Engine coolant

Safety

• Never open a cooling-system pressure cap when the radiator is hot. Steam and boiling coolant can burn you.
• If you see or hear steam, do not open the hood until the radiator has had time to cool.
• Do not store used ethylene glycol in open containers or leave it in puddles. It is a regulated substance. Ask local authorities about disposal.
• If a child or pet ingests coolant, seek emergency assistance immediately.

Symptoms

• A low reservoir, dirty or rusty coolant, or a cracked hose is the manual's reason to service the system. Steam under the hood is a reason to wait.

Diagnosis

1. Check protection every 12 months, before freezing weather where that applies.
2. The 5.7L 2500/3500 row prints the same 18.3 quarts. This page is still the 1500 engine you identified, not permission to use a heavy-duty truck's other fluids.
3. The 6.4L cooling row is 16.6 quarts and is labeled 2500/3500. It is not a 1500 figure.

Tools

• The specified pressure cap

  The warning says not to use a pressure cap other than the one specified. The cap's pressure rating is not reprinted in the sentence that was read, so no psi is added.

Specifications

Steps

1. 01Match the engine

   3.6L is 13.7 quarts (13 liters). 5.7L 1500 is 18.3 quarts (17.3 liters). Both use Mopar 10 Year/150,000 Mile coolant meeting MS-90032.

   1. The fluids table calls the same coolant an OAT formula.

2. 02Check the level on the 3.6L and 5.7L

   The manual has a checking section for the 3.6L and 5.7L engines. Read it in the book for the reservoir mark. This page does not redraw the bottle.

   1. If the coolant looks dirty or rusty, the system should be drained, flushed, and refilled with fresh coolant.
   2. A hose that is brittle, cracked, torn, or loose at the bottle or the radiator is a repair, not a top-up.

3. 03Leave the cap alone while it is hot

   Do not open the pressure cap on a hot radiator. Use the specified cap when one is replaced.

   1. Bugs and leaves on the condenser or radiator can be rinsed with a gentle vertical spray. That is a cleaning note, not a flush.

Common mistakes

• Pouring the 18.3 quart 5.7L capacity into a 3.6L.
• Using the 6.4L 16.6 quart row on a 1500.
• Opening the cap while the system is hot.
• Mixing a different coolant chemistry because the bottle is the same color.

Parts and tools

Outbound links only. BaySheet does not sell parts. Confirm fitment on the retailer page. Amazon links are searches for a real part name plus this vehicle. Tool rows do not get a product search. The search is not a part number.

• Part

  Mopar 10 Year/150,000 Mile Formula OAT coolant

  Meeting FCA Material Standard MS-90032. Capacities are the cooling-system rows above.

  2016 Ram cooling-system capacities (opens in a new tab)Search Amazon.com (affiliate link) (opens in a new tab)

• Tool

  The specified pressure cap

  The warning says not to use a pressure cap other than the one specified. The cap's pressure rating is not reprinted in the sentence that was read, so no psi is added.

  Cooling system pressure cap warning (opens in a new tab)

Questions

Sources

• 2016 Ram 1500/2500/3500 Owner's Manual, cooling system capacities (opens in a new tab). FCA US LLC. Published 2016-01-01. Read 2026-10-15.

Checklist and email notes

The maintenance checklist is on the site now. The email list is not sending yet, so this box will not store an address.

Other repairs on this 2016 1500

All Ram 1500 repairs

This repair on other vehicles

These guides cover the same kind of work. Their numbers belong to those vehicles, not to this one.