I had a compression test done at one of the local Mazda dealerships here back in October before I put the car away for the winter. The results of the compression test are:

Rotor 1: 6.2
Rotor 2: 6.5

Mazda told me that these numbers were fine, but after reading several old post about compression I get the idea that anything in the 6's is not really that great. Right now the car is in at Mazda to get and oil changed and a tune up. They just phoned me and said that my intake manifold is leaking and that it will cost $1100 CDN to fix. I have warrenty on the car and from what I can make of all the fine print on the warrenty coverage that this repair should be covered. I am just waiting for Mazda to get back to me.

My question is. My warrenty expires at the end of May and I was wondering what I should have done or check before this date. The last thing I want to be doing is having to pay for something like a new engine shortly after the warrenty expires.

Any advice or suggestions?

 

That's weird...Usually compression numbers on rotaries have three numbers per rotor...But then again you took it to the dealer and that is a big no-no.

like 8.1 - 8.3 - 8.2

But yeah, form what I have read on the forum you really don't want anything below 7s...

 

First off do the work for the manifold yourself! Dont pay so much! Ouch, buy a used intake manifold here for 200$ or so bucks and install it yourself. Buy the gaskets for it from the dealer though. Save you some money, alot of money.

 

Well, I was told that 6.2 was below Mazda Spec. by my mechanic. He told me that the car would probably keep running and that the motor is just getting worn. I'd pray for a new motor under warranty!

 

Put a mid pipe on and take it to the drag...Blow the motor by doing multiple passes without allowing any time to cool down. then after it's blown, put your stock cat back on and take it to the dealer for a new reman!

Hurry up...according to your waranty, you only have 30 days

 

If it's 6.5 or lower compression under warranty, I think that's good for a rebuild payed out by the warranty company. Ask them.

 

minimum compression straight from the 94 manual is 7kgf/cm2, with a max difference between chambers of 1.5 kgf/cm2. it is strange you only got two numbers, usually you get a reading from each of the three chambers in each housing...all of which should be between 7 and 9 or so... that should be good enough for a rebuild, call up that warranty company!!!!!!!

 

When they gave me the compression numbers I asked why there wasn't three numbers for each rotor. All the guy could tell me was that was the results. I assumed they just gave me the average compression for each rotor.

About taking it some where else there really isn't any where else here to take it. This Mazda dealership has a certified FD mechanic from Japan and other than Mazda dealerships no really knows much about the rotary engine here. There is one guy who does alot of work on the first and second gens, but I was told he isn't really comfortable working on the FD.

 

An update,

Looks like the warranty will cover the intake situation. As for the low compression, Mazda is going to do another compression test, since the first one is from October, to see what if any new results they get. The claims adjuster for the warranty company told me that they would probably not cover the new engine since it would fall under "normal life span wear on the engine".

My question is that I only have 47,000 miles on the car so how much wear could there be on the engine. From what I have seen the average engine life is around 80K miles not 47K. Looks like I might have to fight for the new engine.

 

Hmmm wonder what made them think that the car needs a new intake manifold.

I would ask a few more questions.

The same dealership couldn't figure what was wrong with the car when the mechanic knocked off the hose to the MAP sensor and the car ran like crap. I had to tell what to look for.

Serves me right for getting an oil change there on a lunch break

Oh well.

Good luck with the warranty fight AUM.


thesaint

 

Checked the compression today

8.5 front rotor, and
2.5 rear rotor

talk about a blown rear rotor. By the way this is an original 88 engine that floods easily and cannot idle by itself. It feels normal above 2k RPMs but sounds like a 2 cycle engine, make sense ?

 

i heard the rotary cant be compression tested when its cold or else the numbers are off, can anyone tell me if thats true?