Mazda doesn't have a Clue!
 

Ok I just took my 8 in for the thrid time for a hesitation in 3,4,5, and 6th gear in the 3-5k range . The car just kind of bogs down and then picks back up at the 6k mark. They thought it was coils but the engineers are saying thats not it. And they don't think it's the intake valves. If anyone has had this problem please let me know and the fix if there's one. Thanks guys.

How many miles do you have?

Could be a dirty MAF.
Fouled Plugs?
Bad Cat.

Ive had the same problem. Does it hesitate when revving in neutral? I ran some gum out(fuel injector cleaner) and it cleared it up in about 4 days. Carbon and other crap builds up around the injectors and limits the fuel, that's why it would hesitate.

Edit:Funny, dealer said the same thing to me. They had no idea what it was. Man, I am smarter than them:)

sounds like you're not driving it hard enough. also, start running Marvel Mystery Oil in every if not every other tank of gas.

I've got 9k miles on the car. I try to run it hard every couple days. I had the plugs changed and the maf checked out already. i had the reacall done about 2k miles ago and it was doing it before the recall also. I've been premixing Lucas UCL for about the last 10 tanks or so.

Take off your MAF and clean it. Checking it won't anything except make sure it's working..

You might want to consider taking a multimeter to the coils. Make sure they are in proper working order. Mazda generally won't do this, they would rather just dismiss the problem, especially if the EMS isn't saying they are faulty. The mechanics rely on computers instead of common sense..which is why so many engines have been replaced.

Well I just got my 8 backfrom the dealer. They said the reason the car was bogging down was due to the milky stuff that forms in our oil so they did the TSB for the vent kit and cleaned the intake and I'll be damned if it didn't work. She's running running great again. Thanks for all the info guys

I'd still go to a new dealer from now on. Any dealer that even has "intake valve" as the cause of a problem crossing their minds for a split second should not be working on our cars.

That's why I can't stand going to any dealer. Its always "thats normal" or "noise not found" etc. Granted the rotary probably wouldn't respond as a piston engine would to a vacuum gauge, it still makes me laugh how no one bothers to think to use something because the work isn't done for them...

by intake valve they mean sdais parts. so the first couple times they didnt clean the maf just looked to see if there was a pending cel due to it. this time they found oil in the intake tube so cleaned it and the maf. did thye actually change the vacuum routing to the new way. 06 and later have a sort of PCV system which previous years did not. there is a kit they can get to change this when people have this exact issue. not just the dipstick tube.

Yes thats what they did the funny thing is they didn't even know about the vent kit till I brought in the TSB and asked for them to put it on and I also said hey do you think you can fix this hesitation problem while you're at it.

I'd find another dealership.

or a different car........chrysler........

hahha blue renesis!



sayin that MAZDA doesnt have a clue is kinda wrong dude. its just ur dealer i guess. ive been to plenty of dealers and none of them suspected my INTAKE VALVES to be messed up

everything is solved by a reflash

I didn't mean it as a slam they had just never heard of the 8 having a hesistation problem before. They said that they called the rotary guru's at mazda and that they had never heard of it before either

Last time I heard that there is a crack rotor and need to be replaced.

It could be from the intake, MAF, filter, throttle body all the way to the rotor and engine. Many possibility.

Ask them to do a compression test - do not come back with an other question from them.... "what is a compression test"..... they should know if they sell rotaries. All RX-7 have their compression test results printed in their ads when they sells their cars in Japan. That will rule out a lot happening in the engine.

A rotary engine has no Valves at all, What are you talking about?

the SDAIS system of the intake manifold uses several "valves". one of these not opening can cause several issues

Well problem came back about 2 days ago so I'm going back to the dealer. Thanks for all the info I'll let them know I hope they fix it soon.

Can the milky stuff in the oil cause problems? I thought it was harmless...? It's just moisture attracted to the metal of the dipstick... I thought.

Are dealers usually agreeable to performing a compression test is an engine issue is suspected? How much would it cost to have this done out of pocket?

There's a TSB out there for loss of power which requires them to perform a compression test. Check the TSB sticky and print it out. Make sure they tell you what RPM they perform the compression test at. Also I get the milky residue on my dipstick like a ton of other people every winter when it gets cold. No issues. Don't worry about it. There are some other older threads on this forum about it. Search around and you'll see.

I had the white stuff in my oil as well and the car would alot of time bog down in 2nd gear. The dealer said there was a TSB out for the foamy oil which installs a breather tube. They also replaced the starter as well. The car doesnt bog down at all now and it has been about month.

they said that the milky stuff wouldn't hhurt. I haven't seen the TSB about the compression test I'll ask them or look it up Thanks. They installed the breather tube and I haven't had any more of the milky stuff. I saw the valves when they pulled them out and they didn't look good thats why they thought the vent kit would fix the problem. Well I'm going back to mazda tuesday and we'll see what they say.

I had a hesitation/sputtering at lower rmp. It was driving me crazy because the dealer could not detect it at first. Eventually (after several weeks) it got worse. At one point I was driving on the on the highway and the power completely dropped out - I couldnt get the car over 40 mph. Took it back to the dealer and they found that it was an ignition coil. Back to full power after they replaced it. The Dealer also said that several other cars have experienced this too.

This could be your problem - I doubt it is related to the "milky" oil deposits that show up in colder weather. Many early threads on this say that this is normal. Dealer confirmed this too.