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Radiator cap

I just changed the radiator cap on my 2007 Jeep Compass (2.4L, front wheel drive). Earlier in the year the coolant bottle was low, so I topped that up. The level in the cap neck was fine the whole time. More recently I noticed that there was always an orange build up on top of the cap, and then I noticed some staining on the hoses below the cap. Also, the coolant, while still orangey red, is cloudy.

The new cap from the dealer ($45!!! but I digress), aside from having a plastic cap over the stamped metal, is a 17# cap. Just noticed that the old one is a 16# cap. I bought this car used, so I don’t know the history.

The dealer parts guy swore that this was the correct cap - showed me the part number on the diagram and all that. What has running my coolant at 16 pounds instead of 17 pounds done, if anything? Is this related to the cloudy coolant at all? Thanks.

The PSI rating of the cap is the pressure the cap opens at. So that 1 PSI difference isn’t going to matter. From what you’re describing it sounds like you may have gotten a bad new cap. It does happen. Take the cap to a nearby shop and have them pressure test the cap. This will determine if you got a bad cap.


Thanks. Everything I described above was with the old cap. Trying the new one today.