I have a 2003 Disco w/ 70,000 miles. Just had a valve job done (it needed it). Also replaced h20 pump, fan belt, exhaust manifold, ignition coils, wires, plugs and probably a few other things I can't remember. As soon as I got the truck back the check engine light came on. When starting cold it runs beautiful, but when you start it warm, it will run great for about 20 seconds then run rough for about 20 seconds then it clears up and is fine. It only runs rough when idling, not at speed. Any ideas what this could be? The mechanic seemed either confused or was trying to hide something - I took it back and he cleared the code once but it came right back when I drove it out of the shop. I took it back and he replaced the hdo sensor (?) - said it might need a new oxygen sensor as well. Any thoughts would be appreciated!!

 

What codes did you get?
And exactly what sensor did he replace?

 

Sorry, meant to say he replaced the water sensor (I think that is what he said - sorry again, i am not real car tech literate). I did not see the codes - the first time he ran them there were 3-4 and they had to do with misfires in different cylinders. He cleared these and when the CEL came on again the codes were different but there was a code for a faulty oxygen sensor. I got the car back this afternoon - same problem occurs: runs rough 20 seconds after starting but then it clears itself up. This time the CEL has not come on....yet.

 

Did he install new spark plugs and plug wires?

 

Yes, new spark plugs, wires and ignition coils.

 

if your not good with working on cars i would say take it to another shop.

 

Your guy needs to find out what he did wrong and fix it...for free.

 

I agree, give it back to him and let him fix it.
Also, why did you do a valve job at 70,000 and be specific , not it needed one???

 

I plan to take the truck back to the mechanic - just wanted some input from experienced owners so I can make an educated argument if needed. This all started when the truck stalled and would not start - was diagnosed as bad ignition coils. The truck also had an exhaust manifold leak, was leaking oil pretty good, had intermittant coolant leak and was running a little hot. Since he was going to be that far into the engine to replace the coils, I figured I would just get everything out of the way at once and do the valve job also.

 

I doubt you needed coils, sounds more like a crank sensor failure.
It is too bad you were not able to get the codes. In the future, it is a must before you expose yourself to a lot of crap from a mechanic taking advantage of your lack of experience.