355 PPI numbers

Settle down, I wasn't referring to your comment but the one before yours. The compression numbers are very low for the compression ratio that the F355 should generate. Now take a deep breath.

John

 

Seems like an ideal result.
We move beyond testing 355s to testing 355 testors.
Curiosity has me waiting for the second set of figures. You too, I imagine.

 

When he asked if it was a 95 I only assumed that would be the comment. Made a mistake in tagging your comment. I owned a 95 F355 and it was a big topic. One in which many people felt under valued the car. Thought I was assisting by illustrating that it was not really a problem. Sorry for stepping on your toes.

John

 

I agree. I'm chomping at the bits to find out what the second test at a different facility shows. Please let us know if you can find out.

 

I assume we all know that if test #2 comes back clean we need a third test.

 

^ THIS is what your compression should look like. If the place that did your compression says those are the numbers they get all the time , in the 130's, you need to take the car somewhere else and tell them they are ***king idiots. Compression number half of that they are supposed to be inst telling you ANYTHING! This acutally makes me angry. How can someone touch an f car AND charge you for it if they dont know what they are doing and have no common sense

 

it wont need a 3rd test if the 2nd one is done warm and properly.

 

I am the seller. I was not aware of this thread when I started a thread in the 355 section:
http://www.ferrarichat.com/forum/showthread.php?t=205995

 

I think this is a good read for those of us who don't really understand the test. Hard to interpret the numbers if you don't know what your supposed to see:

http://www.dietersmotorsports.com/Compression-leakdowntest.htm

 

This also suggests two things: (1) what Artvonne said is right but (2) the results don't completely add up.

If the test was done properly, then clearly cylinder 7 has something wrong with it. It is possible that there is carbon preventing a valve in 7 from seating and thus dropping the compression on that one spot. I feel like the numbers show a problem with 7, but they don't show why there is a problem. Based on the information here, how can you say that there is a problem with intake and exhaust valves and recommend valve guide replacement? I just don't think there has been enough investigation.

Repeat the test. If it appears that #7 is low, then it is time to find out why, and it is time to find out what will be needed to fix it.

 

The second shop is 200 miles away. Now I'm paranoid to drive it down.

 

Another good read:

http://www.ferrarichat.com/forum/showthread.php?t=86495&highlight=compression+test

Sorry Artvonne, but I had to LOL (it's only funny because you are OK, but the description is priceless!)

 

I think the car is fine and the pepople who performed the PPi are morons. A honda tech could tell you that the numbers they came up with are incorrect. You would KNOW if the car had half the compression its supposed to have by driving it. I think these guys should give you your money back for the ppi. I wouldnt worry about the health if the car if you as the owner cant tell the difference. On the otherhand the leakdown numbers do look correct. So cyl 7 could have a bad/leaky guide. But for your own assurance i would have a retest done by a fellow techsavy ferrari owner near you or fly someone down (if they are cool enough ) that actually has the knowledge to perform a ppi. My 2 cents ,,,,keep the change

 

I wouldn't be. In fact I'd do my best to be present for the test. Especially the section where #7's leak down is tracked aurally.
You stand to learn a fair bit about your motor and diagnosis in general. Pick up your own mechanics stethoscope on your way home.
Test #1 was tainted by closed throttles in my guess. I wouldn't let it worry me as far as driving the car goes.

 

Thanks guys for the advice.
I drove down to Columbus OH last night, smooth drive... got 23mpg . This morning I took it in to NJB (www.ferrariguys.com). Jack and Craig were stand up guys. They did an outstanding job of explaining the process to me. They ran the test dry which yielded 190 to 205 all around. They added lubricant and it raised each cylinder by 15 to 20 lbs. It wasn't all good news though. They found that 2 of the CV boots were toast. I'm staying another night and having them replace all 4.

I can't say enough good things about NJB. They even gave me a loaner. Jack offered me the SL600 but I didn't want to take the chance. I took his Jeep instead. He gave me a tour of his warehouse... had some awesome cars... Mangusta, Ghibli, 550 Spyder replica, a few Ferraris etc.

 

What were the leakdown percentages by cylinder? That is the big number. The compression sounds good.

 

I have to say, the CV boots vs. compression is pretty funny. The first shop bungles the compression test, and they miss the boots, which you can see with the car on the ground and a flashlight.

Sounds like you are on the right track now!

 

Agreed

Jack and Craig are class acts. I purchased a Dino 246 GTS from them a few yrs. back for my brother-in-law.
Their customer service and facility is 1st class.

 

Jerrari, unless they are giving this car away don't buy it. We just wrapped up a head job on a 355 with the same compression results.
Another shop previously "repaired" the vehicle, I will not mention the shop or machine shop names.
Our car initially had low compression on ONE cylinder, the valve guides were the suspected culprit.
The heads were removed and sent out for new guides and valves all around.
After the heads were put back on and the engine reinstalled, the car had low comp on all cylinders.
Suprisingly enough, the car ran very smoothly at idle and under load, it was just anemic.
We got the car and performed a compression test hot/wet (a small amount of oil incylinder to ensure ring sealing) and found 120-130 psi on all 8 cyls.
Compression should be 200 give or take 10 psi for a sound sealed engine. We then ran a leakdown test to identify the comp loss.
We found all the intake valves not seating correctly, we had suspected either a bad valve job or bent valves.
After head removal we found all intake valve seats not sealing at all, valves were not bent.
We sent the heads to our machine shop and rectified the problem much to the customers delight.
The engine now runs as strong as any 355 and relatively smooth (2.7 motronics have a rough idle).
The moral of this story is two fold, one-don't buy a car with bad comp results and two-have a reputable facility fully gauge the situation.
Any job done twice is not going to be cheap and without heartaches. I hope this helps to sway your decision.