2001 nissan sentra with QG18 engine. at cold start, it misses for about 10 seconds and then resolves.the MAF is new and plugs cleaned and injectors cleaned via fuel additive. cant imagine what it is

Oh, car has done about 60,000 Miles (thats 100,000Km" ) Oh, car has done about 60,000 Miles (thats 100,000Km" )

hi guys hi guys

hi guys hi guys

hi guys hi guys

hi guys hi guys

sorry for late response. ok.. car still no change.. noticed that the idle rpm is much lesser than 700 without AC, and also its running a 35 amp battery where the recomennded amperage is 45 i belive. dunno if these contribute. air flow sensor is new.. but i'm gonna get a second opinion with a nissan specified consult analyser.. will keep informed. sorry for late response. ok.. car still no change.. noticed that the idle rpm is much lesser than 700 without AC, and also its running a 35 amp battery where the recomennded amperage is 45 i belive. dunno if these contribute. air flow sensor is new.. but i'm gonna get a second opinion with a nissan specified consult analyser.. will keep informed.

Id like to share something else too. Id like to share something else too.

eight months ago i experienced over heating... checked and changed thermostat, checked radiator/ hoses/ water pump/ heater core and the works. could not find a leak. finally attributed to a failled radiator cap which sucks in air!!! ok this solved the heating issue 100% till i did a coolant change. drained all the coolant and ran engine untill all air was expelled. ran for week and topped up again... after about 500 Km's noticed radiator low on water (about 1 pint/ 1/2 litre).... no visible leaks. its beats the hell out of me to observe that expansion tank was full but radiator needed liquid badly!!! is it the cap again??? or anything else... could it be coolant getting into a cylinder , causing my initial problem which is engine miss??? but once again to remind that i did run 2thou Km's without liquid reduction.... eight months ago i experienced over heating... checked and changed thermostat, checked radiator/ hoses/ water pump/ heater core and the works. could not find a leak. finally attributed to a failled radiator cap which sucks in air!!! ok this solved the heating issue 100% till i did a coolant change. drained all the coolant and ran engine untill all air was expelled. ran for week and topped up again... after about 500 Km's noticed radiator low on water (about 1 pint/ 1/2 litre).... no visible leaks. its beats the hell out of me to observe that expansion tank was full but radiator needed liquid badly!!! is it the cap again??? or anything else... could it be coolant getting into a cylinder , causing my initial problem which is engine miss??? but once again to remind that i did run 2thou Km's without liquid reduction....

hi jeramy, tks for the reply. yes i did a hydrocarbon check and turned out rather hazy!! in sense the color did not change.. My other confusion is , if there is a gasket leak it would be consistant right? in this case i even went at 100 mph many times and did not lose liquid(refer first post, wher the first rad cap change gave me a 100% cure). and even as we speak, i have been monitoring the coolant and have not yet seen a drop since i lost 1 pint.. over here the driving conditions are severe, stop- go- stop - go with A/C for like 2 hrs a day sometimes.. Anyways after loosing the 1 pint, i exchanged rad caps with a pal (same .9 Kg rating) and re clamped the hoses and now been monitoring for loss of liquid. still done only 100 kms and no decrease yet. so back to my confusion, if its a gasket leak, will it show up sometimes and be normal at other times or will compression leak out at all times ?? great help guys. this is my first time in an international forum and im so greatful.. cheers hi jeramy, tks for the reply. yes i did a hydrocarbon check and turned out rather hazy!! in sense the color did not change.. My other confusion is , if there is a gasket leak it would be consistant right? in this case i even went at 100 mph many times and did not lose liquid(refer first post, wher the first rad cap change gave me a 100% cure). and even as we speak, i have been monitoring the coolant and have not yet seen a drop since i lost 1 pint.. over here the driving conditions are severe, stop- go- stop - go with A/C for like 2 hrs a day sometimes.. Anyways after loosing the 1 pint, i exchanged rad caps with a pal (same .9 Kg rating) and re clamped the hoses and now been monitoring for loss of liquid. still done only 100 kms and no decrease yet. so back to my confusion, if its a gasket leak, will it show up sometimes and be normal at other times or will compression leak out at all times ?? great help guys. this is my first time in an international forum and im so greatful.. cheers

So it's. It leaking coolant? Your kind of all over the place with your facts! Have you checked fuel pressure? Does it hold with the key off or does it drop fairly quickly? So it's. It leaking coolant? Your kind of all over the place with your facts! Have you checked fuel pressure? Does it hold with the key off or does it drop fairly quickly?

