Changing Type of Spark Plug Lower Engine Temp?

[thstone]

The problem is that there are far too many other variables that you can't keep constant in order to say that the spark plug change was the cause for such a small change in temp as shown on the gauge cluster. Even if you had Durametric data, there are still far too many variables in play.

That is why people are saying "placebo" - they don't mean that you're not seeing a difference on the temp gauge, instead they are saying that it is highly likely NOT the spark plugs and much more likely one or more other variables that can affect the reported coolant temp.

[KRAM36]

Originally Posted by thstone

The problem is that there are far too many other variables that you can't keep constant in order to say that the spark plug change was the cause for such a small change in temp as shown on the gauge cluster. Even if you had Durametric data, there are still far too many variables in play.

That is why people are saying "placebo" - they don't mean that you're not seeing a difference on the temp gauge, instead they are saying that it is highly likely NOT the spark plugs and much more likely one or more other variables that can affect the reported coolant temp.

What other variables could be involved? I changed the plugs, the temp went down slightly, yet it's much warmer outside now.

Did my thermostat decide to stick open or partially open at the same time I changed my plugs?

I've been thinking about getting one of those lower temp thermostats for years. I've heard pros and cons of running the lower temp stat. I'm not even going to think about it now that my car is at the temp where it should be at.

[maytag]

Originally Posted by KRAM36

What other variables could be involved? I changed the plugs, the temp went down slightly, yet it's much warmer outside now.

You're kidding, right? You can't imagine any other variables? Yet you mention one in the following sentence.
How about barometric pressure change? How about where you bought your fuel? (And where THEY bought it? )
How about your fan running more, 'cuz it's hotter outside?
How about relative humidity change?
I can think of dozens of variables, if you want me to continue?


Sent from my SM-G970U using Tapatalk

[Starter986]

Originally Posted by maytag

You're kidding, right? You can't imagine any other variables? Yet you mention one in the following sentence.
How about barometric pressure change? How about where you bought your fuel? (And where THEY bought it? )
How about your fan running more, 'cuz it's hotter outside?
How about relative humidity change?
I can think of dozens of variables, if you want me to continue?


Sent from my SM-G970U using Tapatalk

Yes. Continue.

[maytag]

Originally Posted by Starter986

Yes. Continue.

Why? Because you've already discounted the several I gave you? Or the dozen or so offered by another astute poster?

To me, if there is in fact a temp difference (I'm not sold on the accuracy of the factory needle) it's just as likely caused by the plug- installer bumping the temp sensor while he was down there.

Add mentioned below: there is ZERO science to support the postulation. You said below that you think he laid out science; he didn't. That's pure conjecture. Guessing. There's nothing there that holds water.

Sent from my SM-G970U using Tapatalk

[thstone]

Originally Posted by KRAM36

What other variables could be involved?

Ok, here's twelve to get us started...

Air temp
Humidity
Pressure
Percentage of cloud cover
Throttle position over the past 5-30 minutes
Load over the past 5-30 mins
Length of time at idle over the past 5-30 mins
Length of time at various speeds over the past 5-30 mins
Fans cycling on or off
Inaccuracy of the temp sending unit
Inaccuracy/inconsistency of visually sighting the temp gauge
Amount of other traffic

[Starter986]

Originally Posted by thstone

The problem is that there are far too many other variables that you can't keep constant in order to say that the spark plug change was the cause for such a small change in temp as shown on the gauge cluster. Even if you had Durametric data, there are still far too many variables in play.

That is why people are saying "placebo" - they don't mean that you're not seeing a difference on the temp gauge, instead they are saying that it is highly likely NOT the spark plugs and much more likely one or more other variables that can affect the reported coolant temp.

What would be those variables? Were those variables not existant before the plug swap? You're suggesting that absent any other anecdotal evidence (of which there is none... he changed his plugs, nothing else) that the ~4 degrees spontaneously happened and had absolutely zero to do with it?

I'm interested in your response, and anyone else who suggests a placebo is in effect. I'd like this to make sense for me. Thank you.

