Temperature Fluctuation

[shaammika5]

I have an issue with my nissan premera car.its tp11 2000 model with 1.8cc.the previous radiator started to coolant leak. So I replaced a recon radiator of fb15.but after few days ago I realised the car temperature goes up at the certain time . specialy wen I drive in up cuntry areas and the trafic time.but dis is not hapend always.next thing is the temperature goes up and within few second it goes down.i checked that then I got to know when both fans are on, the temperature goes down. I sent it to garage but he checks the temperature with gage and said nothin wrong with the temperature. But still meter indicates temperature goes up and with both fans on it goes down.pls help.

tnx.

[maheshw]

im just telling you. TP11 comes with 1.8cc engine. but the radiator of FB15 is a 1.5cc? was that different can be one reason. even if the fans woring when temp goes high, i feel they are not kicks on correct engine temp. had similar issue on a FB14. issue was a 12V relay which connected to fans.

[GayanR]

Hi shaamika I'm not that knowledgeable on this to comment,but I had some experience.By the way have they replaced the original thermostat?Certain thermostat comes with various temperature settings to be open at different times.Might be your new one opening too late for the car.

I had a smiler issue it was a failing water pump

Edited August 11, 2014 by GayanR

[The Don]

I have an issue with my nissan premera car.its tp11 2000 model with 1.8cc.the previous radiator started to coolant leak. So I replaced a recon radiator of fb15.but after few days ago I realised the car temperature goes up at the certain time . specialy wen I drive in up cuntry areas and the trafic time.but dis is not hapend always.next thing is the temperature goes up and within few second it goes down.i checked that then I got to know when both fans are on, the temperature goes down. I sent it to garage but he checks the temperature with gage and said nothin wrong with the temperature. But still meter indicates temperature goes up and with both fans on it goes down.pls help.

tnx.

You need a radiator of at least the same size and the same number of cores. The FB15 radiator might not be big enough to cope with the cooling needs of your car.

Up country and traffic are normally the places when this is most obvious, as one stresses the engine keeping it in high revs and the other limits the ambient air that will flow through the radiator cooling it.

Get the correct replacement radiator, or get one made by one of the radiator companies like D*MO or ct to suit your car.

[shaammika5]

I think my previous one has double core model.but thre problem is after replace dis radiator I traveled to up country without any probs.nothin hapnd.but my second tour on same month dis insident hapnd.is dare any relationship with thermostat. Bcs thermostat not inside.

[shaammika5]

Hi shaamika I'm not that knowledgeable on this to comment,but I had some experience.By the way have they replaced the original thermostat?Certain thermostat comes with various temperature settings to be open at different times.Might be your new one opening too late for the car.

I had a smiler issue it was a failing water pump

Tnx ur coment.do you no any place to buy temostat.

[The Don]

I think my previous one has double core model.but thre problem is after replace dis radiator I traveled to up country without any probs.nothin hapnd.but my second tour on same month dis insident hapnd.is dare any relationship with thermostat. Bcs thermostat not inside.

Where does the thermostat fit in your car. There are two thermostats in the car.

We have the thermostatic valve which opens up to let hot water through which some people refer to as a thermostat. This controls flow of water through the system.

We have the thermostatic switch that triggers the fans. The fact is the thermostatic switch is a little irelevant when running AC as that normally brings both fans into operation irrespective of temperature.

If overheating happens only when the car is under load, usually there is either a blockage in the system, the radiator cores are blocked or the radiator is not up to the job.

Thermostats are available in Panchi. Take a sample.

[shaammika5]

Tnx for all.i ll check.do u any any expertise to look my car.any mechanic around colombo

area.

[aps]

Tnx for all.i ll check.do u any any expertise to look my car.any mechanic around colombo area.

highly recommend radiator repair place from katubedda junction towards moratuwa (200m) in galle road (land side),

[shaammika5]

Guys tell me is temostat necessary to the car.bcs my car doesn't have it.if it is important where can I buy this. Car is 1.8cc primera P11 2000 model.QG18 De engine.

next thing is if the car at idling position without a/c on the heat meter goes up.but with d fans start it comes to normal position.i chekd d radiator its ok.i put a double core rafitor but problem remain same.both fans r worked. termo suvitch also gud.

