# piston restoration



## vw_owner (Dec 19, 2008)

i've had this 89 Cabrio since 92 and has run like a champ, bone stock. started smoking and burning lots of oil lately so i decided i will go ahead and change the rings and H/G, along with anything else that looks like it needs to be done, but i am curious the best way to clean the stock pistons without having to take them to a machine shop. i have always just dropped in JE's and such for all of my race motors, so i have never really cleaned the carbon off of the stockers. TIA


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## where_2 (Jul 21, 2003)

*Re: piston restoration (vw_owner)*

I would do it gently with a wire brush on a dremel. Then run some "techron" through it when you have it all back together. A bottle of "techron" every 3k miles will keep things amazingly clean. 
If your engine started burning oil "all of the sudden", I'd be more inclined to think it was a valve stem seal that went bad, rather than being a ring. If you've got the head off, a ring would likely leave a scratch in the cylinder walls that you could see. 
Remember, those hydraulic heads they used after 1984 push a bunch of oil through the head to keep the lifters pumped up. There's ample supply to run down the valve stem if you have a leaky valve stem seal. Since you've owned it all this time, and not mentioned having any head work done. Take the head to a machine shop and have them run through it. It'll run you around $450 with parts unless something is majorly wrong with the head. (mine cost $630 three weeks ago, it needed welding to fill a hole some froot loop drilled into the combustion chamber of #4 cylinder when they attempted a faulty repair of a broken stud in the tranny end of the engine where the coolant flange attaches. I bought the engine used, I hadn't been driving it this way). 
Just my $0.02, but even the junkyard 1985 Golf_//_GTI engine I threw into my '80 Scirocco_S in 1993 got the head reworked by the local machine shop. I replaced all the gaskets in the block, but didn't pull the pistons or the bearings. That engine ran another 80k before I sold it in 1998. Last I heard, it was 120k miles beyond my installation, and needed the head reworked.


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## alpinweiss (Aug 10, 2007)

*Re: piston restoration (where_2)*

You are correct, as usual.
Although piston rings often got replaced on these engines after a lot of miles to control oil consumption, they were rarely the problem. Valve stem seals are more commonly the culprit.
If money is tight, the valve stem seals can be replaced with the head still on the engine. This may be beyond the skills of some home mechanics, and requires a few special tools. This procedure will require removing the timing cover, timing belt, valve cover, camshaft, lifters, spark plugs, etc.


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## vw_owner (Dec 19, 2008)

*Re: piston restoration (alpinweiss)*


_Quote, originally posted by *alpinweiss* »_You are correct, as usual.
Although piston rings often got replaced on these engines after a lot of miles to control oil consumption, they were rarely the problem. Valve stem seals are more commonly the culprit.
If money is tight, the valve stem seals can be replaced with the head still on the engine. This may be beyond the skills of some home mechanics, and requires a few special tools. This procedure will require removing the timing cover, timing belt, valve cover, camshaft, lifters, spark plugs, etc.









as i do already realize this, i have already done the entire head portion of this "tune-up". almost done though, just going to re-check my gapping of my pistons rings next weekend when i get back from travel, time the motor, then back in the car and running http://****************.com/smile/emthup.gif


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## where_2 (Jul 21, 2003)

*Re: piston restoration (alpinweiss)*


_Quote, originally posted by *alpinweiss* »_You are correct, as usual.
Although piston rings often got replaced on these engines after a lot of miles to control oil consumption, they were rarely the problem. Valve stem seals are more commonly the culprit. 

Which is why when I dropped my spare PG block off at the machine shop the other day, I was surpised when the shop foreman began talking about replacement pistons and such... Of course, he has seen the inside of a few more engines than I have... but my inclination was to hone the cylinders lightly, re-use the pistons, drop a fresh set of rings, HD oil pump, and bearings into it, then bolt everything back together...








I certainly have no idea what sort of care this block received before I bought it, but if the cooling jacket is any clue, it was poor at best.








Amazingly, the pistons were not drastically coated with a thick layer of carbon...


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