Knocking and Pinging?

4915 Views 14 Replies 8 Participants Last post by JSquared, May 31, 2009

JSquared

Discussion Starter · Mar 29, 2009

I have an 07 dbl 2wd with 35K miles. In the last 8K it has started knocking and pinging between 20 and 25 mph when driving conservatively. I had them look at it at 30K and they said I needed the injectors cleaned. So I did that. They said I needed to use higher octane gas. That doesn't sound right. If that is the case, it should have needed that gas from the beginning. They also said I should get the plugs changed. 30K seems kind of early for that. I have read other posts on here where people have said that is when it is recommended. I looked in my maintenance manual and it doesn't call for plugs until 125K. Anyway, it is still knocking after having the injectors serviced. Has anyone else had this problem and what was your solution?

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badass03taco

· #2 · Mar 29, 2009

let me go out on a limb here and try and guess when it does it. you're leaving a stop light, barely in the gas, you creep along slowly speeding up and the auto tranny does its normal shifting barely noticing anything it shifts so nicely, then as you slowly come up on 20-25mph the trans shifts from 4th into overdrive gear dropping your RPMs down to about 900-1100RPM. if thats the usual time when you hear the pinging then i know why. my truck does soemthing very similar, and when i run regular unleaded it will ping when it shifts into overdrive at a low speed. but when i run premium it wont do it. the reason it pings is because you are putting a load on the engine when it shifts into overdrive at such a slow speed.

i think you just have crappy gas. the reason it pings is because the engine is detonating. the fuel/air mixture is igniting before the piston reaches TDC and the spark plug is firing. there are a few ways your engine can detonate, one is having crappy fuel that has a low flash point. another is from having an engine that is so hot, the heat in the cylinder walls will ignite the fuel/air mixture before the spark pulg fires. another is from a boosted application, if you are turbocharged or supercharged, you're forcing in more air into the combustion chamber and the increases cylinder pressure along with heat can cause the fuel/air mix to ignite before the spark plug fires. its called pre-ignition or detonation. most likely yours is from the load of it shifting itself into overdrive at such a low speed and RPM and crappy fuel.

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badass03taco

· #3 · Mar 29, 2009

one more thing, completely run that tank of gasoline you have now out of the truck, and go fill up with premium fuel for one tank. ride the truck around that whole tank and see if the pinging quits. if the premium fuel does stop the pinging, then try this:

change your spark plugs to a colder plug. take a plug out and go to a local auto parts store and tell them you want one step colder plug. by getting a plug that does not burn so hot, maybe you can keep the combustion chambers from reaching such high temps. after you change the plugs out go back to your crappy regular unleaded fuel. i'll bet with the colder plug it quits pinging.

Tacotrauma

· #4 · Mar 29, 2009

First of all, valve decarb is complete nonsense, it wont fix any thing, and it hardly does anything, you'll never notice any change in your preformance after a decarb, its just a bogus service we do to make money. Second, factory plugs usually need changed at 30k, pull one out and see what condition its in. Have you ever ran it when it was out of oil? do you have any leaks? is it an engin knock? Do you feel it under your feet?

ForTech

· #5 · Mar 29, 2009

You neglected to state, but I assume you have the 4 cylinder? Hard to diagnose without the most important piece of info...

Jeddak

· #6 · Mar 29, 2009

JSquared said:
I have an 07 dbl 2wd with 35K miles.

So it is a double cab? You have a V6--copper plugs, due to be changed at 30K.

JSquared said:
I looked in my maintenance manual and it doesn't call for plugs until 125K.

Only on I4, they have iridium plugs, V6 has 30K copper.

Change your plugs!

JSquared

Discussion Starter · #7 · Mar 29, 2009

Yeah, since it's a dbl cab, it's a V-6.

Unless Mobil has changed its gas, I don't think that would be it. I have a speedpass and use exclusively Mobil or Exxon gas. It used to be fine in my truck.

So are changing the plugs worth the $100 the dealer wants or is it something I can do in a couple of hours. I thought I remembered reading something on here a year or so ago about it being difficult to change the plugs. I have reasonable technical ability and tools. Do you have any recommendations for plugs so I'm not changing them every 30K?

