The Autonerdz Community Forums - Engine "rattle" immediately prior to kno

Qwix0r Senior Member Offline crap, what did I do now? Posts: 132 Baltimore Maryland USA Gender:	Re: Engine "rattle" immediately prior to kno Reply #15 - Mar 20^th, 2008 at 3:22pm Sleuth, I heard that water trick only worked with leaded gasoline , due to the chemical make up of the carbon. I havent personally checked to see if this was true though. Qwix
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Ronnie Super Nerd Picogroup Offline Love Pico Posts: 714 Gender:	Re: Engine "rattle" immediately prior to kno Reply #16 - Mar 20^th, 2008 at 4:57pm Wilf used the water blast treatment awhile back on a vehicle and it sandblasted the combustion chambers pretty good from what I remember. I know antifreeze and water will sand blast a combustion chamber. Ronnie.
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joecar+

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Re: Engine "rattle" immediately prior to kno
Reply #17 - Mar 20^th, 2008 at 5:37pm

The MAF is in front of the TB... would I spray(mist) water directly into the MAF...?
I don't want to wet the MAF elements, I don't know if they would be harmed.

I could remove the MAF (it seems to run without the MAF) and spray water into the TB like that.

So, I would set the spray bottle to fine mist, and spray water in as I open the throttle wide (same as yo would on a carburettor)...?

Oh... that only works for leaded gasoline...? I can try it and see.

Thanks.

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joecar+

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Motor did not stall when I applied TEC...
Reply #18 - Mar 22^nd, 2008 at 4:30pm

Ok, I applied Seafoam...

I slowly poured it into a funnel I connected to the PCV vacuum port at the front of the intake manifold (motor was stumbling as I poured)... then when about 1/4 bottle remained I quickly poured it in... but the motor would not stall (it bogged down real low... maybe 200-300 rpm, but kept spinning and recovered)... is this ok...?

Now I'll let it sit for 6+ hours or till the morning... then it will be fun. Grin

BTW: Being a DIY and being in a residential area means I have to watch what I do to respect the neighbours (noise late at nite, smoke, etc...).

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Sleuth

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Re: Engine "rattle" immediately prior to kno
Reply #19 - Mar 24^th, 2008 at 3:36am

Yup, so now you wait till morning and "drive it like you stole it" out of your neighborhood onto a bypass. The chemical has probaly soaked down into your oil rings(gonna clean them out) so when do this type of treatment I always level my speed off(once all the smoking is done) and drive between , say 40mph to 60 on a gentle increase, then back down to 40, gently for several miles to seat the rings back in There is a chemical called "Chemflow" that works well for getting the sludge out of piston rings, have used it many times for stuck oil rings in Chevy`s without pulling the engine down--using the procedure mentioned by Tom. As for carbon, the best way I have found is to use a chemical(like run0rite etc..) and administer it into the intake system as a mist loading the engine down slowly, then tapping the rpm to 2-3 k a few times, letting it load back up and continue till you use all the chemical--when she starts to load up and miss--rap it up a few k-letting it load back up a bit--then continue. Clear your codes and adapts. I have never seen the runrite hurt an o2 sensor or Catalizer. "Tune-up in a Can" brings back the part throttle response that seems to get lost with carbon buildup around the valves and piston tops. Never seen a customer balk at the bill when administered correctly either.Sometimes , depending on the engine etc, I move the connection around to make sure I get the cleaner throughout the entire engine, the pvc hose sometimes will not allow you to get good cleaning on the front of the engine
Dave

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joecar+ Guru Member Picogroup Offline Posts: 443 Southern California California USA	Re: Engine "rattle" immediately prior to kno Reply #20 - Mar 24^th, 2008 at 10:59am "Drive it like you stole it"... It smoked pretty good, huge cloud of dark grey smoke on the freeway... Most of the ping seems to be gone, there is still some left... and it is preceeded by the "rattle" noise; should I give it another dose...? I'll record some more logs. Thanks.
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Sleuth

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Re: Engine "rattle" immediately prior to kno
Reply #21 - Mar 24^th, 2008 at 1:31pm

Does it do it when it is COLD? Is it overheating? No water on the MAF.err.Sure if your neighbors can stand it, Guess you`ll have to say it "Mosquito Control" this time? Might want to take a look at the timing chain for wear perhaps? Dunno...at wits end. Perhaps some more and diffrent patterns to Look at, I`m sure someone will pipe up when they see something. Wonder what the Cam-Crank relationship is at when it does the deed?

