1995 Chevy G30 Van 5.7L V8 Engine Knock

[frankytheg30]

My G30 has developed an engine knock. It only knocks under load, in lower RPMs there is no knock/very slight knock and if I put the throttle to the floor there is no knock, it is when I am trying to maintain speeds between 35-55 on an incline is when it knocks the most. However, when the engine warms up the knock goes away a little bit and other times it will go away entirely. So far I have changed out the EGR valve and after changing that and letting the engine warm up there was no knock whatsoever, but on a cold start the knock is still there but not as bad as before. Any ideas for what else could be causing this issue? I am happy to answer any questions to the best of my ability but I must say I know next to nothing about engines and mechanics, I bought this van with the intention of learning how to work on vehicles because of how universal and easy to work on this engine is.

 

[scott2093]

Can you pull codes? Could it be bad gas?

 

[Schurkey]

Can you pull codes?

"Codes" are merely the beginning of diagnosis. Better to view the entire data stream with a proper scan tool, including looking at the knock sensor data.

 

[scott2093]

Yeah I got thrown in the deep end a few times...lol
Agree

 

[frankytheg30]

Can you pull codes? Could it be bad gas?

What do I need to pull codes? Would it be easier to take it to a shop that has the equipment?
I'm still on the same tank of gas that I put in when I got it, I've heard pulling a tank cleaner then filling it up with 93 octane has helped.

 

[Schurkey]

What do I need to pull codes? Would it be easier to take it to a shop that has the equipment?

"Codes" are merely the beginning of diagnosis. Better to view the entire data stream with a proper scan tool, including looking at the knock sensor data.

Yes, it would be "easier" to take it to a shop...but then you don't get to keep the scan tool.

I'm still on the same tank of gas that I put in when I got it, I've heard pulling a tank cleaner then filling it up with 93 octane has helped.

"Octane" means nothing. What you need is Top Tier fuel, which has added detergents. That and a suitable fuel filter.

 

[frankytheg30]

Yes, it would be "easier" to take it to a shop...but then you don't get to keep the scan tool.


"Octane" means nothing. What you need is Top Tier fuel, which has added detergents. That and a suitable fuel filter.

I ordered a OBD II reader with a OBD I converter so I can run the codes so I'll give that a shot. I'll check the filter as well to see if that needs to be replaced.

 

[scott2093]

I ordered a OBD II reader with a OBD I converter so I can run the codes so I'll give that a shot. I'll check the filter as well to see if that needs to be replaced.

Can't you jump your obd1 port to see if there are any codes? I wouldn't waste money on a code reader and especially one that needs some kind of converter ...
But whatever. Maybe it'll be cool...and help you which is the goal.

Just change your fuel filter. Not sure how you plan to check it but, from what I understand that is an involved process by monitoring pressure that I'm guessing you would rather not get into.

 

[Schurkey]

I ordered a OBD II reader with a OBD I converter so I can run the codes so I'll give that a shot. I'll check the filter as well to see if that needs to be replaced.

"Codes" are merely the beginning of diagnosis. Better to view the entire data stream with a proper scan tool, including looking at the knock sensor data.

I don't know how much more I can amplify this. A code-reader is a waste of time, money, effort, and enthusiasm. Code-readers are JUNK.

You need a SCAN TOOL, or a scan tool simulator--software plus a cable or dongle to view the data stream on your computer.

What, exactly, did you buy? Link? Part number?