Good day all.
I'm new here so i'll try to keep it as tidy as possible.

I own a 2005 Tucson 2.0 GLS, Love my car, done over 100k kms with it and done nothing to it but normal maintenance. In my opinion one of the best "budget" SUV's.

But lately its been frustrating me a bit, every now and then, more so then not it looses power and jerks and struggles to get through the gears and up to speed.
Once up to speed, if you "coast" on a specific speed eg 100km/h, not accelerating or decelerating there is a nasty gggrrrrrrr noise, sounds like a valve is trying to climb out of the head but starts 1st time everytime, idles perfectly, no smoke no other symptoms.

The jerking is more evident in lower gears but you feel the lack of power all though the gears. this happens whenever it wants, hot or cold, days it doesnt do it, the car pulls and performs great, the days its being a little bastard it does the above.

Also worth mentioning the ggggrrrrrr noise was there when i bought the car well before the jerking started, just thought it might be relevant to mention. Another fun fact is my cheap OBDII plug with torque on my phone used to work on the car, now the plug can find the ecu??? The lights on the plug is flickering, so there is power to the connector, but not finding the ECU, also no engine light on....dash is clear(No lights on)

It's a great car and i don't mind the fuel consumption as i came from a 4L Ranger, so this 8.5 - 9.2 L/100KM is heaven to me.

What i have done to try and solve this.

- Full service (Incl. Timing belt.).
- Cam shaft sensor.(Friend suggested it)
- Fuel system flush.(Bottle of Spanjard's stuff)

Any ideas as this is super frustrating and i don't want to change cars as i really like this one. Sitting on 234k kms now.

 

If the jerking is the result of a misfire , that should have thrown a code in the vehicle' computer.

Did anyone check the condition of the catalytic converter? Sometimes the substrate can break loose and restrict the exhaust providing a low power problem After it relocates, the engine restriction is gone and everything is fine. Have you had anyone else check to see if they could come up with anything? Second and third opinions never hurt.

 

Good morning Hanhy.

Thanx for your reply.

I know you will find this hard to believe, because i did. Double and tripple checked, this car never came out with a cat, no cat, no O2 sensors, nada, nothing. i had the agents pull up the full fish charts and they confirmed this car doesnt have one. very weird but like that from factory.

After all the above was confirmed i went home and pulled the entire exhaust system from manifold right to the back to inspect it all. Also to inspect the exhaust ports to see if i can pick up any tell-tales there, but nothing, all four burns nicely, no overfueling or oil or anything.

A Missfire like you said will pull a code / engine light yes but it idles perfectly fine.

I really dont understand this car, and usually i can figure stuff out, but this one is giving me a go.

Please give me more opinions or places to look...

Thanks again.

Nicho.