348 with Milky Coolant

It sounds like a head gasket is bad. Unfortunately one has to remove the motor to get the head off and redo the timming belt. 10k sounds high, but it will be around 5k-6k on the better end of estimates. Sorry to hear about that

 

348's cool so well that oil in the coolant wouldn't per se be the cause of the engine temp shooting up.

That fact, combined with the effort, time, and expense of the Major Service + top end rebuild would cause me to *first* flush the coolant from the radiators, re-fill with 50/50 Prestone premix + Redline's Water Wetter (1 bottle) as well as change the engine oil to Red Line's 5W40 (save the old oil for inspection).

Next, verify that both radiator fan fuses in the passenger-side footwell are good, and replace both radiator fan relays with new Bosch 113's. Likewise, replace the Veglia thermoswitch on the right side radiator fan.

Verify that your head bolts are torqued properly.

Then I'd start the engine, drive around for a bit, and check if the fans are kicking on and that the engine is cooling properly.

If so, then when the engine was cold I'd re-check the radiator fluid. Ferrari engines use a sand-casting process that can leave sand deep in the engine for some time...eventually contaminating coolant. The above process gives you one shot at cleaning that out just in case that's the "milky" problem instead of the head gasket.

Inspect the new coolant and the old oil. Compare the results of those inspections with the results of the engine running (e.g. cooling properly or not) with the new fluids. At that point you should know if your friend needs a top end rebuild or not.

 

348 engines cool very well.

But we don't really know how he defines "milky." Lots of things could cause it. It could be as you say, a blown head gasket (one would expect other poor running conditions as well as contamination in the oil, if so, though) or from header bolts that aren't properly torqued (perhaps allowing seap-age).

But it could be that a prior owner used one of the liquid "Radiator fix" sealers which has decided to degrade now, or it could be from the original factory sand casting, or it could be a rusty heat exchanger for his cockpit heater, or from a rusty radiator, etc.

I'm just saying that if it was *me*, that I'd flush and re-fill the radiator on the off change that the problem wasn't a blown headgasket. There just isn't a big downside to a quick flush, re-fill and drive test if he is otherwise planning on pulling the motor and rebuilding the top-end, anyway!

 

I agree with ND that there are a few things to be done before the motor is taken apart and flushing the system well is a good place to start. The cooling systems in 348's do have very good reserve capacity and are not prone to overheating easily. In any event some diagnostics need to take place before an estimate should be prepared. The shotgun approach often leads to desired results but all to often at too high a price.

 

In addition to the above, you can get a CO test kit that detects CO in the coolant when engine is running, however, the best test I know is to do a leak down and check coolant for air bubbles being blown through.

Somewhat funny side bar, I was having having overheating problem with my prior car (Ferrari but not 348), so I did a leakdown and scrutinized the overflow tank for bubbles, nothing not a single micro bubble for the first 5 cylinders - feeling pretty good - get ready for #6 my face 5 inches from the tank, turn on the air (100psi remember) - next thing I know I get a face full of coolant and a geyser shooting up to the ceiling of the garage.... didn't need to do much more investigating after that...

 

Point #6 at this link would be my guess: http://www.barsleaks.net/how2works.html


"If there are any other brands of stop-leak products in your market, follow the same procedure as described above with these other brands. They will also stop leaks, but there will be an accumulation of residue which actually can plug up the radiator core or other parts of cooling system."


...But if not that, then my second guess would be the sand-casting process.

Just make sure that your buddy's 348 isn't overheating or losing coolant. That would be something else entirely.