My car wont shift into 4th gear, could it just be a sensor or is transmission shot? ?

Question

one week ago my check engine light came on, today if I go past 30mph it sounds like my car is going to blow up. I dont know if they have anything to do with eachother or not.

Answer 1

First We really need to know what model of car it is. assuming that its an automatic. It could be as simple as a shift solenoid. I have seen many solenoid concerns on the Focus 4f27e transmission. if its a taurus or windstar it could be that the valvebody has a broken retainer on one of the shift valves. So I hope that you see it really does matter which model that you have, because of the different transmissions that are used.  

Answer 2

what kind of car? Auto or manual?

Low on tranny fluid usually gives you loooooooong shifts

Answer 3

if its automatic try shifting yourself.

When it sounds like it is going to blow up check the rpm meter to make sure it is under 8 or it will blow up if  your rev limiter isn't  working

Answer 4

could be low on tranny fluid

Answer 5

You probably have an engine problem causing issues,making it seem like a trans problem.

Alot of people can't tell the difference sometimes.

One quick thing you can try,that will help if you have time,is to get the check engine code read for free at Autozone.

Don't buy anything yet,jsut write down the code.

Then come post it up on Yahoo answers and we can give you a better idea based on the code.

Pretty sure your going to a shop though.