Arese v6 guys - note well !! change your coolant, and keep on top of it!!

[wankski]

so doing my cambelt change 2 mo early caught this: see the ausalfa thread with pics...

http://www.ausalfa.com/viewtopic.php?f=4&t=6026

cliff notes: poor coolant maintenance from PO caused massive rusting of coolant system in arese v6.

in my case, when stripping the engine i noticed a corroded thermo block and transfer pipe and extracting the WP revealed badly corroded bolts and seized on top mount to the transfer pipe...

Hopefully it won't need to be replaced as you can't short of extracting the motor or one of the heads.... $$$

i've spoken LD about it and apparently it's common with another of the ausalfa guys having the issue...

the crap design of the WP fasteners which look like m4 x 1.0 to me are way too small... which means that when corrosion sets in the threads it releases the small bolt and the wave washer that actually presses the WP in place is less loaded and thus, the crappy oe paper gasket leaks to the bolt hole i.e. total corrosion of the bolt in the bore, and the bore being no longer any good...

as it's put a spanner in my cambelt works - i'll be trailering it to LD to take over to fix the WP bores...

LD mentioned retap - i.e. bigger bolt... i would rather helicoil, use a liquid gasket sealing off the WP and using anti-seize on the actual bolts... we'll see what LD do on that score as well...

looks like i've opened pandoras box on this one... but much better discovering it now than letting it get worse and dealing with 12 unusable WP mounting bores and possible coolant leakage right over the cam belt, as the affected area is right over the main timing gear (crank)...   

hmmm... shame - cos what struck me about the alfa v6 design is how good the actual timing system actually is!!.. oe WP utter crap tho... poor oe mounting IMO...

good to know...

learn from me guys... maintain your coolant... that's 50% OAT for us arese guys.... you dunno what's in yours? dump it. it's cheap insurance....

my car (i'm the third owner) had a history and while i was quick to dump the oil, i left the brake fluid and the coolant assuming it was all good as OAT has a 5 yr life and my car is 6yo... i think what happened is the coolant res which has a small crack leaking what fluid is in there was topped up with tap water... until it had mostly water .... i.e. massive galvanic corrosion of all alu-steel interfaces including WP bolts and steel transfer pipe to alu thermo block and alu WP top mount...

so... dunno what's in yours? dump it. replace with 50% paraflu and 50% demineralised  water per oe spec. another local alternative to paraflu is nulon red OAT... can be bought in concentrate or premixed (50/50)

cheers,

joe

[colcol]

Good work Joe, my JTS has a lot of corrosion in the coolant due to the owner putting the wrong coolant in, it,[me], had green Nulon, now it has red Nulon with OAT, which i beleive is an additive to stop growth in the coolant, you actually can get a growth in coolants, and gets a horrible slimy skin on it, i couldn't find any Paraflu easily, but i didn't look too hard, so i used a local equivalent, Nulon Red, Nulon recomend it on their website for Alfa 156's, Repco also do a red coolant as well, i would be repairing the rusted threads with a Recoil or Helicoil, as the thread inserts will be stainless steel, and you will be able to use standard bolts and water pump, if you drill and retap the bolts to 5mm, up from 4mm, you will have to drill out the waterpump holes to 5mm, Colin.

[colcol]

If you repair the threads for the water pump, you can use a thread repair system called 'timeserts', which i am told are better than helicoils and recoils, but i don't know where you buy them or how to use them, but they were used in magnesium gearbox cases in BMW Getrags, but these arese V-6's are better than the GM units, because they are Italian, [as they shoud be], Colin.

[wankski]

yeah, i like time-serts, made by wurth - they are better as they bed in to be permanent whereas its possible with binding w/ the stud to pull out the helicoil when u next remove the stud...

trouble is, helicoil is widespread, whereas the time-sert is hideously expensive... cheapest i found is around $75 for a pack of 25 serts... just 1 size... so damn expesnive - and so are the tools, so i guess no one uses them...

anyway, all academic as it's up to LD for now...