# Temperature gauge spikes.



## allycat (Aug 22, 2012)

Hi,
I have a Pulsar N16 2004.

For the past 6 weeks the temp gauge spikes to the H level, stays for around 10 - 15 seconds then drops back to halfway (where it usually sits).

These are the symptoms:

1. Car seems to get to operating temperature quickly - within 5 minutes - from cold start in the morning.
2. Seems to go ok for about 15 mins. If I make it to work by then, no problem. After that will start spiking to hot, stay for around 10 - 15 secs then drop back to half way. Spikes every 30 secs or so.
6. The heater doesn't work. Sometimes, there is a blast of hot air before it goes cold and stays cold.
4. When I arrive home from work, check fluid, the reservoir is full to the top and looks like it has been spurting out through "relief" valve at top. Coolant can be seen around on the left side. 
5. In the morning coolant level will be dropped below the empty mark in the reservoir, so I top up to just under full mark.

Things I have tried:

1. Replaced thermostat.
2. Replaced the sender.
3. Replaced the water pump.
4. The cooling system has been pressure tested - no leaks.

If anyone has any idea what could be wrong I would appreciate the input. 

Thanks
Ally.


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## SPEEDO (Jun 9, 2003)

sounds like you have a air pocket in the system, had any work done lately?
put the front end on jack stands/ramps etc to raise it, (with cap off, heater on) warm it up (they make a funnel that attaches to the rad, which will help alot) to burp the air out of it, keep the coolant level up...


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## allycat (Aug 22, 2012)

Hi Speedo,

Thank you for replying, and your advice. 
Just to update... the radiator "blew up" today. And I mean literally. My son was taking it into his work (He works for a car dealership, and the service guys were going to take a look) and he said there was a loud bang followed by steam billowing out from under the hood. So I now have a new radiator and hopefully the problem is now fixed. The needle did NOT spike on his drive home, and the heater works fine.

Ally


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## allycat (Aug 22, 2012)

Seems I spoke too soon.

On the way to work today temp gauge spiked twice then went to hot and stayed there. I pulled over, waited for it to cool down. The reservoir level was on full, but looks like coolant had been spraying out the top (relief valve?). There was coolant in the radiator, level was down but I could touch it with my little finger. 

I drove car home and the gauge spiked and dropped 2 or 3 times. Heater was blowing cold air.

They are saying maybe blown head gasket????? They have also mentioned the air bubble thing but to my knowledge have not done anything about it.

Saying I'm getting a bit annoyed now is putting it lightly.


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## SPEEDO (Jun 9, 2003)

head gskt, I would pull the plugs to check the color, and/or a leak down test. Might also check for the air bubble, has the thermostat been changed? How many miles on your vehicle? Where are you? (curiosity) we(USA)havent had a Pulsar since the 80's


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## allycat (Aug 22, 2012)

Hi Speedo,

I'm in Sydney, Australia. The car is a 2004 model, and has 188,000 kms on the clock. Yes to changing the thermostat.

The service guys are testing it for head gasket. Failing that, no-one knows how the air is getting in to push the coolant into the reservoir.


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## rogoman (Dec 16, 2004)

Make sure to use a Nissan OEM thermostat and install it with the weep hole facing up. Using an aftermarket thermostat will cause problems.


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## SPEEDO (Jun 9, 2003)

Let us know what they find....


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## allycat (Aug 22, 2012)

Rogoman, I checked and it was a Nissan thermostat.
Speedo, No news yet, they looking at it tomorrow. I have mentioned the air bubble thing to them numerous times.

Thanks guys,
Ally


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## allycat (Aug 22, 2012)

Hi again,

Well it's apparently a blown head gasket. They did the 'test' and found exhaust fumes in the cooling system. So my repair bill is creeping up towards the AUD2000.00 mark... oh great!

Just hope this fixes my problem or you will hear my screaming all the way over to the US.

Ally


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