help! low rpm knocking!!

[FXchris305]

hey guys i got an 2004 fx35 with 43k miles on it , last weekend i did an oil change using 5w 30 non synthetic mobile 1 oil and a fram oil filter , the next day around midnight talking to my friend wit my car on idle i notice a lil knocking noise in the low rpm range . i would give it gas n the knocking will go away its only in the low rpm . ide say around 900 to 2000 rpms. i decided to take my car home n leave it for the night till the next day thinking i was maybe a lil low on oil . the following day i couldnt hear the knocking anymore so i just ignored it . the car has been running fine all week . today as i drive in to my drive way n put it in park i notice the same low rpm knocking noise . i checked the oil level it seems fine even though its so hard to see wit the fxs dipstick its all bent n curvy . i look up the forums n search the issue and i see it can be the fuel damper i check it wit a stethoscope but the noise doesnt seem to be coming from there , i also saw a thread that fram filters may cause some noise . this is the first time i used fram in my fx . i also see that somebody else has had this noise and they had there short block changed . i really hope it aint that n its somthing simple. what can this noise be ? its not very loud u can bearly hear it but u can still hear it some what . it wasnt making this noise before . any idea what it can be ? i appreciate any help and info . thanks guys

 

[fxlr8]

Take your stethoscope and listen around the timing chain area and tops of each ignition coil.

I had low rpm knocking and heard it through my stethoscope in those areas, and yes I was the one that had my short block replaced and heads remanufactured.

Does sound pretty similar ///5958

 

[FXchris305]

il be changing the oil and oil filter again tomorrow . see if the noise goes away . ive been seeing in other forums that thr fram filter my goes this kinda noise .

 

[fxlr8]

Sounds like a plan, you could try using sea foam also ///5976

 

[KNFX]

good luck man.

 

[FXchris305]

hey i just got back from the dealer i bought a oem oil filter n 5 new quarts of 5w 30 mobile 1 motor oil . imma go do the change now after i eat lunch . knfx do u still have the knocking ? did u go back to the dealer ? what they say ?

---------- Post added at 11:12 AM ---------- Previous post was at 09:32 AM ----------

hey guys back , i just did the oil n filter change seems to have helped . donnt really hear it as much . im just gonna ride it like it is with this oil change cuz it seems to have helped a lil. and if the noise gets louder imma just tak it to the dealer . my dad took a look at it and told me it sounded perfectly normal that its just how the car sounds . the car runs perfect and its not a consistent knock to just ignore it n take it to the dealer if it get louder

 

[Rubare]

Bro could you try to record the sound.. My FX is doing some sort of knocking sound.. I took it to the Dealership and one of the tech took a ride with me. I took chance of the oportunity to address other issues like why my fx pause shifting from 1-2 2-3 gear. AnywAys .. The tech heard the sound and said that it was the wheel bearing.. That's why it was making that sound.. He felt the harsh shifting and said that it needed a trans fluid change.. So they took my baby over night I'll be getting it tommorrow..

So I would like to hear this knocking sound you guys have being experincing to compare to mine..

 

[MTN FX]

Eng Knock service bulletins---

 

[FXchris305]

Bro could you try to record the sound.. My FX is doing some sort of knocking sound.. I took it to the Dealership and one of the tech took a ride with me. I took chance of the oportunity to address other issues like why my fx pause shifting from 1-2 2-3 gear. AnywAys .. The tech heard the sound and said that it was the wheel bearing.. That's why it was making that sound.. He felt the harsh shifting and said that it needed a trans fluid change.. So they took my baby over night I'll be getting it tommorrow..

So I would like to hear this knocking sound you guys have being experincing to compare to mine..

rubare i would record it but the knock is so low that i doubt ul here it in the video or recording . its a lil knock that comes n goes in the low rpm range . imma try puting different gas . i have recently switch gas brands . it could be that . imma try fiiling up with the previous brand ive been putting in . il let u know . and imma try n get a digital camera to record it for u guys .

---------- Post added at 03:20 PM ---------- Previous post was at 03:18 PM ----------

mtn fx. which gas treatment should i use ? is sea foam good ? i see so much on the wall at autozone

 

[MTN FX]

rubare i would record it but the knock is so low that i doubt ul here it in the video or recording . its a lil knock that comes n goes in the low rpm range . imma try puting different gas . i have recently switch gas brands . it could be that . imma try fiiling up with the previous brand ive been putting in . il let u know . and imma try n get a digital camera to record it for u guys .

