Last post on Oct 27, 2006 at 8:04 PM
You are in the Mazda MPV
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Mazda MPV, Van
#3294 of 4469 bad news about my 2000 MPV engine
Dec 20, 2003 (4:36 pm)
Wretched Ford Contour engine! Read this if you have one.
I hope I am one of a few unlucky ones. I have one of the first 2000 MPVs, bought it in September, 1999. It is a 20th anniversary Mazda Miata blue ES.
The check engine light has always gone on and off a lot. I had it checked out several times but gave up when they never found anything. It would usually go on when I drive uphill on the highway and go off a few hours later. I also noticed that my mileage seemed to be lower than some of the other 2000 MPV drivers. I usually got between 210 and 218 per tank. I think most other people did better than that.
Anyway last week the check engine light starts flashing. I call the dealer and have the car towed in. I was guessing the exhaust system was shot. Not! They tell me to have some hoses replaced and replace the spark plug wires along with the spark plugs. They pull the plug on cylinder number 4 and it is fouled. The Mazda tech rep happens to be there so he tells them he has seem 3 MPVs with the problem in New England. It is always just cylinder #4 next to the radiator. They run the compression test and yeah, I need a valve job.
I have 67,000 miles on the car so the dealer is less than helpful and wants $2500 to do the valve job which will take 2.5 weeks because it is the week before Christmas.
I start looking around quick for another car since I think it is futile to sink more money into the MPV. It is too bad. I really enjoyed driving the car. It was a little more expensive to maintain then I would have liked but it was a great car to drive.
I really didn't notice any problems with the way the engine was running. What I did notice was that my mileage per tank was about 10 gals less than what I had been getting before. There was a gas price war going on in my town so I thought it was just the cheap gas.
Looking back, I had to replace the alternator at around 55,000 and two of the stupid alloy wheels. One wheel over the last two winters. Ouch. I live in New England (pot hole heaven) so I suppose that is the breaks. I had the CD player, radio tuner replaced under warranty. There were little annoyances that got fixed under warranty but I still really liked the car. Too bad. I will miss it.
I will be driving a burnt orange 2003 Honda Element next week. I do dog agility shows and pretty much managed to trash the van carpeting so the spartan Element interior was appealing. I am getting a 4 wheel drive EX for $16,000 with the trade in of the non-repaired van. Had to cut back on the car budget since we had be hoping to get a year or two more on the MPV. Wish me luck.
#3296 of 4469 Transmission Update: Temperature Data
Dec 20, 2003 (5:47 pm)
OK I am very curious about the correlation between temperature and the slamming issue. The hard shift occurs only when the van is operating at its maximum operating temperature. So I went to Sears and bought an infrared laser pointer thermometer, which measures spot surface temperatures. I tested the unit against my home wall thermometer, and it came within 1 degree. The spec claim +/-2.5% error. I expected to find unusually high tranny temperatures when at the point of hard shifting.
I looked at several spots on the transmission housing as my aim point, and found a spot near the dip stick tube. Here is the result:
On startup and initial warmup, the tranny runs at about 150F. Fully warmed and in traffic about 160-180F. On the highway after a high speed run 175F. After 1 hour of brutal stop & go and a steep uphill drive 195F. These are actually pretty normal readings, assuming that the housing temp is not much cooler than the tranny internals. I also tested the intake & ouput side of the tranny oil cooler and found that the intake (hot) runs about 160F, and the output runs at 150F. I am somewhat surprised by the small differential, but that could be due to the fact that the test was conducted while the car was stopped, and no airflow was going through the cooler.
Now for the interesting part: I sampled the temperature after several hard shift instances, and found that there is no direct correlation between temperature and the hard shift! One instance of hard shift occured at 175F just as I was getting on a highway, others while in the stop & go traffic 180-190F, and some between 160-175F.
None of these temperatures, if they accurately reflect the internal ATF temperature, indicates that the tranny is running particularly, or exceptionally, hot.
Here is some information about ATF temperature conditions I found on the web:
"Automatic transmission fluid will provide 100,000 miles of service before oxidation occurs under normal operating temperatures of about 170°F. Above normal operating temperatures, the oxidation rate doubles (useful life of fluid is cut in half) with each 20° increase in temperature.
The approximate life expectancy at various temperatures is as follows:
175°F 100,000 miles
195°F 50,000 miles
212°F 25,000 miles
235°F 12,000 miles
255°F 6,250 miles
275°F 3,000 miles
295°F 1,500 miles
315°F 750 miles
335°F 325 miles
355°F 160 miles
375°F 80 miles
390°F 40 miles
415°F Less than 30 minutes "
So what could be the issue? I noticed that most of the time I have a hard shift, its after the engine has run, been turned off a while, and is restarted. I checked the tranny temp after it was turned off for about 20 minutes and the temp came down to 150F, about a 20-30F differential from when it was turned off.
The transmission temperature is an important datum used by the TCM to determine shifting points etc. I learned from research on the web that some transmissions don't actually have a temperature sensor but derive (simulate) transmission temperature from other engine parameters such as engine temp, air flow, rpm, and even battery temp.
So could it be that our MPV derives transmission temp data? Could it be that the algorithms used are wrong, particularly when calculating data at warm start-up? Could it be that this is why Mazda insists that its a software issue?
Dec 21, 2003 (8:41 am)
Wow, I am impressed! Good job.. Now the next step is to get a flush. Contamnation must be elimnated as a possibility. Then that will leave 2 possiblilites:
#3300 of 4469 hard shift and contamination
Dec 22, 2003 (10:07 am)
I don't really think contamination is the problem causing hard shift, because they occur so predictably and consistently. And, you can learn to avoid the hard shift as notasoccermom described earlier. Most likely it is the control software problems. And, I have a feeling that the 04 are having even worse record than 03, since I don't recall anybody report a trouble-free 04 MPV. I talked to my dealer's service department. They knew what I was talking about but claimed it is "normal." Though the service manager did say that he would need to have a test drive to say anything for sure. So, I will bring it in after Christmas. As I don't expect the problem can be fixed, I do want my case to be acknowledged and documented.
#3301 of 4469 Well, I would hardly consider what kaneonapua did
Dec 22, 2003 (2:13 pm)
as spamming. Truth is - those with the 2-3 tranny shift problem are technically cross-posting all over the place.
Anyways, I'm at 1200 miles on my '03 MPV and I have had no hard-shift problems at all. We haven't been that cold here yet (maybe the lowest low was 20-25 degrees), but as I said, no hard shift problems at all. Also, I asked my dealership about it and they didn't seem to know anything about a hard shift problem (not that this is a be-all/end-all way to figure anything out).
#3302 of 4469 5-Speed Tranny Doesn't Have Filter
Dec 22, 2003 (5:31 pm)
Talked with a Mazda parts guy today and found out that this unit uses a strainer rather than a filter and that it is cleaned rather than replaced. Also there is no pan gasket. Sealer is used.
Dec 22, 2003 (7:38 pm)
havent seen any mpv's that needed valve jobs, but have seen a few tributes that needed valve and in 2 cases, head replacement. the bad spark plug/wire issue on the mpv has been more so on cyl#3 in my experience.