Dave

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joecar+ Guru Member Picogroup Offline Posts: 443 Southern California California USA	Re: Engine "rattle" immediately prior to kno Reply #22 - Mar 24^th, 2008 at 2:22pm Dave, Does it when warmed up 192F-199F; Does not overheat; MAF is clean/dry; Ok, I'll check timing chain. Ok, I'll capture CMP/CKP waveforms on a scope, I'll have to figure out how to do this while driving. Thanks, Joe
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twelch Freshman Member Picogroup Offline I love YaBB 1G - SP1! Posts: 36	Re: Engine "rattle" immediately prior to kno Reply #23 - Mar 27^th, 2008 at 7:25am This just a guess based on description and not being able to hear the noise in person. Have you checked the Bendix drive on the starter? They can get weak and the gear will move when the vehicle is accelerated and hit the ring gear.
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joecar+ Guru Member Picogroup Offline Posts: 443 Southern California California USA	Re: Engine "rattle" immediately prior to kno Reply #24 - Mar 27^th, 2008 at 5:14pm Twelch, I'll check the starter when I check the flex plate. Thanks, Joe
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joecar+ Guru Member Picogroup Offline Posts: 443 Southern California California USA	Re: Engine "rattle" immediately prior to kno Reply #25 - Mar 31^st, 2008 at 7:01am Starter and flexplate are both good.
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Sleuth

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Re: Engine "rattle" immediately prior to kno
Reply #26 - Mar 31^st, 2008 at 2:29pm

Hey Joe,
Do you by chance have a slightly larger cam in this vehicle? If all your components are good and it is a tuning thing, perhaps a play with(dref) the IAT input and perhaps a MAP sensor input voltage --even the MAF -TPS may help resolve this issue, just remember that if you play with these it effects the whole range of operation. I have had to do this with "camed up" engines....It`s tricky for sure cause you have to make the confuser think everything is still ok...
If it is unmodified, you will find your problem with what has been mentioned most likely.
Dave

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joecar+

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Re: Engine "rattle" immediately prior to kno
Reply #27 - Mar 31^st, 2008 at 6:51pm

Quote:

Hey Joe,
Do you by chance have a slightly larger cam in this vehicle? If all your components are good and it is a tuning thing, perhaps a play with(dref) the IAT input and perhaps a MAP sensor input voltage --even the MAF -TPS may help resolve this issue, just remember that if you play with these it effects the whole range of operation. I have had to do this with "camed up" engines....It`s tricky for sure cause you have to make the confuser think everything is still ok...
If it is unmodified, you will find your problem with what has been mentioned most likely.
Dave

Dave,

Good thought, shows you're thinking... Wink

My car is stock, and has always knocked (the dealer technicians couldn't solve it)... I have been monitoring AFR (via exhaust lambda) and it is not lean... I also been monitoring ignition advance, and it looks normal (does not seem to advance excessively).

I have been following up on the suggestions as time permits (I have a wife and a job), and I do appreciate everyone's suggestions, thanks to all.

Next step is to take care of oil thru PCV and potential knock sensor problem (according to TSB).

I am trying to hook up a scope to record while driving...

Good thought tho... I'll do some research into IAT/MAP/MAF effects.

Thanks,
Joe

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Sleuth

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Re: Engine "rattle" immediately prior to kno
Reply #28 - Apr 1^st, 2008 at 5:03am

Hey Joe,
Re-vamping that PVC, say thru a water jug(you would have to make) could also help keep your engine cleaner--like the decarb you did-by taking the opposite side of the engine hose--the one that goes into the air cleaner, install a adjustable pressure relief valve in this hose and adjust to, say 4-6 inches of vacuum on the crankcase--need to plumb a vacuum gauge to set, will give you some mileage also.
Drawback: ?? gets messy in the container,(needs maintenance) but keeps the crude out of your engine

Dave

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joecar+

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Re: Engine "rattle" immediately prior to kno
Reply #29 - Apr 1^st, 2008 at 8:29pm

Quote:

Hey Joe,
Re-vamping that PVC, say thru a water jug(you would have to make) could also help keep your engine cleaner--like the decarb you did-by taking the opposite side of the engine hose--the one that goes into the air cleaner, install a adjustable pressure relief valve in this hose and adjust to, say 4-6 inches of vacuum on the crankcase--need to plumb a vacuum gauge to set, will give you some mileage also.
Drawback: ?? gets messy in the container,(needs maintenance) but keeps the crude out of your engine

Dave

Dave,

I'm going to do something like that, a oil-catch container inline with the hose feeding the PCV valve...

I'm also thinking to fit the later model valley cover that has integral crankcase vapor collector... GM changed from valve cover to valley cover crankcase vapor collection because of oil ingestion... this will also give me the opportunity to inspect/replace the knock sensors, since all of this requires pulling the intake manifold (which on a late Firebird is tucked under the cowl... Shocked

)

About the pressure relief valve in the fresh air hose from the air cleaner to the crankcase: are you saying to allow the crankcase to build 4-6 psi of vacuum before the relief valve opens...? i.e. so the crankcase is always under vacuum and never at atmospheric pressure...? Am I understanding correctly...?
Hmmm.... I'll try that, thanks. Cool

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