96 fzj with 165000, I puchased it about a year ago and when the engine is cold it would make a rattle noise that sounded like bad crankshaft bearings or something loose in the head that needed oil pressure to go away. I read some posts that mention using toyota oil filters because they have a valve that prevents oil leakdown when the truck is shut off. Still didn't fix problem. My mechanic said that it was a common noise and just to keep an eye on it. Though the engine has great oil pressure he said it was worn. Low and behold, I installed a new fan clutch last week and the noise is now gone! So if anyone else is expiriencing a noise like this, dont get pissed like me and price a rebuild, it was a waste of time.
engine rattle upon cold start
- Thread starter Boston Cruiser80
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Oil pressure driven timing chain tensioner?
Start up rattle on 80's is common and generally goes hand in hand with a high start up idle. The valve chatter (aka rattle) is heard as the rpm's race upward during startup and there's little or no oil present. A dirty throttle body will cause unusually high start up rpm's. It is even more prevelant in cold weather. Switching to a Toyota oil filter with an anti-drainback valve generally has no effect. Switching to a smaller oil filter and/or different type of oil has been reported to work sometimes. A thorough throttle body cleaning generally does the trick. If you were truely experiencing the common 80 valve chatter I can't see how the fan clutch had anything to do with it. I imagine it wasn't valve chatter you were hearing.
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I had the same symptoms on start-up and found the fan clutch bearing to be nearly frozen and failing. Fan had started to wobble and that was the noise I heard at start-up.