I broke down my head this morning preparing to do a mild port and polish, and I discovered that I do not have inner springs or lower valve spring seats.
Every head pictured in the MKIII Bentley manual shows two springs per valve including the AAZ, so why am I lacking them?
The head is stamped Germany and has the Volkswagen and Audi logos. The part# is 028 103 373 J
The pump for this engine was an Eco pump. Did they skimp on the springs like they did on the LDA?
It seems like even if you were hungover on the assembly line you wouldn't miss the same pieces on all 8 valves
How worried should I be? Should I just order the missing pieces and install them? I know Prothe sells them
here is everything I took out (you can see both Bentley manuals on the left of the photo. Perhaps that should be the point when you know you have gone too far when you need multiple shop manuals for one car
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and here is the head with just the valve guide and oil seal
Thanks for your help on this. I start to freak out when I take things apart and they don't match the Bentley diagram.
My AAZ head also has single springs. However, mine has steel lower spring seats. The springs will machine themselves into the casting without them. There's two types of AAZ heads. One has 8mm valve stems and guides and the other (later version?) has 7mm stems and guides. I think the latter also has the inner and outer springs.
WHAT THE F**K?? Someone had to have been in there since manufacture and left them out... I can't picture VW falling that slack, at least not the German factory. Get 'em from Prothe;... he's got them cheap, and even if it is Chinese how bad could what's essentially a big washer be?
www.dieselvw.com is his web site. He has springs too, all the valve train components.
I just finished putting my head back together; I replaced one of my cam followers that had stopped rotating and had a cam lobe path worn in it, but everything else was in decent shape. Dual springs, and I shimmed them about 2mm to bump up the spring rate a bit.
There's two types of AAZ heads. One has 8mm valve stems and guides and the other (later version?) has 7mm stems and guides. I think the latter also has the inner and outer springs.
I think you may have it here. The Bentley also says that the stems are 8mm, but mine are clearly 7mm. When I entered 96 Golf into autohausaz (this is the only year that gave me the AAZ code) the guides it tried to sell me were 7mm, and I thought that can't be right, cause the Bentley is never wrong
It seems like 7mm would be less of an obstruction in the intake path, and also less inertia. These seem like advantages what am I missing why did VW go to 8mm valve stems? Are they stronger? Intuition tells me whether you have either size if your timing belt slips or breaks you are going to have bent valves
Are the outer springs "beefier" on single spring version?
Jerry, I was thinking PO hackjob too, especially when I found almost no play in the valve guides I thought maybe a disreputable shop did a half-a**ed rebuild
Get 'em from Prothe;... he's got them cheap, and even if it is Chinese how bad could what's essentially a big washer be?
If it's just soft crappy metal the springs won't have any problem eatting through them. Then not only are you back to where you started but you also have a bunch of metal shavings floating around in your engine.
You are not the only one, I just took my head apart and noticed I didn't have the inner springs ETKA says I am supposed to have. I have 8mm valves I don't know what year the engine came from. I don't recall seeing a lower washer but I will double check tomorrow.
my 98 tdi lacked them too.. single spring.. no seats... and original... 283k and no wear from lack of seats..
i used some 16v v springs/seats i had.. the single springs are LONGER due to lack of seats.. so you cannot just add seats and a inner spring..
hope this helps...
I don't know what I should do. I am going from a german head to a chinese head.
Further looking in the ETKA shows that there are two different part numbers for the outer springs
why i mentoned single spring is longer due to lack of seat... length differance is thickness of seat...
so yes cannot add seat and inner spring.. need seats and both inner/outter springs..
the good... hydro valve springs seem interchangable..
I read in my bentley manual that I just got today and it says some newer cylinder heads may not include the lower seat and the inner spring. Also says the exhaust valves are sodium filled and can not be machined. The intake valves can be though.