DemonicPupil

My oil pressure keeps spiking like a son of a bizitch. Sometimes it's at idle, sometimes it's while accelerating. It's VERY random. The car seems to also be getting quite warm. My temp guage is hitting the 1/2 mark and I'm starting to get a little bit scared to drive it much more than down the street.

What are some things I should take a look at? Could one of the oil lines be pinched? Are there any triggers that make the oil flow to one place that maybe it can't flow due to kinked line? etc. etc... the car seems to be running smooth otherwise and the fuel problem seems to be fixed..


This is an 87 GXL no mods other than a header and cone filter (as far as I can tell anyways)

classicauto

iTrader: (3)

whens the last time you changed your oil?
whens the last time you checked the level?

not being ignorant....but ya never know....start with the simple stuff

DemonicPupil

Month or so... not very long ago... only put about 500 miles on the car since then...

Oil level is full

lupin

iTrader: (3)

I had the same problem, except it overheated once and I saw a milkshake in my overflow canister. My answer was to swap in a fe engine.

MrFuzzy

iTrader: (1)

Could be the sensor

need-a-t2

iTrader: (9)

Are you basing this info off the stock gauges? they suck! If you are, i would highly suggest getting some aftermarket ones and see what the pressure ACTUALLY is. same goes for the coolant sensor.

But to answer your question, ther are a few valves in the oil system. 1)The thermal pellet is located right behind the e-shaft bolt inside your drive pullys. i'd suggest replacing that. lots of companies make replacment aluminum blocks that go there and keep oil flowing evenly to both rotors at all times. 2)one located on the bottom side of your front cover, you have to take the oil pan off to get to it. I doubt this would go bad, as it's just a spring and a copper cylinder. 3)oil pressure regulator, located on the underside of your motor, under the oil pan. cheap tp replace with an FD one (80psi, and about $30 IIRC).

there are some good places to start!

DemonicPupil

Ok... so say the Oil Pressure sender is bad...

The car is running the temp guage to the half way line... I suspect lots of air in the coolant system because I replaced the hose going from the block to the throttle body (firewall side where the throttle cables connect)... For the life of me, I can't figure out how to re-pressurize the system... I've searched around, saw a few things, such as pumping the radiator hose, but when I try to get the cap off... coolant just keeps firing at me.. so i figure it's full... where do i put anti-freeze to get rid of the bubbles if i can't get anymore into the filler neck?

classicauto

iTrader: (3)

wow......talk about an about face - lol

well the coolant LEVEL might be up the top of the filer neck on the rad....but it doesn't mean that there isn't an air lock in it somewhere....

however if you had an airlock and drove the car for any amount of time long enough to heat the car up......and had no overheating issues - I wouldn't be worried, just keep a CLOSE eye on your temp gauge....and as mentioned - aftermarket gauges help loads in these cars due to the inaccuracy of the OE gauges, as well as the fact that the don't tell you much...meaning how many degrees celcius is half way up the gauge? (you would know if you had a haynes, but you see what Im getting at)

need-a-t2

iTrader: (9)

or downloaded the factory service manual for free another thing i would highly suggest doing!

classicauto

iTrader: (3)

yeah it is....sorry sometimes after a while some of real common sense things slip by me

Dom_C

pump the hose when it's cold. . lol

theman4444

Hey dem. you pm'd me about my high pressure problem. Firstly I was going to tell you that my problem which I have not fixed yet is mostly gone. Sometimes I get low oil pressure and sometimes I get high but now a days it pretty much fixed itself. I'd bet a million dollars though (not really) that it is your sender and that if you got an aftermarket autogauge that you would not see those high numbers at all.

That being said there really isn't any problem with having higher oil pressure unless you do actually get above 120psi. In which case you could blow an oil seal.

On the coolant temp subject you should definitely find out if you have any bubbles and then just buy a new aftermarket temp guage if you want to be sure.

Thats all. Good luck.

Terrh

iTrader: (7)

it sounds to me like a sender or grounding issue.

The "best" way that I've found to fill the car with coolant is to undo the screw at the top of the radiator and pour away until it starts to come out that hole, then put the screw in, squeeze the lower rad hose several times to "burp" the system, fill the rest of the way and put the cap back on.

