98 Neon DOHC, 70k miles, manual tran.

car runs great engine not missing, smoking... tran shifts easily... but...

loud rattle.

only after engine is warm
loudest 2500 - 3500 rpm
seems quiet when acceralting (noisy when constant speed)
minimal noise when no load (clutch in)
increases with RPM (not car speed), 120 beats / minutes (depending on rpm)

sounds like heat shield (but very consisitant) or lifter rattle.

I changed oil (brand), no change.

Thanks

 

Sounds like a case of classic valve rattle.

Pop off the valve cover and check the clearance between the cams and the shims.

If out of spec, all you need to do is replace the bad shims with a thicker/thinner one that will do the trick. The part stores will have what you need and if they do not, a machine shop will.

 

Engine has "Hydraulic Lash Adjusters", no shims from what I can see from the Service Manual.

Thanks

 

plugs 10 years old

 

DOHC or SOHC? Your post said DOHC and you have hydraulic lashes? If that is the case, then your cost just jumped because to replace one of them is $60 - $80 a piece.

 

has anyone heard of an upstream catylic converter for a dodge neon (2000). do you have to buy it seperately? what is it called?
secondly...my engine light is on..how do you reset the codes?

 

I have heard of an upstream Oxygen sensor which is before the catalytic converter, and a downstream O2 sensor which comes after the catalytic converter. Perhaps that is what you are looking for - the upstream O2 sensor.

As for the engine light being on, it is trying to tell you that there is an error code in your PCM. You can go to autozone/advance/oreilly's/napa to get a free readout of the codes - AND - they will usually clear it for you.

You can also do the key dance (on-off quickly three times) then back on to get the 2 digit error codes. I believe that it is easier for 2nd generation neons - because the codes appear on the panel directly instead of reading blink-codes like us first gen's have to do.

You can then disconnect the positive post from the battery for a few minutes to let the system clear its memory.