n00blar

Well, now that the injector mini project's out of the way; there's something I noticed on the oil pressure and temperature gauge.

Here's what I noticed.
1. When I start my ZX, the oil pressure needle gauge stays on the third mark, if you start counting from the right, and not in the middle mark where the lb/in2 label is located. I don't know if this fine or if there's something wrong going on.
I know the needle never hits the middle mark, not even after the car's been parked for over 8hrs.
The needle does go up if I go faster, which I think is a good sign. I've taken several pictures, so that may give some of you an idea of what I'm talking about.

2. After runnig my ZX for about 30 minutes, I notice that the temperature needle is now close to the F mark on the gauge. I'm wondering if there's something going on there. I've replaced the radiator (new), fan clutch, water pump, thermostat, thermostat housing, thermo-time sensor and temp sensor as well. I also replaced the thermo-time wire (the fuel injector cable looking one). Since I live in Miami, I want to make sure I'm not frying my ZX once the summer gets here.

Here are the pictures.

Thanks once again.

jfairladyz

The oil pressure guage is is reading really high if thats at idle. It shouldn't be nearly that high unless you're on the accelerator. It could be a faulty sending unit. Or you could have a restriction in the oiling system that is causing excessive oil pressure.

On the temperature guage, the needle really shouldn't go past the half way mark unless you're idling on a hot day after some heavy driving. Or, you've got something wrong with the cooling system. If it's straying just a wee bit over the center line of the guage then that's no big deal. After 20+ years the cooling system is bound to be below par. YOu didn;t mention replacing the radiator. An inefficient radiator will easily cause the temps to be higher then they should. Also, if this temp problem only happens when the car is idling or creeping along then it may be your fan clutch.

jfairladyz

EDIT above ^

n00blar

Oh yeah, I forgot...I did buy a new radiator and fan clutch also. The fan is the same one the car came with.

As for the oil pressure, any ideas as to where to look for?
The pictures labeled just started...nope, I didn't have my foot on the accelerator and the same goes for the picture labeled 30 min....I had the car just sitting there idle.

jfairladyz

With the cooling you could have deposits in the engine itself inhibiting the coolant flow enough to cuase minor cooling problems. There are some silly thing too that you wouldn't think to look for like the thermostat housing. It's right above the exhaust manifold and if you've got an exhaust leak right around there it can raise the temp of the thermostat housing which is where the guage is getting it's reading from. IT doesn't mean your engine is actually heating up, just that the housing is hotter then it's supposed to be.

For the oil pressure it could be as simple as somebody before you installed a higher pressure pump or a higher pressure spring into the pump. Has the car done this since you've had it? If so then that could be it right there. The pressure isn't high enough to be a bad thing. Just dont go revving the engine while it's cold with that much pressure.

Other than that I dont know of a means of testing the sender cause I dont have an resistance reference readings for a given pressure reading.

If you were running no pressure or really low pressure then I would start worrying.

n00blar

I did replace the thermostat housing, and I've let the car idle for like 10 minutes before running it and I know there's no leaks from there.

Yes, those oil pressure readings have been that way since I got the car, but then again the car was in really bad shape when I got it 3 months ago. I'm going to look to maybe get a replacement oil pressure sensor. As for the oil pump..that's something I've never done, so I'm going to have do read the good 'ol Haynes book.

jfairladyz

No I didn't mean the thermostat housing leaking. I mean the exhaust manifold leaking. The heat from the leaking exhaust can heat up the thermostat housing and give you a false reading.

n00blar

Oh! I'm going to look into that.

Thanks.

lww

Also, DO NOT TRUST THE FACTORY GAUGES!!! They weren't a very good design to begin with and after nearly 25 years are probably worse now!

Get a REAL coolant temp gauge and oil pressure gauge and connect them. You don't have to mount them in the car just get wires long enough to reach the gauge.

I've actually run the wires through the side of the hood and into the car through a cracked passenger window to the gauges sitting in the passenger seat.

Until you KNOW your car is actually running hot or the oil pressure is REALLY high, you'll just be wasting your money by throwing parts at it.

I know someone that replaced his ENTIRE cooling system more than once before he put a REAL temperature gauge on it and realized his stock gauge was reading about 30% hotter than it really was!