[KRAM36]

Originally Posted by Starter986

What would be those variables? Were those variables not existent before the plug swap? You're suggesting that absent any other anecdotal evidence (of which there is none... he changed his plugs, nothing else) that the ~4 degrees spontaneously happened and had absolutely zero to do with it?

I'm interested in your response, and anyone else who suggests a placebo is in effect. I'd like this to make sense for me. Thank you.

Exactly and it wasn't just on one certain day. It's been every drive since the plug change.

Originally Posted by maytag

Hey there, friend: you can call me stupid all ya like.... but YOU are the one making a fool of yourself here.

The ecu doesn't HAVE to control "the intensity", as you call it. All the ecu has to do is measure (with the o2 sensor) how close to stoichiometry the burn is, and then adjust from there, as necessary.

You're sure arguing a lot, for a guy who doesn't understand the subject matter

Hey there buddy, I didn't call you stupid, I said your statement was very stupid and it was.

If the ECU isn't getting a proper/full burn reading from the O2 sensors the ECU may attempt to fix the issue with a air to fuel ratio adjustment, however there is only so much the ECU is going to step in on this as the ECU will override the O2 readings with the Mass Air Flow Meter readings and decide to give you a code for a bad cat(s). What do you guess my ECU is thinking about my O2 sensor readings, when I have 200 cell cats in my headers and no secondary cats (although the secondary cats have no O2 sensor after them)? Oh and when I put the new headers on, I also put all new Bosch O2 sensors on the car. The proper O2 sensors, not those kits where you splice in a new O2 sensor. Apparently the cat efficiency isn't bad enough to throw a CEL, but my Durametric will tell me the cat efficiency is below normal. However I did clear all codes from the car yesterday to see if I'm still getting the cat below efficiency warning again. Did you read the part of my post where I said my car eats a lot of gas? Actually, she is quiet a pig when it comes to fuel. The ECU is not attempting to cut the fuel on my car, which is a good thing for this engine as running them lean will kill them quickly, especially with the intake mods I have made, the car gets a lot more air in the intake now.

[Quadcammer]

Originally Posted by KRAM36

If the ECU isn't getting a proper/full burn reading from the O2 sensors the ECU may attempt to fix the issue with a air to fuel ratio adjustment, however there is only so much the ECU is going to step in on this as the ECU will override the O2 readings with the Mass Air Flow Meter readings and decide to give you a code for a bad cat(s). What do you guess my ECU is thinking about my O2 sensor readings, when I have 200 cell cats in my headers and no secondary cats (although the secondary cats have no O2 sensor after them)? Oh and when I put the new headers on, I also put all new Bosch O2 sensors on the car. The proper O2 sensors, not those kits where you splice in a new O2 sensor. Apparently the cat efficiency isn't bad enough to throw a CEL, but my Durametric will tell me the cat efficiency is below normal. However I did clear all codes from the car yesterday to see if I'm still getting the cat below efficiency warning again. Did you read the part of my post where I said my car eats a lot of gas? Actually, she is quiet a pig when it comes to fuel. The ECU is not attempting to cut the fuel on my car, which is a good thing for this engine as running them lean will kill them quickly, especially with the intake mods I have made, the car gets a lot more air in the intake now.

since you are being so aggressive about this, its time to call you out for a distinct lack of knowledge.

1. In closed loop, the car is reading the MAF voltage as well as the 02 sensor voltage, as well as half a dozen other sensors to determine how to maintain a stoich a/f ratio.

2. The 02 sensors that are used for A/F adjustment are PRE-CAT. The efficiency of your cats has nothing to do with the a/f.

3. If your ecu has to adjust a/f beyond typically 25%, you will receive lean/rich codes. Again, cat efficiency does not apply.

4. If your car is running rich, then you have some problem, potentially related to your maf sampling tube if you just stuffed in a 987 airbox.

You seem to have basically no clue how modern fuel injection operates, so I'd probably tone down the condescending commentary.