KNOCK CONTROL absurdly high, and PSI (TC) not reading

[gtman]

What??

I think he's saying he's pissed his area sells E15.

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[LBP]

If a pressure test checks out, my best guesses would be a faulty knock sensor (uncommon but not unheard of) or maybe an issue with the injectors. I’d seek a professional diagnosis.

Semi-off-topic rambling:

Some areas/states have different allowances for ethanol content in gasoline that is still sold as gasoline. It’s a cost-saving measure as ethanol is cheaper than petrol largely due to subsidies. Ethanol has a higher octane rating (detonation resistance) than typical gasoline, but a lower energy density and lower stoichiometric ratio (amount of air needed for complete burn) which can overcome the lower energy density. This is why running ethanol on an appropriate tune will allow for more power but will absolutely tank your MPG; just dump even more fuel in there with extra boost and you can still get a complete burn and no knock.

The main issue with E10 and E15 “gasoline” is that it’s often dogwater skunk gas dosed with ethanol to reach the advertised octane rating. You still get the lowered fuel economy but little to nothing else to show for it. There are other issues as well - ethanol is corrosive and can gunk up injectors, it can cause cylinder wash down and oil dilution, it absorbs moisture from the air even more aggressively than petrol, and so on.

Ethanol and ethanol tunes can be tons of fun but they come with a set of risks and drawbacks. If you’re not running a tune for ethanol, but can’t get away from having it in your pump gas it’s pretty much just an annoyance.

 

[SethNES]

Because octane. You may want to read up on our engines.

Lower mpg though. There is a station that sells pure gas. It's more expensive but I might fill up there before going to parents.

Edit real reason why I hate ethanol is because most of it is made from corn by Monsanto with government subsidies. Stop making it from corn with tax payer money and I'll stop hating.

 

[courrey]

Shit! Well isn’t this becoming a son of a bitch?!?!
So of course DRobs opinion is highly weighted. He knows a lot and we have likely all referred to him on many issues.

So you isolated the fuel. It can’t be that!
You think you’ve tightened down the heat shield.! You’re saying the motor mounts are definitely solid and not loose!

Last ditch effort, I highly suggest you replace the knock sensor.Who knows ?

in the meantime, maybe see if a friend has a cylinder pressure gauge kit. They are easy to use and cheap. I own two. Maybe the friend can help?
Make sure you unplug ALL spark plugs while doing it.
Cylinders should read about the same psi and I think they should be around 150-170 psi. Take note to which cylinder is the lowest. Test this several times to ensure consistently.
OR take it to a shop and have them do it.

I am not totally sure what a cylinder should read if the rod is bent. I assume lower than the rest.

At that point, you may have an answer you may not like but it’s an answer.

After that, pulling the oil pan and physically inspecting the rods is next but even then, I doubt the naked eye could see the bend????

Keep us up to speed homie

I had already ran a compression test and the motor was healthy. I really don’t know what it could be. I’m hopeless.

 

[Jason Baker]

Well you can’t give up. This is half the fun!
Again, I’d replace the knock sensor and reassess.
Did you ever post a video with audio for us to listen?
You have ruled out most likely culprits. Just keep going til it’s fixed homie.

You’ll get this.!! It will probably be something really dumb too.

Curious. What was the compression on all 4 cylinders?

 

[courrey]

Well you can’t give up. This is half the fun!
Again, I’d replace the knock sensor and reassess.
Did you ever post a video with audio for us to listen?
You have ruled out most likely culprits. Just keep going til it’s fixed homie.

You’ll get this.!! It will probably be something really dumb too.

Curious. What was the compression on all 4 cylinders?

I’m not too sure what the compression on all four of the cylinders was but my mechanic only tested cylinder 4 just because the spark plug was more burnt than the rest. He said it was plenty compression. But that said hopefully I figure it out soon, stuff is stressing me out

 

[Jason Baker]

I’m not too sure what the compression on all four of the cylinders was but my mechanic only tested cylinder 4 just because the spark plug was more burnt than the rest. He said it was plenty compression. But that said hopefully I figure it out soon, stuff is stressing me out

We all know the feeling bud. Nothing worse than getting stranded when you could have prevented it.

One thing at a time man! Try the knock sensor as a last effort.
Then it may be time to explore more expensive options.

 

[David228cx]

He only checked one?
Have your mechanic test them all!

Just because one is good doesn't mean all of them are.

 

[gtman]

Courrey, doing the investigating and work yourself, up to a point, is a smart move. But there's a point you need to turn things over to a pro and if it's not the sensor, I think it's at that point.

 

[courrey]

We all know the feeling bud. Nothing worse than getting stranded when you could have prevented it.

One thing at a time man! Try the knock sensor as a last effort.
Then it may be time to explore more expensive options.

I appreciate it man, all you guys helping me out. I’ll update you guys once I have the time to check it all out. It will be fixed though, eventually.

 

[courrey]

That

Courrey, doing the investigating and work yourself, up to a point, is a smart move. But there's a point you need to turn things over to a pro and if it's not the sensor, I think it's at that point.

that being said, do you know where the location of the knock sensor is ?

 

[Jason Baker]

Knock sensor is circled in RED. Easy to remove and replace. NOT so easy to get too. Either reaching in from the top/back of the engine OR from underneath the motor as you face the front of the car are really the only two ways.
Small black and round sensor to the left of the alternator post. If I recall, it's a 10mm.

Don't mind the massive hole in the lower end. Also SEE BELOW!

 

[Jason Baker]

Knock sensor is circled in RED. Easy to remove and replace. NOT so easy to get too. Either reaching in from the top/back of the engine OR from underneath the motor as you face the front of the car are really the only two ways.
Small black and round sensor to the left of the alternator post. If I recall, it's a 10mm.

Don't mind the massive hole in the lower end. Also SEE BELOW!

Where did you end up on this homie?

 

[courrey]

Where did you end up on this homie?

Hey man sorry for the late update reply. Not much have I done, I’ve just been driving the car trying not to beat on it too hard. The mechanic suggested I wait till after the valve cover replacement that I solve the issue to eliminate one problem at a time so I’m just waiting on that. My rv6 turbo came in, so after this is solved, I’m gonna end up installing my radiator, turbo, and inlet pipe along with a PTR flex fuel kit, haha. I’ll keep this thread updated !

 

[Jason Baker]

Hey man sorry for the late update reply. Not much have I done, I’ve just been driving the car trying not to beat on it too hard. The mechanic suggested I wait till after the valve cover replacement that I solve the issue to eliminate one problem at a time so I’m just waiting on that. My rv6 turbo came in, so after this is solved, I’m gonna end up installing my radiator, turbo, and inlet pipe along with a PTR flex fuel kit, haha. I’ll keep this thread updated !

You may wanna budget for a TSP block of this persists. Welcome to the jungle homie

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