328 Cam seal housing O ring leak

I am replacing cam seals now but not able to fathom your description of trouble with that o-ring, perhaps because my car is 2V.

I was surprised to find *none* of the RTV I used last time still around. Perhaps I was too conservative in that regard.

I, too, am unconvinced about the merits of the various gasket sealers, though they do not seem to do any harm. Since I have the "grey" gaskets this time perhaps I better use them.

Off tomorrow to the Volvo dealer to get my valve shims .

 

O ring never leaks on the bottom half. It gets damaged right at the parting surface of the head and valve cover. There will be a big chunk missing at that point.

Ferrari fought this for a while and finally supplied us with an O ring with a durometer rating and a section thickness that actually worked. Those have not been in the supply line for many years and all we get now is some generic crap of either buna or viton. Neither work very well.

There are 2 TSB's on how to modify both the valve cover and the seal housing to mitigate the problem.

The real problem is those idiots in Maranello took a perfectly good cam seal/valve cover design (2V) and fixed it (4V).

 

During this time period Ferrari changed their TSB numbering system a few times.

There is one dealing with the same matter on 348's Numbered Area 1 (engine) #3 dated July 1 1994. It may also be TSB 615.

It is 2 pages and shows modifications to be made to the gasket, valve cover and cam seal housing.


Also look up 10-31

 

I had the same issue in the same location as described by the OP. Upon removal of the front bank valve cover (just two months post major service) I found the exhaust cam seal housing O-ring damaged at the location where the lateral aspect of the valve cover meets the head. It was just as Rifledriver described with a chunk of O-ring missing at this spot. Perplexed at the time as I was confident that the valve cover went on straight without any O-ring binding. Repeated the whole procedure on the front bank with new cam seal housing O-rings and valve cover gaskets and still have a very slight leak at this location. I've done some research since then and read about the valve cover and seal housing modifications that can be perfomed to help with this. Unfortunatley, I never came across any specific documentation regarding the procedure. Many thanks to Brian for chiming in and providing the SB#'s. For some reason SB 10-31 is not in my library. If anyone has a reference for that I'd greatly appreciate it. In the meantime, I'll see if I can find the documentation regarding the 348 dealing with the same matter.

 

I am looking for the same service bulletin SB-5666 for the 348 and cannot find it. I can find the title but not the content on AutoMD. If you find it, please share.

 

There was a link or thread on here that gave a URL where all the 308 TSBs could be found & printed. Trying to find that...

 

Thanks Greg, I believe this is the link that you're referring to: ferrari documentation - service bulletins. Unfortunately the SB 10 (engine) series ends at SB 10-25 and the one that Rifledriver referenced (SB 10-31) is not there. Let me know if you have a link to something else that includes SB 10-31.

 

Brian talked about a technical service bulletin for the 348, issued in 1994. I will not be covered by the 328/308 information database.

The NHTSA has a database that I am trying to find, to no luck yet.

 

Yep, I plan on searching for the 348 related TSB's shortly but Brian also referenced SB 10-31 in post #6 which carries the same SB nomenclature as those in the Service Bulletin link that I provided in Post #10. Note that the SB list in that link is not just for the 308/328 but all models from 1979-1989. Whether that link is all inclusive or not is another story.

 

SB 10-31 is dated 10-10-91

 

Thanks Brian, that certainly explains why it's not listed in the previous link.

 

Brian, would the 328 be a good candidate for the oil drainback holes in the heads?

 

Doesn't hurt but that alone will not cure it. All the 4V V8's had the same problem for the same reasons.

It is not unlike a lot of the problems on older Ferraris. They work and come up with a component that will do the job. Once the production of parts shifts out of the hands of Ferrari and their suppliers are no longer in the loop or are not held to the same standards someone looks at the part and says "Hey, we can make this cheaper". That is the case with those O rings.


Most do not know but Ferrari sells rights to manufacture and distribute parts for each model after just a few years. Ferrari has not made 328 parts since probably the mid 90's.

They just middleman them.

 

Did you ever get the TSB in its full glory at all? I am curious what it suggests to do.

 

Yes, as you state, I was told to cut the gasket shy of the o-ring. With expansion/contraction (I guess) the gasket can cut the o-ring. Then a small dab of sealant goes in that spot. I've had decent luck but do have a small weep at the rear most cam on my engine from this location.

This may have just been the "explanation to a dummy" that I received because I was not capable of undertanding the whole issue. When I pulled my cams there were about 3 layers of sealant at that joint, spent a lot of time cleaning before putting together. The o-ring was compromised on mine at that joint but I don't remember if it was missing a chunk or pinched or what.

Someone was reportedly working on trying to make a better o-ring but that may have gone out the window due to cost/benefit.

Sometimes I wonder if trying to fix every leak on a leaky engine is one of those great tasks that keeps us going for a lifetime. I hear some have never leaked. In my case I took my car from about 8 leak locations to two known weeps that did not cause a drip ever (for two years). After almost three years and 18k miles I do get drips. Good thing I'm planning the service again and then I'll be here asking for suggestions while mine is in pieces. Bon Voyage!

 

I asked a contact at Maranello Parts and all he could find was change notice 103. This detailed a design change of the seal carrier. But I dont think this is the right one because unless I am misreading it, it addresses a different issue namely the lip of the actual cam oil seal contacting the inside of the hole in the carrier. It adds a chamfer there.
It also adds a drain groove into the carrier so any oil reaching the seal recess can flow back into the head.
Unfortunately they marked it "not for publication" so cant upload it. But maybe there is another one for the O-ring issue.

 

The drain groove is one of the modifications.

 

I use a round file.

 

Bringing an old thread back to life. In the prior discussion I had been hunting for the service bulletin (SB 10-31) which Brian (Rifledriver) had referenced describing the alterations to the cam seal housings and the heads to prevent cam seal leaks. I ultimately found it and applied those changes to my 328. I'm happy to announce that after 2 and a half years my 328 remains leak free and the shiny clean alternator that I rebuilt is happy that oil isn't dripping on it anymore. Below are the details of SB 10-31 if anyone is interested. Note that one of the procedures not well described in the bulletin is the repositioning and possible enlargement of the oil passage ways in the head. A quick search here using 'oil hole drilling jig' will give you several posts describing the procedure but basically you need a special tool which I believe can still be rented from Daniel at Ricambi. Daniel was kind enough to loan me that tool and I had my cam seal housings machined to accept the new oil drain back grooves. If anyone is interested I have an extra set of cam seal housings with the oil drain back grooves and chamfer already machined if anyone is doing a major this winter and wants to swap their old ones out for the updated versions: http://www.ferrarichat.com/forum/ferrari-parts-collectibles/508033-cam-seal-housings-drain-back-groove.html
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