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how can i tell if my tensioner is about to give way and be totally done. I ask this because someone else i know had their timing chain tensioner give way and it just about destroyed the engine. he had to salvage parts from a parts vehicle to put a new engine together in working order. I am randomly getting noise that sounds like it could be either from one or both pulleys; or the tensioner; but how can i tell which one it is?
RX350 timing chain only has one pulley, and the tensioner pushes a plastic guide rail. Do you mean the serpentine drive belt?
Would love to see more pics from when you pulled your engine if you have any, especially the timing chains, tensioners, and anything else you like to share.
Here is a pic of the timing tensioner, that you would see if the RX350 (3.5L 2GR) inspection plate is removed. You can see on mine there was very little stretch in the chain after 91K miles, only out 1.5 notches. 2nd pic shows the only idler pulley, below the 2 intake camshaft sprockets. There are 2 more chains that connect the intake to the exhaust cams.
I wonder if the tensioner can be properly inspected thru the acces cover.
After seeing this I hope there is a way to see and know for sure the chain isn't flapping back and forth while engine is running.
I suppose you could idle it and have someone rev it with cover off, may get some oil mist. It does have oil passage which pushes it out, and is has a one way detent to stop it going back, so unless the detent failed, I don't see it collapsing.
I'm still not sure which tensioner the OP is referring too, the drive belt pulley tensioner, or the timing chain tensioner.
[QUOTE=Margate330;11011750]I wonder if the tensioner can be properly inspected thru the acces cover.
After seeing this I hope there is a way to see and know for sure the chain isn't flapping back and forth while engine is running.
No access cover, the cover basically covers the whole front of the engine. Quite a lot of the Ford mod motors= 4.6/5.4 as well as the 6.8 v/10's w/ many miles w/ hardly any problems w/ t/c's, tensioners, guilds....All one has to do is change the oil/filter at regular intervolves. The gr2 has three chains w/ two that tie the int/exh cams together vs the 1/3mz's that have their int/exh cams tied together via gears w/ the crank driving the exhaust cams which are driving the intake cam via gears. Quite a lot of ohc/dohc's are driven by chains, even thou there are a few driven by a belt.
I would say do it by sound. If the chain is flapping back and forth, you should be able to hear it. Use a mechanic's stethoscope or a long screwdriver up against the cam cover and you will hear it if it is flopping around. But, don't let the fact that other cars have issues get you paranoid about your Lexus. There's a reason Lexus can charge a premium!
I suppose you could idle it and have someone rev it with cover off, may get some oil mist. It does have oil passage which pushes it out, and is has a one way detent to stop it going back, so unless the detent failed, I don't see it collapsing.
I'm still not sure which tensioner the OP is referring too, the drive belt pulley tensioner, or the timing chain tensioner.
im referring to either one or both! because if one or both of those fail I know some type of damage could occur i would think. Like i said i know someone that had that happen to them.
03-10-21, 08:14 AM
tensioner
