ReDHot7

These are probably newbie questions, but this is my first Rotary and i've had it for about a week now. FYI, it is completely stock right now. Here are my Questions:

1) My oil pressure gauge is only at about 15lbs/in (normal driving) and sometimes when i'm in 5th just cruising it is touching the top of the 0, is this normal?? It does go up to about 50lbs during hard acceleration.

2) Is it possible to change the apex seals yourself, or does the engine need to be machined/planed by a professional shop?

3) What exactly is the Air Separator Tank? I've seen upgrades for it in the cooling section at the Rx7 store. Is it just an overflow tank for the radiator?

thanx.

SanJoRX7

Okay, I'll do the honors

1) The oil pressure gauges on FD's tend to read relatively inacurrately since the sending unit gets gummed up or fails altogether. My FD will usually read somewhere in the middle of the range sometimes, and almost nothing at others. It's something I've learned to live with.

2) Yes, you can change the apex seals yourself. You can buy them from various sources, but doing the job requires complete disassembly of the engine, and countless hours of work, unless you've done it before.

3) The AST does just what it says it does...separates air. Basically, it's there to get the air out of the cooling system...offers it an opportunity to rise out of the coolant, as having bubbles in the system is bad (i.e. inefficient cooling). The overflow tank is something completely different and wouldn't need upgrading The only reason that aftermarket AST's are offered is that there was a tendency for the factory units to fail on 1993 models, and as a safety upgrade, people would replace the plastic factory unit with a metal one, like the one from Pettit.

Werd.

Flyrx7

iTrader: (1)

Uhhh, lets see, its his first rotary, doesn't know what an AST is, and you tell him he can change his own apex seals?! Just about the same as you can do your own dental work! Yeah, sure you can change your own apex seals, but you really gotta know what the hell your doing, you just don't become a rotary mechanic just by thinking you are, it's a little more complicated than changing your plugs ! . Don't get me wrong, if you are mechanically inclined, have some pretty serious tools, patience and a workshop manual (maybe even a friend that has been there before) you could do it, but to take some casual advice from one person with the offhand remark that you could do it, (sounds like "anyone could do it") might be folly. No disrespect SanJoRX7, just because you and I may be able to do it, doesn't necessarily mean anyone could do it. ReDHot, do yourself a favor and get a manual, then read the whole engine disasembly/assembly chapter and make your own determination. Do that and research as much as you can. Good luck to you!

Regards,
Frank

White94RX

Disassembly of the engine is definately something I won't do myself. I didn't even want to mess with the downpipe for fear of breaking the studs. I had Mazda do it.

An exhaust or intake, on the other hand, is easy as pie.

Ralgh

As far as the AST goes I talked to a guy the had two fail. The first was driving on the freeway. The engine overheated and was ruined before he could get to the side of the road. The other went just as he pulled into his driveway and the engine was ok. I have been told many times before you spend any money on anything for the car get one of the replacement AST. I got mine from Tri Point and easy install and no problems. My brother got the AST bypass from M2. I figured Mazda put it there for a reason so I will keep it.

apexkw

i agree with tom, i think that since mazda put it there it should stay there. i just got my fd not to long ago and the first thing i got was a radiator, the second was a turbo timer and the third is going to be the ast, third only because the guy i bought it from just put on a new one 4000 miles ago when he had the enginge and turbos rebuilt.

DHALL

I just replaced my oil sending unit today. It was $80.00 from Mazda, and I had the same prob. most do. But I have a new motor with only 400 miles on it so I figured it would be a good idea to know exactly how much oil pressure I had. As soon as I started the car up and drove it, it never went below 15, stayed right around 60 and went all the way up to 120, yippe.

SanJoRX7

I think maybe my point wasn't gotten across properly when I say "Yes, you can do your own apex seals." Indeed, one would need a lot of mechanical inclination, tools and time, but the question was "can you do it?", and the answer is of course, yes. Now, I certainly didn't mean to imply that just any Joe Piston can go out and rebuild their rotary, but strictly speaking, it's possible. So, to sum up, unless you're a seasoned rotary mechanic it's probably not a good idea to try to rebuild your motor, but hey, it's a free country, do as you please

Patrick

ReDHot7

i just wanted to thank you all for not ripping on me in your replies. it is nice to know you guys are willing to help out a new owner.

i ordered the Mazda service manual and a History of the Rotary book yesterday.

so, I shouldn't be too worried about my oil pressure being that low?

Flyrx7

iTrader: (1)

Yeah, it's kinda' nice when we can all get along
Glad to hear you are starting your research project, they should almost offer a college course on this car! Some tech college could make a few bucks here.
As far as your oil pressure gauge goes, it is a typical problem and most often than not (99% of the time) just the sending unit. You can replace the sending unit real easy for about $80-100. It is the big rubber housed cannister on the driver side (LH drive, that is ) of the engine under the oil filter, on the rear housing, with (1) spaded wire connected to it. I've heard of people actually taking these off the engine and cleaning them internally (carb spray, etc) and re-using them, might try that before you start shelling out dead presidents. Should almost be one of those "periodic maintenence" items. Ok, back to those books now, ya' hear?

Regards
Frank