I just put a new motor in my 89 gts in february. Everything has been goin good so far, except on one long trip right after I put it in it over heated which freaked me out but it hasnt done that since. Sometimes when its idling high at start up it drops down for a second but then goes back up which is a bit weird too. But my main issue is the oil consumption. Its not drastic but since the new motors been in I've gone through about a liter of oil. Its not smoking or anything and it doesnt seem to be leaking. I took the hose off that goes from the valve cover to the intake one day and there was a bit of oil in there. Is the pcv valve in there some where? I was looking at it and I couldnt figure out how to get it out if it is. Its not really a huge problem but I would really like to get it figured out. Every little thing about this car kind of sketches me out now after having the motor blow up on me.
Do a compression test and see if you're losing any oil through bad rings.....even though its new something could have gone wrong....
Im not sure. I've just been adding oil everytime it gets low. On the 600km trip home after putting in the new motor it went through probably about 200-300 ml of oil. I know its not big but its kinda bothering me. As for the compression test I'll give that a try. Its still running fine though.