Sorry it should have read "so it's not leaking coolant?" Sorry it should have read "so it's not leaking coolant?"

hi jeramy, hi jeramy,

yeah its been a roller coaster, so sorry about the un arranged facts, hope u understood the scenario. If need clarification lemme know, i'l try n re set it... i really appreciate your interest. ok as for the fuel pressure, when i switch the ignition i do hear the pump kick in, but i have not technically checked. the thought crossed my mind, but since the problem was not showing up all the time, i figured the pressure must be ok. i did mention that its running a 35amp battery and usually should be running a 45 amp. can this effect the fuel pressure? or if the battery is a bit low also can it effect? i dont wanna be too happy, but since my last post where i put coolant / swapped rad caps and re clamped hoses, the car is starting smooth all the time, and not lost liquid yet..... i'm keeping my fingers crossed and keeping an eye on the coolant too. yeah its been a roller coaster, so sorry about the un arranged facts, hope u understood the scenario. If need clarification lemme know, i'l try n re set it... i really appreciate your interest. ok as for the fuel pressure, when i switch the ignition i do hear the pump kick in, but i have not technically checked. the thought crossed my mind, but since the problem was not showing up all the time, i figured the pressure must be ok. i did mention that its running a 35amp battery and usually should be running a 45 amp. can this effect the fuel pressure? or if the battery is a bit low also can it effect? i dont wanna be too happy, but since my last post where i put coolant / swapped rad caps and re clamped hoses, the car is starting smooth all the time, and not lost liquid yet..... i'm keeping my fingers crossed and keeping an eye on the coolant too.

btw jeramy, where about in US are you? i have family in Atlanta. btw jeramy, where about in US are you? i have family in Atlanta.

I'm not sure what you mean by 35 amp battery? Batteries are rated by CCA (cold cranking amps) the battery should be more like 500+ CCA. Unless you are referring to the group size? Next time it starts to act up hook up a scan tool that can read live data. Turn the key on but do not start. You will want to notate coolant temp. It should be close to the ambient air temp after the car has sat overnight. I would be curious to see fuel trim data once the car has started also. I am from Minnesota ;) I'm not sure what you mean by 35 amp battery? Batteries are rated by CCA (cold cranking amps) the battery should be more like 500+ CCA. Unless you are referring to the group size? Next time it starts to act up hook up a scan tool that can read live data. Turn the key on but do not start. You will want to notate coolant temp. It should be close to the ambient air temp after the car has sat overnight. I would be curious to see fuel trim data once the car has started also. I am from Minnesota ;)

got it... i will locate a scan tool and keep it ready. hope i will never have to use it!!! Will look into those parameters. hopefully i wil be able to get the readings from the tool since most probably the expert who uses it wont be around. i can get a generic OBD 2 scanner. i suppose that will do. got it... i will locate a scan tool and keep it ready. hope i will never have to use it!!! Will look into those parameters. hopefully i wil be able to get the readings from the tool since most probably the expert who uses it wont be around. i can get a generic OBD 2 scanner. i suppose that will do.

Thanks a million and will keep you posted. hopefully my next message will be just to say hi.. cheers Thanks a million and will keep you posted. hopefully my next message will be just to say hi.. cheers

