Failed Hydraulic Timing Tensioner

[Alex3000gt]

While replacing some noisy lifters on my race car, my friend noticed the timing belt appeared slack around the water pump.

Dug into it a little further and found this:
http://img694.imageshack.us/img694/3351/img0962du.jpg


Just installed this new in June, haven't even put 3,000 miles on it as the car sits in the garage most of the time. I am in contact with the seller (Parts Dinosaur) and am in the process of warrantying the part.

Looks like the tensioner blew a seal and leaked hydraulic oil. Luckily it did not jump time.

[MR2]

Daaaaaaaamn. lucky catch, go buy a lottery ticket.

[Alex3000gt]

Daaaaaaaamn. lucky catch, go buy a lottery ticket.

That is what I said. This is a lucky motor. When I did the timing in June the tensioner (who knows how old it was) had also failed.

Lightning does strike twice.

[green-lantern]

Damn! I don't think I've seen one make a mess like that. Definitely a good catch!

[shmoo]

i have never been as deep as timing. can someone tell me what is wrong with this picture?

[Alex3000gt]

i have never been as deep as timing. can someone tell me what is wrong with this picture?

Of course, my friend.

Here is what the image "should" look like. Find the difference between this one and the picture above:
http://img844.imageshack.us/img844/3162/img0960h.jpg
http://www.3sx.com/store/catalog/timing-belt-tensioner-nonoem-14-400l.jpg

The metal "plunger" has completely depressed into the tensioner housing. This happened because a seal failed and all of the hydraulic fluid inside the tensioner leaked out - preventing the tensioner from applying force on the "plunger".

[Alex3000gt]

http://img847.imageshack.us/img847/5771/img0954w.jpg
Pic as the car is right now.

[BigTyla]

Nice find!

[$$$PIT]

I had that happen to me on an aftermarket tensioner. But never on an OEM tensioner. Which was yours?

[Primus101]

You do realize it's quite normal to have the belt loosen up around the waterpump after parked for a bit, right? The tensioner gets compressed from the sprung valvetrain(front head) pulling on the belt. Was it obvious that it was leaking? The tensioner has a heavy spring in it that applies pressure on the plunger- the hydraulics are to dampen the movement.

[MR2]

the plunger has actually gone negative from it's normal resting position even when new...normally after you set it it push's out at least a half cm...the tensioner idler assembly thing is not even resting on the pin, it's resting on the hydraulic assembly itself :|

[AdamVR4]

Did the plunger extend at all as you spun the engine?

Careful putting the crank pulley bolt into the crank sprocket without the pulley. In ~2005 I had to help not one, but two local guys that did this... When the bolt bottoms out, the last thread can be deformed and the bolt will bind on removal. One of them snapped off in the crank, the other luckily came out with a lot of force.

[Alex3000gt]

Torquing down the crank pulley and intake plenum tomorrow then cranking her up.

Cross your fingers.

[Chris@Rvengeperformance]

very typical of the non oem tensioners

[Alex3000gt]

very typical of the non oem tensioners

First out of five for me. Can't speak to what tensioner was on the car when I purchased it though.

[wingnut]

Shim it with a washer this time?!?

[TUFFTR]

I use about 4 flat washers, or a CV nut which is actually perfect for the job.

After having an aftermarket tensioner fail on me WHEN TURNING THE ENGINE BY HAND I do not have faith in them anymore. OEM or NOTHING.

[wingnut]

I use about 4 flat washers, or a CV nut which is actually perfect for the job...

...head washers seem to be a good fit as well :D

[green-lantern]

They will all go in like that if the engine stops in a spot where the cams are putting a lot of tension on the belt. At TDC it will stay out but rotate the engine about 1/4 turn and come back in an hour or longer and it will be pressed in. Of course if the tensioner is leaking fluid that is bad.

[Ninja Performance]

Looks like a non OEM tensioner pulley as well? (it's green instead of brown/orange)

As stated many times, at rest the belt slackens around the water pump. It's normal.

-Chris

[stealthee]

I use about 4 flat washers, or a CV nut which is actually perfect for the job.

After having an aftermarket tensioner fail on me WHEN TURNING THE ENGINE BY HAND I do not have faith in them anymore. OEM or NOTHING.

This happened on a "customer's" car. Had a guy I had sold parts to previously call me up about doing a 60k, offered to pay me well so I took it on. Had everything all lined up, turned it over by hand to make sure it was still lined up nad before I turned the crank a quarter turn the tensioner failed and the cams jumped. Against my wishes we ended up putting the old tensioner back in because no one local had a tensioner in stock, and he had to have his car the next day.

[Alex3000gt]

Well you guys are scaring me. I'll go OEM on critical items like timing components next time.

[green-lantern]

Definitely one part I wouldn't skimp on. It's just too important and worth the extra few bucks.

[Erron Spalsbury]

The washer trick does work. I was always scared that during startup if the slack was removed too quickly that the washer may have a chance to slide out between the rod and tensioner and end up in the belt. You can tack weld them into place but I started doing something a little different. Once everything is installed and the pin on the tensioner is removed, I take a big 'ol prybar and move leverage the rod back further and then tighten the nut on the tensioner pully. I leave about 1/16" worth of available extension so when the belt goes slack at idle it only moves that little bit. With the engine at idle, the 1/16" on the rod is present again. I'm pretty confident with this mod as I've had mine on the race car for over 5 seasons now and the daily for about the same time frame.

[green-lantern]

The washer trick does work. I was always scared that during startup if the slack was removed too quickly that the washer may have a chance to slide out between the rod and tensioner and end up in the belt. You can tack weld them into place but I started doing something a little different. Once everything is installed and the pin on the tensioner is removed, I take a big 'ol prybar and move leverage the rod back further and then tighten the nut on the tensioner pully. I leave about 1/16" worth of available extension so when the belt goes slack at idle it only moves that little bit. With the engine at idle, the 1/16" on the rod is present again. I'm pretty confident with this mod as I've had mine on the race car for over 5 seasons now and the daily for about the same time frame.

Interesting, That shouldn’t hurt the tensioner so that does seem like a great idea. I always made sure I could turn the engine around and put the pin back in because I didn’t want it too tight but I don’t see how it could hurt the tensioner like that. I think I’ll do that next time. I didn't like the washer thing much ether because what you said or the tack welds possibly hurting the seal or slightly warping the end in an oval shape around the rod.