Weird noise from car help... (VID)

[4urxtc]

Here is video of the noise that just started. Since this noise the car has run maybe a total of 30-40 secs. Please let me know what you think it is.

It is a 1992 Sc400 with 179,000 mi. on it. No mods of any sort.


Is this rod knock, Or lifters, or maybe shims.

The sound increases as the rpm's rise. Also, the noise was not here when I shut it down a few days ago. Then I started it up later and it went to idle at 1k rpm but was idling kinda weird like it had cams. Oil levels, trans. fluid, and everything I could see where fine. So, I really don't know what is wrong. My guess is rod knock just from the sound of it.

Any help will be greatly appreciated.

Thanks
Matt

 

[Lextech]

More than likely it is not a rod or engine damage, since the sound was not there when shut off, then appeared when restarted later. It is probably a piece of carbon on top of a piston. Sometimes the intake valves get VERY heavy deposits on the tulip portion of the valve ( between the stem and head ). These deposits can absorb fuel and cause a noise/misfire until the car warms up and sometimes small pieces can come off and land on top of a piston and make a noise/miss. Try revving the engine for several seconds and see if it clears up. I know this sounds like a strange suggestion, but I have seen this exact thing dozens of times, and have only seen 2 V-8 engines with a rod knock in the 17 years I have worked on Lexus.

 

[4urxtc]

Do you think I should try Seafoam in the fuel, oil, and thru the brake booster vaccum line? I just don't want to further the damage that may already be there.
If you think this is ok let me know. Thanks

 

[WDoherty]

mine did this also after sitting for a long time. I eventually just drove it and it went away.

 

[4urxtc]

That is so weird. I have never had a car that has done this. That is why I am so skeptical about it. I know I am going to Seafoam it and also change the spark plugs/oil. Then see how it sounds after that. I hope it is ok.

I appreciate your comments very much. I thought I was screwed.

 

[WDoherty]

it totally suprised me too, b/c i have had some questionable engines and never anything like that. Anyway, it dissappreared and i've heard nothing since, its gotta be something with the design.

 

[4urxtc]

Well, I went out and turned the car on until it warmed up. Long story short the rod knocking sound went away pretty much. I still think that a spark plug is missing so I will change those. I also did seafoam thru the Brake booster vacumm line. It didn't smoke as much as I thought it would. It smoked alittle initially a good ploom, but after that it was a little bit for about 30 mins. Car idles like the spark plugs are fouled now but, better than Rod Knock.... :smileysex I will get some spark plugs on Monday or Tuesday when I have a chance. Just one question.. What is the best one to get to replace OEM ones with that are not super expensive.


So thanks to all who responded to my thread.... :beerchug:

 

[WDoherty]

bosche platinum, cheap plus they gave me better gas mileage.

 

[4urxtc]

bosche platinum, cheap plus they gave me better gas mileage.

Sounds good I will look for those. Any other things I should replace while I am in there. Thanks

 

[WDoherty]

opps, i spelled bosch wrong. you might check the resistance of the the spark plug wires to see if they are all good. Its in the service manual, but as long as your under 20 or 25 ohms, your good.

 

[4urxtc]

opps, i spelled bosch wrong. you might check the resistance of the the spark plug wires to see if they are all good. Its in the service manual, but as long as your under 20 or 25 ohms, your good.

You and Lextech have been the most help out of anyone I have ever come across on here.

I will see if I can get a multimeter to see if they are fine.

Thanks again for your help