348 Cam Seals at Wit’s End!

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When I got my car in 2022 the seller had just given it a major, but I soon realized it was leaking from the cam seal area.

My mechenic said he couldn’t warranty another shop’s work - obviously - so out came the motor and another major was performed.

It still leaked.

In 2023 he replaced the seals again (motor in place) and used a different sealant.

it still leaked.

In 2024 he tried again, this time paying special attention to deburring the cam cover.

it still leaked.

In 2025 out came the motor.. again; all new o-rings and cam seals. He ran the motor for several hours and drove the car several miles. Said it was for sure fixed.

Spoiler alert: it’s leaking again

Could something be causing these rings/seals to quickly fail? I have a hard time believing my Ferrari speciality shop has installed them wrong four times.

I dunno, excessive oil pressure? Crank case pressure? I’m not a mechanic or an engineer, I’m just grasping at straws.

Any thoughts appreciated.

 

Ps, it’s primarily the driver’s side that’s problematic.

 

I would fire you as a customer. There is no longer any profit in that relationship.

 

This topic may be covered in this series of videos?

https://www.ferrarichat.com/forum/threads/major-service-for-355-video.700438/

 

Live with it . It’s an inherent trait you get used to it .

Every Ferrari over the past 30 yrs has never been dry at the cam seal / cam cover area for long after a “ major” . Just to be clear after the rocker covers have been removed and cams to replace the seals .
If it makes you feel better here’s the list .
Previous pair
Testarossa….leaves parallel oil stains on the garage floor .
360 M …..told byFranchised dealer to “watch as they all weep “ when doing a belt job ( in situ )

Current pair
208 GT 4 …l.like yours lasted a few months after a complete cam seal job involving removal / refitting etc by an independent.
348 very slight told to “ watch it and ck the oil level now and again “ . By respected Indy .

The 208 had its gear selector shaft seals done ….lasted about a yr before started dripping . There’s a drip tray under it . But like yours if you wipe your fingers under the edge ( motor not running after a lay up ) you can feel a few drips .


I have a theory …..when they are hot stuff expands and actually seals they don’t leak . Don’t leak enough to bother anything.
It’s when they are stood idle infrequent use as they sit cold and contracted gaps open and oil weeps out forming droplets .

As an experienced owner none of this detracts from the ownership experience it all par for the course in my book .

Compared to mechanical hassle of close rivals like Porsches and Mcclarens , BMW M s , Merc , 5.5 s and 6.3 s owners ……we have got off lightly us Ferrari owners with a bit of cam seal / cam cover weeps .

They are tough cars early Ferrari V8 s . Chillax about it .

 

I appreciate this perspective and in-and-of-itself I’m not too worried about the oil, but multiple people, including mechanic, have told me that leaking driver’s side cams can quickly take out the alternator.

 

Maybe. Maybe not.

 

I appreciate this perspective and in-and-of-itself I’m not too worried about it , but multiple people, including Boeing have told me that there airliners CAN fall out of the sky and kill people .



As yelcab says “ Maybe , maybe not “

 

I do not have a problem with leaks. I only buy the seals from ricambi. Some 348 heads have not been drilled for oil return. I think ricambi has the drilling jig.

 

https://www.ferrarichat.com/forum/threads/stress-of-ferrari-ownership.707571/#post-150161357

 

I think Choony has a 94 spider. The oil weep problem was supposed to have been fixed by then?

 

1) How to address the root cause of the leak. A DIY for not the faint of the heart.
https://www.ferrarichat.com/forum/threads/348-cam-weep-hole-drill-procedure.309629/

2) How to protect alternator.
https://www.ferrarichat.com/forum/threads/alternator-shield-diy.604393/

This forum is a great source of information!

 

I’ve talked with Eric (Ferrarium) at length about this. He was able to seal his cams. That alternator cover was just a bandaid.

Letting them leak is certainly a choice, but it doesn’t have to be your destiny.

