hello my name is XXXXX XXXXX have a question was the vehicle warmed up when this happens
interesting that would explain the coolant temp
ok sorry i type slowly
ok how is your maintainance you said it was sludged so do you change the oil regularly?
well it is starting to sound like your EGR valve is sticking
the freeze frame narrows a little it could also be clogged injectors or a vacuum leak but being that it only happens at 1500 rpm i would tend to think its carbon deposits in the EGR system i would try cleaning the carbon out with a little carb cleaner and a toothbrush and put it back to see if it helps first
give me a min to think
if you had a oscilloscope you could test the secondary ignition system, the gap on the plugs could be off. causing it but it would be unusual in such a narrow rpm range i am really wanting to say its carbon buildup
my best advice is to perform an air induction cleaning, and clean or replace the EGR and see, past that
its going to take some research
glad to help if you need any further help dont be afraid to ask
ok p0300 is a common problem with the vvt motors in an h3 it can be caused by alot of things most commonly soft seats on the valves that allow the pressure to leak by, other issues can be fowled spark plugs, fowled fuel injectors the cam phaser losing oil pressure due to sludge a cam to crank shaft issue phase issue, leaking cylindars, a bad cam or crank sensor a bad coil , etc... the p0300 is a hard code when it is flashing that means you can be causing catastrophic catalist failure. which in itself a restricted exhaust can cause a misfire, the first step is to find which cylindar is misfiring by attaching a scan tool and watching the misfire data, unfortunately there is no easy fix for this you can try the easy stuff and see if the plugs are fowled etc however to diagnose the cylinder misfire you need some specialized equipment.
I am going to opt out and see if anyone else has any ideas for you to try sorry i couldnt be more help