grimfate

Hey all,

I'll try and make this brief:

2004 AT RX8 was suffering hot start problem (started perfectly when cold, but needed 10-15 minutes to cool after turned off) so I took it into my local Mazda dealership to get it looked at. After a few days, I was told it passed a compression test. (They have the equipment for rotary engine compression tests.) A few more days, they tell me it's my start motor and that I need a new one. A week later, now they tell me that they can no longer get it to start at all. Something about seals and compression, and flooding whenever they try to start it, and having to pull the spark plugs out and then put them back in. So, according to them, now I need an engine rebuild.

Here is my confusion: When I took the car in, it was working fine, except for the hot start problem. They told me that it passed a compression test and they thought it was the starter motor. Now I'm told that it doesn't start at all and I will need to get my engine rebuilt.

So I'm wondering: Is it possible that the mechanic screwed up and caused it to no longer start, or is it more likely that the engine was about to die and it just so happened to be while it was in the hands of the mechanic? And are there any questions I should ask them when I go to pick it up tomorrow?

Thanks in advance.

P.S. If it matters, the dealership doesn't do rotary engine rebuilds, so I don't think they're trying to sell me on an unnecessary rebuild.

Loki

iTrader: (1)

The "something about seals and compression" is sort of the important part there. The symptoms point to low compression, but you say it passed the test. Do you have the 6 numbers the test produces?

It sounds like it's flooded, that might make some sense, but they should know how to deflood it. What might have happened is they moved the car around the shop and only let it run for the time needed to do that. With a weakened engine, and especially a weakend ignition system, it might have flooded.

The simple fix for that problem is to hold the gas pedal down all the way while cranking for 5 seconds, repeat 3 times, try to start normally. If no luck, repeat again. If that doesn't do it, yes they have to pull the spark plugs. But again, none of this should be news to them, it's even in the shop manual.

If the compression is indeed passing, consider when your spark plugs and ignition coils were last changed. You need to refresh those every 30k miles or so.

grimfate

Thanks for the reply.

As a lot of people have said on here that the hot start issue is likely the engine failing, I was expecting that to be what it was, but, yes, the mechanic said it passed the compression test. (If it actually didn't, I'm going to be pretty annoyed that they made me buy a new starter motor.) I think I recall them saying that each time they tried to start it that it would flood, which I assume means they de-flooded at least once and it just flooded again, but I can't remember for certain. I shall be sure to ask about that tomorrow. But it does seem strange if they wouldn't know about de-flooding a rotary.

Unfortunately I don't have the numbers for the compression test. I will definitely ask for them tomorrow.

Spark plugs were replaced ~3 months ago and 2 of the ignition coils have been replaced in the last 2 years, and I definitely haven't done 30k miles since then. And if it were either, I'd hope they would have found them during their investigation.

And thanks for the advice on de-flooding. I will definitely try it once I get it back in my possession, just in case. Don't want to have to replace the entire engine if it's just the mechanic not knowing what he's doing.

Loki

iTrader: (1)

Does that mean the other 2 coils are much older? Usually you want to replace all 4.

grimfate

I would imagine they're much older, but it seems like an expensive operation at this point if they're not the cause. That said, it'd cheaper than a new engine. I'll hopefully find out more from the mechanic today.

My main concern, though, was the fact that I took in a working car and am getting back a non-working car. Wanted to know if that was just something that could happen with rotaries or engines in general, or if the mechanic may have screwed something up.

Loki

iTrader: (1)

Definitely cheaper than a new engine. You really don't want to get the coils to the point where they're showing symptoms. It's hard to know what the mechanic may have done, but they have everything at their disposal to diagnose the problem.

If they really think it needs a new engine, what exactly is broken?

UnknownJinX

A telltale sign for a bad coil is the little white spots under it. There are some other ways to test them, but a good practice is to replace them if there is no proof that they were changed before. The OEM coils are pretty crappy.

I would ask for the actual compression numbers and normalize them. You paid for that, there is no reason for them to not give the numbers to you.

grimfate

He mentioned something about the seals in the engine needing replaced. He said it was low compression, so he may have been explaining to me what causes low compression. Which still confuses me when I supposedly passed the compression test.

Anyway, I got the car back. Unfortunately they didn't have the compression test numbers on hand, so they are going to email them to me. I can't wait to see what they are.

As for the car itself, I'm not sure the correct terminology: It cranks, but doesn't fire? Turning the key produces a whirring noise, but it doesn't sound like it's even trying to start, so I would guess the pedal to the floor method ain't going to work.

Still not sure why this happened while it was within the mechanic's possession or why I was told it passed the compression test. He sort of explained it, but it came off sounding like "the compressions were good, but not good enough", "this sort just happens with rotaries" and "I couldn't say what the exact reason for the car no longer starting". (I have a shocking memory...)

Thankfully it turns out there is a rotary expert in town, so I'll get a second opinion from him. And it's good to know that if I do get it rebuilt that I won't have to take it out of town to do so. (I'd hate to think what the cost of transporting a car between cities is.) I'll keep the ignition coils in mind when I get it going again.

Thanks for your help, guys.

NotAPreppie

You can also try adding a little oil to the combustion chambers. Pull the vacuum plugs from the lower intake manifold attach one end of a hose to a nipple and put the other end in a bottle of oil. Crank for a few seconds. Repeat with the other nipple.