Removing varnish during a rebuild

[jyoung8607]

Hey all,

Doing a partial rebuild on my 2004 Passat with the 2.8L 30V V6. It had a timing slip and bent all the center intake valves. I've got parts on the way, but while I'm waiting, I'd like to do some cleanup.

I'm not super excited about all that buildup, considering she gets a steady diet of VW 502.00 Castrol Syntec at the manufacturer's recommended OCI, but it's neither here nor there. It's all getting torn apart to install and lap in new valves; I'd like to clean them up before reassembly. There's lots of opinions on what to use as an additive in a running car, but I'm having trouble finding good ideas for something to use off-car during the rebuild. Any ideas?

Jason

 

[Virtus_Probi]

I'm really straining my synapses to remember this, but didn't somebody mention toluene for this application?
Not sure it that's easily available to the general public, used to use it in chem class all the time until it gained a reputation as truly nasty stuff that should generally be avoided. Maybe it would be OK for a one time engine rebuild, IDK.

 

[Quest]

If you are going to tear down the engine for rebuild, why don't you drop off your cylinder head and/or block to local rebuilder for steam cleaning?

Q.

 

[WobblyElvis]

I have to ask why bother?
The product will cost money, it will be time consuming and is probably nasty stuff to work with.
I don't think a little varnish causes any harm.
To each his own.

 

[wemay]

Proof that even stout synthetics succumb to varnish. But that engine doesn't look so bad to me unless the image is deceiving.

 

[Trav]

Brush this on and let it soak, it cleans it right up


http://shop.advanceautoparts.com/p/gunk-carburetor-parts-cleaner-complete-kit-cc3k/7040709-P

 

[CarbonSteel]

Originally Posted By: Trav
Brush this on and let it soak, it cleans it right up


http://shop.advanceautoparts.com/p/gunk-carburetor-parts-cleaner-complete-kit-cc3k/7040709-P
or Berryman B-12 Chemtool if you cannot find the above. Either will completely remove the varnish and IMHO, if you are taking the time to rebuild, then definitely remove all of the varnish.

 

[Chris B.]

Another reason to change oil a bit before the manufactures recommended OCI. It is a little to far to go with that oil in that engine.

 

[ExMachina]

I don't see much varnish here.
One big warning: Do not use any kitchen cleaning pads, especially the green ones with the fibers, as it contains abrasive powders. Engine builders have been warning about it for a long time.
I'd even be careful of any lint off any cloth you'd use, or any lost bristles off an old toothbrush, nothing left behind, you know.

I like the B-12 Chemtool suggestion. I'd go for something with PEA in it, like the "Gumout multi-system tune-up" (walmart, everywhere) which is listed as safe to be in the oil in case any is left over, no problem.
After cleaning, put a little assembly lube on the cam lobes and oil the chain and camshaft bearings with light 0w-20 motor oil.

 

[bigt61]

Be careful with the B-12 around anything with paint.

 

[ExMachina]

jyoung8607, thanks for the engine porn! nice

 

[philipp10]

if you ask me, it doesn'nt look like enough to worry about. Why bother, the motor won't run better.

 

[bdcardinal]

If it were my build, that engine would be clean enough to eat off of before going back together. That is just me, and I like to spend the time to make it look perfect.

 

[jyoung8607]

Originally Posted By: philipp10
if you ask me, it doesn'nt look like enough to worry about. Why bother, the motor won't run better.

If the motor was together and running, I'd tweak OCIs or run a maintenance dose of something and not worry about it much. But, the motor is apart. I can't put it back together like that.

 

[jyoung8607]

Originally Posted By: Quest
If you are going to tear down the engine for rebuild, why don't you drop off your cylinder head and/or block to local rebuilder for steam cleaning?

A reasonable question. In short, it's a budget sensitive job (my daughter owns it now), it's high mileage/low value car, and the heads are in good condition and don't need machine work. The bottom end is in good condition and is being left alone.

 

[Lasthope05]

I frequently rebuilt engines and cylinder heads. Grab a gal of acetone from homedepot and go to town. It cuts through varnish like butter and is safe to use compared to other chemicals.

 

[Robenstein]

Originally Posted By: Virtus_Probi
I'm really straining my synapses to remember this, but didn't somebody mention toluene for this application?
Not sure it that's easily available to the general public, used to use it in chem class all the time until it gained a reputation as truly nasty stuff that should generally be avoided. Maybe it would be OK for a one time engine rebuild, IDK.


Available in most hardware stores. It is a common solvent used by wood workers/refinishes. About 6 bucks a quart.

 

[jyoung8607]

Originally Posted By: ExMachina
jyoung8607, thanks for the engine porn! nice

Thanks.

If you'd like some more, and the story behind it, it's up on the Ross-Tech VCDS forum here:

http://forums.ross-tech.com/showthread.php?3397-She-s-dead-Jim

Long story short, the timing belt tensioner pulley disintegrated and caused a small forward skip in timing.

 

[alcyon]

Originally Posted By: wemay
Proof that even stout synthetics succumb to varnish. But that engine doesn't look so bad to me unless the image is deceiving.
this engine must be hard on oil. My low performance motor stays varnish and sludge free even at 10k mi oci.

 

[Trav]

Originally Posted By: bdcardinal
If it were my build, that engine would be clean enough to eat off of before going back together. That is just me, and I like to spend the time to make it look perfect.


+1 I want it like new.