Any simple way to check if a 355 has potential valve guide issues or header cracks

Put enough miles on most any car and you'll have valve guide issues, but it's probably closer to 35k miles for the 355. You'll see some considerable smoke out of the tailpipes, especially at startup.

Header cracks will emit a tell-tale ticking sound that grows larger as the damage begins to threaten other components. OEM 355 headers will get these sounds at or before 25k miles.

 

Yep, leak down test, copression test and a thorough listening to with a scope to see if there are any tell tail noises as per exhaust ticking.

 

if I'm not mistaken, Ferrari switched to better valve guides after assmebly # 27689 (according to my old notes on the 355). Most of the guide problems related to 355's built prior to that assembly #.

A compression test is also another way to see if there could be valve seating issues.

Ray

 

I'm fairly sure that a leakdown test will tell you how well the valves are sealing...


....whereas a compression test will tell you if the timing is set properly (i.e. valves opening/closing at the right time).

You could have great valve sealing per a leakdown test and still have lousy compression due to valves not closing at the right time (open valves make for poor compression!).

 

Especially if 1-2-3-4 have a different average compression than 5-6-7-8

Jay

 

No visual signs only leak down test. Have yet to see one with bad guides smoke on start

Dave

 

While a leakdown or compression test would be a "part of" a PPI, by themselves they are just what they are. You asked if there were a simple way to test the valve guides, and there really isnt. Short of dismantling the engine and stripping the heads to check for physical wear, a leakdown and compression test is the only alternative. A smog test or visual smoke indication isnt going to be worth much either, as state of tune could create problems that may be easily corrected. But probably the biggest question is why buy a car that could potentially require a $20K repair and not spend a few bucks getting a leakdown/compression test? And running around with a stethoscope to hear exhaust leaks only takes a few minutes.

 

If the car is in another state, I would be particularly fond of the PPI. I can understand looking the car over yourself (assuming you know what you are looking for) but otherwise the PPI is your best friend. One saved me 10k.

 

Question on the stock headers...Will all 355 headers go bad or just certain years???

 

I don't know. I suppose that it is possible that the OEM headers were improved in later models of 355's, there are more than 1 or 2 styles (2.7 style, 5.2 style, for sure).

But I've only seen people write about them going bad, not that some were improved. Everyone seems to point to aftermarket replacements or ceramic coating...a few may be able to be welded/repaired, potentially.

 

My car is a 1997 5.2, just wondering if I should replace them before they go bad. How hard is it to inspect them? Can I remove the heat shielding with them on the car?

 

The later "improved" exhaust manifolds were related to the air injection rails, and had nothing to do with the exhaust manifold pipes themselves. They still failed.

They can be repaired, but not by welding...no one has been sucessful at that, since the pipes actually melt and collapse on themselves. The only repair is to completely cut out the bad sections and replace with thicker, higher grade stainless steel.

 

heatsheilds are not easily removed...about the only thing you can watch for, is the telltale noises, and if you see the asbestos wrap being pushed out from under the sheilds. Just replace them...they WILL fail.

 

I've seen one 348 with bad valve guides smoke on startup. Mine prior to a top end rebuild.