Ricambi - are the seals you sell fundamentally different than the ones Ferrari provides? Eric said they might be.

 

I have never had a repeat problem with the tolerance of the chromed shaft sealing area to the seal. Lots of things make this work or not like softness of the seal material to be pliable to seal but hard enough to last 5 years and 30kmiles. I think the problem is the shaft seal area is just a few thou too small for the seals as provided in industry. The shaft could be made bigger for the 95th percentile of seals available in that size but in reality the shaft is good for 5th percentile available seals. That means you have to be very careful who you get your seals from.

If I had a repeat problem with this I would consider nickel or chrome plating the sealing surface only either myself or professionally. It's not that hard of a process to do. The hardest thing would be the guess as to how many thou to add. I have felt some sealing rings quite tight on the shafts and some seals where I question if that's going to work. There were some guys who made their own valve cover gaskets (not the ferrari OEM ones with red sealing rings) who's source for cam seals were quite suspect. I have done a bit of plating and even built my own rectifiers to plate and etch metals. With electro or electroless plating you can easily add plating to make a more "proud" sealing surface. Even low phos electroless nickel plating has rockwell about 60 plenty hard for a long lasting build-up of the surface.

https://caswellplating.com/one-plate-1-electroless-nickel-kit/

https://caswellplating.com/nickel-chrome-combo-kit-1-5-gal.html

 

Great reply, thank you.

 

Our cam seals are supplied to us from Hill Engineering and listed as 163987. Hill doesn't manufacture them in house, but source them from an outside vendor (I don't know who). The original-original-original 134714 still exists, and is used in other locations on other Ferraris, but as a cam seal, we spec the Hill 163987. The 134714 is multi-material, of aluminum and rubber; the Hill 163987 is entirely rubber. They are double-lip 50x65x8 seals.

For my 2-cents, on a 348, a leak at the cam is probably not a problem of the cam seal per se -- it's either the lack of an oil-drain back hole (most likely), or scrogged installation of the VC gasket, nicked cam o-ring, or pinched seal.

 

Excellent post. Tell me, aren’t spiders supposed to have the drain-back hole?

 

I didn't bother to read any of the replies so sorry if i am going over old ground.

I was there when the factory was having so many issues so I'll just go over the cures. It isn't that hard.
A. Its almost never the seals, its a combination of the O rings and the gaskets at the corners.
B. If it is the seals be sure the correct ones are used. They are directional and I have seen 328 seals used and they turn the other way. That will leak like the Exxon Valdez.
C. Many different O rings being sold. Some of them are correct. For sure a product to get from a knowledgeable source like Ricambi.
D. The are several bulletins and unpublished factory modifications to prevent the leaks. If your guy does not know them fire him and get someone who does. One hint, if the guy is not in his 60s he cannot know them unless one of us old guys taught him.
E. The valve cover gaskets should be considered a partially finished product. They do not fit and will leak if installed as delivered. They need to be made to fit correctly.

 

Honestly, I don't know. I'll try to dig up the original bulletin, and see what the date is.

 

Drilling the holes helps but I have seen many cars without the drilling done that are bone dry. It is not a panacea.

Holes or not there still needs to be a gasket or O ring issue for the oil to get out.

 

Just FYI when I had my major done at Auto Sprint, Giovani said he replaced the cam seals with silicon ones, better material than the original rubber and I have no drips in 5 years.

 

Whoops, I didn't see this was a 348 thread. My cam seals were on a 328. Sorry folks.

 

I have seen many orings being cut by the gaskets...

 

That was the primary problem. The 2 valves went for years without issues. When they designed the QV heads some moronic engineer decided to reinvent the wheel. Stupid design.

 

"In 2024 he tried again, this time paying special attention to deburring the cam cover."

All I need to know. Clueless idiot. Fire him. He'll never get it fixed. He must be learning his trade on FerrariChat.