I have been trying not to post this question because I know that there are a lot of threads on engine failure, but nothing has really addressed the questions that I have. My car is a 2004 Base, no mods, manual trans, with just under 90K miles on it. The symptoms are as follows:

Very rough idle at operating temperature

Sporadic stalling when it was hot out, but hasn't done it since winter started

Loss of torque at low RPM (I know that many would say that the car had no torque to begin with, which is sort of bollocks, but I am having trouble getting the car to go from a dead stop and particularly on a hill. I have been driving stick for over 20 years solidly, but right now I have to feather the clutch constantly to prevent stalls at low speed.)

When it was summer, the car would have trouble starting when very warm, but in winter, it hasn't had an issue.

No CELS

All maintenance done including plugs, wires and coils. Has a new O2 sensor.

I took it to the dealer, who kept it for two days verifying the rough idle and loss of low end torque. The went through all of the fuel maps and said that all looked fine. They checked the intake manifold and SSV valve, which was operating normally. They also checked for flow through the cat, which they said was fine, and they checked the compression, which they said was fine, but they would not give me the results. I trust them that the results were passing.

What I really want to know, is do these symptoms sound like a failing engine, or do I need to start thinking about other things? All of the easy stuff has been done. The only other thing that I could think of was a fuel filter/ pump assembly. Could that be causing a problem like this?

I am used to reading about engine fails as having high end power loss not low end torque loss like this. I have no idea where to go from here so any help is appreciated. Thanks.

 

You said you took it to a dealer...did you pay for all those test? Ask for all the results in writing. Have you cleaned the MAF sensor? Have you tried to decarbon the engine to increase the compression? Add a can of SeaFoam best results half or quarter tank(at Walmart $8) and drive it hard near the red line a few times. If one can improves it try a second treatment. Let us know if it helps.

 

The dealer is pretty straight, and we have a relationship. They charged me one hour of diagnostic time for everything they did.

I did clean the MAF sensor before I took it up there hoping to save myself a trip. I HATE dropping my car off for work.

I've used Lucas injector and valve cleaner through the tank pretty regularly particularly when I could hear grinding coming from the rotors on start up, which I have always taken to be a build up of carbon then taken it up on the highway for a 600 mile round trip run that I have to take every few months for work. It does a nice job of blowing the carbon out.

Any opinions appreciated.

 

I would try swapping out the ignition coils

 

I tend to agree w/Old Rotor; try and get a look at your actual compression numbers as your symptoms of loss-of-power and hard-starting/poor performance as it gets hotter are classic symptoms of compression loss. Dealers don't typically have a problem with giving you a copy of their compression test sheet so I would press them for it. It should show your cranking RPMs and the values for each rotor face on both front and rear rotors.

Other than this, the only thing you can do is make sure all your sensors are clean (including the ESS) before the parts-swapping begins.

 

Actually, I think that I have some ignition coils lieing around somewhere so I might just do that because it is free. I don't think that they are the problem though because it runs well at high RPM. Still free is worth a shot.

Charles, you are probably right. I did ask for the compression numbers, and they did not want to give them to me. My plan at this point is to run until Spring. Wait until warms up when it will be running worse, and have them recompression test the car with me paying for it, which will mean that they have to give me the numbers. The problem is that they only charged me for one hour diagnostic and didn't break out the compression test as a separate test. That could mean that they didn't do it, but I think that they did. Either way, I didn't "pay" for it. I paid for a bunch of other stuff. The service guy told me that the talked to Mazda about the car.

Thinking more about it. It seems to me that the numbers were probably a borderline pass, and Mazda didn't want me to have the numbers because I would start arguing for a new motor. The car still drives poorly with near stalling at start up. My plan is to start again with the Dealer in the Spring.

Thanks for the replies.

 

Hot Engine + Hot weather + Hard Start = 99% chance that the engine is bad.

You might trust your dealership. but the "not giving you the compression test results" sound kinda fishy to me.

Did they even do it ? ... Thats my question.

 

You're probably right.. But call MNAO, they'll get the stealership sorted out.

 

It's a question, but I do trust these guys. They have been very fair and competent and always done warranty work without a hassle. I believe that they did it, and I think they felt (and I think that they were) fair in not charging me for all the time that they put in.

 

The problem here is that, its "pretty obvious" that your engine has a problem when its hot.

