In last weeks episode of Sons of Anarchy there’s a scene where one of the bikers confronts someone in a car and pulls out a large (think Ka-Bar) knife and stabs it through the grill of the car, rupturing the radiator, supposedly rendering the car inoperable. Two questions.
First, is it really possible to stick a knife through a cars grill and kill the radiator, and secondly, would a hole the size that a larger knife would make really disable a car?
I think so. If you look at a rad most of the surface would be composed of a matrix of thin fins and channels, which is easy ruptured. I was changing a rad once and my mechanic friend made a point of removing and setting aside any screwdrivers or other tools when handling the new radiator, for fear of accidentally rupturing it. Seems to make sense.
Now, whether that would disable a car, I suppose it would eventually, but you could probably drive for a while until all your coolant ran out.
A big hole in the radiator will allow most of the coolant to drain away after the car gets warm and the coolant starts pumping. If the car overheats the engine can become damaged and stop working. I would not run my car without coolant for fear of ruining the engine. But the car will run for at least for a little while and possibly indefinitely in cool weather if the engine is not loaded to heavily.
I was once working underneath a car, removing a bad alternator, and as I pulled the old part I somehow managed to slam it into the radiator. One of the wire posts on the alternator pierced the radiator, and the coolant leaked all over the place. So now I had to replace the radiator as well. And find some clean clothes. Did I mention I was under the car? In a parking lot? In February? That was not a good day.
So, yeah, if someone can get a knife through the grill of a car (which would depend greatly on the car model), they could puncture the radiator.
Well, at least it was antifreeze.
Absolutely, so long as there is sufficient access through the grill’s openings. Radiator cores are made of very thin metal. Older ones were brass, modern ones are aluminum, about the same gauge as an aluminum beverage can. A pocketknife will go through it without much effort. It’s no challenge for a big knife.
Eventually, from loss of coolant. How long it would take depends on how big a gash was made and how low it was in the radiator. A leak very the near the top would not prevent the engine from being run for a fair amount of time. A good-sized one near the bottom, however, could drain the radiator in minutes, and significant overheating could result within ten minutes of running the engine.
A related question: Are there many(any) modern cars that come from the factory equipped with an aluminum radiator? I haven’t seen one before. I thought most car makers didn’t use aluminum because of problems with corrosion when it comes into contact with the rest of the car body, and that the copper/brass ones had superior heat dissipation properties.
Assuming, as was the case in the show in question that the car had been recently running for some time wouldn’t you burn the hell out of your hand from the steam that would escape? I remember from auto shop in high school that you’re not supposed to open the cap on the radiator until the car cooled down enough, so wouldn’t the stab hole cause a similar reaction?
Unless you are trying to impress someone with your extensive (lack of ) vehicular knowledge. In which case, go right ahead, it makes for an impressive show. The burns will eventually heal.
My experience comes from working in a muffler/radiator shop in the mid 80’s. Many Volkswagens since the mid 70’s came with radiators with aluminum cores, the tanks were plastic. Subaru and Saab used them in the 80’s. We replaced a lot of these brass replacements. Aluminum radiators will work perfectly fine, they just need more maintenance that brass radiators. Many then and today use a sacrificial anode, it is made of a softer material than the radiator and it theory it will corrode instead of the aluminum radiator. FYI, most radiators used in racing such as NASCAR, F1, IRL and other upper levels of racing are made of aluminum. They weigh less than the copper/brass that was used in the past. They don’t have to worry about corrosion, they all run on straight water for cooling and they receive maintenance after every race. I even used one in my NASCAR tour car I raced back in the late 80’s. It cost twice as much as a copper/brass but required much less airflow to maintain the same engine temperature.
Actually if you ran a knife though the grill, it would have to put a hole in the AC condenser first before it even gets to the radiator. The AC condenser is made of much heavier gauge metal than a radiator, due to it having to deal with a much higher pressure (up to about 450 PSI)
Could you drive a K bar though an AC condensor? Probably. Would a K bar be long enough to go though the AC condenser and into the radiator? Maybe, it would depend of the distance between the grille and the AC condenser. On some 1970’s vintage GM cars that distance was about 2 feet. On some modern cars it is only a couple of inches.
Also I should add that, if the car is turbocharged, there probably is an intercooler between the AC condenser and the radiator, making the bad guys job just a bit harder.
Any idea what kind of car it was?
Actually most modern vehicles have an aluminum radiator. You’d be surprised how much aluminum cars have these days. Many body panels are aluminum, and some more expensive cars are almost totally aluminum.
It was a Saturn Aura.
Looks like it would take a damn long knife.
A Ka-Bar might be a little too short to be able to get through both the air conditioner and radiator but I’m assuming the radiators are positioned about at the front cross member.
Yeah, I beat you, but you got the pic I was trying to find. 
Look at your link. See the grill badge? Go straight back from there, see the rectangular opening? at the back of that is is the hood latch. The AC condenser is right behind the hood latch, and the radiator is right behind that.
You need somebody on their way to a ren fair with a short sword.
[nitpick] not cross member, but core support is the word you are looking for. [/nitpick]
Actually Rick, I can touch the radiator through the grill with my fingers if I do it all the way to the left or right side of the opening. The radiator is still at least 5 inches away, at the top opening of the grill. If I remember correctly the actor hit the grill about midway over between the badge and the side, and midway down. I don’t think it would have been possible for him to disable the vehicle with the knife he used.
so once the hole is there, can you use egg whites to close it ala macgyver?
Black pepper works better.
Don’t forget, you are touching the AC condenser, NOT the radiator. Add about 2-3 inches for the leading edge of the radiator.
