Rattle under load
Thread Starter
|
New User
Joined: Jun 2011
Posts: 17
Likes: 0
Rattle under load
Hey all. I replaced my girlfriend's heads a little while back, and everything went great for a while (passed CA smog, wahoo), but a rattle has recently developed during acceleration in particular, but at idle as well. It goes away or is drowned out by engine noise at speed, but comes back if you touch the throttle.
It sounds like it's coming from under a valve cover, but the rockers are all nice and tight. They wiggle a bit side-to-side but I believe that's normal though it makes a sound similar to the rattle I'm hearing (which is really just the clicking of metal against metal consistent with engine speed; no knock or banging). I've searched around and my best guess at this point is a bad lifter. Anything else I should look for, or other likely culprits?
As a side note, I'm getting an occasional misfire, but I found a vacuum leak which I suspect is the cause. The two problems don't appear to be related as they don't happen at the same time (and it's a pretty good vacuum leak), but I thought I'd mention it in the interest of full disclosure.
It sounds like it's coming from under a valve cover, but the rockers are all nice and tight. They wiggle a bit side-to-side but I believe that's normal though it makes a sound similar to the rattle I'm hearing (which is really just the clicking of metal against metal consistent with engine speed; no knock or banging). I've searched around and my best guess at this point is a bad lifter. Anything else I should look for, or other likely culprits?
As a side note, I'm getting an occasional misfire, but I found a vacuum leak which I suspect is the cause. The two problems don't appear to be related as they don't happen at the same time (and it's a pretty good vacuum leak), but I thought I'd mention it in the interest of full disclosure.
Senior User
Joined: Jan 2011
Posts: 374
Likes: 0
From: Connecticut
Rattle
I had a 90 Nissan Stanza; twice heard a rattle. First time, I didn't know what it was until it was too late. Ended up being the timing chain and I floated the valves. I had it fixed and it worked out fine for a bit, then the rattle came back. Almost had it home when I threw the chain again (and floated the valves). I did the repair myself this time and found that the crank sprocket rotated about the crankshaft. I fixed that, replaced the chain and tensioner, and she stayed together for the life of the vehicle.
If you have a chain, I recommend that you check the tensioner. In my case, the tensioner was working, but the slippage about the crank under even a light load created slop in the chain and the rattle under idle. Fixing that, if it's your problem, is cheaper than the topend rebuild.
Kevin
If you have a chain, I recommend that you check the tensioner. In my case, the tensioner was working, but the slippage about the crank under even a light load created slop in the chain and the rattle under idle. Fixing that, if it's your problem, is cheaper than the topend rebuild.
Kevin
Thread
Thread Starter
Forum
Replies
Last Post
wolgie
Explorer, Sport Trac, Mountaineer & Aviator
186
Oct 24, 2024 09:16 AM
okdothat2
Explorer, Sport Trac, Mountaineer & Aviator
8
Dec 24, 2004 06:54 AM
