# Nissan sentra gxe error code p0300

**URL:** <https://community.cartalk.com/t/nissan-sentra-gxe-error-code-p0300/37197>\
**Category:** Maintenance/Repairs\
**Tags:** nissan, sentra\
**Created:** [September 26, 2009, 9:13pm UTC](https://community.cartalk.com/t/nissan-sentra-gxe-error-code-p0300/37197 "2009-09-26T21:13:01Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![suddhad](https://avatars.discourse-cdn.com/v4/letter/s/ce7236/32.png) [@suddhad](https://community.cartalk.com/u/suddhad)\
**Post date:** [September 26, 2009, 9:13pm UTC](https://community.cartalk.com/t/nissan-sentra-gxe-error-code-p0300/37197/1 "2009-09-26T21:13:01Z")

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I have a 02 nissan sentra gxe. The service engine soon light came on a few days ago. I am also loosing coolant. I did a pressure test and there is no visible coolant leak. Looks like I need to replace the head gasket. Did anyone have this problem and did replacing the head gasket fix the issue ? It looks like quite an expensive fix.

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**Author:** ![NatReader](https://avatars.discourse-cdn.com/v4/letter/n/5f8ce5/32.png) [@NatReader](https://community.cartalk.com/u/NatReader)\
**Post date:** [October 23, 2009, 5:36pm UTC](https://community.cartalk.com/t/nissan-sentra-gxe-error-code-p0300/37197/2 "2009-10-23T17:36:49Z")

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sounds like head gasket. Look for milky color in oil, also there are ways to check for air bubbles in radiator which is a sign and possibly white smoke out the pipe. Gasket itself is not too expensive, it is the labor of like 6-7 hours due to getting to the cylinder.

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**Author:** ![NatReader](https://avatars.discourse-cdn.com/v4/letter/n/5f8ce5/32.png) [@NatReader](https://community.cartalk.com/u/NatReader)\
**Post date:** [October 23, 2009, 5:39pm UTC](https://community.cartalk.com/t/nissan-sentra-gxe-error-code-p0300/37197/3 "2009-10-23T17:39:51Z")

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You also need to do a compression test and look for 120 psi across the cylinders. If you show across 2 cylinders low pressure you can be sure of the head issue. Also do a leak down test if possible. All these will give you information on valves, rings and gasket.

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**Author:** ![vtcodger2](https://avatars.discourse-cdn.com/v4/letter/v/e68b1a/32.png) [@vtcodger2](https://community.cartalk.com/u/vtcodger2)\
**Post date:** [October 23, 2009, 8:33pm UTC](https://community.cartalk.com/t/nissan-sentra-gxe-error-code-p0300/37197/4 "2009-10-23T20:33:51Z")

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If you are going to do a compression test, that means removing the spark plugs. Look at the plugs when you take them out. If one of them is shiny and clean, that’s a pretty good clue that you are leaking coolant into that cylinder.