nickbroker

Okay guys I'm new to the rotary world and I just picked a 1993 RX7. Supposidly has a street port and was rebuilt 8k miles ago bye A Spec in Illinois. Few things I know it has is a Microtech lt-10s, apexi turbo timer wich wont turn on thinking pwr or wiring issue, A/C,PS removed. Apexi dual cones. Found her in a shed and had been sitting for 4 years. Finally went through her and got it up to snuff and got it running.......... Blue oil smoke pretty thick at idle and as acceling in 1st gear,

As soon as i start getting into it ---SMOKE GONE! only time it re- appears is on the downshift to stop sign and the whole circle starts all over again!

Any clues guys, does this sound oil seal-ish or turbo seals from sitting that long or could it be something else completely. I'm willing to listen and want to learn so please let me know if you have seen this issue before!

nickbroker

Well after running it and doing a hot compression test shes running 110 compression on front rotor and 65-70 on rear rotor.... before I ran it I pumped MMO into the cylinders and let sit almost 2 days turning over by hand just as a precaution.

Now since this motor sat for 4 years is it still possible something is stuck or do you guys think she should be pulled and rebuilt. I just hate throwing money at something if I havnt checked all the possibilitys

Thanks

rx_214

Blue smoke is engine oil. Sitting around for 4 years would possibly mean the oil seal is stuck and oil just sits there and get burnt away once it's moving.

Keep driving the vehicle and monitor the engine temperature, see how that goes... but with the rear rotor having a lower than 90 compression reading, that may be the culprit of what's happening.

Are you experiencing loss of power? High engine temp? or anything specific? If so then you should expect to do a rebuild and check over all the seals.

nickbroker

Thanks alot RX.

Funny thing is it has tons of power till it obviously fouls out rear plugs from of oil! The motor does not even get up to half way on the gauge and doesnt seems to be overheating in any way.

Im going to start her tonight after the MMO soak for 48 hours and hopefully I can come back with some sort of improvement.

Also is it normal do you think from doing the MMO soak when I turn motor over it leaks oily/black residue from where the exhaust and turbo meet? I thought that was strange but it has to go somewhere right!

1988RedT2

Compression on the rear rotor is definitely cause for concern.

Just out of curiosity, is it manual or automatic?

Re the oil leaking out between the turbo and exhaust: Yes, it's got to go someplace and if you put MMO in the engine, it will be pushed out when you crank it over. Could be that the connection is somewhat loose, or the gasket is worn out or missing altogether.

rx_214

It could also be that the engine has been rebuild by the previous owner, but the rear rotor wasn't done right... cause compression for front is 110 and for rear is 65-70 is a very weird combination, but it could be many other things given that it's been sitting for 4 years.

Check over the connection like 1988RedT2 said, and I wouldn't be surprised if there are minor vacuum leaks or wiring issues/bad connection. I'd check over all the fuse as well just in case.

And with the oil leaking form the turbo and exhaust, check the BOV and also the exhaust manifold, these are the stuff I can think of on the top of my head.... with a garage space you should be able to check over these stuff fairly easily.

Not sure how the tuning was done on the Microtech, but I'd check over the dyno mapping when you have access to the equipment... however it's not the priority at this point, cause it's more important to check over all the hard parts first.

nickbroker

Well I am gona go with your idea RX, I do believe it to be a oil seal and thats why im loosing the compression on the rear rotor. She just runs to damn good for it to be major internal problems in my opinion. And Redt2 I do believe it was just the mate on the exhaust manifold or gasket is bad and it is a manual.

I really am pondering selling her as is, I mean she runs and drives but as stated no doubt needs a good going through. Just a terrible scenario and makes me sick as this thing was rebuilt bye A-Spec in Shaumberg Illinois about 7-8K ago. And due to absoloute stubidity from the old owner it has to be ripped back apart.

Just to show There is a Apexi AVC-R in the glovebox not hooked to the Microtech but hooked to some wiring under hood that doesnt power up just hanging out and a Haltech E6 just laying in back hatch. I dont understand some ppl.

rx_214

All about commitment man, owning a sports car is not cheap, let along making it looks nice and build right to how you want it.

nickbroker

Another question is can bad oil control rings/ oil seals make the compression low on ONE rotor? Just assuming here, but if it leaks oil in combustion area it must also be able to loose pressure out correct?

I get the exact same low compression reading on all 3 faces is really the thinking behind this question. and kind of hopeing this doesnt sound like major component failure and more to do with seals/gaskets.

I thought it wasnt smoking while going through the gears but I am certain it does now. It actually starts to burn more oil the hotter the engine gets it seems, and when you REV she really billows out the cloud= Blue! But runs pretty decent and smooth!

Again this car sat for over 4 years and wasn't started. Under 10k on rebuild from the previous owner. 110 ish on all 3 faces front rotor and 65-70 on all 3 faces rear rotor after running about 10 minutes.

Attached is a pic at startup but it gets way worse when hot and rev!

nickbroker

No ideas or recomendations on last question guys???