Radiator Cap Pressure

[TimmyTXJ]

Hey guys,
Stupid question... what's the CORRECT pressure rating (Like from the FSM) for the radiator cap ('93 w/ 4.0)? My Haynes Manual says 16 to 18psi but every parts store I've hit online shows a 13psi cap.

[Carves]

Havent got a 93 FSM ... but the '93 part number is J323 9375.

From the '94 and onwards FSM's

RADIATOR PRESSURE CAP
All radiators are equipped with a pressure cap.
This cap releases pressure at some point within a range of 83-110 kPa (12-16 psi). The pressure relief point (in pounds) is engraved on top of the cap (Fig. 5).

Fig. 5 in those FSMs ... show a cap with 16psi marked on it.

[TimmyTXJ]

Thanks Carves! That part number pulls a 13psi cap so I reckon I shall stick with that.

[finneys98xj]

Yea 13 is what have

[TimmyTXJ]

FYI,
Installing a new radiator cap (13psi) was good for about a 5 degree reduction in engine temp. Such a simple thing but I'm willing to bet most folks forget about this when chasing overheating problems.