rx7dan

iTrader: (1)

Heya guys,

I bought my first 3rd gen rx7 yesterday. It is in immaculate condition. Garaged nearly 100% of the time and only has 43k miles on the ODO. Before I bought the car I took it up to a Mazda dealership in Duluth, GA and had them run some tests on it including the infamous compression test and everything passed with flying colors. So, this morning I crank the car up and let it warm up a bit before I start out of my neighborhood. A few minutes later after the engine has reached optimal operating temp I open it up...

Would you believe that there was a small boulder right in the middle of the road almost 1/16 of a mile from where I opened it up! I hit the friggin rock going 80 as there was no where for me to swerve to miss it. It made a very loud thump under my car and a small piece of plastic with a triangle hole cut in it came flying out with the rock! After cursing the world I pulled into the driveway and let it sit for a few minutes. There isn't anything leaking and the car still seems to drive okay. So, my question is... Does anyone have any idea what that little piece of plastic was? I can take some pics if need be.

Thanks in advance to anyone who takes the time to help.

-- Dan

gracer7-rx7

iTrader: (16)

Jack the car up and take a look

rx7dan

iTrader: (1)

Yea, guess it is time to invest in one of those jack things.

Tim Benton

iTrader: (1)

So you went back and found the piece of plastic that the rock knocked off? Yeah take a pic and post it if you haven't figured it out yet. What was the compression numbers for the engine?

Tim

rx7dan

iTrader: (1)

Tim, here are those compression numbers...

Compression test @ 642 rpm
Rotor 1: 5.7-5.9-5.6
Rotor 2: 6.1-5.8-5.7

Compression test @ 760 rpm
Rotor 1: 5.8-5.9-5.7
Rotor 2: 5.9-6.2-5.9

I'm not sure I understand exactly what these numbers mean, but I would assume that because they are close together that it is good. Plus, the guys at mazda thought they were awesome...


Also, I figured out what that piece of plastic was... it is off of the shield that protects the engine. Specifically, from the passenger side of the car.

ShiftRX7

for my understanding, compression should be between 7 and 8 to be perfect; your numbers appear a bit low to me, in line with the 43k miles of the engine.

i think you plastic piece can be the under engine cover, that basically protects engine parts from this kind of small accidents...

gracer7-rx7

iTrader: (16)

What kind of compression tester did they use? Typically it is tested @250 RPM. Not sure what difference testing at a higher RPM makes to the numbers... It is good that they are close but they are a bit low. The FSM states that minimum acceptable number for Mazda to consider replacing the motor is 6.0. But so long as the car starts and drives well and makes decent power, keep driving while you save for a fresh motor.

rx7dan

iTrader: (1)

lol, wut u talkin bout Willis! New motor even without extra HP / Boost mods done? Figured it would last awhile if it were only updated with the preferred mainenance mods like:

1. Downpipe (wrapped in fiberglass and coated with the 1200 degree spray)
2. Fluids flushed (oil, tranny/differential, power steering, and coolant)
3. New Koyo/Fluidyne radiator + coolant hoses
4. Vacuum hose job (Replace & ZipTie)
5. New AST

** Anything I'm missing on this list absolute MUST have list please feel free to chime in ***

Thanks,
Dan

twinsinside

iTrader: (34)

You'll want aftermarket gauges too.

The stock gauges in these cars are bordering on worthless. The 93-95 versions didn't even include a boost gauge. Oil and water temp, oil pressure, boost at a minimum.

If the stock coolant overheat buzzer comes on, you may have already toasted the engine. High heat will damage the internal orings, allowing coolant and oil to leak and requiring an engine rebuild.

Also, please drive responsibly, you're lucky you only hit a rock. If you're not used to the car it's very easy to spin it out of control. I'm all for bugs in your teeth speed, but do it at the track where you won't hit stuff.

Destiny09

help please we just got a 83 rx7 and we want to know where is a good place to get parts for them ???

canonize-ryda

ebay

kimletrim

iTrader: (1)

tHANKS, I think that is a good starting point.

oyy0

don't buy much from egay, you will eventually regret it.

mazdarotaryfan

its not about what marketplace you buy parts from, be it this or some other forum, ebay, etc. it is about the person or vendor you buy from. thee are great sellers on ebay and thee are crappy ones also. doesn't mean you shouldn't buy anything from ebay at all.

canonize-ryda

where can i go to get a compression test? a mazda dealership? and how much does it cost?

motorrotor

Why not just go to Autozone or Napa and buy a compression tester? They range anywhere between $29 and up. You just remove the spark plug and screw it in its place and have someone turn the motor over while you watch the dial. Unless you get one that has peak and hold on it. Then you can check compression anytime.

The dealership is going to stick it to ya good not to mention the time and trouble of having to go there and deal with the service department. I know I've always hated it.

Lurch1363

Ya they normally charge a fee just to test it (not sure how much). Just run down to the parts store and pick a tester up.....please disable fuel before you test it though.