He'd blown nearly a $1000 bucks on parts and labor to find out there was absolutely nothing wrong with his car...

chinesekid

damn.. i have the same problem with the temp... as my earlyer post... but i havent replace the radatior or anything yet... so do i just get a better gage first? or replace the componests first?

thxone

I know my temp sits just a hair below half and has slightly been above one time but it was 86 degrees outside and I was idling in the yard for a while but my oil too is high like that but only til the car warms up then its between half and three quarters of the qauge on the high side until I push the gas then its right where his is. Looks normal to me, at least thats what I am use to seeing.

n00blar

Good suggestion!

Well, my dashboard is almost out, since I'm in the process of getting a replacememnt dash, I guess I can buy some decent gauges and test to see what kind of readings I'm getting.
Heh, and I was reading my Haynes book, just last night, to see if it would be a good idea to change the oil pressure sensor.

n00blar

Sigh!

Ok, I think I may have found the reason why my ZX may be running a bit hot - it's a leak!

And now, the part that's leaking is under tha dash and next to some part of the AC system. I don't know, at this time, what this part is called - I'm going to look it up on Haynes.

I turned my car on and I saw, not just a leak, but a squirt of antifreezer, so for now I drained my radiator again. Removing this part seems a pain in the ****!

Here are some shots of what I'm talking about. Pictures labeled Leak 1, 2 and 3 are zoomed in to kind of show where the leaking area is. The other pictures labeled PIcxxxxx are pictures of the part.

And I was gonna take my ZX for longer test drive, good thing I found it on time.

jfairladyz

Thats the heater valve. Those puppies aren't cheap new. Probably up around $130 - $140 new. Might be able to find it cheaper at a discount parts store though. But if it's just a hose connection leaking then it's not as big of deal. Just replace and or tighten the hose.

n00blar

Ok, the Haynes book calls this piece Heater/A/C control assembly. Advance Auto Parts doesn't have this part.
The heater part you mention, doesn't look the same.

SHADY280

does anybody know if those can be removed?, mine even has a heater sensor thingy into the airbox, but yeah those always seem to leak. if you like to tinker, they can be fixed, but i cant remeber what i did. its just cheaper than a new one. and what do they do, i think the later models dont have them, or the sensor part, i think.

SpeciallySpiked

Yes, mine is leaking too, I can't put my heater to cold without it spraying antifreeze all over the passanger area. (I'm guessing we're talking about the same thing here and if we are...) I believe it channels the hot coolant from the engine through a heat exchanger to give you the hot air of the heater, or it puts it back into the engine to prevent the air from coming in hot (wow I made that sound kinda weird)

I ended up getting one from another 280ZX and I'm in the process of seeing if I can just replace an O ring instead of removing the entire thing. For mine I know it's just the seal inside because it won't leak when I have the setting on hot.


Good luck with that though, hope your carpet didn't get messed up

n00blar

Ha! The interior of my ZX is crap at the moment.

jfairladyz

The one in the link is for the auto climate control. You have the manual climate control (judging from your pics). I checked around the site you linked and they appear to only carry the auto control valve.

But that is technically the part you are looking for. It's just not the right part for YOUR car. You need that heater valve, but for the manual climate control.

n00blar

Oh, I see.

I've been looking for that part and it's a no go ... can't seem to find it; I may try some of the yards around here.

Thanks for clearing it up J!

jfairladyz

I know places like www.zcarparts.com and www.blackdragonauto.com carry them, but they're pricey through those guys. The dealership should still be able to get a hold of it too.

n00blar

Yeah, they're pricey alright! $104.00 for the one I need.

n00blar

Geesshh!!
Do I have to remove the dash in order to remove this little piece!?

SpeciallySpiked

yeah, it's a pain especially the screws that are in there tight and stuff.
My dad ended up just cutting a bunch of stuff while we were at the junkyard getting one so I don't even know how to get em out, they seem like a huge pain though if he cut them...

SHADY280

i did mine without removing the dash, but as i found, it is much easier to just remove the dash, its 8 bolts and some wire clips, and a speedo cable, pretty simple. does anybody know what that piece is really for??