Assume that your location info is right (PA), Its pretty cold out right now, and it masked the problem well.

Maybe wait until the summer comes ... go there on 90+ days then they "might" see the problem.

 

This is my plan, although they did confirm for the record that the car was idleing badly and lacking power at the low end.

I do thank everyone for confirming my suspicion that it must be the engine failing. The only other thing that I could think of was a restriction in the fuel flow from the tank, but they said that the fuel maps all looked fine.

Right now because of the weather, it basically feels OK, although I still have the standing start stumble. I don't think that there is much else to do about it until Spring comes.

Thanks very much to all who posted!

 

Bring in a copy of this "TSB" I feel it will help get you running better but might not be the final answer. The thing is it might get you running better for a few thousand miles then the warranty is over.....

http://www.finishlineperformance.com...4-08-1924g.pdf

 

Thanks for the TSB Rotor. It is true that I could go in for the decarb procedure, which they definitely didn't do, but I think that I prefer to run the car until Spring/Summer and see about it then unless it gets worse before then. There is a fear of running out of warranty, but I have 10,000 miles to go. I guess that I will find out what it will do.

 

What would be the threshold value for compression that would compel the dealership to replace the engine? I'm asking because my engine, which seemed fine until Friday, has started being fussy about starting when warm.

I'm in lower Fairfield County, Connecticut. On my way home from the train station, I stopped in at an auto parts place to buy some premix. I then proceeded to the filling station, where I added the premix (4oz), then pumped my fuel. The dashboard gauge had shown I was 3/4 down with 1/4 remaining. When I arrived at the filling station, my Scangauge II showed my coolant temperature as 179F. When I went to restart after paying for the fuel, the Scangauge II showed my coolant temperature as either 177F or 178F (I'm not really sure). The engine turned over but would not start. I tried again and thought I'd somehow flooded the engine. I didn't remember the deflood procedure correctly, so I pressed the throttle down all the way, tried to crank, repeated twice more, then figured let me check the manual before I tear anything up. I then followed the pedal pressed and crank, then pedal released and crank procedure and that finally got the engine going again, though it was about 5 seconds before the idle stabilised.

Today, I ran some errands, since I wasn't even sure if the car was operational, and I would rather find out on the weekend than when I am trying to get to the train station first thing in the morning. At one point in the course of the errands, I shut the engine down (I'd been driving for about half an hour including about fifteen minutes of highway driving so I'm convinced the engine was as fully warmed up as it can be in the weather we've been having without me blocking off the radiator and one of the oil coolers), so I could deliver the materials my wife has sent me out to deliver. Sure enough, the engine turns over at the usual rate; but takes longer than I am accustomed to to catch and come up to idle speed.

I will be ordering a compression tester shortly; but I am not clear on just how bad it has to be before MazdaUSA opens its wallet and gives out a rebuild.

 

It seems I'm SOL... I tried placing an order for a compression tester at http://www.twistedrotors.com/ after learning that the group buy was closed; but both the blue and the green display models appear to be out of stock.

 

Please give us the history on your car,miles, model,year,. The service it's had parts replaced. Did you do all four coils , wires and plugs? Type of driving it gets(long commutes, short trip), fuel used(reg or prem), ever flooded. Just any thing that you can add. Done any decarbon cleaning?

 

Dont order the compression tester so fast just yet.

Follow Old Rotor's advise, give us a brief history of the maintenance history of your car. it helps.

 

Car has 47.6K miles, is a 2004 purchased in October of 2004 (manufactured in June of 2004). Parts replaced include coils (BHR coils & wires, along with a set of fresh plugs were installed at 40K miles when the OEM ones failed). All four coils were replaced with the BHR kit.

From purchase until Summer of 2008, I was driving a short 12 minute commute to the local train station, which involves 3-5 minutes of highway driving and the rest are surface streets. During Summer of 2008 through until the beginning of Spring of 2009, I was highway driving to and from work, 500 miles per week round trip. Starting in Spring of 2009, I switched back to my original commute to the train station. (I had 800 miles between my prior oil change and the current one this past weekend).

In addition to normal wear items, the only items I know that have been replaced are the coils, plug wires (and plugs but I think of that as a wear item), the rear O2 sensor, and the left front sway bar end link.

