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Cooling Mod for 03/04 Cobras and DOHCs in General


Well-Known Member
On the '03/'04 Cobras, only the cylinders on the passenger's side head have an outlet for coolant to exit from the head. The coolant that exits goes on to the heater core. There have been numerous failures reported of the rear two pistons on the driver's side (cylinders #7 and #8) on modified Cobra's. One of the most viable theories for these failures is related to the lack of an exit for coolant on the driver's side head. This theory is that coolant more or less gets stuck in a pocket at the back of the driver's side cylinder head and this causes localized overheating at the #7 and #8 cylinders. A probable cure for this problem is to modify the cooling system so that coolant can exit the driver's side cylinder head and join the coolant flow leaving the passenger side head on it's way to the heater core and then on to the radiator.

Nice Write Up..



New Member
The Cooling mod shown In the picture ( ldc chicago cooling mod kit) works great keeps 7 and 8 happy. better fitment and quality than some of the other kits out there to date until my development piece comes out. \when installing it do it while the motor is out of the car to save some headaches. other wise transmission removal is necesary. the even flow cooling mod can be done with out tranny removal as it goes on the top of the head instead of the back , easier to install lower quality and one more visable hose added. Definetly noticed that its easier to bleed the cooling system in the dohc motors. for more flow remove the restrictor in the heater hose coming off the head by removing the clamp thats in the middle of the hose, squeezing the hose directly behind the restrictor with some pliers till it pops out. then seperate the two plastic pieces and chuck the rubber grommet that comes out between it. re assemble the two plastic halves and reinstall in hose with clamp. the small rubber grommet thats in the hose is to stop gushing noise in the heater core, the larger plastic grommet is to prevent coolant surges that may pop the core.