99 - bone stock: Currently have a ghost knock sensor code and a MAF (Forgot to plug the sensor back in when i cleaned the TB --- Autzone will not reset the code for me .. said it was new law??? WTF ? anyway off to HF to get a reader) ... anyhow the light was on before i changed the stat --- and it was running very cool before.

Cleaned the TB last week and noticed an increase in RPM at idle. But, after further review and a couple of REALLY cold days, I realized that my thermostat was stuck open and and I was never warming the car up..... I had really never notice the high idle / low temp and i guess i just got used to driving it that way. It finally dawned on me that I hadn't remembered seeing my fan come on ummm like ever

Fast forward:

I changed the thermostat -- drained the radiator via lower radiator hose --- ended up putting a gallon of Peak back in with distilled water to top off. I have heat cycled the car 5 times --- with the last attempt not bubbling any ---

Car warms up quickly and will stay at 45-50% on the guage while driving on flat roads... the minute you start climbing the car heats up and stays closer to 70% for the rest of the trip. You pull back on a flat surface and let it idle in 40 degree temps and it takes a long long time for the fans to cut off.. in fact after 10 minutes I just killed the car. Problem occurs with the heater on or off. Car stays closer to 65-70% on the guage until you kill it and let it cool off.

The only thing that was changed is coolant ratio -- i am sure i have a higher content of AF at this point ... and a new thermostat (purchased from Autozone)

I have read all of the threads that I can find:
*I dont' seem to have a leak
*neither hose seems to have a vacum on it (meaning sucked flat)
*I didn't see much contamination in the fluid i drained (but i didn't flush it)
*Water pump seems fine --- (based on fluid circulating and heat in and out of radiator hoses)
*the last heat cycle produced no 'burping'
*Car ran very cool with thermostat stuck open

I am tempted to take the car and let someone flush it b/c all i can think of is I still have air in the system. I hate to spend $60 bux on a flush and have a bad radiator --- <insert guess here>theory being that the radiator was good enough to handle the cooling when the coolant was constantly flowing -- but, once it warms up it is not good enough to help cool it down all the way? </end guessing>

Have i missed anything? One good thing is that car is idling correctly now i know most of the threads I have read have the car when operating normally at the 50% mark and my car is over that threashold. Perhaps a higher threshold thermostat was installed?

Thanks for any help.

dan

 

When you were bleeding the system, did you have it set to heat with the blower motor on, or with the heating system off?

 

Heater on with the blower running.

I got the car warm -- killed the car. Opened the cap and started the car.... got it warm again and blipped the throtte until it stopped burping... top off and put cap back on ... drive around for 5 minutes ...

Repeated process several times. I also let the car sit until all the way cool and did it to more times. (side note ... most of the time the radiator fan was running --- so I am pretty sure that the stat was open... also both radiator hoses were getting warm)

I sure hope it is is air in the system --- am I doint the 'burping' correctly?

 

Sounds like it, on both counts.

Does the level go down at all after it gets hot? If you keep the revs high, will the temp go down?

 

The level has never dropped much --- in all the time of heat cycling .. i have probably added less than 1/3 of a gallon? and that includes what burped out.

One interesting thing: last night when the tempature climbed while driving around ..... I took it out of Overdrive to elevate the RPM's and the temp started to drop thinking maybe incresed flow might help... and it does... it will start to drop the needle if the RPM goes up.

Same thing while idling ... increased RPM seems to cool it better.

 

High revs that decrease coolant temp always point me to low coolant level (air) or possibly (plausible, but unlikely) a poorly performing water pump.

Best you can really do is try bleeding again, short of taking it to a shop.

 

thanks for the help .... i think i will take it in and have it flushed and make sure it is done correctly.

 

What kind of thermostat did you put in? The Nissan one comes in with its housing ready to install. If you get after market and had to remove old thermostat to install new one, make sure the new one is installed with the same orientation as the old one. There is a hole on the thermostat valve that has to be at the right location.

 

I don't believe there's an aftermarket thermostat out there right now that comes seperate from the housing.

 

the stat that went in one was one piece included in the housing.

 

It's probably air trapped. Bleed it again, leave the cap off the radiator until the fans come on and cycle. Hold the engine speed at 2500 RPM's while you do this. The sytem needs to get really hot with the cap off the radiator and engine speed up so the pump is pumping hard.

We do a lot of head gaskets at my shop, bleeding some cars out is a real pain sometimes. I had a tough time getting mine to bleed after a simple coolant drain and refill. My BMW 3 series was a real pain after a coolant tank blew out.

The key is to get them hot while open with the revs up. Make sure the fans cycle on and off once or twice.

Good luck!

 

Well I took that car in and had it flushed and it didn't fix the getting warm ....I picked up a ODB II reader on the way home, cleared the codes and immediately I got a P1105

p1105 MAP/BARO Pressure Switch Solenoid Valve, p1130 Swirl Control Valve Control Solenoid Valve.

I read through a ton of threads and some of the 1105's came after cleaning a TB. So i pulled off the Airbox and sure enough I had pinched a vacuum hose that runs to the front of the car and connects to what i think is the control solenoid valve (connects to the MAP Sensor and it was pinched between the TB and it's coolant hose. I moved it to the other side of the coolant hose and CEL went away <knock on wood> Idle is great, Temp is running right at 45-50% on the gauge.

Only code left is the KS --- and i think i will switch the harness out first before attacking the beast to see if i can get lucky I might have to try it though at some point.... just to say i did it

Thanks for the help --- advice --- and to all the other threads that are value add.

peace -

dan

 

Did you use any liquid sealer for the thermo?

I've just used a new gasket and the thermostat itself. I hope it doesn't leak.