three knocks heard at idle after sitting overnight

Status
Not open for further replies.
Thank you Clevy for the input....

Could be a possibility just not sure on how to go about testing the knock sensor...

I thought it could be the combustion chamber.. ran BG 44k, once, and the oil level dropped, ran lucas upper lube, and ran the Techron 2 times so far, might do a third soon...

I did read online of a Red Line, additive.. how would that be?

Thank you
 
Originally Posted By: npfd
Thank you Clevy for the input....

Could be a possibility just not sure on how to go about testing the knock sensor...

I thought it could be the combustion chamber.. ran BG 44k, once, and the oil level dropped, ran lucas upper lube, and ran the Techron 2 times so far, might do a third soon...

I did read online of a Red Line, additive.. how would that be?

Thank you



Look at the mds of the products your interested in. There is a product called "guaranteed to pass" with 25-35% amines,so if the redline or techron branded stuff is less concentrated I'd try to find gtp instead.
Or double dose weaker stuff.
For significant build up 1 tank won't be enough and I'd even consider a piston soak via a vacuum line with mmo or something.

Again,just ideas,
 
another not so good update, after about 1.5 months i had to add oil from one bar to 4....

After we had some rain, then washed the car, noticable oil spots on the driveway, rear part of engine..
When it rained, had the car nosed in, washed, car reversed in...

Since we got the car I've noticed it being 'wet' around the oil filter adaptor, in recent times, about a year, valve covers, bottom sides of engine a bit...

I notice more oil 'usage' in summer than in winter... pcv was changed in 2012 January... maybe try changing to another one..

Whenever I added the techron, I noticed a different smell on startup, as approaching the car...

thanks
 
Sounds exactly like the noisy vent valve Saturn VUEs commonly did, but that part is at the rear of the vehicle. Same scenario though, drive off in cooler weather come to a first stop- three knocks. The vent valve circuit being tested. Its supposed to be silent but the valves get noisy after awhile.

Could be some other solenoid underhood like the purge doing the same thing.
 
Thank you Moklock,

I noticed a few weeks ago, I heard the first know then got on the gas to accelerate and didn't hear the rest.

I could be making things up, but its not the first time I've had my head, turned left, and heard the knock from the back of the car.

Unless its the solenoid getting stuck?

The exhaust smells on startup, even reversing into the cloud of it.. unless there's a small leak somewhere..

Thank you
 
hi all another update,


I do recall last year, that after I shut the car off while sitting in it for 5 minutes, I heard that double knock while sitting.. sounded in the front as always.

Now with the weather being colder, I shut off the car, I happen to do things near it for a while and hear half a knock to full knock in the back of the car.... and looking up on the web here, other GM's cars with evap knocks...
http://www.saturnfans.com/forums/showthread.php?t=112013

Most likely it could be just the evap system, but with knocks like that does the canister have to changed?

Thank you all again for the suggestions, its been very helpful.
 
Just another update....

Usually check the oil every month, this time went 1.5 months, and itwas about a quart low.
One thing is the temperature has warmed up from the - 5 celsuis to about 10 c now.. would the warm weather have burned out all the condensation? I try to drive it at least 5 kms one way.. to warm it up....

I don't do much mileage and just surprised it would do that.

I read up on something like this
http://www.lubegard.com/C-182/LUBEGARD+Engine+Flush

any ideas please?

Thank you
npfd
 
My guess would be pre-ignition, due to carbon in the cylinder(s).

Of course that is just a guess, based on an intermittent sharp tap I was getting at idle when I first got my current car.

(Probably not the same sound and not nearly so regular, but then it isn't the same car)

Arranging for the engine to suck water into the intake seemed to fix it, and the price was right.
 
thank you Ducked,
is this the procedure of spraying mist water in the intake?
I'm not comfy trying that out yet.... any other addivites, that worked for you?

Thank you
 
Originally Posted By: npfd
thank you Ducked,
is this the procedure of spraying mist water in the intake?
I'm not comfy trying that out yet.... any other addivites, that worked for you?

Thank you


Never tried anything else that worked. In my implementation, I ran an IV line into one of the (many) rubber tubes hanging off the (mid-80's) carburettor that saw intake manifold vacuum. If I did (or do) it again I'll try and arrange misting or suction into the air intake.

Other improvised solutions I've heard of include:-

(a) Brake fluid dropped onto the piston crown though the plug hole (theory being that its a powerful solvent, eg for paint - suppose you could apply other solvents in the same way)

(b) A grain or few of rice, ditto (theory being that they rattle around for a while, dislodging carbon, and then they burn off - I got a similar but more drastic effect with a broken bit of piston ring;no remaining carbon but lots of little dings in the piston crown and the plug side-electrode flattened)

Water seems less likely to be damaging than either of those. Dunno about commercial products. I used something called Redex (UK market) sometime in the 80's. Didn't seem to do anything.

Nice things about water: Cheap, Open-source formulation, fairly fully-understood mechanism of action, low toxicity, No abrasive residue (assumes distilled water. I was using aircon condensate which should be close. Scottish tap water is probably mostly close enough too).

Spraying water in by hand is likely to take a tediously long time though.
 
Last edited:
Perhaps you could get (pay?) someone to endoscope your engine?

Would probably be impossible here, but I've heard its not expensive in the US?
 
Status
Not open for further replies.
Back
Top