Rattle at high rmp...is it detonation? is my motor pooched?

[jshot]

Owned my first grand national (87) for just about a month now, new to fuel injection and turbos.

this has happened about 5 or 6 times. this does happen time at high RMP 2'nd and 3'rd gear. first gear shift before high rpm. thinking around 5k, there is a rattle sound then i let off. No i am reading all about detonation. I hope this is not the case. Have i pooched my motor with detonation?

before i bought the car it had only a few thousand miles on in the last couple years. If it is detonation i am sure with a lot of persistence and MONEY i can figure it out i am sure it needs a fuel tune up and i have a crack in the drivers header which i have learned is normal. the question is there damage now.

i will drain the oil tonight and look for metal. there was no metal in the oil when i first changed the oil when i got the car, but it probably wasn't too old. NO SCANMASTER YET Will order ASAP

 

[williambavila]

Yes that's detonation. Just a matter of time before the insides are on the outside

Sent from my SM-N950U using Tapatalk

 

[jshot]

I have also heard CAT could be the source.

 

[williambavila]

I have also heard CAT could be the source.

SMH

 

[jshot]

SMH

i know. Just hoping.

 

[mikestertwo]

this has happened about 5 or 6 times. this does happen time at high RMP 2'nd and 3'rd gear. first gear shift before high rpm. thinking around 5k, there is a rattle sound then i let off. No i am reading all about detonation. I hope this is not the case. Have i pooched my motor with detonation?

Keep your foot out of it until you find out what you have. Is the car all stock? What chip is in the computer? Any mods?

 

[jshot]

Keep your foot out of it until you find out what you have. Is the car all stock? What chip is in the computer? Any mods?

as far as i know the car is stock. all i know is it has the hot wire kit. It even has the original coil pack (sticker on top). No mods that i can see. I will have to check the Chip.

 

[williambavila]

http://ihadav8.com/forum/VortexBuicks/

 

[williambavila]

You can get some great info on the link posted above and this site. Just be careful of what you are told and who tells you.Have a great day and good luck

 

[Chuck Leeper]

Yet another candidate for membership in the DOTCC....

 

[jshot]

You can get some great info on the link posted above and this site. Just be careful of what you are told and who tells you.Have a great day and good luck

beauty thanks.

 

[jshot]

how can i tell if the damage is done?

 

[mikestertwo]

how can i tell if the damage is done?

If it's still running ok with no strange noises the engine is most likely ok. The stock pistons are pretty tough. If there is no erythematic noise from the bottom end your rod bearings are ok. Sounds like you were letting off of it as soon as you heard the noise. Most damage is done from prolong states of detonation. I'm sure your ok. Just stay out of it until you find out what you have and make the necessary adjustments to keep it out of detonation.

 

[williambavila]

who did you buy the car from maybe they can answer some questions rather than a bunch of folks that dont know what the combo is. I would start there or give us his\her name we probably know them

 

[jshot]

I did ask the previous owner. He believed it yo be stock. I also have a list of previous owners at home. All from Ontario Canada

 

[dynoman]

Get rid of that stock chip and get one from Eric @ Turbo Tweak . The original chip has to much timing for todays gas and you car will run much better with a TT chip . Get that header fixed also .

 

[williambavila]

Get rid of that stock chip and get one from Eric @ Turbo Tweak . The original chip has to much timing for todays gas and you car will run much better with a TT chip . Get that header fixed also .

what timing is the stock chip set for?

 

[dynoman]

I believe it's 22 degrees @ WOT.

 

[jshot]

yes i will defiantly be doing a lot of things including a chip.

 

[jshot]

If it's still running ok with no strange noises the engine is most likely ok. The stock pistons are pretty tough. If there is no erythematic noise from the bottom end your rod bearings are ok. Sounds like you were letting off of it as soon as you heard the noise. Most damage is done from prolong states of detonation. I'm sure your ok. Just stay out of it until you find out what you have and make the necessary adjustments to keep it out of detonation.

ok i drained oil and removed the filter. i did not see anything that scares me. definitely nothing magnetic as i ran it into a magnetic pan and let it sit. Nothing. had a few shiny flecks but i could count them on one hand.

what do you mean by "erythematic noise ". i took a video for the audio of it at idle. ignore the rough idle and header leak at this time. here is a link to the video