i have a 99 mustang that has had a ticking for a while now. everyone always said that it could be a hydraulic lifter. I kinda have just ignored the problem and now it is running horrible. It is really missing or chuging bad at higher rpms. It does idle ok, and run fine if i am extreamly easy on the gas and accelarate slowly. It seems to run a little better when it is cold, but still not good. There is no SES light on.

I have replaced the coil, plugs, wires. no difference.
I took it to a couple local garages, they hooked it to a computer and none of them can really give me a definate answer.

I think it has something to do with the ticking in the valve train. But what exactly...FML

has anyone had, or know of something that would cause this?

 

My 02 gave me similar problems. I changed the plugs, wires, and the egr valve sensor. None of that helped. It turned out that my cats had failed and clogged my exhaust. May not be your problem but something to check.

 

What kind of plugs do you have, what kind of plugs did you take out? A bad lifter will constantly tap. An exhaust leak will also sound like a tapping lifter, but it's usually more audible under acceleration. Get under the car and look for an exhaust leak, it will be obvious if there is any soot near any of the flanges.

 

i took out the original plugs i belive. @ 170k and replaced them with bosch plugs. not sure exact ones.

i will get under it and check for an exaust leak, would an exhaust leak make the car run really bad. Clogged cats sound possible though. how would i go about checking my cats? i guess i could just cut em out for good??? I do live in MI

 

Sounds to me like your original plugs were toast, and bosch plugs are about the worst thing you can put in there. Get some NGK TR5's, they're cheap, and work GREAT. You can get them here, these guys are local to me and I;ve used them for over 10 years www.thunderracing.com

 

thanks, i didnt really know what plugs to get, i just got whatever autozone had. But could the plugs be the problem?

 

All the points above are good recommendations, but I am inclined to go back to that ticking noise. Sounds like you have a hydraulic lifter and or valve problem. My guess if you run a good compression check while you have the plugs out to change them, you will find a low reading on one or two cylinders. If it is low on two adjacent cylinders, could be a more serious problem such as head or head gasket. Good luck!

 

so, a cylinder compression check will show a possible lifter/ valvetrain problem?

 

Only if the lifter is sticking the valve open.

 

ok, will do.
just curious, replacing lifters- how hard to do this?