hi jeramy, been awhile. i really need some sound technical advice and cant seem to find anyone over who can brainstorm a old issue. Ok this is it, some while ago i think i mentioned about my car losing water and over heating, or vice versa .... i dunno which ones happening first. anyways the issue resolved after i changed the radiator cap. drove like 500 Km,s since the last cap change ,and again it started to heat up (Last thursday while on afamily trip) anyway stopped, waited till it cooled and checked the water level, water was boiling over the expansian tank and finally i had to top up with about 2 litres. so started to drive again only to experience boiling after 10 Km's. once again cooled and filled water. so before it happened again, i bought a radiator cap from the next town and fixed , it was tighter than the previous, but seemed to seat well. After that i drove like 600 Km fully loaded with 5 passengers, luggage and AC and 200 Km of it was climbing. did not experience any overheating or loss of coolant. Ok so obviously the cap did the trick! but so did 2 caps before this!!!! im confused, why does fitting a new cap solve the issue for wew 100 Km's and after than what happens to them,, the Rad caps in the marked are not original but all every one uses them. can you imagine of a issue that wastes the cap after a while?? or have i been **** unlucky with all caps??? its hard to imagine that 2 caps were faulty! ...... these are my observations 1. while checking the latest tight fitting cap after the trip, i noticed the bottom rubber not being uniformly pressed. 75% of the diameter war hard pressed and other had seated but not pressed as hard. 2. the dude who i bought the cap last thursday removed the hose to the bottom of exp tank and sucked in to test cap, and said the old cap was sucking in air while new one was not. i did not know if this was a sale gimmick, and didnt want coolant in my mouth, so i did not check. 3. i'm also not sure about the exact rating of the cap since i dont have the manual of car, but similar models use 0.9 bar caps which i have been deligently using... so now im totally confused and would love to have some expert advice. this is seriously cramping me cos i feel the car is unreliable. I have 2 other vehicles, a jeep and a toyota yaris, never ever open radiator cap. really appreciate. thanks hi jeramy, been awhile. i really need some sound technical advice and cant seem to find anyone over who can brainstorm a old issue. Ok this is it, some while ago i think i mentioned about my car losing water and over heating, or vice versa .... i dunno which ones happening first. anyways the issue resolved after i changed the radiator cap. drove like 500 Km,s since the last cap change ,and again it started to heat up (Last thursday while on afamily trip) anyway stopped, waited till it cooled and checked the water level, water was boiling over the expansian tank and finally i had to top up with about 2 litres. so started to drive again only to experience boiling after 10 Km's. once again cooled and filled water. so before it happened again, i bought a radiator cap from the next town and fixed , it was tighter than the previous, but seemed to seat well. After that i drove like 600 Km fully loaded with 5 passengers, luggage and AC and 200 Km of it was climbing. did not experience any overheating or loss of coolant. Ok so obviously the cap did the trick! but so did 2 caps before this!!!! im confused, why does fitting a new cap solve the issue for wew 100 Km's and after than what happens to them,, the Rad caps in the marked are not original but all every one uses them. can you imagine of a issue that wastes the cap after a while?? or have i been **** unlucky with all caps??? its hard to imagine that 2 caps were faulty! ...... these are my observations 1. while checking the latest tight fitting cap after the trip, i noticed the bottom rubber not being uniformly pressed. 75% of the diameter war hard pressed and other had seated but not pressed as hard. 2. the dude who i bought the cap last thursday removed the hose to the bottom of exp tank and sucked in to test cap, and said the old cap was sucking in air while new one was not. i did not know if this was a sale gimmick, and didnt want coolant in my mouth, so i did not check. 3. i'm also not sure about the exact rating of the cap since i dont have the manual of car, but similar models use 0.9 bar caps which i have been deligently using... so now im totally confused and would love to have some expert advice. this is seriously cramping me cos i feel the car is unreliable. I have 2 other vehicles, a jeep and a toyota yaris, never ever open radiator cap. really appreciate. thanks

Where are you buying the caps from? How many miles on the vehicle? What condition is the coolant in? Have you pressure checked the cooling system for leaks? Where are you buying the caps from? How many miles on the vehicle? What condition is the coolant in? Have you pressure checked the cooling system for leaks?

hi, Ok the caps have been bought from 2 different dealers. not from factory or dealership. but brands that are being widely used in colombo. my other 2 vehicles use same quality. The vehicle has 55,000 miles. Coolant is new, non mix green type manufactured in UAE. Radiator was pressure tested and hydrocarbon test, as well as basic bubble check done when hot. no one in my area seems to have the tech know how and equipment to pressure test entire system. have visually checked hoses, radiator huck, water pump for leakages when running normal op temp at idle. hi, Ok the caps have been bought from 2 different dealers. not from factory or dealership. but brands that are being widely used in colombo. my other 2 vehicles use same quality. The vehicle has 55,000 miles. Coolant is new, non mix green type manufactured in UAE. Radiator was pressure tested and hydrocarbon test, as well as basic bubble check done when hot. no one in my area seems to have the tech know how and equipment to pressure test entire system. have visually checked hoses, radiator huck, water pump for leakages when running normal op temp at idle.

