# Car still overheats over 3000RPM f



## asleepz (Feb 24, 2004)

Alright whenever I run my car over 3000RPM for about 3 or 4 minutes she overheats. Water pump changed. I have 2 other things
New Radiator (this could be it)
Catalytic Converter (does that create overheating problems?)


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## Zen31ZR (Mar 24, 2004)

SKD_Tech said:


> Alright whenever I run my car over 3000RPM for about 3 or 4 minutes she overheats. Water pump changed. I have 2 other things
> New Radiator (this could be it)
> Catalytic Converter (does that create overheating problems?)



Catalytic converter would cause drivability issues more than overheat problems , I would think. Slowly dropping to idle after you stomp on it , for one. Also a stuffed up sound coming out of the tailpipe. It also won't like to rev and you won't get much boost out of the turbo. 
But coincidently , 3000 rpm is the cutoff point between the sequential injection and batch fire mode. Might be running VERY lean in batch fire mode , for whatever reason. Is this at part throttle or under load? 
Also , make sure some dork didn't install the 'stat upside down.


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## 0341TODD (Nov 15, 2003)

Just cut your exhaust off like I did- works great!


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## asleepz (Feb 24, 2004)

how loud is the 300ZXT without exhaust I don't wanna be illegal too much here. We have to get brake tags and stuff like that. I don't have any emission standards but I think we have to have a muffler


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## Zen31ZR (Mar 24, 2004)

SKD_Tech said:


> how loud is the 300ZXT without exhaust I don't wanna be illegal too much here. We have to get brake tags and stuff like that. I don't have any emission standards but I think we have to have a muffler


It's plenty loud , enough that bikers ask me if it has a V8 in it. But so far no noise tickets from the cops , although I guess that might be because I don't look like a ricer.


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## asleepz (Feb 24, 2004)

Hmmm it's something to think about. I would just take it off from the manifolds back. Then get some stainless pipe and run another. I just don't really wanna take the risk of getting a ticket.

*Sees a cop and slams on the clutch*


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## Zen31ZR (Mar 24, 2004)

Probably be alright if you run the pipe all the way back to the stock exit location. Mine currently ends just behind the seats. Probably just would have left it the open downpipe but I put the front part of my new catback on , upside down , to direct flow to the ground. You can see a pic of it in my gallery. Did that because I didn't want to cook the brake and fuel lines.


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## Spongerider (Nov 18, 2002)

SKD_Tech said:


> Alright whenever I run my car over 3000RPM for about 3 or 4 minutes she overheats. Water pump changed. I have 2 other things
> New Radiator (this could be it)
> Catalytic Converter (does that create overheating problems?)


Did you change the water thermostat? If not that is your problem. If so was it Nissan OEM?


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## asleepz (Feb 24, 2004)

Nissan OEM and yes I installed it correctly.


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## Spongerider (Nov 18, 2002)

SKD_Tech said:


> Nissan OEM and yes I installed it correctly.


I won't rule out the water thermostat and water pump yet. Could double check your part #'s? 

1) Have you pressurized you water system?
2) What are you boosting at?
3) Does your exhaust smell like rotten eggs, smell sweet like radiator fuild?
4) Check your timing as well?


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## '85 fairlady (May 1, 2004)

SKD_Tech said:


> how loud is the 300ZXT without exhaust I don't wanna be illegal too much here. We have to get brake tags and stuff like that. I don't have any emission standards but I think we have to have a muffler


No muffler + no cat = loudness


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## asleepz (Feb 24, 2004)

1) Have you pressurized you water system? Nope
2) What are you boosting at? Stock
3) Does your exhaust smell like rotten eggs, smell sweet like radiator fuild? Hmm haven't checked
4) Check your timing as well? perfect


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## Zen31ZR (Mar 24, 2004)

[QUOTE='85 fairlady]No muffler + no cat = loudness[/QUOTE]

You have an NA car. Turbos muffle a lot of sound , it's quieter than you might think.


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## Zen31ZR (Mar 24, 2004)

SKD_Tech said:


> 1) Have you pressurized you water system? Nope
> 2) What are you boosting at? Stock
> 3) Does your exhaust smell like rotten eggs, smell sweet like radiator fuild? Hmm haven't checked
> 4) Check your timing as well? perfect



Pressurizing your water system will only tell you if you have a leak. That won't tell you if , for instance , your radiator was clogged. Perhaps the block needs to be flushed.


