87 4Runner unidentifiable engine noise
#1
87 4Runner unidentifiable engine noise
I've been trying to figure out what the source of my engine noise is. I pulled off the rocker arm cover and took a look at the timing chain along with the guides. I also did a valve adjustment. Everything looks normal and clean but I still have the engine noise. It's a combination of tapping, clicking, and intermediate clanking. Anyone want to take a jab at figuring out what this could be?
Here's a link to the video... notice at 0:21 you can hear the tapping
https://photos.google.com/share/AF1Q...FtR3ZmRjY3LWhB
Drivers side guide...looks intact right? It felt like the plastic guide but appears to be metal at the bolt connection.
Notice the colored link does not match up with the marker on the camshaft gear.
clean
passenger side guide
Here's a link to the video... notice at 0:21 you can hear the tapping
https://photos.google.com/share/AF1Q...FtR3ZmRjY3LWhB
Drivers side guide...looks intact right? It felt like the plastic guide but appears to be metal at the bolt connection.
Notice the colored link does not match up with the marker on the camshaft gear.
clean
passenger side guide
#2
Possible things I'm thinking it could be:
1) Faulty Oil pump
2) Timing chain loose (It moves about 1/4" from the drivers side guide when I push on it with a screwdriver)
3) Bent Valve?
4) Timing chain is set wrong (the colored link doesn't line up with the notch...will it always line up or does it travel as it spins?)
1) Faulty Oil pump
2) Timing chain loose (It moves about 1/4" from the drivers side guide when I push on it with a screwdriver)
3) Bent Valve?
4) Timing chain is set wrong (the colored link doesn't line up with the notch...will it always line up or does it travel as it spins?)
Last edited by razorman8669; 07-10-2015 at 09:58 AM.
#3
The colored link on the timing chain doesn't always line up with the dot on the cam gear, only after so many turns of the motor. I forget how many. Turn the cam gear until the dot is at 12:00, then look at the timing mark on the the crankshaft pulley. If its at 6:00 then you're good, if not, then thats probably your problem. What do you have the valves set to? How many miles on the engine? It must be a rebuild since it has metal chain guides (much better by the way), the stock guides are plastic. Check your ignition timing, it should be at 5 degrees BTDC with the diagnostic terminals crossed. Also, make sure you're getting oil pressure, the timing chain tensioner relies on oil pressure to keep the chain tight. Thats why it moves when the engine is off. Don't over torque the valve cover bolts, if you over torque them it makes thing very noisy. Just make sure they're snug. Check the inside of the valve cover to see if the rocker arms are tapping on the cover.
Last edited by noahstancik; 07-10-2015 at 12:05 PM.
#4
The colored link on the timing chain doesn't always line up with the dot on the cam gear, only after so many turns of the motor. I forget how many. Turn the cam gear until the dot is at 12:00, then look at the timing mark on the the crankshaft pulley. If its at 6:00 then you're good, if not, then thats probably your problem. What do you have the valves set to? 0.008" IN 0.012" EX How many miles on the engine? 275000It must be a rebuild since it has metal chain guides (much better by the way), the stock guides are plastic. Check your ignition timing, it should be at 5 degrees BTDC with the diagnostic terminals crossed. Also, make sure you're getting oil pressure, the timing chain tensioner relies on oil pressure to keep the chain tight. Thats why it moves when the engine is off.I had the ignition timing adjusted about 6 months ago, and my oil pressure gauge on the dash points to the 1/4 mark on idle, and the half mark under normal driving...I'll go get them checked at my shop tomorrow to verify it though Don't over torque the valve cover bolts, if you over torque them it makes thing very noisy I tested this out by loosening the bolts up until oil was spewing out the sides of the valve cover, and it had no affect on the noise.. Just make sure they're snug. Check the inside of the valve cover to see if the rocker arms are tapping on the cover.see image
#6
Try tightening the valves up a bit. I have mine adjusted to .004" in and .007" ex. Because the valve train was way too loud for my liking. It's much quieter than the stock specifications. Some people have problems with their engine missing, but I've had mine like that for about 20,000 miles with no ill effects. It's worth a try and you can always go back to stock if you need to. If that's not your problem then it could just be a worn out engine. That's all I can think of. I'm no mechanic however, I just like to tinker lol
Last edited by noahstancik; 07-10-2015 at 05:37 PM.
#7
Thanks for the reply Noah!
i'm a bit worried about bent valves with those clearances... seems a bit small...from what I've been told, you should have looser valves rather than tighter.
on that note, I dont think the noise is from solely the rocker arms tapping... it's a bit more of a clanking sound than what I believe a valve could be putting out.
i'm a bit worried about bent valves with those clearances... seems a bit small...from what I've been told, you should have looser valves rather than tighter.
on that note, I dont think the noise is from solely the rocker arms tapping... it's a bit more of a clanking sound than what I believe a valve could be putting out.
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#8
Registered User
Thanks for the reply Noah!
i'm a bit worried about bent valves with those clearances... seems a bit small...from what I've been told, you should have looser valves rather than tighter.
on that note, I dont think the noise is from solely the rocker arms tapping... it's a bit more of a clanking sound than what I believe a valve could be putting out.
i'm a bit worried about bent valves with those clearances... seems a bit small...from what I've been told, you should have looser valves rather than tighter.
on that note, I dont think the noise is from solely the rocker arms tapping... it's a bit more of a clanking sound than what I believe a valve could be putting out.
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