General Does Heat Soak Cause Knock "Detonation" ?

[Xtremboost87]

My car is reading a lot of knock and pulling timing. I have a ECU Chip tune, nothing to log with. Not sure if its real knock or phantom knock. I've been working on the car for several hours trying to track down the issue. Now that it's really hot out it's gotten worse. It was happening every time I try and accelerate. So I got a new knock sensor and that seemed to only help a little. Still happens but not every time I touch the gas. Got new spark plugs and the car runs better but didn't help with the knock. I've got it pin pointed to the fact that it only happens at right around 2500 RPMs. I've gone through and tightened down everything I could think of. Any other ideas? Could the heat be part of the issue? Seeing as it's gotten a ton worse now that it's hot outside?

Later same day:

Then I heat wrapped my tubular manifold and also took off my air filter to see if maybe it's not getting enough air. Also added another electric slim fan on the radiator. Went for a drive and NO KNOCK!!! I drove the car around for quite a while and never saw a count of knock show up. Pulled better than it ever has. Then I went to Walmart, when I came back out and drove the car it was seeing knock really bad again and pulling timing every time I tried to accelerate. I can only think that heat soak would be the cause of the issue. If I pop the hood after its been sitting there is a ton of heat built up under there. The upper IC pipe gets so hot you almost cant touch it. It stayed that way all the way home. So it seems like once it gets heat soaked it cant cool back down enough. I don't know, Just looking for any thoughts on what might be going on or what to do? Thanks.

 

[96dsmftw]

In regards to the upper IC pipe, if your intercooler piping is getting that hot try wrapping it temporarily and see if the problem goes away or takes longer to come back. It should help point you in the right direction at least. What are your coolant temps? I would put the intake filter back on too, don't want something getting there. Also, you could try boxing out your intake from the rest of the bay, using the hole in the bay under the filter to pull cool air, instead of hot engine bay air.

 

[GST with PSI]

How are you monitoring knock if you don't have the ability to log?

To answer your question simply; any time your intake/engine temperatures increase the probability of knock occurring also increases. I suspect that if your engine is heat soaked to the point where it's causing knock under part throttle at low RPM, there's another issue.

The best way to possibly track down an issue like this is to get some means of logging so you can see what's going on with the car. Without some information to analyze, it's pretty hard to give you good advice. Yes, heat soak can cause knock. No, I don't think that's your problem given the details you've provided.

 

[Xtremboost87]

The stock boost gauge reads the knock. My coolant temps where getting up between 195-205 while driving. After adding the extra fan and wrapping the manifold it stayed around 180-185. And like I was saying this significantly helped because the knock went away completely until the car sat and heat soaked. I'm thinking about venting the hood and also wrapping the upper IC pipe.

 

[Xtremboost87]

And yes I'm going to clean the filter and put it back on its pretty clogged up.

 

[GST with PSI]

How are you monitoring coolant temps?

 

[Xtremboost87]

After market gauge

 

[Xtremboost87]

I have a 180 t-stat. In the car maybe I should try a 160 as well?

 

[Xtremboost87]

My other thought is could something be messed up in my Ecu or maybe even the chip and cause this to happen? The tune as far as air fuel ratio's is a very safe tune. Idle and cruising it's right around 14.8 and under boost 10-10.5

 

[awdmonster1904]

My other thought is could something be messed up in my Ecu or maybe even the chip and cause this to happen? The tune as far as air fuel ratio's is a very safe tune. Idle and cruising it's right around 14.8 and under boost 10-10.5

I would look for any possible way you car is getting Phantom rock check your knock sensor make sure it's operational or just buy a new one
If your air flows are on the spot and you think there's no way it should be knocking I would look into phantom knock
I would also recommend to go with DSM link

Back in the day I was having the same issue and it ended up being a sensitive knock sensor when I purchased the Dsm link I was able to ignore it till 3000 RPM when my turbo would start spooling 16g back in the day

 

[Xtremboost87]

So today I did a custom hood vent above the turbo and manifold. Turned out really well and works great! And knock on wood but I think it eliminated my knock issue. Drove it awhile and the car ran perfectly and pulled so hard. No knock. I even stopped the car and turned it off for a little while to see if it would heat soak again and cause knock again like last time. NOPE! After sitting to where it did it before this time still no knock and it pulled great! I really hope this took care of it once and for all.

 

[Xtremboost87]

Here are the pictures