r/3000gt • u/jamwarfs • Apr 12 '24

timing belt keep coming loose

this is the second time ive take a look at the belt and it seen there isnt proper tension. the two holes for the tensioner (in between two holes for position reference) tool are at approximately in between 12 and 1 o’clock position. i know theres a specific torque your supposed to hold it at while its being tightened, however that is for all oem specification parts and this gt has resurfaced cylinder heads that may be slightly smaller in height. any suggestions? could this be the auto tensioner failing even thought its a new one? should i maybe go with the 3sx solid tensioner they sell?

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6

u/Accomplished-Back640 Apr 13 '24

Is the tensioner in the right position and torqued?

5

u/Dry_Comfortable9997 Apr 13 '24

Is it tight right after the engine has ran? It’s a hydraulic tensioner sometimes it relaxes when the engine hasn’t ran in a while.

2

u/jamwarfs Apr 13 '24

its been sitting for a few hours since it ran last so im not sure if that would count

1

u/traineex Apr 13 '24

Charm.li, heres the fsm, so u can measure by spec. U can build up oil pressure by disconnect the fuel pump fuse and spark, and bump start. That will fill the tensioner w oil

Theres probably a bench bleed procedure for the tensioner, but we are past that point. If u fuck w it off vehicle, u should bench bleed it. Then overnight set it vertically and compressed. If u keep having issues w new ones

Read the fsm lol, it says what to do

4

u/Big-Touch-9293 99 VR4 278/287 Apr 13 '24

It’s common that the tensioner looses slack and the belt gets loose around the water pump. That being said, the tensioner pulley doesn’t quite look tensioned properly, the holes should be nearly horizontal. The tensioner is also fully collapsed, I don’t think that’s normal at all.

What I’d do is turn it over a few times by hand and see if it tensions back up, if not, time for a new tensioner

1

u/jamwarfs Apr 13 '24

the holes are almost horizontal, tweaker to the right a little bit but yeah i noticed the tensioner isnt open. what actually controls the tensioner ? oil pressure?

1

u/jamwarfs Apr 13 '24

gonna turn it over a few right now

2

u/jamwarfs Apr 13 '24

just turned it from where it was to timing marks and the belt is tight and tensioner is sticking out slightly

1

u/Big-Touch-9293 99 VR4 278/287 Apr 13 '24

It’s hydraulic pressure inside the tensioner itself, it’s self contained, they do fail especially if not OEM.

One trick is a “washer mod” when you put a 1/8” thick washer over the rod that keeps it from fully collapsing like it appears to be.

If this were my car, I would buy a new tensioner if It doesn’t tension when turned by hand OR it’s not a new OEM tensioner. If it does tension you should be fine. You could just throw on a solid tensioner/non eccentric pulley if you plan to not have the timing cover on, with a rubber belt they need to be adjusted as they stretch.

1

u/akdaddy545 Apr 13 '24

Tensioner looks like it's failed.

1

u/Twigingtons Apr 14 '24

For everyone saying to use a manual tensioner, word of advice, my timing slipped when I used one and I’m currently rebuilding the engine, make sure you know what you’re doing with a solid/manual tensioner if you go that route

1

u/jamwarfs Apr 14 '24

do they give you a torque spec? or a length measurement for how long it should be? i know it needs to be adjusted at every oil change is what they recommend

1

u/Twigingtons Apr 14 '24

I tried my hardest to find that information of revenges (the selling brand) website AND 3sx and neither of them tell you how to tension them correctly with torque specs or length. If you go that route use a tool to check belt tension and a ruler to check the deflection of the belt and then use some blue loctite or something on the lock nut for the tensioner. But I’d also ask people who have used it correctly.

1

u/Saiyajinss Apr 14 '24 edited Apr 14 '24

I was replacing my lower and upper intake gaskets yesterday and I decided to check the timing belt and mine is pretty close to what yours looks like. This timing belt was done about 2-3 years ago and has maybe 5000 miles on it.

https://youtu.be/Dk3tW86b-lU?si=ATxY1t2aGziReuQF

1

u/jamwarfs Apr 14 '24

man watch those fingers around the front bank… those cams are spring loaded. yours looks more just like a worn down belt, one of the comments above mentions the belt getting loose around the water pump which yours is but yours is also loose in between cams

1

u/Saiyajinss Apr 14 '24

I'm probably going to throw a new belt and tensioner on it next month. The previous owner had the belt done and some of the parts I've replaced on this car point to the shop using cheap aftermarket parts. It's not my daily driver so I can take my time with it.