# '03 Sentra - Continued Misfiring Issues



## blutundehre (Nov 3, 2007)

I am new to this forum and I'm not sure if I'm posting this question in the correct area. I am having two issues with my 2003 Nissan Sentra. The first one is in regards to misfiring. My car, for awhile now, has been turning over a bit before it would start - followed by a rough idle which smooths out after a few seconds. A few weeks ago it registered as a misfire on my computer. I took it into the shop and had it fixed. The mechanic told me the spark plugs were really wet. Now, two weeks later, it is doing the same thing and registering as another misfire. I took it back to the shop and was told the same thing - the spark plugs are wet. The mechanic is telling me he has no idea what is causing the continued misfiring issues. And recently I have noticed a strong smell of gas while I'm driving. Do you know what could be causing this?

Secondly, I just had my thermostat changed about a month ago. Today, my heater would start blowing cold air anytime I was stopped or idling, but would go back to hot when I would start driving. Right before I got home, it consistently blew cold air. I wouldn't think my thermostat would be going bad already - Do you know what this could be? 

Thanks so much in advance for any help with this. The mechanics are really giving me the run around.


----------



## dreamskyline (Nov 19, 2006)

what model of sentra do you have?also what engine does it have? it could possibly be the camshaft position sensor,there was a recall on it or the crankshaft position sensor, i dont remember,maybe its retarding the timing too much causing not enough air in thr air/fuel mixture which would cause the misfiring and might be why the spark plugs are wet and the rought idle,all signs point that way,call your local dealer with your vin and see if there are any recalls that need to be performed.as for the heater problem,if you have the QR25 engine as in the SER and spec v then you should know that it has 2 thermostats,one for the head and one for the block,also it could possibly be the coolant line that runs into the throttle body,it might be clogged or pinched,seeing as there is only a difference when the throttle is open,i HIGHLY doubt its the coolant line due to its small size and i dont think that would have much of an effet on the temperature,i know there is one on the QR25 engine but not sure abou the QG18 in the SE models,also maybe the coolant/water mixture isnt correct,you want to try and get it to about 50/50 antifreeze and wateri dont know im just throwing ideas out there now,try that and report back.


----------



## BH Factory (Nov 2, 2007)

you have a blown head gasket and the coolant system has air bubbles in it. that is why your heater goes from hot to cold


----------



## blutundehre (Nov 3, 2007)

*'03 Sentra*

I'm not familiar with all the technical terms in regards to vehicles....but I do know that my car is a 2003 Sentra GXE if that changes anything. Would this car have two thermostats? I'm going to try out some of the suggestions and see what I can find. Thanks.


----------



## dreamskyline (Nov 19, 2006)

blown head gasket??did you determine that with your magical powers?have you by chance looked at his car??well if it is a blown head gasket then check to see if the car smokes or if there is a leak coz if the gasket is blown your coolant will leak and it will smoke,how many GXE's has anyone ever heard blowing a head gasket??c'mon do you race the car every day and bounce off the rev limiter???it would be pretty hard to blow the head gasket on one.check for the recall ask the dealer about if it has 2 thermostats and report back.


----------



## BH Factory (Nov 2, 2007)

dreamskyline said:


> blown head gasket??did you determine that with your magical powers?have you by chance looked at his car??well if it is a blown head gasket then check to see if the car smokes or if there is a leak coz if the gasket is blown your coolant will leak and it will smoke,how many GXE's has anyone ever heard blowing a head gasket??c'mon do you race the car every day and bounce off the rev limiter???it would be pretty hard to blow the head gasket on one.check for the recall ask the dealer about if it has 2 thermostats and report back.


Yes my magical powers which happens to be the fact that i specialize in nissans at my shop. i have had numerous sentras come in (specs and 1.8) for blown head gaskets. he wont necessarily blow white smoke until the headgasket is completely gone. the headgasket is on its way out which is why he has a rough idle at a start and why the plugs are wet. i hear these symptoms all the time and they are all the samething in the end.


----------



## Spddracer (Jan 31, 2003)

You are probably correct but to just say ITS blown without having it checked would be a guess at best. 

Blut* Heres what to do to check the Sentra 1.8

After car is hot, Pull the plugs out. Let it sit for a bit and come back and have a look in the cylinders with a flash light. There will more than likely be coolant in one of the cyliders, Probably #2 or#3 .

The 1.8 does have a problem with the Head gaslets leaking. This will cause the missfire and hard start.


----------



## dreamskyline (Nov 19, 2006)

i understand the spec v's coming in for head gaskets coz of the 2 different thermostats,it causes uneven temperature in the engine which warps the gasket,most people with specs if the are really concerned about it just change out the thermostats with two of the same one or modify the block thermostat,i also understand that you have seen theses symptoms a lot and this is what it ususally is, but to strait out tell them its this or its that isnt very good advice,i wasnt trying to discredit you but maybe you should have said hey check to see if the head gasket is leaking or hey,it might be a blown head gasket,check that first,i have an 02 spec v and when i first got it there was a red wire in the engine compartment next to the battery that wasnt connected,like someone cut it and left it,i have no idea where it goes.one day i decided to reconnect it when i was doing a project under the hood ,after that when it would rain the TPS wouldnt work,no throttle response,the car wouldnt hold an idle either,i checked the tps,it worked fine,checked the MAF,it was brand new,long story short after much frustraition i cut the red wire on the drivers side in the engine compartment that i recently dissconnected and now the car runs perfect in the rain,so long story short you really never know what it could be until you know.


----------



## BH Factory (Nov 2, 2007)

dreamskyline said:


> i understand the spec v's coming in for head gaskets coz of the 2 different thermostats,it causes uneven temperature in the engine which warps the gasket,most people with specs if the are really concerned about it just change out the thermostats with two of the same one or modify the block thermostat,i also understand that you have seen theses symptoms a lot and this is what it ususally is, but to strait out tell them its this or its that isnt very good advice,i wasnt trying to discredit you but maybe you should have said hey check to see if the head gasket is leaking or hey,it might be a blown head gasket,check that first,i have an 02 spec v and when i first got it there was a red wire in the engine compartment next to the battery that wasnt connected,like someone cut it and left it,i have no idea where it goes.one day i decided to reconnect it when i was doing a project under the hood ,after that when it would rain the TPS wouldnt work,no throttle response,the car wouldnt hold an idle either,i checked the tps,it worked fine,checked the MAF,it was brand new,long story short after much frustraition i cut the red wire on the drivers side in the engine compartment that i recently dissconnected and now the car runs perfect in the rain,so long story short you really never know what it could be until you know.


there was nothing else to check or have him look at. the other mechanincs already did it. they pulled the plugs and saw that they were wet. the only thing to do is smell the plug and tell me if it smells like coolant. the other mechanincs just couldnt put two and two together.


----------



## xbrandonx (Mar 27, 2004)

I believe BH is probably right....Sounds like a headgasket to me as well.


----------



## silverbullet_specV (Oct 24, 2007)

drain the oil and check for water, if your plug is wet then take the plug out put a towel inhole, turn it over and look for excess fuel


----------



## BandS13lover (Sep 27, 2007)

replace head gasket, common problem.......... dont worry about sending head to machine shop just sand it with a medium grit sandpaper and check for warpage. there will most likely be none. ive done like 20 of these with same problems. trust me. im a nissan tech. car wont smoke, have water in oil or anything like that.


----------

