How can I tell whether my engine matches my ECU

[William]

Just been reading with interest the post about chips. My car had a new engine a year ago and I don't know how old the engine that went in is as i did not source it myself. Just want to check my ECU matches my engine and my chip matches that! So....questions:

1. how do i establish how old my engine is?
2. where is the 173etc code located on the ECU?

Thanks

[Simon13]

its on a big green sticker on the ecu. take the panel off under the s/wheel and the ecu is above the speaker on the right. you can't miss it

[Speedtouch]

Engine age can be approximately determined on the 325i by looking at the block number to the right of the nearside engine mount; 25 6E is the early (pre 1988) high compression block while the 25 6K is the later (1988-on) low compression one. Look at date stamps on the ancilliary parts also, which will give you some idea (assuming they haven't all been renewed!)

[Ant]

look @ the engine number William, K for cat prepped post 88 motors, E for pre sept 87 high CR

the chassis number is on a label on the side of the ECU if you want to confirm its originality