Over the years I've read a lot about how fighters and other aircraft using liquid cooled engines were a flying crash waiting to happen, and that a well-placed blob of spittle from an angry Nazi Gauleiter would cause a cooling system failure and an immediate engine seizure, followed by a spectacular crash.
I call B.S. and say that that "problem" was an overstated issue that was largely a non issue.
In all of the reading I've done on the air war in Europe over the years, I've found many mentions of this "problem," but I've found VERY FEW credible accounts of aircraft being downed because of their cooling systems being drained from battle damage. And in most of those it would appear that even had the cooling system not been damaged the plane still would have gone down simply because of the total damage sustained.
The cooling systems on liquid-cooled aircraft during the war were generally well protected by a combination of armor plate and other systems and in most cases were largely inaccessible to being damaged by bullets. Explosive shells were another matter, but then again, the damaged caused by explosive shells was often enough to bring an aircraft down whether the cooling system was damaged or not.
Many of the war's most successful aircraft used liquid cooled engines, including the Mustang, the Spitfire, the Typhoon, the Tempest, the Lancaster, the Mosquito, etc.
The Mustang, Typhoon, and the Mosquito (as well as the Lockheed Lightning) were well known for their low-level attack and reconnaissance missions.
Had they been as vulnerable to ground fire as is alluded, it's likely that A) their loss rates would have been much higher, and B) they simply wouldn't have been used for those kinds of missions.
"The gift which I am sending you is called a dog, and is in fact the most precious and valuable possession of mankind" -Theodorus Gaza
Baby Jesus cries when the fat redneck doesn't have military-grade firepower.