# Possible Blown Head Gasket ?



## milesk072296 (Mar 12, 2016)

Hello, so first off, I have a 2002 Nissan Sentra GXE 1.8L. Recently my car has been having really rough starts and then after about 15 seconds it smooths out and runs perfectly. It threw a code for cylinder 2 misfire so I replaced all my spark plugs but then it threw the code again. So then I replaced all the coil packs and the code stayed off. Ran fine for about a month but now same problem. The coolant is leaking somewhere because I usually have to refill my reservoir about once a month. I looked into the reservoir and my nightmare came true... There's oil in it. My oil on the other hand has no coolant in it, so is it the transmission oil that's in the coolant? 
So I figured it was a coolant leak and bought some Blue Devil Head Gasket Sealant and did what it said.. No good.. And now the car will barley start  I have already replaced one of its head gaskets about 2 years ago but it seems like it's another one.. I was going to try another sealant called Bars since the 3 mechanics I talked too all recommended that one, but if the car won't start the sealant won't do anything. So I'm assuming I'm shit out of luck on this car huh


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## SPEEDO (Jun 9, 2003)

sounds like a head gskt, don't use the "fix a leak" stuff, it can plug up cooling jackets that your engine needs, get good head gskt and new head bolts


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## jdg (Aug 27, 2009)

x2 on the don't use the head gasket / block sealant stuff. It might've barely worked on engines back in the day when they were 100% iron, but not these days. Not even close. And you're just inviting more problems by using the stuff...which you already did use some of the stuff...and may very well have to tear everything down to ensure that sealant crap is completely out of there.
But that's just me...


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## rogoman (Dec 16, 2004)

Run a compression test on all cylinders to see if there is a blown head gasket. If you find a suspect cylinder, run a leakdown test on it to pinpoint the source. You can also run a pressure test on the coolant system to see how well it holds it. Another test you can perform is by using a chemical test for the coolant; this will tell you if combustion gases are getting into the coolant. Look at the transmission fluid for any traces of coolant.


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## milesk072296 (Mar 12, 2016)

Could it be a possible fuel issue? I plan on running a compression test to make sure of a blown head gasket.


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## SPEEDO (Jun 9, 2003)

after you shut off your engine, the pressure is probably forcing coolant into a cylinder, causing a rough start up, once it burns out, it will smooth out.. when you replaced the plugs did you notice the color?? and which cylinder it came from? as rogoman said, run some tests


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## milesk072296 (Mar 12, 2016)

The sparkplugs were pretty clean, no build up or anything on them. The misfire code was off of cylinder 2. I replaced all the plugs and coil packs. Ran fine for about a month and then one day it didn't want to start unless i gave it gas while turning the key. There's no code that showed up.. I just pulled out all my spark plugs to check if there was any coolant on the tips of the plugs, and there wasn't coolant but there was oil. Going to get a compression test done to see if it is the gasket going. Could it be just a bad O-Ring so oil is leaking through?


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## SPEEDO (Jun 9, 2003)

you may have bad tube (spark plug) seals, they are mounted on the inside of the valve cover... I don't think anyone sells replacements (not sure if they are crimped in or if anyone even sells just the seals..maybe rogoman knows??) probably looking at replacing the valve cover


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