Hi Everyone,

I've exhausted my internet research and unfortunately I am no closer to locating an answer than when I first began, yet hopefully you guys can help me reach the truth!

I have an 04 Xfire manual with about 89k miles. For about a month now the engine has been making a knocking noise. The following video I found illustrates the exact noise my car is making:
One of the comments suggests that its the water pump and the idler pulley, could this be? Seems odd to me.

I believe the nosise is coming from the passenger side of the vehicle. The knocking does not seem to grown when I accelerate, and is most noticable when the engine is idle. I recently switched the engine oil to a thicker grade 0-40w (mechanic recommendation) and the only change this did was to have the noise dissipate for the first minute or so that the engine is on, then the noise comes back.
I have no noticeable performance issues. I performed a maintenance checkup about a year ago and spark-plugs were changed.

Please Help!

 

Sounds like it might be a stuck/collapsed hydraulic adjuster in one of the rocker arms to me.
I would suggest you get a mechanic's stethoscope, remove the engine cover and listen up and down on both valve covers.

Are you sure Mobil1 0/40w has always been used ? Cheap oil can cause this by building up carbon/gum deposits in the tiny little holes the lifter adjusters have.
I have an 89 Ford Probe ( Mazda MX6 ) that had a noise like this, I removed the rockers and manually cleaned out all the little passages, fixed 'er right up.

 

Thanks for the quick response.

To answer your question, yes. I've always used the Mobil 1 synthetic oil on my Xfire. The only change was switching to a thicker viscosity this last time.
I've already ordered the stethoscope, and I hope to be listening/identifying the specific problem area very soon.

I'll keep you posted.

Thanks Again!

 

Broomstick stethoscope works fine.

 

An 18" 3/8 drive extension works well also.

Jeff K

 

Please share the outcome with the Forum.

 

Man that stethoscope is phenomenal, it amplifies everything tenfold! I think you are on to something ala. The noise is definitely originating the valve cover on the passenger's side. Hopefully I can find a reputable mechanic in the next couple of days who is willing to take a gander at it. Once I have more information I'll post an update.

 

Find an independent repair shop that specializes in German / Mercedes vehicles . . .

 

3yrs ago.......have you identified the cause yet? Stuff like this is helpful to others. Thanks!

 

Yea , thats the thing that's annoying. They present a problem an never return, to give their solution. When people search , then find a thread they think will help, with their problem , it's incomplete..

 

The OP sold the car before finding the problem, he states that in a post in this thread. He got an SRT.

 

Am I missing something? # 7 says he'll update. Don't see ," I sold it".

 

Sorry, wrong guy.

 

FWIW; mine had same noise with poor idle but great acceleration.

I found not ONE, not TWO, but THREE!!! Loose plug boots in my quest to cure the sudden rattle.

I checked the plug boots over and over to ensure they're locked on.

Test drive went well and rattle/stumbling idle have cleared out. No stored codes. No CEL.

Hope this helps anyone with similar symptoms. Check your wires often. I used to after new plugs installed, but they were always gudentite!