Pls give me advise. If it is electrical case tell me nissan expert electrician as u no.tnx

[Rumesh88]

Thermostat is a must (otherwise Nissan would have saved millions on their production cost by removing it). From your observations above it looks like your water pump (wasted propeller/not enough pumping power at low RPM). Do you (or those who owned the vehicle before you if any) use coolant?

[The Don]

Please don't open separate topics for the same problem.

[The Don]

The answers to your questions are very simple.

1. Make sure you have the correct thermostat for your engine. If you don't have a sample, buy it from the agent. They are not that expensive.

2. Make sure your thermostatic switch which powers the fans is in good condition and is the correct one. This operation is sometimes overridden when the AC is on.

3. Make sure the water lines are clear, the radiator is not blocked and you use a good quality coolant.

In all the cars I've used, when the above three were true, the temperature always held steady. Sometimes when the cooling system has been modified, you might see a slight fluctuation when the fans come online and then go offline. But most of the time it should be fairly steady.

[Amila_Silva]

highly recommend radiator repair place from katubedda junction towards moratuwa (200m) in galle road (land side),

I second that. The place is Radco Auto Radiaotor Works.

I faced a similar issue with my car once. When I was in heavy traffic, I noticed that sometimes, the temperature gauge goes little bit high and when I started to drive fast, It comes to the normal position. So I stopped the car, popped the hood and noticed that both fans are continuously spinning. However when I put my palm behind the radiator fan, i felt the air flow was not that strong. Then I (now be extremely careful when doing this... or use a person you hate to do this) moved my fingers towards the fan and touched the fan's spinning blades. (If the force is too much you have to take away the hand immediately) To my surprise the fan rotating speed was reduced and eventually I was able to stop the fan.

So the fault was in the radiator fan. Even though they were spinning, it was not enough. When it spinning for too long it get heated and the rpm becomes low. So the airflow force get sucked into the radiator is not enough to cool the water when the vehicle is in traffic. I bought a genuine radiator fan moter (Mitsuba) from Teck Motors and replaced the original one and the problem was solved. The original one became faulty when the ODO was at about 115000 kms.

So I believe it is better to follow what Don has mentioned above since they are more related to your issue. But it could be a completely different unimaginable thing like I mentioned here. Hope this will help someone because it was really hard for me to find the problem of this particular issue.

Edited August 15, 2014 by Amila_Silva

[The Don]

I second that. The place is Radco Auto Radiaotor Works.

I faced a similar issue with my car once. When I was in heavy traffic, I noticed that sometimes, the temperature gauge goes little bit high and when I started to drive fast, It comes to the normal position. So I stopped the car, popped the hood and noticed that both fans are continuously spinning. However when I put my palm behind the radiator fan, i felt the air flow was not that strong. Then I (now be extremely careful when doing this... or use a person you hate to do this) moved my fingers towards the fan and touched the fan's spinning blades. (If the force is too much you have to take away the hand immediately) To my surprise the fan rotating speed was reduced and eventually I was able to stop the fan.

So the fault was in the radiator fan. Even though they were spinning, it was not enough. When it spinning for too long it get heated and the rpm becomes low. So the airflow force get sucked into the radiator is not enough to cool the water when the vehicle is in traffic. I bought a genuine radiator fan moter (Mitsuba) from Teck Motors and replaced the original one and the problem was solved. The original one became faulty when the ODO was at about 115000 kms.

So I believe it is better to follow what Don has mentioned above since they are more related to your issue. But it could be a completely different unimaginable thing like I mentioned here. Hope this will help someone because it was really hard for me to find the problem of this particular issue.

Amila Silva, you have a point. The radiator fan could be a culprit as well. It might not be spinning at the required rpm. Also check the fins. If they are damaged it might not be cooling well. I've had to twice replace the fans. The issue is the used ones we get don't last that long.

[Amila_Silva]

Amila Silva, you have a point. The radiator fan could be a culprit as well. It might not be spinning at the required rpm. Also check the fins. If they are damaged it might not be cooling well. I've had to twice replace the fans. The issue is the used ones we get don't last that long.

Yes Don You are correct. If the fins are damaged or the fan blades are not tighten enough still the fan will spin and the rpm gets low by the time and eventually the fan blades will spin in a very low rpm.