My engine temperature is Low on the stock gauge. i know they can be in accurate but, in this case it seems odd..

 

problem being, the temp sits at the 1/4 mark and rarely goes above this even when taken on a long drive, but weirdly. once the engine is turned off, then on again within (minutes) the temp falls even lower, then rises again to about the 1/4 mark.

 

has, no water leaks, as coolant remains high, and no air locks, the coolant temp sensor also doesnt work as when disconnected the fan doesnt kick in, and yes ive checked the relay and replaced with a working one.

 

car also seems to be using LOTS more fuel than usual, help me sort this cold running. as ive no idea what can cause it.:blink:

the temp gauge is a regular thing.... look at the front of the block on the coolant pipe, there are two sensors there, the one to the right (the smaller one) may have a loose connection and or the copper spade attached to it may be loose....

you can tap it with the end of a screwdriver (and hammer, gently) to improve the contact or I found it worked well to put a bit of copper wire around the base of the spade where it was loose and tighten it up with a pair of pliers (kid of like a cable tie)....

thanks medallion man..for your view, but mines near new. anyone else?

sounds like your thermostat is stuck open to me.

 

if its stuck fully open then the engine will not get up to full temperature in this weather, also if the engine is not up to full working temperature the engine temp sensor (blue i think) will be telling the ecu that the engine is not warmed up yet and will be injecting lots of extra fuel accordingly

changed the thermostat in October..... with a genuine unit from z centre...

Have you pulled the sensor out and cleaned it? Also check for corrosion on the sensor the ecu reads also. Pull the connectors apart and clean them well also.

Is there any way you can get an a/m water temp gauge on it Aaron, just to see the difference and rule out the standard water temp gauge as faulty.

 

Al.

the water temp sensor (one which shows dash reading) is new, the coolant temp sensor ( yellow i think) needs replacing, but that doesnt show the low reading as it goes to the ECU.

 

AlanZ- probabily not mate, but i know something is def wrong as the sender is new, as is the water pump and thermostat. think is i dont wanna drive it 250 mile round trip to zworld just for these petty parts. as its overfueling, that nearly 100quid in fuel alone!

Do you have the ecu chipped Aaron?

 

Al.

yes by john dixon. but this is a recent fault, used to sit in the middle, but has started dropping. why do you ask Al?

Some chips will overfuel to an extreme, where it can keep the engine cold, in winter and cost you many ££££'s..... lol

A JD chip would be fine am sure.

As to your cold running and over fuelling........ 1 min..

 

Al.

Do you get black soot over the rear bumper after a drive?

 

Al.

thanks al. i rarely see you on here, but give me a txt soon, i may take a trip down to z world with you in convoy. Have u spoken to Osty1 lately...

not really, but i have Huge 5 inch cans on the back, which do sooot up pretty quickly, and sometimes get popping through the exhaust and misfires. had it down at Z world in October for conzult, and only issue was timing slightly off after having the new engine fitted....

Heavy over-fuelling will leave some heavy black soot on the rear bumper no matter how big your tailpipes, and i mean alot of soot, like a chimney...lol.

 

If you have o/f issues, the next thing to worry about is bore-wash, fuel literally washing the piston bore away.

 

Boost leak will always make the 300 o/f, even a very small boost leak, which is hard to find.

 

Do you get a smell of fuel when pulling up to a set of traffic lights after normal driving?

 

Just throwing some ideas here Aaron.

 

Al.

Edited January 26, 201114 yr by AlanZ

My 300 is o/f and i do get alot of the black soot on the rear bumper, some popping/banging from the zorsts, but my mpg is not that bad.

 

Al.

Also read this...

 

http://www.aus300zx.com/forum/archive/index.php/t-282874.html

 

Al.

nope, no leaks, or boost leaks, no fuel smells ever, all pipes, changed. new fuel temp sensor, new fuel pressure regulator, tank is fine, all lines are clipped and tight, trust me Alz, ive been over and over this car since i got it in July. but it seems the more things i change the more than need changing. beginnning to Pi33 me off. but i think surely soon i must of done EVERYTHING. this HAS to be the last thing to do. :-)

 

look like Zworld is my only answer, but having spoken to Jeff, and done all hes said were both near out of ideas... really dont wanna spend 100 on petrol though, GRRRRRRRRRRRRR even a 100quid repair will cost me 200 at that rate. :-( why cant we have an East Anglia 300zx mechanic

I am around this weekend, and can come over to you and take a look if you like Aaron, albeit I am not a 300 mechanic, but might be able to throw some light on her for you.

 

Al.

Have you comp tested the cylinders at all, wet and dry? If not we can do that this weekend , just to rule this out.

 

Al.

i'll have to let you know time/weather depending if thats possible alan, the car isnt with me at the minutes so will have to go collect it etc. etc.

 

just in case you've not got my number, coz im unsure of yours since it changed a few months back.

 

07814379101 thanks matey, can you send me a txt so im able to let you know about weekend.

 

Aaron.

Text on its way buddy....

 

Check here for info, will take some time sifting through the online help, but might be worth it.

 

http://www.aus300zx.com/forum/index.php

 

Al.

Did u get my text Aaron?

 

Al.

Just a thought, could be clutching at straws.

If the ECU temp sensor is giving a incorect high reading to the ecu because it is faulty or there is a bad conection, the ecu will try to return the engine to the correct running temp. This would mean over fuleing and possably slightly higher revs on tickover to increece the flow rate in the cooling system. I would see if a new/ borrowed ecu temp sensor rectifies the problem. also make sure the conector is free from muck and grunge.

 

Hope this helps

 

Allan