Start the car and let it idle for a minute or two, take the cap off and top it up.

You can also try just letting it idle with the cap off while you're topping it up, its a bit harder to do though depending on where your rad cap is.

DemonicPupil

Well... my 86 is easy.. it has a cap on the therm housing AND the radiator. The 87 though just has it on the therm housing. I've read the FSM, i just thought maybe people would have better hints/tricks to do it. Such as the few that have been posted above.

I went ahead and bought one of the cheap mechanical guages from Advanced and will be hooking that up tomorrow. Hopefully everything will turn out fine, I can get the air out of the coolant system, and then this car will run correctly.

She pulls like a son of a bitch when everything is healthy. Much much harder than my 86 (172k). Makes me look forward to rebuilding the 86 and 88. I look forward to being able to just drive it without worrying about something going wrong after each trip.

matts86fc3s

my fc runs way over 110 psi... thats normal if you have an fd oil pump or mazda racing pump... they put those even in standard rebuilds. i have an fd oil pump in my rebuilt + ported motor. so A) you either have a rebuilt engine and you dont know about it, or B) your sender is reading wrong

DemonicPupil

I can't get the damned aftermarket oil guage to install.

The fitting that came with the stupid **** won't thread into the hole that the stock pressure sending unit was in. It's just a TINY bit too big, and advance auto doesn't seem to have **** as far as an adapter or replacement goes. Now wtf do I do?

Any other spots I can do this in? Talk about a pain in the *** to even get to the hole as well...

DemonicPupil

Ok, so here's what I'm going to try... any input?

I hacksawed the thread and hex off of the Oil Pressure Sending unit that I took off the car. So now I have a nice 1" long hex section to work with and I have the original threaded section to thread back into the motor. My plan is to Tap the hole on the hex (it's about 1/8" hole) to the size of the stupid fitting that came with the pressure guage. Does this sound like a viable option??? (I don't own a Tap & Die set, so I have to purchase one to do it) Should I use any kind of sealants?

need-a-t2

iTrader: (9)

you could just get an adaptor for your local hardware store. more than likely they are both NPT fittings. it will probably be under $2.00, and alot eiser (and cheaper) than tapping the old fitting.

DemonicPupil

Considering my searches found nothing as far as installing these **** SunPro guages goes, or any guage for that matter. I'm posting up a picture of the fitting I made. I called every hardware store in the area, tried lowes, home depot, etc. All of them told me that they do not carry anything with a metric thread.

I'm one of those people that says I need a tool, then decide to do it half assed without buying the tool because "I'll never use it again." So... a tap & die set got put off probably 10 times. Finally went out and bought one, it sucked ***, but I was actually able to use it and recommend it as a must have for those that procrastinate like me.

To make this fitting, I used the 1/8" NPT 27 tap and the 1/8" NPT 27 die. I hacksawed the tube end of the Oil Pressure Sensor off. I tapped the inside of the tube and then i rethreaded the fitting that came with it. They thread up real well. Make sure you cut the pressure sensor as close to the electrical portion as possible so you have room to get the tap far enough in.

nopistons13

i have the same problem and i am leaking TONS of oil by the sensor. I have oil all over my plug wires and my coolant hose. Where coudl this be leaking from, and why?

DemonicPupil

I'd go with replacing that sensor. Just installed this into my car... everything is working perfectly. The adapter I made does not leak and goes in like butter. It's nice to put it in with a socket, rather than a fricking wrench too!!

Thanks to everyone btw. Went out and filled coolant while cold, let it warm up, topped her off and now she runs at 1/3ish... no rising or lowering, so it's a steady 1/3. Oil PSI is chilling at 25-30 at idle and no higher than 70ish at cruise/acceleration.

Finally got this ******* car in good running condition.

nopistons13

Thanks man. Ill give her a shot.

HAILERS

The threads are 1/8 BSP. I've found adapters at Home Depot. Also if you look at a Pegasus catalog they have the adapters also.

That said, what DemonicPupil did is more rewarding. I've done the same thing. The sender sticks out further, which is good.

More information on this can be found if you do a expanded search on this site and type in the words 1/8 BSP. You'll get about ten/fifteen hits and different info in some of them.