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## asleepz (Feb 24, 2004)

How do you flush the block? Just run water through it? Via Hose?


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## Zen31ZR (Mar 24, 2004)

SKD_Tech said:


> How do you flush the block? Just run water through it? Via Hose?



Not quite so simple , I was thinking more of disassembly and then a healthy power-washing.

You're going to have to list everything you've done to the cooling system so far , I've pretty much forgotten. :loser:


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## Asleep (Jan 19, 2003)

run the car and check the radiator for cool spots. it will be noticeably cooler if you have a blockage. it sounds like a classic blocked radiator symptom. oh and, dont use your bare hands to check it, it will be hot.  a thin leather glove should work perfect for feeling a temperature differential.


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## Zen31ZR (Mar 24, 2004)

Asleep_94_Altima said:


> run the car and check the radiator for cool spots. it will be noticeably cooler if you have a blockage. it sounds like a classic blocked radiator symptom. oh and, dont use your bare hands to check it, it will be hot.  a thin leather glove should work perfect for feeling a temperature differential.


Seems to me he just had the radiator replaced.


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## Asleep (Jan 19, 2003)

[email protected] said:


> Seems to me he just had the radiator replaced.


actually, he doesnt actually say he replaced it yet, it just says he has a new one... unless i missed it somewhere.


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## asleepz (Feb 24, 2004)

No I haven't replaced it yet. Plan on it though it's got a pin hole in it and needs to be replaces anyways. I am going to take my pyrometer out to it today and check out for any cold spots. Thanks for all the help guys I will be getting back to you


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## Spongerider (Nov 18, 2002)

[email protected] said:


> Pressurizing your water system will only tell you if you have a leak.


And a cause why he is overheating.


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## asleepz (Feb 24, 2004)

I can get one from Advanced under 200 I think.


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## Zen31ZR (Mar 24, 2004)

Spongerider said:


> And a cause why he is overheating.


 It won't tell you if the radiator is clogged , for instance , is what I'm saying. Pressure testing is worthless except to find leaks , and a pinhole leak won't cause overheating until you have lost sufficient quantity of coolant.


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## Spongerider (Nov 18, 2002)

[email protected] said:


> It won't tell you if the radiator is clogged , for instance , is what I'm saying. Pressure testing is worthless except to find leaks , and a pinhole leak won't cause overheating until you have lost sufficient quantity of coolant.


I disagree there are steps need to be done before you can conclude what a problem is. This is just one step toward finding the answer. And yes, I do 95% of the work on my Z so I do know how to problem solve.


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## Zen31ZR (Mar 24, 2004)

Spongerider said:


> I disagree there are steps need to be done before you can conclude what a problem is. This is just one step toward finding the answer. And yes, I do 95% of the work on my Z so I do know how to problem solve.


Hehe , not arguing with you bro , we just have different approaches to things , I guess. :cheers:


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## JAMESZ (Mar 12, 2004)

Go to your local radiator store and have them boil it out (need to take out the radiator. They can check for leaks and fix them also.


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## asleepz (Feb 24, 2004)

I Am Getting A New One!


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## 0341TODD (Nov 15, 2003)

I put a big magnaflow glasspack on my downpipe with a dump and it ends right after the drivers seat. Its really not loud at all- The glasspack is huge like a normal muffler size- 14x20 and it took alot of the harsh tone out of the exhaust- Like balliztik, I thought it ran a little too close to the brake and fuel lines for me.


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## asleepz (Feb 24, 2004)

hmmm cool. I'd rather just run a straight pipe but that sounds good too. Wish I had a damn sound clip


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## Zen31ZR (Mar 24, 2004)

SKD_Tech said:


> hmmm cool. I'd rather just run a straight pipe but that sounds good too. Wish I had a damn sound clip


If I ever get my track vids DLed (I'm to0 lazy  ) , you'll have plenty of sound bytes from a full open exhaust.


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## Zen31ZR (Mar 24, 2004)

SKD_Tech said:


> I Am Getting A New One!


Think Fluidyne makes one for ours too. Probably hideously expensive , though.


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