Oil has been changed every 3 months or 3000 miles. For the first 2.5 years, this, along with all maintenance, was done on schedule by the dealership where it was purchased. When they went out of business, I tried the dealership that bought up their remaining inventory; but I found they charged 15 to 20 percent more and were very sloppy (eg: they told mazda n.a. that they updated the car to the latest pcm flash; but the door jam sticker showing date of pcm flash update is the one done by the original dealership in 2006 so I don't know what pcm flash is actually on the car).

After deciding to minimise the business I did with the new dealership, I started taking the car to a Valvoline oil change place. I believe the car was 2.5 years old at this point, possibly 3. I had them switch to 5W20 group III "synthetic" and had them switch again 6 months ago to 5W30 group III "synthetic". I changed out the coolant to Evans waterless coolant this past Summer. The intake is stock with a washable/reusable green air filter installed at the same time as the Evans waterless coolant.

Coils were replaced at 40K miles, switching to BHR coils. The rear O2 sensor was replaced this past Summer (only the second CEL I've ever gotten with the car). Two weeks ago, I ran a can of seafoam through with a tank of 93 octane.

The car has generally been run on 93, though during the Summer of 2008 when I was driving to Englewood Cliffs, NJ for work (putting 100 miles on the car round trip each work day) I would alternate half tank of 93 followed by half tank of 89, then run the tank down to the warning light and start again with a full tank of 93 in order to keep the average to 91 and slightly defray my costs. Once prices came down, I went back to a steady diet of 93.

My current commute is a short hop to the train station and back, so my mileage between oil changes is 800 miles or less.

I began premixing in the Spring of 2008, at first using 6 oz of MO per tank, and then switching to 4 oz of 2 stroke oil per tank in the Summer of 2009.

The second dealership swapped the battery at my expense in 2007, saying the warranty was pro-rated. I do not know if the starter is the original model or the uprated one. I don't have a garage, and it's a trifle cold to check without one.

 

This might help you ...have you seen it?

http://www.finishlineperformance.com...5-08-1883f.pdf

 

Yes, and thanks for the reminder. My car's symptoms are actually the opposite of those in the TSB. When it's cold, it's a cakewalk to start. It's when it's warm that it's a pain to start. I apologise for not explaining that.

I very much appreciate the help in this matter, and despite this problem, my opinion of the car has not soured at all. I very much enjoy every trip I take in the car, and I can't say that about most of the cars I've owned. Even if it turns out that the engine needs replacement before the year is out, I still plan to keep the car a very long while.

 

I used to have the same issue where cold starts were fine, but warm starts really struggled.
I was always afraid to go to the gas station because it was so difficult to start it back up (and embarrassing).
After I installed the upgraded starter, I no longer have issues with warm starts.

Not sure if this will help in your situation and its possible that what others have said is correct in that the engine is on its way out, but I wanted to throw in my experience with warm start issues on my '04.
But you also have an '04 so if you haven't upgraded the starter, its something you should do regardless.
Good luck and keep us posted.

 

Hopefully this isn't a threadjack, but I'm subscribing to this, since I have the same symptoms - starts fine when cold, but difficult to start when warm. Lately it takes me up to 3 tries to get the car started if it only sits for a short time (getting gas, quick stop at the store, etc.) I arrived here after doing a search for "updated starter", so I'm obviously considering one.

Quick history: bought car in Feb. '09 w/ 49K miles on it. Car now has just over 57K miles. Replaced coils, wires, plugs back in Dec. due to a failed coil. Just started premixing 3 tanks ago. I'm currently using ~4oz of Royal Purple 2 cycle oil per tank, but have a case of Idemitsu waiting on the shelf when it's gone. I've changed the oil twice since purchase - Royal Purple 5W-30 at 50K and RP 10W-40 at 55K. I've been sampling the oil each 2.5K and switched ot the 10W-40 based on the results (viscosity wasn't holding up). First oil change showed some wear metals, but they have been improving. Based on records that came with the car, PO used a quickie-lube place and put 5W-30 dino oil. I run a bottle of Techron through at each oil change, but I'm thinking about switching to Seafoam. Also, based on PO's records, plus a call to Mazda, all recalls/updates have been performed. Only engine-related modification is a K&N drop-in installed shortly after purchase.

I haven't darkened the doorway of a dealer yet as the nearest one is about an hour away, though both of the ones I have access to have generally treated me well and saved me some money and effort on occasion.