---------- Post added at 03:20 PM ---------- Previous post was at 03:18 PM ----------

mtn fx. which gas treatment should i use ? is sea foam good ? i see so much on the wall at autozone

I haven't tried the seafoam but read good things about it however any fuel system cleaners like STP,Gumout etc.... should work fine just make sure to add it to a full tank of fuel.I usally do this after every oil change as part of my regular service routine. I was running the lower octane fuel when gas prices were at 5 a gallon and noticed my MPG's had dropped off even when I went BACK TO PREMIUM. The dealer tried to sell me a full fuel system clean for $$$$$$$$ so I used the fuel additive cleaner for three tanks in a row and milage went from 16 avg to 18 avg.The dealer said even though the 35's can run regular unleaded it is best to run premium to keep injectors and fuel system clean.Besides your fuel miage is better with premium so your not saving money in the long run.

 

[FXchris305]

ive always used premium its that i recently put premium gas at citgo gas station which i never do and i did cuz it was cheaper than the rest . my bro said sometimes they scam u saying ur putting in premium and its regular at low brand gas staions . il never go there again . my next fill up will be shells vpower or mobile premium like i usually did and see if that seems to help.

 

[Holyfield]

+1. I would recommend RXP fuel system cleaner. I run it about once a year, and all my emissions go wayyyyy down after. Cleans out most all of the carbon deposit build up.

I haven't tried sea foam... but it looks interesting.

I haven't tried the seafoam but read good things about it however any fuel system cleaners like STP,Gumout etc.... should work fine just make sure to add it to a full tank of fuel.I usally do this after every oil change as part of my regular service routine. I was running the lower octane fuel when gas prices were at 5 a gallon and noticed my MPG's had dropped off even when I went BACK TO PREMIUM. The dealer tried to sell me a full fuel system clean for $$$$$$$$ so I used the fuel additive cleaner for three tanks in a row and milage went from 16 avg to 18 avg.The dealer said even though the 35's can run regular unleaded it is best to run premium to keep injectors and fuel system clean.Besides your fuel miage is better with premium so your not saving money in the long run.

 

[KNFX]

knfx do u still have the knocking ? did u go back to the dealer ? what they say ?

Yup, still have the knock. Its at the dealer right now, undergoing testing. Had a tech ride with me when I brought her in, tech acknowledged the knocking and said it was definitely not normal. Gotta wait and see what happens...

Good luck with your knock, hope it gets resolved without too much stress.

 

[Toncruse]

ive always used premium its that i recently put premium gas at citgo gas station which i never do and i did cuz it was cheaper than the rest . my bro said sometimes they scam u saying ur putting in premium and its regular at low brand gas staions . il never go there again . my next fill up will be shells vpower or mobile premium like i usually did and see if that seems to help.

I used Citgo once and my FX knocked like crazy, took it to the dealer and he diagnosed "poor quality gasoline." I only use Shell 93 now, and I have had no further issues.

 

[KNFX]

My brother put Citgo into his accord.. messed up his engine. Could be coincidence, but I'd rather not find out.

 

[FXchris305]

yea i imma wait till the next fill up. n fill with shells like i used to . ive been driving the car today n its running fine , just that lil knock that u can bearly hear in the low rpms it must be the gas . il let u guys know wen i fill up wit the new gas how it goes

 

[Rubare]

Hope it goes well bro!!

 

[RATED G]

SEAFOAM at your own risk!

I did this 2 fill ups ago and my engine is blown.

While I had a similar if not the exact same knocking, I thought it was just the fuel dampner and / or build up of carbon. I picked up seafoam a few weeks ago from the US and added it to a tank of gas and drove and did not notice a difference and then after the second tank emptied, I filled up for a third tank - drove 5 minutes and head the loudest knocking coming from the top (drivers side) of the engine - its a sequence knock (knock / nothing / knock / nothing etc... and quickly knocking)

Mechanic says rebuild the engine (105000 MILES) - or replace. Too bad a replacement is $4000 up here plus install.

Vehicle is a 2003 FX45 with tech package and REBUILT, so I may just part out!

 

[fxlr8]

I bet the seafoam did not blow your engine.

 

[RATED G]

It may not have, but I am just warning as I read both good and bad on the seafoam treatment