# Need help with troubleshooting



## fkumro (Nov 9, 2007)

My gf has a 2000 Sentra GXE and hasn't kept up on maintenance for sometime now. She drove for months with a bad MAF, and bad coolant temp sensor. I replaced those and it turns out she needed both cats + piping + o2 sensors replaced, we had this work done (and no she doesn't have the cash for a new car, we have to make this one work). The first cat they put on was bad so it threw a code and they replaced it for free but now we have another code coming up. She hasn't got that code read yet (will tomorrow so ill update the thread) BUT the car keeps eating up coolant. Every week I am putting more in either the radiator or the plastic 'overflow' jug. The car is not blowing white smoke (or any smoke at all) and seems to not loose any power. Any ideas what this could be? Also is there suppose to be lots of vacuum when you take the gas cap off? I mean lots, you can hear the air getting sucked in for a couple seconds. The code we are getting read tomorrow only comes on when she is down to 1/4 tank gas and going highway speeds. 

Any help would be great since I'm not that familiar with nissans


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## b15chik (Jun 4, 2005)

headgasket is gone.
and give her a little fyi, if she doesn't want to buy another car she's going to need to keep up with maintenance on hers, lol. it just leads to bigger problems. sucks though headgasket isn't exactly cheap to replace. but it's somewhat common on the 1.8's


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## fkumro (Nov 9, 2007)

I was hoping it wasn't the head gasket  Is there any test I can do to double check this? Also what am I looking at for replacement costs (just estimate so I don't have a heart attack at the shop - unless i do it myself) ?


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## b15chik (Jun 4, 2005)

it's not an easy job to do by yourself. i'm not sure what the "normal" cost to get it replaced it, i usually have very smart friends help me with stuff like that. 
when you change the oil there will probably be coolant in the oil if it's a headgasket leak . 

but white smoke, eating coolant like crazy, it's a headgasket. you can have a shop do a leak down test. but really, if coolant is disapearing there's not really anything else it could be. unless you have a hole in your coolant lines. but then you still have the white smoke.


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## fkumro (Nov 9, 2007)

Thanks for the quick replies  One more question, is it normal to have a large amount of vacuum behind the gas cap ? You can hear the suction when you take the cap off...

I never had this on my chevy or toyota so I'm curious


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## b15chik (Jun 4, 2005)

hm no i never noticed anything. you do have a flap in your truck on the left side (the other side of the gas cap) i think does something with that. i'm sure it's fine


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## fkumro (Nov 9, 2007)

Well it looks like the car is going into my friends shop on Tuesday for a test and fix if needed. Thanks for your help :cheers:


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## KUMADE8 (Nov 9, 2007)

*trouble*

U can have a block test or have the radiator coolant sniffed to see if there are any hydrocarbons (exhaust) in the radiator. This is not to expensive. If the head gasket is bad you will find exhaust emissions in radiator coolant. For you gas cap try a new cap the vent may be bad. There also may be a problem in evap system.


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## fkumro (Nov 9, 2007)

The car had an EVAP code thrown and it was caused by rust where the gas cap seals. The rust was sanded off and coated with rust proof paint. I will try a new gas cap since its cheap and if not oh well its only like ten dollars.

Thanks!


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## fkumro (Nov 9, 2007)

Turns out the head gasket is fine, might be a leak somewhere that is just slow enough that I don't notice any puddles, or not. I really don't know, just have to check the hoses and heater core. Also the one shop either installed a bad 02 sensor or another shit cat cause the code is back. Damn California emissions!!!


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## b15chik (Jun 4, 2005)

the headgasket is a common issue for the 1.8. if it's a small issue now, it will be a larger one later, lol.


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## fkumro (Nov 9, 2007)

Yea, but all the tests came back positive (no leaks in the gasket). So it might be a small leak in one of the hoses or heater core (she needs to pay attention to things, I'm trying to teach her lol). If for some reason the tests were not correct and the gasket just decides to leave us, I will be pissed.


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## b15chik (Jun 4, 2005)

well that's great the tests came back good. hopefully it's some kind of a leak somewhere else. but the symptoms you described pointed right to headgasket


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## fkumro (Nov 9, 2007)

The signs def pointed that way, which after the tests were done my friend (shop owner) and I were confused. We sat there and just looked at the engine like "WTF where is it going" lol

Thanks for all your help btw :cheers:


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## b15chik (Jun 4, 2005)

well really i didn't do anything if that isn't the problem, but you're welcome


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## compprat (Jun 13, 2006)

There should be some moisture coming out of the exhaust if the head gasket is blown.


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## b15chik (Jun 4, 2005)

compprat said:


> There should be some moisture coming out of the exhaust if the head gasket is blown.


hence the white smoke, lol
you're a little late to the party!! :fluffy:


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## b15chik (Jun 4, 2005)

oh btw, check out a company called blackstone labs
they can do an oil analysis on your oil and check for head gasket issues
they will send you a kit, and you send the oil in and they'll send you a very detailed report


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