Oil Temperature Problems! Big Problems!
 

I just purchased a 1993 base FD3 94K But she already has an issue/issues. The oil temp goes insanely high after 7-10 miles of driving. (I can see a small oil leak right under the turbo) Which was only after this happened. Figures......that's my luck with cars.

I do want to mention that the oil temperature hit 300 degrees, and the engine shut down. Thank God for the auto cutoff sensor! The oil pressure is normal once the engine warms up. This did only happen one time, and now she is just collecting dust until I figure this out. I cannot drive it more than a few miles after it's warmed up. This is really killing me, especially after i just spent a ton on this beauty.

Please, any input would be much appreciated.

Thank you.

One sad RX-7 owner right now:(


Troy

In order for your oil to cool down, it has to circulate thru the oil cooler(s). Apparently that isnt happening. It sounds like either your oil pump isnt working, or you have a blockage in the oil lines somewhere, and it cant flow.

I would start by getting under the car and following all of the oil lines to and from the oil cooler to make sure nothing is crimped.

I really hope that's the problem, if it is the oil pump or and /or the cooler(s) is this a big job? I thank you for the input, hopefully this is the only problem.

It doesn't seem like anyone really had an idea of the problem that I posted. Well I'm going to get under the car and take a look. Do you have any other recommendations that I need to in to consideration? Is it the OMP? (Oil metering pump). I've read that they do go bad (low milage) and they are a pain in the rear to change.

Thanks again!

The OMP just injects oil into the rotor housing to keep things lubricated. It wont have anything to do with your oil temp.
Are you also seeing really high coolant temps? The oil contributes quite a lot to cooling on a rotary, so one would expect if you had high oil temps, you probably also have high coolant temps.

+1, i would say either something is blocked (unlikely, those are some decent sized hoses, and if it is blocked your system must be full of crap!), or dead oil pump...or a faulty sensor reading high.

Oil pressure is normal but your oil is overheating? How about coolant temps?

Any modifications?

Not at all, I didn't see anything out of the ordinary. Maybe the oil cooler is bad, or like you said possibly a dead oil pump. I have to get this fixed ASAP it's killing me!

Not knowing what the issue is just kills me! Ok so the OMP is not the problem, so I guess I move on to the oil pump/ oil lines. No modifications YET! bone stock. I have a lot in mind to what I want to do, but as for right now all I want is to have a little fun and drive her.

Please more input would definitely help me out in a huge way. This forum is unbelievable, you guys are great!

Thanks for the input, I really appreciate it.

If you have a bad oil pump you will get oil pressure readings below factory specs.

Here's a link to get you started on the oil system.

http://www.turborx7.com/images/Technical/oilpath.jpg

But I'm not, Im going to check all the lines and really get in to it, I can't have this hanging around and not knowing. Well I guess I'll keep asking and doing until I get it figured out. Please if you have any more suggestions I am open 24/7.

Much appreciated nguybao!

Thank you.

How are you measuring the temp? You have an aftermarket gauge?

I'm thinking you are using aftermarket gauges to monitor oil temps and pressures. If not, the pressure sender could be bad masking the issue.

Oil Pressure Problems

Also, oil system clean and full?

If you're sure the leak from the turbo area happened only after this overheat incident, then it might make sense to start the checking the oil lines to the turbos for blockage.

Check to see if the oil cooler lines are connected to the correct sides of the oil cooler. There is an internal oil thermostat in the cooler, so the oil needs to be flowing in the correct direction. The internal thermostat could also be bad, causing the oil to bypass the cooler.


https://cimg3.ibsrv.net/gimg/www.rx7...2fa7b312e8.jpg


https://cimg4.ibsrv.net/gimg/www.rx7...1007966411.jpg

You won't have oil pressure if the oil pump was bad and that motor would have long since spun a bearing. I agree check that you have the oil cooler lines hooked up the the proper orientation. You could also have an issue with the oil cooler thermostat though I have never seen a stock one fail.

after a few minutes of warm up, if you put your hand on the oil cooler, is it warm or does it remain at ambient temp? Once the oil cooler thermostat opens up, it should get warm to the touch right away.

Wait... what? :scratch:

Not aware of any overtemp protection on these cars.

Also curious how you're monitoring oil temp. Not many people install oil temp gauges. Something is funny here...

perhaps he's talking about water temp gauge?
Although he said when it hits 300 degrees, so there must be some sort of gauge/display to show the actual temperature.

Ya that's why I suspect he was using aftermarket gauges.

Ok so I didn't have enough time today to realy get into it, but I did start it up let run a few minutes and yes the oil cooler gets warm to the touch. But I really didn't spend enough time to get this problem solved. So tomorrow I will spend the entire day trying to fix it. It does have aftermarket guages, on the A-Pillar.

But the oil temp guage is working fine as far as I know. I don't know if this matters but this all started after i just let the car sit for about 45 minutes in my driveway. And then boom it started when I was driving on the highway to a friends house.

I immediately pulled over when I looked at the gauge. It also started to sputter and kick right before I shut her down. The second time was when I was driving around my block just to see if it would happen again and and yes again it happened.

I pulled in my driveway and I could see a little bit oil oil leakage below the turbos, and the rest is pretty much what I described in the first post. So anything I should look for while really getting into her tomorrow? Anything in particular I should do? I'll post in real time tomorrow so any help would be greatly appreciated.

Thanks guys!

Can you take a picture of this oil temperature gauge? Do you know where its temperature probe is located?

Have you checked your oil level? This situation is pretty rare, I've certainly never seen it before.

You've been asked this and haven't answered--- what are your coolant temps like?

I would be checking the thermostat built into the oil coolers, as Banzai mentioned.

The sputtering and shutting down is very bizarre- there is no circuit or failsafe in these cars that would do this. That alone would be very concerning to me.

It almost (and I'm going to sound nuts for even suggesting this) seems like the oil temps are gradually getting so high that the thing is sputtering from sheer bearing heat and resistance and shutting down.
That, or it really doesn't have enough oil in it, or a major oil gallery in the block is plugged up.

Where are you taking the oil temp reading from on the block?

I would drain out whatever oil is in it, change the filter, put new mineral in it, and add some oil flush. Idle it for 20 minutes to flush and then drain that out. Fill with good oil and give it a try.

Otherwise I'd be taking the oil pan off, checking the oil pump pickup, check the oil coolers & thermostats, check the oil pump... All the major stuff, failing the simple flush method working.

Oil Temp
 

Oil levels are fine! And yes, I have answered that question! Coolant temp is normal. I haven't had a chance to get into it because Ive had family over all weekend long, so no chance to really delve into her. So all these excellent questions will be answered as soon as possible. I wish I did have the time today but, it's not going to happen.

I'll keep you all posted, probably this Saturday I'll tear her apart and figure this out. I have a friend that's going to help and he's very knowledgeable when it comes to rotary engines.

If your coolant temp is normal...then I think you have a faulty oil temp sensor :)

When you say that you "just let the car sit for about 45 minutes in my driveway".
Do you mean you let it idle that long?

If that is the case...
You know there are no fans to cool the oil radiator when the car is parked.

The only thing that can limit the high temperature rise of the oil in this situation is the slight heat transfer to the water jacket in other parts of the engine.

What is the oil temp at cruise?

Are the cooler fins straight? Blocked with bugs?

Tne next most logical solution (as mentioned above) is replacing the vernatherm (thermostat)... it is probably staying open.

i remember when I had to replace my oil cooler it was a pain In the ass