Intake Temp & Pinging/Knocking

[BuffaloXplorer]

Two unrelated questions:

1. On an 80* day, does a 145* intake temp sound right? The X gets SO hot its almost unbearable to be around after it's been driven for a while. According to my CarChip, the IAT on the average 80* day is around 145*, while the coolant temp never gets above 215* and usually fluctuates between 195*-205* (according to my CarChip, not the guage).


2. What does a "ping" and a "knock" sound like (i know it's tough to describe in words). Has anyone ever posted a .wav file with such sounds? When people say their engine "knocks," is it usually very noticeable? Like an older engine knocking to a stop when shut off - like it's being starved of fuel?

I've got a what seems to be a very low "knock"ing sound coming from the backside of the engine that i can barely hear when near the engine, but you can feel it in your feet & hear it when sitting inside at idle.

 

[Blue_Oval_Ford]

Dude, I am having the same issues as you. My truck is horrible when taking off from a start after setting at a stop light for more then a few minutes. Power is almost nonexistent.

 

[BuffaloXplorer]

I'm not without power, though. I've got seemingly good power at takeoff, just as long as i turn off the A/C - i lose ALL low-end torque with the A/C on, but it all comes back as i hit 2nd gear.

Standing nearby you wouldn't hear the "knocking" unless you listen oh-so-carefully. I never get "pinging" or "knocking" on accelleration or on the highway as others describe. However, the 10mpg is killing me, and i'm not looking forward to the 300+ mile trip (towing a loaded (open) utility trailer) to the adirondacks next weekend.

 

[aldive]

1. On an 80* day, does a 145* intake temp sound right? The X gets SO hot its almost unbearable to be around after it's been driven for a while. According to my CarChip, the IAT on the average 80* day is around 145*, while the coolant temp never gets above 215* and usually fluctuates between 195*-205* (according to my CarChip, not the guage).

At what speed is the IAT this high? Have you monitored it at various speeds?

 

[BuffaloXplorer]

I'll have to take a look, but last i checked the graph charted by CarChip was pretty consistent between 140-150* during a 10 minute drive through the city - much stop & go. Unfortunately, i don't have real-time scanning capabilities so i can't see what's happening until i download the data.

 

[aldive]

I have repeatedly shown that my IAT was within a couple of degrees of ambient temperature at speeds over 40 MPH.

IAT does get on up there when stuck in traffic.

 

[BuffaloXplorer]

I'll jump on the highway this afternoon and see what happens with the temp.

 

[IAmTodd]

Best I can describe the ping as placing a marble in a tin can. Almost sounds like a popping noise.

 

[BuffaloXplorer]

nope - no pinging here...definitely closer to a knock.

 

[BuffaloXplorer]

I have repeatedly shown that my IAT was within a couple of degrees of ambient temperature at speeds over 40 MPH.

IAT does get on up there when stuck in traffic.

I just got back and, as i had mentioned, the city driving resulted in 140*+ temps. I jumped onto the highway and it dropped down to a low of 114* at between 65-75mph. According to Weather.com it's 90* here.

I don't know if these extreme under-the-hood engine temps are hurting performance or not, or if other factors are causing the engine to get so hot, but the coolant temp again was well within spec. I may consider reinstalling my factory airbox to see where that gets me, (but i doubt it).

This truck is killing me. I didn't even reach 10mpg this fillup today - 164mi on 16.8g OUCH!

 

[Creager]

when you floor the gas to you get a popping, knocking, sparking type of noise?

when i run 87 i get spark knock like a byotch around here: 80 degrees, 77% humidity

89 seems to fix the problem, unless im flooring it in overdrive (the knock is not there in any other gear)

 

[aldive]

You need to hook up a scanner and get real time IAT. I have never seen IAT that high in my truck here in Florida.

 

[BuffaloXplorer]

I get no type of knocking at all when in motion. All in all, it runs pretty well - but for as much gas as it uses it better!

 

[BuffaloXplorer]

You need to hook up a scanner and get real time IAT. I have never seen IAT that high in my truck here in Florida.

Are you sure you're reading/scanning the actual intake temp, as opposed to the ambient air temp sensor? I believe that later-model 2nd gens have an ambient temp sensor just in front of the grille, which i could see being much closer to actual outside conditions than the temp inside an engine bay operating in 90 heat.

Also, a quick look into the haynes manual shows the corresponding resistance values for this intake air temp sensor....from a low of 50* (58.75k ohms) to a high of 248* (1.18k ohms) - i can't imagine that an intake temp of 114* in 90* weather is all that odd.

 

[aldive]

Are you sure you're reading/scanning the actual intake temp, as opposed to the ambient air temp sensor?

Also, a quick look into the haynes manual shows the corresponding resistance values for this intake air temp sensor....from a low of 50* (58.75k ohms) to a high of 248* (1.18k ohms) - i can't imagine that an intake temp of 114* in 90* weather is all that odd.

Of course; I am reading IAT via an OBD II scanner.

I just had to make a run to Venice. The IAT was 92 F whereas the ambient temperature was 90 F. This is a typical range for me at any ambient temperature at sppeds over 40 MPH.

 

[aldive]

Did a 72 mile drive this morning to test a new computer tune and had my OBD II scanner hooked up and monitored the IAT.

The trip was all highway driving. Ambient temperature was 95 F and the IAT was 97 F.