jonahdeich

I sent my mustang to a mechanic recently and upon inspection realized that their is thick heater hose running from the hole in the passenger side valve cover to the edelbrock carb and heater hose running from the waterpump to a hole in the top of the intake manifold. Is this how its supposed to be done?? I have never seen these hoses run like this!!!

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Starfury

Yes and no. The routing is ok....ish. The hoses themselves, not so much.

The hose from the WP to the intake was probably done because of a leaky heater core. Pulling the hose from the heater core and routing it to the intake bypasses the heater core. Not going to cause any damage, although you won't have any heat, and you should probably fix it before winter. That said, I'd at least shorten it in the meantime so it stays away from the fan. On the upside, heater core replacement on 65-66 cars is cake.

The hose from the valve cover to the base of the carb is...kinda ok. The connection on the valve cover is a PCV valve, and the nipple at the base of the carb supplies it with manifold vacuum, which is exactly what you want. Although I switched sides on my motor, so the pcv is on the front left and the breather is on the back right. Cuts down on the amount of oil that gets sucked in through the PCV valve.

More problematic is the hose itself. Heater hose is NOT rated for use in a PCV system, and it will quickly disintigrate from the inside out from contact with oil and caustic emissions gases. You need oil resistant hose for this (fuel hose will work as well).

As an alternative to the straight-up PCV nipple, I'd recommend using a PCV valve from a 70's Chevy V8 which usually comes with a 90* nipple. This makes hose routing cleaner, and I haven't run into any problems running it on my car.

racer_dave

Ummmm. no, and it depends.

The hose from the valve cover to the carb sounds like they are trying to vent the crankcase into the carb or possibly be trying to pull vacuum in the crankcase. In either case, not right. Not sure if you had/have an PCV/EGR valve or the like, but if they were trying to vent the crankcase then it should have gone up to the air cleaner not the carb base.

The hose from the water pump to the intake is bypassing the heater core. Is there a good heater core in the car for them to hook the heater hoses up to? If not then all they could do was loop it. If there was, then it should have been hooked up correctly.

So I'd ask the shop why? and why? Let their answers determine whether or not you take it back to them.

jonahdeich

I fixed the hose problem and used the stock pcv hose and valve and switched the exit on the edelbrock to the back. The heater turns on and runs but the hoses are cut off at the firewall so bypass is good. Should I be good from now on? The hose is replaced and correct valve is used. Is the heater hose bypassing the core fine to drive with for a while?

Starfury

Dave, that PCV hose is a vacuum hose, not a breather hose. The breather hose (if it had one) would connect from the breather, visible on the opposite valve cover, to the air cleaner.

The entire point of a PCV system is to put a vacuum on the crankcase and pull blow-by gases into the intake to be re-burned.

Jonah, what "stock" pcv hose?

The heater hose is fine, as long as it's not in danger of being caught in the fan.