Poll 355 Valve guides

On my 1995B the valves guides were replaced in addition to an engine rebuild due to poor compression results. The final bill was unspeakable. Luckily all this was done by the previous owner who threw in the towel after this fiasco.

 

May I ask what specifically constitutes "poor compression results", i.e. what were the compression values?

Thanks very much,

Joe

 

I can't speak about compression values, but in a leakdown test, less than 10% leakage of each cylinder means you're in good shape. The leak down test on my 348 before I bought it showed each of the 8 cylinders leaking only 5 or 6%.

 

I have all the receipts, none of which show the compression numbers.

 

I'm not a mechanic, but I remember being told that a leak-down test is an indication of whether or not there's good compression...

I was told that doing a compression test as well as a leak-down test would be superfluous--that a leak-down test is good enough... I dunno

 

personally i think that ALL F355's pre '98 WILL HAVE the valve guide problem
if not before 30k, then before 40k, 50k, or 60k miles.

personally i think there is NO WAY a pre '98 F355 will go past "let's say 75k miles" without needing a valve job

this is sad when you can get 125k miles out of a 328 without any top end problems or bottom end problems

the future will tell

 

I agree with Dave on this. Of the many things I learned on my trips to Maranello one of the things I found so striking was in the production of the engines were a sometimes quizzical combination of high tech and old world methodolgy. A great deal of old fashioned hand work is involved in the production and assy of the cylinder heads. It was admitted to us on several occasions that turn over was very high and I believe that spotty quality work is sometimes the price paid for that. I have many times taken apart cyl heads to find valve seals smashed or broken in various ways that can only be accounted for by assy problems. I recently saw a 360 motor with it's oil pan off that had the #4 main bearing laying against the windage tray with both nuts and washers laying in the oil pan (this was not causing any noticable problems). I have to believe that other problems such as those mentioned by Dave happen too, it's just impossible to prove by the time we get in there to see it. We had a 97 or 98 355 burn a valve at 7 or 8k miles, when we got a look at it, it was obvious that the seat was WAY to thin to last. I have also seen 355's go many, many miles with out incident. I don't think the QA problems are new, Ferrari goes through cycles of it. The difference is now IMO that the cars are highly enough stressed that you can't get away with much.

 

No valve guide issues to speak of here.

97 355 spider 18K Miles

When I bought my car Ferrari of S.F. did a compression test in Bar's

My results
Cylinder #1 = 12.5 Bar
Cylinder #2 = 13.5 Bar
Cylinder #3 = 12.5 Bar
Cylinder #4 = 12.5 Bar
Cylinder #5 = 13 Bar
Cylinder #6 = 13.5 Bar
Cylinder #7 = 13.75 Bar
Cylinder #8 = 13.75 Bar

All told Compression % of 185 - 215 ..... Just as the factory wanted !!!

This from the MotoMeter print out I received. No valve guide issue here.

Mario

P.S. My car is for sale... I want a Red/Tan 355B

 

I did have valve guides replaced on my prior 95 Red/Back 355B at 17K miles.

I voted twice.

Mario

 

Problem with the comp. test and leak down tests are they will only show if there is carbon on the seat or valve, or if the valve is not seated properly. If not, the results will show fine. On the first 97 I did the comp and leak tests showed only 2 cylinders with a problem. When dissambled every valve in both heads were ready to change holes. There was no question as to if there was a problem with the guides as the head of the valve could be moved side to side in excess of 3/16". This is grounds to condemn a Chevy with 3/8" dia. valve stems.
As Brian said, at 8K+ RPM there is little room for error.
Dave

 

How'd you do that?

 

He did it once in FL. and once in NY.

 

Hi Michael,
Before I purchased my F355 I looked into the valve guide issue and was told
to make sure I get a car with an assembly number greater than 27689 by a F-car tech at a dealership......they just happened to have one

Another interesting poll would be something like this, if it could be done:

95 355 valve guide problem: Y/N
96 355 valve guide problem: Y/N
97 355 valve guide problem: Y/N
98 355 valve guide problem: Y/N
99 355 valve guide problem: Y/N

--tony

 

My '98 GTS with September '97 build date had the valve guides replaced at 12K miles.

 

Aren't some of these valve guide replacements preventative measures. Ie, the car did not have any symptoms of valve guide issues, but the owner nonetheless had the guides changed for peace of mind. Those should be flagged, and not given any credit to for purposes of this poll, right Michael?

 

Come on, that doesn't matter; they're "an issue" if they're replaced...

Let's keep partisan ship out of this!

 

I have been fixing these things a long time and I've never heard of someone changing valve guides because they might go bad, but then I hear of people changing waterpumps because they might go bad.

 

While tracking my '95 355 at the Texas Driver Magazine event at Motorsport Ranch, I broke an exhaust valve, caused by a bad valve guide. What Norwood discovered was one bank that showed pretty good on the leak down, and one that didn't. I am choosing to replace all them while we are in there so it will become a non-problem on any sale in the future. While in there, we are rebuilding the water pump, and doing all other normal maintenence.
People had noticed some smoke out of one side under acceleration, but I never noticed it down on power until the valve broke, and I could hear extra exhaust noise. I had just seen some increased oil usage, so it had been coming for a while. Bad news is I'm down for about a month.
So in my little over a year ownership I have fixed the seat guide/convertible top issue, bad exhaust header issue, and now these guides. I hope to hell I have a car I can enjoy for years to come without these costly glitches. A few cruises with the top down should solve this depression.
Still love my

 

Boy Michael you better pray this valve guide thing never happens to you!!! I'll say a prayer for you too because I hope it doesn't...

 

I had to deal with this question (valve guides) when I sold my 1995 355 C back in January. This post brings up a lot of good information but also some that is false.

Go to: http://ferrarichat.com/forum/showthread.php?t=5554&highlight=valve+guides

Regards,

Jon P. Kofod
www.flatoutracing.net