Engine making rattling noise

leftynridge

Member
Aug 30, 2009
401
0
16
dayton, ohio
So I just took my 88 turbo to the dyno about two weeks ago. Before I took the car I changed the oil using 6 quarts of castrol full synthetic. Over the last two weeks I noticed that the car was blowing white smoke at cold start and also under high boost. I thought that it could be the turbo seals going bad or maybe it could be burning oil. It also has a small oil leak.

I took the car for a spin yesterday and got on it on the highway. As I got a block away from my house I heard a rattling noise. I pulled into my driveway and shut the engine off and checked my oil. It was 2 quarts low on oil. I don't think that it was leaking this much oil in such a short period of time. Went up to autozone bought two quarts of oil and put into the car when I got home. It rattled when I started it and then smoothed out. At idle it does not make any noise at all. If I push the accelerator hard up to about 4K or slowly push the accelerator it will make the rattling noise as well. It sounds like its coming more from up top then anything. Do you guys have any idea's? Thanks
 

supraguy@aol

Well-Known Member
Dec 30, 2005
4,238
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48
Atlanta
hmm. Not a good sound to have after getting low on oil.
Reading threads like this has made me paranoid, and I now check my oil level every single morning.
Are you sure it was white smoke, and not blueish white?
Regardless, the telltale sign of rodknock for me was a rattling under part throttle around 2500-3000rpm.
I suggest you check the block at idle with a mechanic's stethescope, and do the pull-a-plugwire check.
Remove(and then reconnect) each plugwire, one at a time while the motor is running. If you hear the knock disappear, you've found
a rodknock cylinder. This is assuming you can hear a knock at idle(which should be easy w/ a stethescope).
 

IJ.

Grumpy Old Man
Mar 30, 2005
38,728
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I come from a land down under
supraguy@aol;1587229 said:
hmm. Not a good sound to have after getting low on oil.
Reading threads like this has made me paranoid, and I now check my oil level every single morning.
Are you sure it was white smoke, and not blueish white?
Regardless, the telltale sign of rodknock for me was a rattling under part throttle around 2500-3000rpm.
I suggest you check the block at idle with a mechanic's stethescope, and do the pull-a-plugwire check.
Remove(and then reconnect) each plugwire, one at a time while the motor is running. If you hear the knock disappear, you've found
a rodknock cylinder. This is assuming you can hear a knock at idle(which should be easy w/ a stethescope).

This exactly.... :(

Safer to pull Injector clips though.
 

leftynridge

Member
Aug 30, 2009
401
0
16
dayton, ohio
I have friend that is coming over later with a stethescope to confirm. You can't here it at all at idle. Just when you slowly push the accelerator or push it hard to 4k RPM. If you just tap the gas up to about 3k you can't hear it either.
 

leftynridge

Member
Aug 30, 2009
401
0
16
dayton, ohio
supraguy@aol;1587229 said:
hmm. Not a good sound to have after getting low on oil.
Reading threads like this has made me paranoid, and I now check my oil level every single morning.
Are you sure it was white smoke, and not blueish white?
Regardless, the telltale sign of rodknock for me was a rattling under part throttle around 2500-3000rpm.
I suggest you check the block at idle with a mechanic's stethescope, and do the pull-a-plugwire check.
Remove(and then reconnect) each plugwire, one at a time while the motor is running. If you hear the knock disappear, you've found
a rodknock cylinder. This is assuming you can hear a knock at idle(which should be easy w/ a stethescope).

Not 100% about the color of the smoke.
 

Ogapostrophe

New Member
Jun 27, 2010
13
0
0
Spring Hill
Don't fool yourself into thinking its anything other than rod knock unless you can physically see another cause.. hah. Hope for the best, but prepare for the worst. Wasn't the end of my cars life for me though. 17k miles later it finally decided to pack up, not even due to it's horrible knock. The BHG got to it instead. hah.
 

leftynridge

Member
Aug 30, 2009
401
0
16
dayton, ohio
Ok my friend just came by and he said that he is about 100% sure that its a rod knock. Did not have his stethescope so unsure which one that it is. He suggested pulling the pan and changing the rod bearings. He said you have nothing to loose but it might get me by until I finish my rebuild. What do you guys think?