



Tom

 

[900t]

All the oil-related problems people are reporting is due to people not changing the oil frequently enough, or using a non-synthetic oil. (ie doing the factory interval but with dino oil).

 

[GaryG]

The story I read about ATF said to use 1/2 quart. You wouldn't want to overfill the sump and cause other problems.

 

[TGA78]

The story I read about ATF said to use 1/2 quart. You wouldn't want to overfill the sump and cause other problems.

Yea, when ever you add anything to your oil you must first make sure you’re not going to over fill the system. I usually drain some old oil first. Then add the ATF, check the oil level and top of with fresh oil.



I never exceed the max oil level in any car. The last thing you want is for the crank to start slapping in to the oil in the pan. This can happen even when you are slightly over full and pulling a high G turn. When the crank makes contact with the oil in the pain it will cause foaming and air bubbles in the oil. If any of them manage to travel up the pickup tube and under a main or rod bearing look out. BTW this can also happen when running autocross events depending how the oil pan in your car was designed, even if your oil isn’t over full. Though with the lousy stock handling of a Saab I doubt we have anything to worry about.