Engine Knock MAF Related?

[J Browning]

For months now I have been trying to figure out what is causing my engine knock. I finnally took it to a dealer and he said the MAF sensor was giving "slightly" bad readings is all they could find but were not sure what could actually be causing it. There only recomendation was to replace the MAF sensor (60k on ST) and see if that would help. Glad I paid them $95 for a flipping guess, none the less.



Higher octane gas helps but is not a cure all. Temp really seems to efffect it. If its 80 and below you rarely hear it, if its 110 (I live in AZ) it gets real bad. (Not engine temp, that stays steady enitre time)



Does our vehicle have a temp sensor that could be effecting the ECU?

Do we have a knock sensor? Would knock throw a CEL code?



What do you think, suck it up and replace the MAF? or look somewhere else first?

Spark plug gap is good. I have cleaned the MAF with elec. cleaner several times.



Lastly, good place to get a good deal on one or just stick with autozone ($140)



Thanks, Jason

 

[Rick Hite]

I think it is the maf if you buy one at autozone I think they will take it back if it does not work.

The maf dors tell the ecu what the temp of the air coming into the intake. I do not think that

the st has a knock sensor

 

[Ron N]

I haven't seen it but according to the book the St has knock sensors in the engine._Ron

 

[Richard L]

Don't ever let a dealership or repair shop swap parts at your expense. If they think the MAF is causing the problem, then let them commit to it and if it doesn't fix the problem, you don't have to pay for it.



I was common many years ago to fix all customer complaints by recommending they get a tune-up. When the tune-up did not solve the problem the dealer would always say that the customer wanted a tune-up!



Just tell them you want the problem fixed and you will not pay for unrelated parts and labor. The dealerships have some very expensive diagnostic equipment and if it is used properly it will locate and guide the tech through a check-out procedure for all suspected parts.



...Rich

 

[Todd Z]

Could it be the Timing chain rattle, and not spark knock???



Can try cleaning the throttle body or clean the MAF...



I have a stock MAF here I could ship to you for a deposit fee, You can see if that fixes it..... Then take it from there...



Let me know... i will let the owner of it know what I am doing with it...

Todd Z

 

[J Browning]

Yeah, didnt let the dealer fix it but I did have to pay the $90 diagnostic fee for them to give me that guess.



As far as the timing chain rattle I stressed that as well since I have an 01 and they swore up and down that the warranty dosnt cover my vehicle and that it was not the timing chain. However the noise is only apparent from 2-2.5k in higher gears 3-5. I never hear it in 1st or 2nd.



My whole statement on the knock sensor was that if it was engine knock shouldnt the knock sensor be going off or at least retarding the timing?



I will check with A-zone on their elec. part return policy.



IAC has been cleaned several times as well. I will take my TB apart though and make sure it gets a good one over.



Todd, I will keep you in mind, thanks for the offer.



jason

 

[Dave S]

I'm having the same trouble with my 2005. I have had it back to the dealer three times and each time they tell me they can find no problems or hear the knock. I also get it in the high gears when light throttle is applied. It seems worse when the weather gets hot and the truck is loaded down.



I just talked to another Ford Service manager about the problem and he claims it is probably carbon build up. He said they could clean it out with some solvent for about $30.00. Not covered under warranty apparently.



Let me know what you find out. Both seem to be similar. Mine also goes away when I put premium fuel in it - but at today's gas prices......forget that!