Knocking from engine when cold/initial startup

onEdge24

Registered User
Any Help appreciated-

In the morning my car knocks pretty loudly if i dont warm it up, but it will go away within a mile or so after driving, same thing at the end of the work day except it barely knocks at startup(cant hear it unless i really try and turn the radio off completely.)

Once the car is warmed up a little the sound goes away and it runs pretty good. I'm looking for some troubleshooting advice and what I should look for to prevent/minimize damage in the future.

This started right when my crank sensor went out. I have replaced it and since then it has done this. When the sensor went out initially , I got it to crank once with the towman there and the knock sound was pretty pronounced there and he said it sounded like my lifters, dunno. He towed it home for me where I replaced the sensor that weekend. Could the sensor being bad have messed something up that somehow just wont go back?

I have since had an oil change, old oil was way black. The serviceman checked it, nothing but oil, not contaminants evident. And I had them put in 1 quart of lucas oil stabelizer. Can't tell that it has really helped. I do have a slight oil leak, but I have had that since forever...bout a 1/2 quart or so every 3-4 months. Oil pressure is there (all i can tell ya with our damn gauges). An i do get my oil changed every 3 months no matter the mileage.

Also it has been pretty cold here lately and every morning until recently I have had to scrape ice off my windows to drive (sux :p ) so I dont know if that has anything to do with it.

I am really tight right now and would like to do any diagnostic/repairs myself if possible.

Thanks in Advance

Gig'Em

Chris
91 SC
College station
 
Yes cold weather will cause some engines to be more noisy until they warm up. But consider it a warning of something you're gonna have to deal with later if not sooner.
The way you describe the noise makes it difficult to help right now because you say a knock sound but the tow truck guy(who has probably heard lifters before or he does'nt know what he's talking about) said lifters. Lifters do not knock they make a ticking or tapping noise. The knocking of a rod sounds more like a thock sound that is lower in frequincy than a tap or tick.
Exhaust manifolds leaking will make a tick sound very simular to lifter noise.
Try to be more detailed in what the sound is like and maybe we can point you in the right direction.
 
Could be a piston. If they have taken minor damage from spark knock they will knock untill they get warmed up some. I have had this on my pontiac t/a. Make sure your timing is doing like it is supposed to. But if it's knocking already the damage has been done. Hopefuly it's just something else simple for you.
 
How many miles are on your motor and what kind of oil do you use? My XR7 has 196,500K on it and did this also, but it it only did it when it started to run at the fill mark on the dipstick (I had a valve cover leak). I used to use Valvoline Max Life 10w30 but have now switch to Valvoline Synpower 10w30. Now I have no knock or anything.

Depending on miles, maybe your oil pump is weak and takes a little bit to get going with the cold weather? Just a thought though.

Shane
 
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