Have oil in my radiator fluid reservoir tank. Let a friend due a tune-up on car and i gave him a pcv valve to put on car he put it on the left valve cover in rear (if looking at car) in my book it shows the pcv valve on the right side front valve cover (1996 mustang V6 3.8)

It goes in the one that says fill cold , the other one is brake fluid .

Thanks for choosing FixYa and welcome to the site. At your mileage, it is time to do a tune up anyway. You are going to want to change your serpentine belts. You will want to change your spark plugs/coils, wires, coil packs, distributor cap. You are going to want to change the transmission fluid and filter. Also, flush your radiator and change the coolant. You will want to purchase a new fuel filter and air filter also. It would be a good time for a new PCV valve to. If you want to balance the front end and tires, I would do it. If not, the tune up should increase engine performance. If you have any questions, feel free to ask and thanks for using FixYa.

New spark plugs, oil and oil filter, transmission flush and fill, fuel filter, air filter, coolant flush and fill, clean throttle body plate and bore, clean the MAF sensor, replace any loose or cracked vacuum lines, PCV valve, new air filter, new battery.

99% of the time all you should ever need for a tune up is new spark plugs, and a clean air filter and throttle body. But since your inquiry indicated "major" I gave it more critical thought.

Just basically spark plugs and an air filter. The plugs don't need replacement until 100,000 miles. The fuel filter is located inside the fuel pump assembly in the gas tank and is not serviceable. It doesn't require a PCV valve and there are no adjustments available for the throttle body, idle or timing.

- Spark Plugs (make sure they are gaped properly)
- Spark Plug Wires
- Coil Packs (if needed) or Distributor Cap & Rotor (which ever so equipped)
- Air Filter
- Fuel Filter
- Oil
- Oil Filter
- Transmission Filter (optional)
- Transmission Fluid (optional if you do change the trans filter you will need the fluid)
- PCV Valve (optional)
- Bottle Of Fuel Injector Cleaner (add to fuel tank kind)

There is no radiator cap. The over flow tank is part of the cooling system and feeds coolant directly into it (and/or circulates coolant through it). Unlike a true overflow that will just catch any excessive coolant and store it until the radiator cools down and sucks it back in.

So think of the reservoir on your vehicle an extension of the side tank of your radiator.

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

It sounds like you're having a few problems. The "oil in the coolant reservoir" issue could be due to a blown head gasket, which is a common issue on Dodge/Chrysler V6 engines. Also, because of damage to the radiator, there could be a coolant leak or you could have air in your cooling system. I would have that looked at and/or replaced after having the head gasket checked.

On the left side of the engine compartment there is the reservoir for the power steering fluid. Make sure that you do not put steering fluid in the radiator reservoir.

chk your PCV valve. If faulty it will allow oil to be sucked up and burned. Its the critter stuck into the valve cover and has a rubber hose on it. Good

luck, Ned It's an easy fix and inexpensive. So not to panic.

Twice in two years now my Saab 9-5 has had a pin-hole in the oil cooler, which has caused oil to flow into the reservoir. A way to tell is if coolant/oil is coming out of the reservoir cap. The reservoir cap is rated for the pressure of the coolant system, which is significantly lower than the oil pressure. When there is a hole in the oil cooler, oil will be forced out at relatively high pressures, causing the reservoir to fill and then over pressurize and spill out of the cap.