I have a question about engine flushes. I did a search and found that B&G engine flushes can be good for maximas. Can engine flushes cause more problems like using synthetic oil on high mileage cars? I have 76000 miles on my '95 and it is running a little sluggish on me. Firestone has a "topend" flush for $85, is that different from the B&G? Has anyone used Firestone?

 

Why is using synthetic oil bad for a higher mileage car? I was told by a "reputable" mechanic that as long as your car is burning oil now, it won't burn the synthetic stuff.

 

Why is reputable in quotations?

You're missing a word, I htink what you meant to say was that as long as your car is NOT burning oil now, it won't burn the synthetic stuff ... right?

I've got 84.5k on my 95 SE, going to switch to synthetic at my next oil change ... not burning, no leaks (or if there are, it's not measurable!!!), so hoping for a trouble-free switch.

 

Switching to sythetic on high mileage cars can be trouble sometimes becuase normal dyno oil over time can cause swells in leaks. Once synthetic is used, it's strong detergent formula combined with its general synthetic properties (not sure what exactly) can loosen up that "sludge" and can reveal leaks that you never knew you had.

 

You pretty much hit the nail right on the head there.

One other thing is that the synthetics that use a higher concentration of esters not only have natural cleaning tendencies, but can help promote seal swell as well.

 

I did the BG Engine Flush at the dealer last may @ 74K, never seen so much sludge taken out at the time, cost me $89 w/ the dealer but I thought it was well worth it. That time car ran much better under my care, but now is garbage since my brother has it for good this time