Hello jeramy. Hope you are doing well. Did the final inevitable thing. the vehicle started its nonesense after another few hundred Km's. This time we pulled a flex tube the size of the expansion tank tube and pulled it right into the car. leaving the bonnet not ajar.. At idle thier were no bubble, but as soon as we started driving around, bubbles started to emerge from the tube which was held inside a transparent water bottle. this continued till the water was totally expelled from the bottle. Having the conclusion that the head gasket is leaking exhaust gas, we pulled the head off and inspected the gasket. there were damages between no 2-3 cylinder plus a doubtful area between num 1 and the timing chain side. anyway pressure tested and polished head and fixed back using genuine parts. in the process put back brand new thermostat valve, brand new fan temp sensor and cleaned radiator and put another new cap. Car is running fine as in top hose hot, bottom hose warrm, fans kick in on time etc. at idle it takes a long time for fans to kick in, temp does not reach half. but on idle when rev to about 2000 Rpm, then it kicks in. thats the scenario. I really really appreciate your time and effort. i still do have one query. can the initial reason for overheating be the gaskets in the first place? and can the issue be intermitent if so? meaning can i run a couple of 100 k's without the leak and can it come back. this is really bugging me and i cant get proper sleep thinking about it. i would be ever so greatful if you could enlighten me on this. pl do not consider me as a pest with hardly no knowledge or with my facts mixed up... just confused.. tks a million again. Hello jeramy. Hope you are doing well. Did the final inevitable thing. the vehicle started its nonesense after another few hundred Km's. This time we pulled a flex tube the size of the expansion tank tube and pulled it right into the car. leaving the bonnet not ajar.. At idle thier were no bubble, but as soon as we started driving around, bubbles started to emerge from the tube which was held inside a transparent water bottle. this continued till the water was totally expelled from the bottle. Having the conclusion that the head gasket is leaking exhaust gas, we pulled the head off and inspected the gasket. there were damages between no 2-3 cylinder plus a doubtful area between num 1 and the timing chain side. anyway pressure tested and polished head and fixed back using genuine parts. in the process put back brand new thermostat valve, brand new fan temp sensor and cleaned radiator and put another new cap. Car is running fine as in top hose hot, bottom hose warrm, fans kick in on time etc. at idle it takes a long time for fans to kick in, temp does not reach half. but on idle when rev to about 2000 Rpm, then it kicks in. thats the scenario. I really really appreciate your time and effort. i still do have one query. can the initial reason for overheating be the gaskets in the first place? and can the issue be intermitent if so? meaning can i run a couple of 100 k's without the leak and can it come back. this is really bugging me and i cant get proper sleep thinking about it. i would be ever so greatful if you could enlighten me on this. pl do not consider me as a pest with hardly no knowledge or with my facts mixed up... just confused.. tks a million again.

Also could this have anything to do with my initial problem which i came into this forum for, the one in which the engine mis fires sometimes . it has yet to surface, but i have only run 100km after HG repair. was not vigilant enough to see if during the miss, the heating issue starts. tks and cheers Also could this have anything to do with my initial problem which i came into this forum for, the one in which the engine mis fires sometimes . it has yet to surface, but i have only run 100km after HG repair. was not vigilant enough to see if during the miss, the heating issue starts. tks and cheers

I would suspect that the overheating is what did in the head gasket. Engines don't like to be overheated or run out of oil. If the head gasket failed in between cylinders than the misfire was probably related. The important thing is you identified the major problem and repaired it. There is no reason to worry about anything. Half the fun of owning a car is wondering what you will have to fix next! :) I would suspect that the overheating is what did in the head gasket. Engines don't like to be overheated or run out of oil. If the head gasket failed in between cylinders than the misfire was probably related. The important thing is you identified the major problem and repaired it. There is no reason to worry about anything. Half the fun of owning a car is wondering what you will have to fix next! :)

hi jeramy, hi jeramy,

hi jeramy, hi jeramy,