4000 Max RPM in Park for 2000 Buick 3.8 V6 K VIN Engine?

Car will not exceed 4000 RPM while in Park or Nuetral. Runs fine until RPM hits 5000 on Highway then check engine light came on & blinked & binged for a few minutes then stopped.No code shows up. Took it to my Mechanic of 30 years who also got no codes. all 3 ignition coils replaced over last year.checked vaccuum,OK. All wires , Plugs OK. Was able to get to 6 to 6500RPM last week. Any Ideas on what may be limiting the engine speed ?

When was the last time that the fuel filter was replaced?

35K & just installed new one yesterday.

car has 60K now.Fuel filter replaced at 35K & Just yesterday also. all normal maintenance performed on regular schedule.Use same gas , nothing different lately.

If I’m not mistaken, a blinking check engine light indicates a cylinder misfire. The engine could be detecting that and limiting the engine speed. Also, in park and neutral, many engines limit the engine speed with a rev limiter, which is usually set around 4000.

I saw this problem once when a timing belt jumped a tooth.

thanks for your input ,mechanic mentioned limiter at 4000 also. just started car today in a rainy atmosphere and imediately started to run rough and ck eng light blinked on and off 4 to 5 times then stopped. drove car ten blocks to garage and gave him the keys. will know more tommorrow. defitely a misfire of sometype.

Thanks to all that responded.Turns out plugs & wires were bad. I was told two days ago they checked out OK, and a fuel filter was installed. May be time for a new mechanic! Total cost was $500.00 for 6 Plugs @18.00ea,1 wire set @ $79.00 & 1 Fuel Filter @ $27.00 & $ 225.00 labor. If I had the time I could have saved myself $380.00.
Another lesson learned!!!

yikes! Thats a lot! Well to be honest, sometimes putting in new plugs and wires can be a hassle. I worked on a car once (1990 Grand Prix) where I had to remove the engine mounts and rotate the engine in order to get to the rear spark plugs. (and even then, it was still a tight squeeze)

They make em hard to access (Plugs) on firewall side of engine. Even with exorbtant charge for plugs and wire set, my thought is mechanic should have diagnosed this two days earlier and charge would have been $140.00 less. say laveee…