I'm hoping someone here can shed some light on an annoying issue with my 2002 P5. Have been searching past threads but so far nothing sounds exactly like this.

When I'm driving, the power I'll get when I hit the gas might be great, or it might be crap. There doesn't seem to be any sense to what is going on with it. These days it's usually just runs badly enough to make me want to sell the damn car. Then, occasionally, I'll give it gas it will give me everything all the way to 5k or so (I'm letting up on the gas, the engine would keep going).

Anyway, in trying to get to the bottom of this, I yanked the plugs. 1 and 3 came out slightly scorched with the electrodes partially eaten away. 2 and 4 looked perfect. I dropped in a new set of plugs. Things improved for a little while, but then returned to being unpredictable. The second set of plugs came out the same way as the first, burned electrodes on 1 and 3. dammit.

So, I took the car into the dealership where it came from (Vancouver, WA) to have it checked out while it's still under warranty. I'm extremely unhappy with the service I received there. I was told that everything is fine and there was nothing to fix. The service advisor said that the burned plugs were nothing to worry about. Preignition not a problem? Um...

I have built a number of engines in my time, and I know this guy is fully of crap. I did find a thread where a few people noticed that their P5s occasionally seemed to dish out more power than normal...does anyone have anything that might be able to help me out here? Ever experienced the same thing?

Must admit that I am puzzled. With all of the injectors having the same pressure behind them, there are a limited number of causes to take in consideration. Do I have clogs in two injectors? Are the two injectors being told to inject less fuel than the other two? Is the timing off on these two cylinders? ..and then only sometimes?

Mazda recommends a fuel systems flush at 30k miles, had that done, made no difference. There was a service advisory to replace one of the valves, which was also done. This smoothed out the idle but had no effect on the bad running. Don't know which valve (part no is N236-13-980A)

I would really appreciate some insight here. Test drove another P5 before I bought this one and it dit not have any of these issues.

BTW, no mods, 34k miles

Thanks

 

I seen the same thing.....and I think it is the intake getting heatsoaked.

When it does not have power feel the intake, it is hot.

 

That's something to think about, and I have seen that happen on other cars, but I believe this is different. This issue occurs with minimal changes in driving conditions and often very quickly. The best analogy I can come up with is that it's like running my old Datsun 1600 when the carbs were unbalanced. It sounds off, like two cylinders are misfiring. Then, without warning or any action on my part, it's back to running really well.

To me, this is unaccaptable on a car this new. I just sold an 89 323 for $250 that ran better than my P5, and I plan to hound Mazda until I get an explanation. Pouring through the servce manual as well, slowly.

Looking forward to hearing from the rest of you, thanks for the input chuck.

 

Sounds like a malfunctioning COP. Cyl # 2&4 are one the same coil. Might want to start there.

 

I agree. I pulled my plugs for the first time at 34k miles and they were all identical... Textbook tan colored electrodes, no spots or scorches. So look at either the coils, wires or computer.

 

There was a recall for the coils on the 99-00 models. Were the 2001's or later affected?

 

I would recommend the wagner motorsports AEM ecu. you'll be surprised with how crappy our stock ECU is....from what I hear the AEM turns the protege into a BMW.

 

For some reason I wasn't getting notified about your responses. Odd.

Anyway, car is still running like crap - running great one minute than garbage the next. Going to a different dealer, this week hopefully.

I considered the coils as a possible source or the issue, but the way mine are configured, 1 and 4 are on one coil and 2 and three on the other. Since 1 & 3 show signs of detonation, I am leanign away from ignition and operating from a few other possibilites:

1) One and three show detonation while the others do not, indicating that either timing or mixture is off from time to time.

2) As near as I can tell, timing seems to be controlled uniformly accross all cylinder, making it unlikely that timing is the issue.

3) There are two possibilites for mix being off. The first being that two of the injectors could be intermittently malfunctioning. The second being that the valve train is malfunctioning causing less fuel/air mix to get to those cylinders.

4) There are a few reasons I am looking at the valve train. First, I get significant startup noise in the top end even after sitting just a couple of hours. Second, until the car warms up there is a very audible deep knock on acceleration. Not pinging, but more like rod knock, but that goes away suddenly if the engine is revved past 2800-2900. Third, on idle after warmup, I can hear valve tap fairly frequently. I suspect one of more blocked oil passages.

I'll be making another attempt to get this looked at by a compentent dealer mechanic this week. I have a bad feeling about these problems and that I'm going to lose this engine. If they aren't able to get this sorted for me I'll have to sell the car and try again. This is very frustrating.

Thanks again for the advice and, of course, anything else would be much appreciated.

Mike

 

Mazda recommends a fuel systems flush at 30k miles

Was this the fuel system flush where they hook the CAN to the fuel rail or just dump a can in the gas tank ........if in the tank it does F*** ALL , nothing, it is just crap.

 

It was the "hook up the can" version, took a few hours to do. Given the other issues that are present I'm leaning away from fuel injectors right now but they will be on my list of things for the mechanic to consider.

 

01-004/03 2001-2003 PROTEGE/PROTEGE5 - RATTLING NOISE AT 1000-3000 RPM COLD ENGINE
APPLICABLE MODEL(S)/VINS

2001-2003 Protege (2.0L FS only)

2002-2003 Protege5
DESCRIPTION

Some customers may experience an engine rattle noise under light to moderate acceleration with engine coolant temperatures below 65 C (149 F) and engine RPMs between 1000 and 2900 RPM

The noise is the result of the intentional swirl effect that is generated when the Variable Tumble Control System (VTCS) plates in the intake manifold are closed. Swirl accelerates the burn of the air/fuel mixture which reduces emissions when the engine is cold. The noise does not have a negative effect on the engine, and disappears as soon as coolant temperature reaches 65 C (149 F). There is a counter-measure to help reduce the noise in order to improve customer satisfaction.

Customers having this concern should have their vehicle repaired using one of the following procedures:
REPAIR PROCEDURE

 

http://web2.airmail.net/theman/protegefaq/tsb/

3rd Generation and look at above mentioned TSB.

I had the same sound and had the above done and no more noise

 

yikes the "intake manifold cleaning kit" huh....I could see this being a problem if you lived on a dusty road with improper air filter upkeep or horrible gas ALL the time.

I worked at a garage for several years and their big scam was to try to sell as many of those as possible because they cost nothing in parts and cost the customer $60+...also I noticed no improvement in anything.

When it comes to fuel system cleaning I only use BG"s 44K....this is sold at my local honda dealership and just pours into the gas tank. Also, BG's makes a wonderful oil stabilizer called BG's MOA. Check these out.

 

Thanks for the link to that page, very useful. The repair for "Rattling Noise" was done the first time I had the car in, and it helped that particular noise a little, but in reading the notes I wonder if the PCM was programmed properly.

I noticed an advisory regarding clutch shudder when cold. Mine does this severely sometimes. Any idea as to whether this would be a warranty repair?

Thanks

Mike

 

Just talked to the service department of another dealership. I described the problems I am having and it took him less than 30 seconds to start attributing the problems to crap he was pulling out of the air. Was shocked that I would install my own spark plugs.

Then he asked, "Do you have carbon in your cylinders?". A valid question, but how the hell do I know? He wants to scope the bores and this makes me nervous. Many engines are going to experience *some* carbon depositing, but who is to say what is excessive? I get the distinct feeling this guy is going to try and soak me for every penny he can get.

I run super all of the time. So did the previous owners. Significant carbon buildup anywhere is going to cause the engine to run crappy all of the time, not just occasionally.

This particular P5 is about to get sold

Mike