[Flyboyjim]

Greetings,

During the prepurchase Inspection on a 33,000 mile 308 two cylinders (7 and 8) had compressions of 100psi while all others were between 125 and 150 psi. The Ferrari dealer performing the inspection found no changes between a hot and cold engine or after putting a squirt of oil in the cylinders. The engine starts easily, idles smoothly and shows no smoke or water from the exhaust.

The car is immaculate in all areas but I would be interested in other owners opinion of the situation. The Dealer said it needs an "Italian Tune-up" - fresh tank of gas with injector cleaner and a fast drive of 50 miles. The dealer does not think it is a head gasket.

How concerned should I be in moving forward with the purchase?

Thank you,

Jim

 

[Abarth]

Did he check the valve clearance?
Could be that or burnt valves in cyl 7 & 8.
Don’t think it’s the piston rings, otherwise it would have changed the result of the test with the oil squirt (a bit strange it didn't).
But I don’t have a F yet and have no experience of those engines, so I hope somebody could fill in their thoughts.
Cheers.

 

[Flyboyjim]

The valves were shimmed 4,000 miles ago but due to the costs of checking them I don't want to have that done. Thanks for your reply.

 

[Saint Bastage]

The choices are

1) leaking Valve (s)
2) Leaking head gasket
3) leaking piston rings
4) Improperly performed test

Seeing as the inspector apparently performed the test more than once with the same result, number 4 is out. He claims number 2 is out leaving you with 2 choices. Valve sealing is the most common issue and is generally caused by a build up of contaminents around the sealing surfaces. If this is the cause then an "italian tune up" with a detergent fuel and injector cleaners will work. Does the car burn more than its share of oil? That would be an indication of bad rings.

 

[Abarth]

The valves were shimmed 4,000 miles ago but due to the costs of checking them I don't want to have that done. Thanks for your reply.

Why don’t you do it yourself???
Just get a set of thickness gauges, take the covers off and check the clearance by yourself. It’s not that hard. I’ll bet you can do it.

 

[Pete04222]

Why don’t you do it yourself???
Just get a set of thickness gauges, take the covers off and check the clearance by yourself. It’s not that hard. I’ll bet you can do it.

Abarth,
There is only so much you can do to a car that you don't own. Non-invasive testing is fine but if someone wanted to buy my Ferrari and showed up with a set of hand tools saying he wanted to pull the valve covers off to check the clearances I'd politely escort him to the door. I'm not going to let you take my car apart to figure out if you want to buy it or not. What if the clearances are not within specs? Are you going to put the valve covers back on? How good a job are you going to do putting a car back together that you don't want to buy? What if you scratch the paint while putting this thing back together? Are you going to pay for that? No, inspection and testing is fine during a pre-purchase but disassembly is definately out of the question.

Jim,
If you are serious about the car but have concerns about the compression and the dealer says all it needs is an Italian tune-up, offer to give it one. Tell him to fill up the tank with injector cleaner and you'll take the car out for a couple hours and if the compression improves you'll buy it. Be serious, leave him a healthy deposit to let him know you're not just jerking him around to go for a joy ride. "If the car is good I'll buy it." The dealer could be right, with such low mileage there could be just a bit of carbon or rust build up on the exhaust valves on 7&8 that a good run will clear it out. If the compression does not improve the next step is a cylinder leak-down test. This is where air is injected into the cylinder and the amount of blow-by measured and you can tell where it is blowing by; either by the rings, the valves, or worst, into the next cylinder or cooling system via the head gasket.

All said, if the car is immaculate in all other areas like you said and it runs and drives nice, I wouldn't be too overly concerned. It's got a couple of cylinders that aren't up to factory specs. Big freakin' whoop, the car is almost an antique. It is not like you are looking for a car with maximum efficiency. If you are looking for a 308 that has 150 psi compression in all cylinders you'll be looking for quite a while. Verify that it is not the head gasket and then don't give it a further thought. My car is far from immaculate but it still seems to be quite the head turner, people are very impressed with my car but not once has anyone ever asked me the status of my cylinder compression.

 

[Abarth]

Abarth,
There is only so much you can do to a car that you don't own. Non-invasive testing is fine but if someone wanted to buy my Ferrari and showed up with a set of hand tools saying he wanted to pull the valve covers off

Sorry about that, I for some reason missed the part with "prepurchase inspection" and made a complete fool out of myself assuming he spoke about his own car.

I wouldn't let anybody touch my car the way i described either just to check something out.

Truly sorry about that Flyboyjim and Pete, promise to read the next post better before I make a reply.

 

[dinogt4guy]

Could not the timing itself cause a variance in the compression test? If it were a bad head gasket there would be some obvious signs.
1. water in the oil
2. gasses in the coolant causing overheating
3. white smoke coming out of the exhaust

You do want to see relatively the same numbers across the cylinders. Hope you can sort this out.

 

[Flyboyjim]

Thank you all for the thoughtful and informative responses. After the "Italian tune-up" all readings are now within 20% of each other.

I have moved forward with the purchase, more confident because of your help. Many thanks,

Jim

 

[dinogt4guy]

Congrats!!

Lets see some pic's!

Cheers!

 

[Saint Bastage]

After you have settled the price debate and the documents are signed, print this thread and show it to the dealer. We want our commisions.