Asked by Oct 02, 2010 at 01:57 PM about the Dodge Avenger

Question type: Maintenance & Repair

it knocks louder if you turn on the ac. should i be worried.

18 Answers


take your car to gas station.. use a higher grade of fuel (97 octance fuel) will solve it on your car.. good luck . from Dave.

1 people found this helpful.

cool will try it and hope it works thanks.


stop telling people to use higher grade fuel. they will be spending pointless money. neither engine is designed to run on 97 octane fuel. if it was than it would say PREMIUM FUEL ONLY, but it doesn't it just says UNLEADED FUEL ONLY. try to explain the noise more. is it more of a ticking or a knocking? can you hear it just driving down the road or only when sitting still? the A/C puts drag (aka load) on the engine, making it work harder. this means your RPMs will drop slightly in park, or hang some what while driving. the extra load of the A/C compressor is probably what's affecting the sound, but again i would need a better description to be for sure.

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actually a higher grade of fuel could solve the problem, if its knocking the fuel is predetonating (firing before the spark plug sparks) premium grade fuel isnt a waste of money at all so stop telling people it is. higher octane fuel is more stable than low octane fuel and may solve the problem. i doubt its any thing more than pre detonation but still thats bad for the engine, ticking would be more of a stuck hydraulic lifter or some thing along those lines i hope that helps


the the octane of gasoline was the only issue then why doesn't every single avenger have a knocking problem? because gasoline isn't the problem. if he has pre-detonation than there is a bigger issue than just his octane rating. could be timing is off, who knows? also people who are not gear heads tend to describe their problems in a worse way than they really are. they shay "knocking" when really it's only ticking. unless you get more information on something like that it's hard to diagnose. and lastly there are plenty of studies that show higher octane ran in an engine that doesn't need it is not justified. you are spending more money for very little improvement if any. don't get caught up in oil company's propaganda to get you to spend more money.

2 people found this helpful.

listen genius, not every car is going to have the same issue if one does for instance, my 2004 ram 3500 had a problem where water leaked into the cab, but my friend who had the exact same truck did not, shit happens. and id love to see that study about higher octane fuel being no more stable than regular octane fuel, cars requiring high octane fuel do so because they have a slightly higher compression ratio under which regular octane would predetonate, more octane molecules make fuel more stable, i dont know much of any thing about these specific cars as a whole but i know almost every car has a slightly different timing some cars will have a slightly advanced time while others may have a slightly retarded timing, it just happens. and i read what the issue was, theres a knocking coming from the engine, and when the AC is turned on the knock gets louder, it says nothing about a tick.

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cars with higher compression NEED the higher octane. the dodge avenger has a compression ration of 9.6:1 which is not high at all. using higher octane is a car that is not meant for it is useless. and if you think about it, it might even be bad for it. higher octane burns faster and hotter and is more explosive. if the engine is not made to handle gasoline that burns that hot, you will get extra wear on the engine. i understand not every car has the same problems, you're missing the point. but gasoline is something that every car needs. 2 engines from the same car are not going to be made different enough to have one need premium gasoline, and the other only need regular. it's not like one of the engines is going to have a 12:1 compression ratio. also with the invention of electronic control units, differences in timing are almost 0. all dodge avengers (with the same engine) have the exact same program loaded into their ECU. with the exception that the 5 speed has a slightly higher rev limiter. other than that all the timing is going to be the same. the v6 does have a distributer, but again if that's the issue (the distributer is not aligned properly) than that's what needs to be fixed, not the gasoline. you are trying to find a simple solution to a more complex problem. and you are wrong.

2 people found this helpful.

like i said i know nothing about these cars as a whole, i think gas engines need to be done away with completely, any thing a gas engine can do a turbo diesel can do easier cleaner and more efficientl. im honestly too lazy to read 3 paragraphs of jargon though.

1 people found this helpful.

gas is where its at for street vehicles. diesel is good for work trucks and semis.

first thing i would check is the haromnic balancer to see if the rubber in it is dryed out and cracked,it will woble and make a knocking noise,since the ac is so close to it turning it on puts more pressure on it, and noise travles,as for the gas postings it dont matter what grad you run,it wont solve your problem.

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A lot of times people describe a tick as a knock. My guess is leaking exhaust manifold or bad motor mount.

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a tick can be any thing hell if it gets louder when he turns his AC on it could be his AC clutch haha

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No. Take off the valve cover and tighten the bolts. the knocking should be fixed, for the time being. Its just the design of the car. Nearly all the old Avengers develope the knocking. All you need is the new gasket for the valve cover. After that use a heavier weight oil.

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lol no it wont

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a heaver weight oil is a bad idea. 10w-30 is the thickest oil that should ever be put in an avenger. the oil journals in this engine and NOT designed for heaver weight oil, and you will just end up with clogged oil journals. besides, thicker oil is not fixing the issue, it's just fixing the symptoms.

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a permanent fix for this issue is to upgrade the lifters. get PT cruiser lifters and rockers and you will never get lifter tick again (assuming you have the 2.0L 4 banger.)

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where do you come up with theses idiot answers.

1 people found this helpful.

it has nothing to do with the gas,it is a lifter noise,tried running part synthetic oil after 100,000 and developed the "tick"on the right side engine closest to the firewall.tried changing back to multi grade oil with no resolve .car has 130,000 miles.,3.6 pentastar engine.

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