I am nearing my engine warranty so for peace of mind I went ahead and got a compression test, it always blows my mind how clueless some dealerships are….either way, 2006, 70,000 miles

7.9, 7.9, 7.9 @250
8.0, 7.9, 7.8 @240

thoughts? they provided me with trailing and leading numbers but i know that I should only have 6 numbers, 1 per face per rotor. Im assuming that the engine should have been at operating temp before tested correct? not cold start.

thanks team

 

Here is the chart I put together.

Numbers look good for the mileage.

 

thanks, I actually have this chart as a picture on my iPhone so I can use it as quick reference. thanks again

 

Those numbers look good to me, and very consistent between faces compared to other people's results I've seen. Not sure what you mean by trailing and leading numbers though?

I was going to ask what elevation you are at, but then I realized your right on the coast and less than 50 feet above sea level



Starter seems a tad slower than most people, but only by a little bit.

 

Leading vs trailing is probably where the dealer tested the compression at the leading plug vs the trailing plug.

 

correct, he tested at all four plugs and gave me numbers for each plug, they were all consistent so I used my leading numbers….I do however get some hot starts issues from time to time, just an extra crank or two usually but i can notice it, is there something else I should be looking for?

 

Coils were replaced about ~15k miles ago fyi

 

An extra crank or two is nothing to be concerned about, as it could be nothing more than slight voltage variances at the battery. You could replace your starter for a new one though, and you would probably start even faster. 250-240 isn't bad, but it shows that wear is starting to set in on it. No need to actually replace it unless it drops to ~210rpm or lower, but ~270-290 would be a noticeable difference in starting speed.

 

Hi I rebuilt my 12a rotary brigeported with new parts besides rotors,irons and housing the engine
Won't start at all unless I pour motor oil in the carb I would like to know if this is normal

 

What is a carb?

 

No it's not normal, but has happened. Compression builds over time but if it still won't start after you break in the engine that something got messed up during the rebuild.

 

I tested my compression at 30k miles with the tr-01 tester. I got an average of 98psi on the rear and didn't test the front. avoiding to the tester website said i should correct it to 101 psi which doesn't include elevation correction. the rpms were 260 and we just took out the fuel pump fuse rather than disconnect the eccentric shaft sensor.

Easy e(Eric) helped me do it and said they were 'like new' numbers. looking at this chat the numbers look pretty bad though so what's the deal? I have no issues at all it actually seems to start better when warm and never takes more than a second to fire up hot or cold. motor sounds healthy based on that but the chart makes it look bad.

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I can't edit but I meant to say 'according to the tester website'.

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You cut fuel yet didnt cut spark, that's not healthy. Always pull the ESS plug the fuel pump fuse is not enough. It means the other plug is still connected and sparking not the best idea.

Those numbers are not ideal but they are not bad.

 

the plug isn't quite as easy to reach in my car. we didn't have time to remove the bottom plate to get to it but I understand what you mean.

looking at the the chart it seems to barely be above minimum compression. I plan on getting a dealer test done but at $220 I don't want to do it until the 60k warranty is about to be up.

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IMO your numbers are meaningless. Who knows what the electric discharge could affect the sensor and readings.

Do it again, the right way. Also the TR-01 must be done on trailing plugs as the timing will throw off the readings if you use the leading.

 

I did do the trailing at least. I'm gonna go borrow the tester soon now that I'm at 50k miles and do it the proper way. it does seem like the numbers were wrong because if I was near failing I think I would be having some sort of issues popping up. I heard many times 'wow you car starts faster than any other rx8 I've seen'.

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Not necessarily. Most people here have made claims that their engine was never stronger until the moment right before it failed. But you never know.

I have a Pettit built engine with 3K miles with 105PSI front and 95PSI rear and I am not to worried about it.

I have been noticing a trend that it seams the rear always tests lower than the front, not entirely sure why.

 

Looking to buy a 2006-08, and was curious as to what a compression test would cost. Was just quoted $238 at a Toronto Mazda dealership. Almost died!

 

Its less than a half hour to test compression. 238 seems ridiculous to me but its better than 5-6k for a new engine if you don't test before the warranty expires and the engine fails.

 

If the car is at a dealer or it's a private sale have them do the test. If they want to sell shouldn't be a problem,if not just walk away. Also get a copy of the test and post it here to confirm the numbers are good.

 

Dealers in CO charge $170US for it, if that helps any.

 

Sheesh, even $170 sounds rather high for just a half hour of labor. I really would prefer to get mine from a dealer, but I would have thought that if a dealership really wanted to move these cars, they would make sure they have a recent compression test to show the customer. This will be my first RX8 and I will soon be driving from Newfoundland to Ontario to find one, (there are none for sale in my province, it seems) so it would have been nice to know in advance where I could find one with a good motor, rather than my jumping around from dealer to dealer getting compression tests done.

And while I am on the subject, if any of you know of any low mileage, pristine RX8's (other than 2004-05) in Ontario, Quebec or the Maritimes, (preferably under $15,000) if you could please give me a heads up, I would be eternally grateful! (must be an automatic)

Glen

 

this is a true statement but not for the reasons you might think it is, it also applies more to turbocharged engines and a carryover from them to hearsay for most other series.

the reason an engine might pull hard right before it blows is usually due to a fault in the fuel system, running an engine lean to the point that is detonates and causes major engine damage. running an engine leaner than desirable will make more power, temporarily. in turbocharged engines the power will actually increase right up until the detonation occurs, giving the feel of more power because there is.

it can apply to naturally aspirated engines but the power difference is marginal and it requires pushing the engine much harder to cause major damage than in turbocharged engines. in a non turbo the power will usually just choke off eventually and the car will buck and knock, in a turbo engine you usually won't feel/hear a thing until you coast to a stop after the engine has stalled.

i'd bet most of the people who say it here are RX7 owners and the 8 owners are just parrots.

 

I was quoted $160.00 cad In Burnaby BC at a Mazda dealer. Car is going in on Tuesday for a check.