Engine Flushing?

[187inc]

What are your thoughts on the best way to flush an engines oil system?

I am asking specifically for my old Audi ('87 Coupe GT, 2.2 5cyl) which has slightly noisy lifters especially when cold. I have read that it quite common on these (and similar VW engines) especially with higher mileage, and can be caused by sludge building up in oil lines, and the lifters themselves.

I have also read people's accounts of flushing their engines to clean them out, freshen them up, etc, but am wary of their effects.. Techniques such as:

Draining some of the old oil, filling with kero/diesel/ATF, idling for a period of time, then replacing oil+fil (once, twice, three times..).

OR EVEN, draining all of the old oil, filling with diesel and leaving to sit, soak overnight, draining all day, then doing the method above.

The first one doesn't seem that dodgy, but the diesel soak sounds real sketchy..

Anyone tried anything like this with good (or more importantly, bad) results?

Jeremy.

[Bling]

//oldschool.co.nz/index.php?/topic/39401-running-diesel-oil-in-a-petrol-vehicle/

 

Have a read of that thread

[Alfashark]

What's the mileage on your coupe? I ask because mine had 330,000 and had a bit of lifter noise. Gave it 2 oil changes a week apart - Got it nice and hot before pulling the plug each time, and added some MBL8 with the second fill up of oil... Problem solved.

[0R10N]

Yeah, some of the old boy mechanics I know swear by a kerosene soak, or even a diesel mixture in engines that appear sludgy.

[JoKer]

dont do this to your Mustang

 

http://mustangforums.com/forum/5-0l-general-discussion/368307-im-done-with-this-car.html

[187inc]

What's the mileage on your coupe? I ask because mine had 330,000 and had a bit of lifter noise. Gave it 2 oil changes a week apart - Got it nice and hot before pulling the plug each time, and added some MBL8 with the second fill up of oil... Problem solved.

That sounds like it could be a good first step, witout too much risk. Where's the best place to get MBL8? BNT/Partsmaster stock it?

[Taistorm]

Can get it from most auto stores. Its the goods but costs like $30-40 from memory. Pretty sure its made up from snake oil

[peteretep]

http://www.stp.eu/uk/products/item/id/52

 

i use that stuff when changing oil, it gives me good results

 

regarding noisy lifters, my understanding is that if the oil is allowed to get too dirty by poor maintenence, then the shit will get into the lifters and be virtually impossible to get out, so you will just have noisy lifters until you change them

[Spencer]

I have no idea about Audis but some/lots of lifters are serviceable, ie you can pop the apart and give them a flush in some solvents.

[187inc]

Yeah I understand that all of these types of flushes etc are not designed to fix such a problem, just looking into ways to quieter the lifters down until i have the time to take the camshaft out and replace them.

[187inc]

I have no idea about Audis but some/lots of lifters are serviceable, ie you can pop the apart and give them a flush in some solvents.

Yeah they come apart, also have springs in them i think, which if broken will make the lifter noisy no matter how clean..

[Spencer]

Cool well get in there and whip them apart, I am un keen on any type of engine flush unless I can pop the sump off and make sure the pickup and sump are clean afterwards.

[Alfashark]

I'd say with two red-hot changes a week apart and some MBL8 in there, you'll be winning.

 

Some of the guys in Europe were talking of KV's running to 8-900,000km with only basic maintenance (belts, tensioners, oil, coolant and w/pump) as long as you're not revving the tits off them every day - Not that there's any point in doing so anyway.

 

Just a thought while talking about lifter noise... If your coupe still has the cast manifold, it may have a tiny crack in it near either the front or rear-most stud - When cold, it can sound just like a dud lifter but after a few minutes running, there's enough heat to almost completely seal it so it blends in with a quiet lifter chatter.

[Slacker_Sam.]

What he said ^^ I had a Mitsi Legnum and it had the noisiest lifters in the world. I did 2x oil changes using that cheap GV oil from repco. Then I used some half decent mobil 15-40, a filter & some MBL8 and hey presto quiet lifters.

[sholdowa]

I used to put in a high detergent diesel oil for a hundred miles or so, then replace with the usual... but that was in the days or 20-50 mineral oil.

