Engine rattling noise

[vette_7t9]

Hi

We bought a 98 sunfire GT, and the engine is making rattling noises, loudest around 2500-3000 rpm. The dealer guy said its normal, and most 2.4 engines do that. Is this true? I am just concerned that the valves might be bad, and i should replace them before its too late. He also said its cuz of the valves, but said its OK for that noise... ANy clues?

[GTP Dad]

You didn't say how many miles on the car but if the valves are making that much noise you may have a stretched timing chain or a bad tensioner that is causing the problem. Take it to another mechanic or another dealer and have it checked. If the chain jumps you could have serious problems in bending the valves, ruining the head or damaging a piston. It will cost a couple hundred to have the chain changed and the cams retimed but it will be a lot cheaper than the alternative.

[vette_7t9]

112,000 km, time to get it changed i guess

[vette_7t9]

i can do the whole job myself, just maybe take the weekend up.

[GTP Dad]

Great! Just make sure you get the timing marks aligned properly as these engines can be a bear to time if you get it wrong. A Chiltons manual would be helpful if you don't already have one.

[vette_7t9]

Hmm, ive done timing 'belts' before, but haven't done timing chains. What is the difference? any more difficult?

[GTP Dad]

The timing chain on the 2.4 can be quite a challange that is why I caution you. Before you begin make sure you get a manual that describes how to do it in detail. If you don't get it timed correctly you can cause a lot of damage.

[vette_7t9]

good to know its hard before i go into it. i'll take it to the garage where i am training at so that there is atleast someone who knows how to do it right to supervise, just in case i do something wrong. the thing is, i don't know when i will have time. the rattling isn't too bad, but it is there. the earliest i can get some time to do the change is approx. 3-4 weeks. do you think it'll hold out till then?

[GTP Dad]

Can't tell although the chains rarely break they just jump time and cause valve issues. If you drive sensibly and don't hotrod it should last that long.
Good Luck!

[vette_7t9]

do you think the ticking noise can be from engine pining, wrong octane of fuel?

[GTP Dad]

Usually ticking is caused by something hitting or not meshing correctly. In your case I would suspect a valve like you previously stated.
The knock you get from low octane fuel is usually a heavier sounding noise than a tick and sounds like the entire engine is rattling. This usually manifests itself under load like climbing a mountain or steep hill. Try a tank full of 93 octane if the noise goes away problem solved if not then the other option is always available.

[vette_7t9]

so by valve not meshing correctly, is the piston hitting the valve?!?! :S yea, i think i'll give 93 octane a try first to see if it is compression, but i doubt it since the sunfire GT recommended grade is 87 octane...

[vette_7t9]

well, just took it to the dealer to get the electric control panel fixed, the guys still said that the ticking is normal.......i dont trust them on it so i must chek it out myself. my dad also has a 93 elantra with a ticking noise too, which is worse than on the sunfire. He said its always been like that, and driven it forever since. its been like 5-6 years sounding like that he claims......now im confused.