I have a 2005 Mazda MPV with 204,000 miles on it. It idles rough and runs rough – seems to get better once it’s up to speed but still misfires. I have had the IAC valve replaced, a tune up, replaced the PCV hose (all within the last couple of months) and none of it has helped. I even took it to a Mazda dealer who had it for a week and couldn’t find out what the issue is. The only other thing I’ve seen online is the coils but my mechanic doesn’t think that is it. What could be the issue?
I’m certain some computer diagnostics and a compression test on each cylinder would indicate the issue. Also a quick check of the coolant level may also be an indicator. A possible blown head gasket or just a simple misfire caused by a sticking fuel injector.
- What is an Engine Compression Test