Valve noise / clatter help needed

Hi,
I have a 400i 1980 with 25.000 miles on the clock and have over the last few years had increased nose from what I believe to be the valve train. The noise sounds like clatter and is not from one valve alone, but from probably several. Or the chain.

It only appears at about 1000rpm’s and not under load. It does not appear below 1000rpm and not above. Can this be cured by adjusting the chain tension? There is still room to tighten the bold on the tensioner.

If not, any ideas

Everything else is just fine and the engine runs evenly without miss-firing. No heat buildup and fresh oil/filters. The motor idles at around 800rpm without noise.

Ideas much appreciated
//RoB

 

At 25K, in my experince with my 1980 400i, it's probably time for a full- on valve adjustment and tune-up. I have no idea of your mechanical prowess, but this is a job for the pro shop. Also be sure that you're using oil wth plenty of zinc. I switched to Amzoil, and the engine tappets quiet down with 30-45 seeconds, and the drive-off time is shortened. This is an all day job for an experienced Ferrari mechanic, and as you can plainly see, there are a lot of parts to remove to get to the valves and tappets. Expect to fairly pay for 8-10 hours of labor in this proceedure, as this is not an "I'll sit here and read a magazine and wait" type of job.
I hope that this is of some value to you. Jacques.

 

Jacques

Thank you for your reply.

The valves were adjusted some years ago (2003) by a very experience Ferrari specialist in the US, albeit that the car now is in Europe. The car has only covered a few thousand miles since then, so I kind of doubt that valve adjustment is the thing. I also would assume that the valves would make noise at lower RPM’s if they were out of spec.

I use AGIP oil as per the Ferrari lubrication sheet and this is changed every few years together with new filters.

The this is that the noice is only there at about 1000RPM without load... And more audible with a warm engine.

I have restored cars for many years so I can probably do it myself but would appreciate the input from fellow Ferrari nuts before taking it apart.

Other ideas?

Thank you
//RoB

 

Perhaps post a video of the noise - will still be difficult to remote-diagnose but would make it somewhat easier. Loose wrist pins can cause a similar noise to valves, but somewhat muffled in comparison, and it disappears or dampens down when under load. Such a noise is generally a bit unregular at idle. Needless to say, if that is the issue then it will be a whole lot more difficult to get rid of - it is mostly harmless though if you don't go crazy on driving your car.

 

Rob
I would adjust the timing chain per the shop manual. It is a relatively easy job with the correct spanner (I use a stubby 13/16" since I could not find a short metric one) on the lock nut. You are working in a tight spot with the engine running, but get the lock nut loose first and the adjustment is quick. I never had significant noise when I did the adjustment but result was always quieter.
Ken

 

Hi,

I will try to adjust the timing chain today. The adjuster bolt is in line with the 24mm lock nut so I don't know how much adjustment is left. Maybe it is too tight? I had somebodu look at it a few yesr ago and the cars has not really had to many miles since then.

If it turn out that I cannot adjust more, do I need to change anythin in the engine when changing the chain? There are some guides and do they need to be changed? Engine has documented 25k on the clock since new. Or can I just "roll in" a new chain.

Someone described the procedure on a different post in such a way that the cams could be un-bolted lifted enough clear the valves. Is this possible?

Does anyone know if there is a gasket set for such and operation or do I need to find out all the individual gaskets needed?

Best regards and thank you
//RoB

 

While this may not make any sense, I suggest you try this. I too had that irritating noise at start up/idle. It would go away at higher RPM's and sometimes after a while of running totaly dissapear.

I read here where another 400 owner(sorry can't find the post), suggested to start the motor, then spray a quick shot of WD40 on the alternator belts. I did as suggested and the noise just stopped.

This was a mechanical clicking noise that I would have bet the farm on it was timing chain or valve noise. I might mention, after 40 plus years owning service centers and doing automotive service and repair I'm not exactly a novice, and was I ever fooled.

So just fire up the motor and while cold hit the belts with quick spuirt and see if the noise goes away.

Good Luck,

Howard Musolf
1981 308gtsi
1982 400i Cabriolet
1988 Lotus Esprit Turbo

 

Thank you.

I have changed the alternator bets a few years ago and I do have the clicking noise when the car has been sitting for too long. This is a different sound.

I went down to the garage today and did a timing chain adjustment as per the Ferrari books. All went well and to my surprise there is really no or very little chain noise or rattle.

I did borrow an engine stethoscope from a friend and it turns out that the noise seem to come from the drive to the vaccum (brake booster) pump drive. Not from the actual pump but from the coupling to the cam. I have listened to the entire engine and albeit the noise can be felt like vibrations at around 1000 rpm on the engine it selves the noise is much stronger on and around the pump drive. Can the drive to the pump or the drive of it be worn or damaged? How is that fixed?

Best regards and thank you
//RoB

 

I remember rifledriver (Brian Crall) mentioning this technique quite a while back & took note, he's highly regarded here @ FChat & F circles, here's what he said...

"The front cover (timing chest) will not come off in the car. The front cover is not removed to do the timing chain. Hook the new chain to the old one & roll it in. Keep the chain engaged on the cams so they stay in time. The other choice is to pull the cams. The chain cannot simply just be fed though and pulled up the other side. I've done it with & without the cams in the car."

 

Brilliant.
Thank you.
I'm closing this thread and opening a new one for info on the vacuum pump drive.
Best regards
//RoB