When my car gets warm (eg after about 10 or 15 minutes) it has a problem. A little bit of power is lost and the car very slightly shakes, a bit like when a rear wheel is not balanced. It doesn't do it from cold, and only seems to be around 2000 rpm.

I haven't got a code reader handy, any suggestions until I can get the codes read? Will a cheap code reader see all engine codes?

 

Clean the MAF first and all the usual places like the part load and full load breather hoses.

 

Does it set a check engine light? If not, it probably won't show up. Most auto part stores will read the code for free. I just added the Auto Enginuity OBD2 reader to my tools. It did not work at all until I spent the extra $250 for the Jaguar enhancement. I have an Actron CP 9XXX series reader and it does the basics, but not much else. $500 is a LOT to spend on the Auto Enginuity unit, but at least it works and pays for itself if you can avoid 1 dealer visit. Clean the throttle body and the MAF first, then check if you have oil leaking into the sparkplug holes. If there is oil on the outside of the plug and on the coil boot, it will run rough.

 

No, CEL is not shown

I did that yesterday, also did the breathers.
I did find a build up of fluid in the plus on the left bank. Mostly coolant but a very small bit of oil. When the coils were removed the top of the spark plug was just visible. I sucked it out, removed the plugs, cleaned plugs and coils, and refitted.
It behaved really well on my way to work (11 miles) after that, whereas before it would start to play up halfway.
I think I'm to blame for getting the fluid in there. When I had everything apart doing a check on things I must have split it and forgotten to clean up.
I'll see how it behaves going back home in a bit.