Q45 Engine - How can I determine year?

[viso]

The bizarre story of my potential purchase of a 1991 Q45 continues ... see related post zerothread/228330.

I explained the chain guide problem to the current owner, documented here at zerothread?id=25201. He was completely unaware of this issue (as are many owners). However, he then recalled that the original motor had failed back in 2001 (55,000 miles) and that it had to be replaced.

My dilemma: If the replacement motor was 1990-1993, then I'm still stuck with the chain guide problem. If it was post-1994, then my understanding is that I no longer face the chain guide issue as steel guides were used from 1994 onward. Apparently, the replacement motor only had around 50,000 miles on it so it might be a post-1993 engine.

Question #1: For a car with a replacement engine, where would I locate the engine serial number?

Question #2: How do I determine the model-year of the engine? I need to be sure whether the car has a 1990-1993 engine or not.

Question #3: When dealing with a non-original engine, what else should I be checking for? (I've already consulted the sticky about buying Q45s but any other info would be appreciated.

Thanks,BTW - This is a terrific forum. Much help already. Much appreciated.

[Q451990]

It takes a lot of work to replace a 90-93 engine with a 94-95 engine due to harness differences. I hear that it can be done, but I've only heard of it once.

Heath

[maxnix]

All Infinitis have a dealer performed sevice history. Obtain the one for your car, or have the current owner do it.

Even if the engine was replaced, it may still have the old guides. Only way to tell is to look.
Modified by maxnix at 2:42 PM 2/15/2007

[q45 for pres]

Yes I had to do the same thing with mine. I was able to research and find a extensive history report of all the changes made on my Q previous to my purchase!