PPI Would you do a Compression Check

If there are little to no service records I would do a compression check and a lea lodes test. And have the rest of the car thoroughly checked out . Bring a paint gauge with you as well.

 

Compression test is not usually part of a ppi. Its additional fees to have it done. U dont need or shouldnt need one for a car with less than 30k miles.

 

With these newer cars, if its running well I wouldn't do a compression check. But that's just me.

 

I would not do a compression test on a motor with only 10k miles, its still brand new.

for that matter I would never do a compression test, but on a higher mileage motor I would do a leak down test. The compression test only tells you if you need to do a leak down test or not, so skip it and do the leak down.

But on that low mileage, I would not do either.

By the way 52k miles when I bought my 360 and I didn't do either test, it was running too good to need that.

 

i did a leak-down test when purchasing mine, as the engine was running a bit rough - turned out the intake gaskets needed replacing, ~$3k off the purchase price just for that.

 

Didnt know thia good info. What exactly does the leakdown reveal?

 

a compression test tells you the pressure that the piston can create and that is all it does. The leak down test tells you where that pressure is leaking, rings, valves, head gasket and that is why to me its the more important test.

 

If you want to buy an extended warranty, Ferrari will require that you pay for a compression test. So if you are thinking that way, you might as well get in done before you buy it. Costs a couple hundred bucks.

 

I am also in the process of buying a pre-owned Ferrari, 2003 360. I am having the Ferrari Dealer do a PPI. I am brand new to Ferraris and just been reading up and doing tons of research, but here are my 2 cents: I spoke to the head mechanic at Ferrari and told him I was looking to purchase the 360, and if they could do a PPI. Sure, not a problem, I believe the price is $660. I specifically asked about the compression test, and his answer was this, and I quote: I can't remember the last time we had a 360 in the shop with compression issues...
The compression test is much more important for older models.As part of their PPI, they WILL drive the car. At this point, the mechanics would note if they felt something about the engine was off.

So too make a long story short, if you get a somewhat newer360, with not a ton of miles on, have the PPI done, ask if the car and engine performed well during the tst, and save yourself $200 by not doing the compression test.
Obviously if you want to be on the save side, then... well you get the idea. Good luck

 

For peace of mind and the fact that you are buying a used car from a used car dealer or a total stranger I always have it done.

I trust very few people on this planet.

 

Do all the tests it is a big investment. As an attorney when people come to me to purchase a home I always tell them to do their due diligence and do a home inspection. Why not do all of the proper inspections when purchasing an automobile that costs as much as a house?

 

Well said. For the amount of money to be spent on purchasing the car, the compression check is just peanuts, and will definitely give you some peace of mind.

 

do it, every time...but i agree, it should be a leakdown.

i trust literally no one

 

Peace of mind is inversely proportional to what you know about simple compression testers.

A simple compression test is done by removing the spark plugs and, in sequence, connecting a basic pressure gauge to each cylinder. The engine is turned over using the starter and the highest reading is written down. If one cylinder show a much lower reading, that MIGHT mean a defect with the valves or piston rings of that cylinder. If all are about the same, you have learned very little other than the starter motor works.

Think about it. A an evenly worn engine with valves and piston rings which ALL leak the same amount, will look pretty much OK, especially if the starter motor and battery are strong. A brand new engine with a weak starter motor might not appear as good when tested because the readings won't be as high. The peak pressure recorded has as much to do with the cranking rpm as it does to the actual condition of the cylinder. True, this test might help reveal a problem with valve timing and might detect a piston sealing problem related to piston position. I would argue a compression check alone is hardly worth the expense, especially if you're paying a Ferrari-style hourly rate to a mechanic.

A leak down test, on the other hand, uses a simple pneumatic device connected to a source of compressed air on one side and connected to the cylinder on the other side. The engine is rotated so that all the valves are closed. The tester has two pressure gauges in series with a small orifice between them. When pressure is applied the cylinder becomes pressurized in a second or two and, if the cylinder has zero leakage, both gauges read the same because the air flow across the orifice stabilizes at zero. Of course every cylinder leaks to some extent causing air to flow through the device, into the cylinder, and out via the valves, rings, and/or head gasket. This causes a differential pressure across the small flow restrictor indirectly measuring the amount of the leak.

The reading, usually read as a percent, is not absolute and will vary depending on the device, pressure used, and orifice size. So you can't reliably compare one test to another done by a different mechanic using a different device. But many are sized so that anything above 20% means you need some mechanical work done. The closer to zero the better. In any case, a leak down test is the more meaningful of the two common diagnostic tools.

In the real world, you might as well do both tests as long as you have all the spark plugs out. A compression tester costs ten bucks and up. A leak down tester cost about fifty bucks and up, plus you need a good source of compressed air.

These tools, used together, are VERY useful when evaluating a sick engine which you suspect is having problems with the rings, valves, valve timing, or head gaskets. They are less important when you're talking about a good strong, low-mileage engine which appears to run perfectly. Running both tests with near perfect results would indeed give anyone piece of mind. Using a simple compression tester alone........... no so much.

 

$660 for a PPI without a compression/leakdown test is the most I've heard fwiw. How many hours are they saying?

I had the tests done on my CS. It was only a few hundred more (my total PPI with the tests was $600 IIRC). Small dollars to help put me a bit more at ease buying my first six-figure exotic car. YMMV.