My 91 Legend has 174,000 miles and is smoking and I suspect it is worn valve guides (it only smokes on starting and while sitting at a stop light). Several mechanics have said when repairing the valve guides, you also need to repair the bottom end of the engine (or just get a newer engine). The reason given is that when the top part is repaired, it will give more power and then the weakened bottom end might fail also.
I tend to disagree with this but would like some expert opinions. I recently did several full acceleration runs of 0 to 60 and clocked about 8.2 seconds - slightly slower than the original 8.0 seconds. If the bottom end was weak then it would have failed under this full load.
So the main question is: Is it reasonable to just repair the valve guides and leave the rest of the engine alone - is the Legend engine strong enough to just have to repair the top part? I would of course do a leak down test and compression test to validate my theory. Of course, if a complete engine overhaul cost just a few $100s more than just the valve guides, I would do that.
2nd question: Can the valve guide repair be done without removing the heads? On some engines, you can use compressed air to help do the job. My mechanic says he would not know until he removed all the equipment above the heads. Any advice on this would be appreciated. Thanks, RIck