Engine flush good or bad

[s2driveruk]

Audi suggests that they do not approve ANY engine flush but won't give a reason why? Surely after over 11 years on the road a flush would seem to be a good thing with an oil change.....

Anyone use one regularly or have any horror stories?

Cheers,

David

[AbsS2]

From what Ive heard flush is only good, if the engine has been treated with it regualrly from the start. Not a good idea if ur starting to do it now apparently.

I may be worng, as usual.

[s2driveruk]

isn't ignorance bliss

David

[Markus]

Well, actually the local Audi dealer has done a motor flush on my dad's A6 as a part of routine maintenance. I think they've already done that a couple of times on his car now. They use the Forté products which seem to have a good reputation.

After I imported my S2 from Germany it was suffering from noisy hydraulic valve lifters every time I had driven it a bit harder. I had a garage change the engine oil and asked them to do a Forté Motor Flush-treatment at the same time. Don't know if it was the treatment or the new oil (Mobil 1 RF), but the noise has disappeared.

If you're thinking about doing the treatment by yourself I suggest following the instructions carefully. I've heard about engines being destroyed because of improper usage (putting the flush in the new oil and leaving it in etc.) of flush-treatments. Also, if your engine has really bad deposits, the motor flush could make big lumps come loose, which then might clog some of the oil lines.

I also got a bottle of Forté Fuel System Cleaner which I poured into a 1/4 tank of gas. I did this only as a pre-emptive action, since I did not have any problem with my injectors. Well, couldn't notice any difference after the fuel system treatment, at least it didn't get worse.

[Markus]

AbsS2:

You do have a point there. If the engine is really "dirty" a motor flush might lead to problems. In that case it would be best to take the engine completely apart to clean the oil channels and all, but how many are actually going to do that...

Another, slightly gentler although not as effective, way to clean the engine internally would be to start using some sort of modern, fully synthetic oil (if not using that already). Most of these oils contain cleaning additives which dissolve some of the sludge and deposits in the engine.

[audiman]

We use engine flush on all cars that come in for regular servicing. The only time we get a problem is if the car has been neglected. This tends to make oil seals leak, but thats the only problem we have had on 2 cars out of the hundreds that we service.

You MUST follow instructions. If it says drive with it DONT. This will cause engine damage, just let it tickover for 15 mins or so until its good and hot.

I have used it on my S2 since i have had it, and no problems with leaks or anything. I have done 25000 miles and change the oil every 3-5k, and use flush each time. I used to get tappet rattle and now that has totally gone, even after doing track seesions!!

HTH

[Audi Parts Guru]

Originally posted by Markus
I also got a bottle of Forté Fuel System Cleaner which I poured into a 1/4 tank of gas. I did this only as a pre-emptive action, since I did not have any problem with my injectors. Well, couldn't notice any difference after the fuel system treatment, at least it didn't get worse.

Markus,how do you know that your injectors were working ok in the first place ?

[Markus]

I still cannot say that the injectors work 100% optimal (hey, they're almost 10 years old...), but I didn't see any signs suggesting that there's something wrong with them either. The engine runs smoothly, power delivery and performance is good, no problems with emissions, runs stable at idle speed etc.

Never had the injectors off to test them, although I remember reading about some guys doing injector tests by letting the injector spray fuel into a bottle. I however think these tests were done on an older K-Jet engine. Don't know if it can be made on the S2 with motronic.

"If it ain't broke, don't fix it."

[Audi Parts Guru]

Within the next few weeks i'm gonna take my injectors out to have them ultrasonically cleaned and then flow tested as I have access to a very nice machine that can do all of this

[audiman]

Injectors can be tested and cleaned as APG said with an ultrasonic cleaner. I had my old injectors done that had covered over 140k, car still ran fine etc, but the report on the injectors before and after made interesting reading. The spray patterns and flow rates were well bad. Expect to pay about 20 an injector.

[Graham]

Nice idea, i have a mate who does all this for corus vehicles, and does guvvies on the side
Graham