ForTech

· #8 · Mar 29, 2009

Plugs are easy to change and relatively inexpensive. Much less than the $100 your dealer charges. I stick with the OEM coppers as I really don't think it's a big deal to swap out the old for new. I don't know why everyone makes such a fuss over changing them so often. Due to my driving style I have to change them every 1.5 years. What's an hour every 1.5 years?

badass03taco

· #9 · Mar 29, 2009 (Edited)

it takes about three minutes to pull your air filter and intake hose off, and then you can see the pass side valve cover easily. it takes about five minutes to change each plug if you're careful and apply anti-sieze to the threads of each plug. the drivers side valve cover is wide open staring you in the face. you dont have to do anything to get to the drivers side plugs. so... about 35 mins changing all 6 plugs, 5 mins to take the intake off, and another 5 mins to put it back on, so 45 mins to an hour TOPS! its not hard to do at all. there are coil-packs on top of the valve cover and one bolt holding the coil packs down, back that one 10mmheaded bolt out, and pull straight up on the coil pack, the plug is under the coil pack. just put a dap of anto sieze on the threads of the new plug and reinstall. it'll be over in no time.

EDIT: plugs should cost no more than about $2 each. so you'll have about $15 in 6 plugs, and one small package of anti sieze and a roll of paper towels. that beats the heck out of spending $100

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briangp

· #10 · Mar 29, 2009

Iridium plugs are expensive in the end, I just ended up paying almost 95 bucks OTD for them. When I pulled my old ones out at 55K (yes these are the origs) they looked like crap. The gap was almost double the new Irids. Anyways, the coppers don't last long, thats a given....

My thought is what someone said before... your gas is crap. Go to another gas station. Oh and you can't blame it on the 'BRAND" of gas station, each station gets their gas from a different supplier, and each gas station has different shit int he bottom of their tanks (IE Water)

05Moose

· #11 · Mar 29, 2009

You just need a long extension and some patience. Removing some parts makes it easier to access ones on the driver's side. The front plug on the driver's side is the one we all have problems with. The wires aren't long enough to get it unclipped from the plug! So plan to spend a lot of time trying to stretch those wires in order to get it unclipped. Otherwise, just do it yourself. You'll be glad you did.

JSquared

Discussion Starter · #12 · Mar 30, 2009

badass03taco said:
let me go out on a limb here and try and guess when it does it. you're leaving a stop light, barely in the gas, you creep along slowly speeding up and the auto tranny does its normal shifting barely noticing anything it shifts so nicely, then as you slowly come up on 20-25mph the trans shifts from 4th into overdrive gear dropping your RPMs down to about 900-1100RPM. if thats the usual time when you hear the pinging then i know why. my truck does soemthing very similar, and when i run regular unleaded it will ping when it shifts into overdrive at a low speed. but when i run premium it wont do it. the reason it pings is because you are putting a load on the engine when it shifts into overdrive at such a slow speed.

i think you just have crappy gas. the reason it pings is because the engine is detonating. the fuel/air mixture is igniting before the piston reaches TDC and the spark plug is firing. there are a few ways your engine can detonate, one is having crappy fuel that has a low flash point. another is from having an engine that is so hot, the heat in the cylinder walls will ignite the fuel/air mixture before the spark pulg fires. another is from a boosted application, if you are turbocharged or supercharged, you're forcing in more air into the combustion chamber and the increases cylinder pressure along with heat can cause the fuel/air mix to ignite before the spark plug fires. its called pre-ignition or detonation. most likely yours is from the load of it shifting itself into overdrive at such a low speed and RPM and crappy fuel.

I paid attention today to it. It is in 2nd and 3rd when it does it.

briangp

· #13 · Mar 30, 2009 (Edited)

05Moose said:
The front plug on the driver's side is the one we all have problems with. The wires aren't long enough to get it unclipped from the plug! \

Yours must have been worse than mine. I had no problems getting mine off. Just loosen the coil pack from the valve cover to allow it to twist and give you some room. Use a screwdriver to give a little leverage, and push the release and it should come off.

Remove the two vaccuum hoses from the little tree that holds them in place, remove the large support bracket for the middle plug (I have no idea what the hell its for) and push all the rest of the hoses towards the firewall to access the other two plugs.. Yeah, its definitely a pain compared to the passengers side bank, but its definitely easier than I expected.

dl1027

· #14 · May 30, 2009

Bringing this thread back to life to post a comment.

I also had been noticing some pinging and also low rpm hesitation (~1500 rpm). Then recently I had been have a discussion about the quality of different gasolines with my girlfriend. I have always been a fan of Chevron but she was telling me that Techron is bad for motors. Well I scoffed at that notion. She ended her little tirade with "76 is the best".

The other day I needed to fill up (running on fumes as usual) and the first station I came by was a 76 so I filled up. I notice an improvement almost immediately. No more hesitation and have not heard the pinging any more. Has Chevron slipped lately?

JSquared

Discussion Starter · #15 · May 31, 2009

I changed the plugs and have even changed gas brands. It runs great on high octane but it still knocks and pings on low octane, regardless the brand.

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