[Muncie]

I.ve done the kero and cheap oil method on my well used and abused 275K.s VN commy the the oil was gross as so i dumped that refilled with ultra cheap engine oil and kero 70% oil 30 kero

to low level on dipstick and fire up let it idle for 20 mins (no revs or load just let it idle) the dump and repeat til clean or you run out of kero and oil and patience. stick on a new filter refill with Good oil and 1/4 bottle of Moreys upper cylinder lube and enjoy. PS it took 5000 k's before the oil even started to darken up again after this. I did this on my rover V8 too noisy as fuck lifters it made a big difference still slight tick, lifters settled right down to normal after 1000k's.

[187inc]

So I've done what alfashark recommended, and had moderate success. Engine runs a hell of alot smoother, and is a lot quieter. Still have one (i think) noisy lifter that stands out until the car warms up for at least afew minutes. Thinking maybe the spring in the lifter has collapsed or something, but overall its far more liveable. As a side effect I noticed to a much greater degree how much the engine sounds like a tractor and have found 2 holes either side of the middle muffler which could be partially responsible, so gonna go to woolf's and get that sorted.

Engine is running rich (looking at the few-weeks old plugs) but not sure wether its the mixture that needs adjusted or just because it has a caked air filter (it does) or a vacuum/air leak (it might) so some further investigation will be needed in that regard. K-Jet indirect fuel-injection enthusiasts I welcome your opinions here.

Will do some further (most likely half-cut) diagnosis on it this weekend. Thinking it could almost (almost) be worth taking to a mechanic/auto sparky to get them to have a geez and see what they think.

Anyone know of someone in AKL that has experience in old euros that doesn't charge in euros?

[Borgweiser]

Anyone know of someone in AKL that has experience in old euros that doesn't charge in euros?

 

No, but start with air filter and checking for vacuum leaks. 9 times out of 11 the fuel filter is the number one problem with rough/rich running on a K jet, from experience.

Start here, don't let anyone talk you into fiddling with settings, a quarter turn either way on K jet equals doom.

Check and make sure ignition timing is bang on also

[Alfashark]

Typical K-Jet issues - Lines perish over time, airleaks start and a lot of places would enrich them a bit to compensate without ever dealing with the real issue.

Sort yourself out with a new fuel and air filter, check the timing and see how it goes.

 

Without pulling the mountain of vacuum hoses off - I made the mistake of pulling a few of mine off before I had some hoses to make replacements, and after nearly 30 years of heat they disintegrated as they were being removed... get an assortment of rubber hose sizes and one by one replace the originals. I think the only one that gets funky is the idle stabiliser valve connection where it steps down in size and has a side branch coming off it.

 

Exhaust-wise, I had a 36" Coby running under the cabin and a small suitcase type muffler tucked up behind the rear bumper/skirt - 3" from the downpipe to the tip, not overly loud but very throaty with tons of bass. Used to set off car alarms when driving through carparks.

[187inc]

Took the car to Woolf, middle muffler was completely f**ked, in fact they said it was surprising it hadn't shat its guts everywhere. So got a new coby put in, is deeper sounding but not heaps louder overall so thats good.

And finally got around to doing some tinkering, took all the vacuum/breather hoses/air box/fuel distributor apart and HOLY shit! The breather pipes, both from the rocker cover and crankcase were all but completely blocked with oiley gunk, which had spread all the way into the air filter box, I have never seen such a wasted air filter. So I replaced the filter and gave the fuel dist a clean, replaced the more generic hoses and cleaned the rest, discovered that the vacuum hose from the dizzy had split almost in two, so I replaced it and the rest of the vacuum hoses. Soaked and cleaned the ISV and the other valve closer to the air box. Cleaned the internals of the throttle body and intake tubing etc. and put it all back together adding afew hose clamps, not very tight just for a bit more grip.

Went to fire it up and it went straight away, idling far better than it was. Revs more freely and is alot more responsive. Is still running rich though so Hopefully this weekend Ill get a chance to check the fuel filter and check the timing. Have ordered a new dizzy cap and HT leads because they are pretty worn out and it can't hurt to replace them.

Just bought a haynes manual, but one thing It hasn't helped me with, which is completely unrelated to the above, is locating the clutch master cylinder. Where is it located? Need to bleed the clutch unless there's a sneaky way to do it?