I have some ongoing pretensioner issues.

Had timing belt on my Ralliart replaced at 90k. I purchased a full Gates kit including pretensioner, not knowing that it is best to leave the original pretensioner if it is working properly. Car developed pretensioner noise within about 1000km. Back to independent mechanic after the belt slipped a tooth (on flatbed truck) who fixed it up. No issues for about 10k until a loose bolt managed to make its way into the timing belt area (long story) so back to the same mechanic to have it removed. Belt required removing therefore tension resetting. I now have the telltale pretensioner noise on startup, only lasting about 2 seconds. Sounds like the pretensioner is failing or wasn't set properly.

The mechanic in question is well respected and experienced and seems to know the process for Magna belts. However, for advice......

1. Would I be best going to the dealer and getting a new genuine pretensioner? Probably apprentice doing it for the first time........
2. New pretensioner by current mechanic, assuming no human error but faulty part?
3. Find another independent mechanic?
4. Can this be changed without taking belt off? I do remember reading something about this on the forums so doable at home?
5. Drive to Mal (not that practical unless I was visiting my ViC based family).

Thanks in advance.

Steve

Ok,
Unfortunately I dont have the time to post up the pics however we just sent a TJ VRX with only 130k on the clock off with a new motor yesterday because of this issue, the tensioner vibration was so bad that the bolt which holds the swing arm sheered off.

More often than not the damage is done when the belt is replcaed, they release the pre tensioner all together and then jam it in a vice to push back the piston. I have never done this as I dont release the piston to begin with. The only time that the swing arm leaves the motor when I do this job is to replace it and the only time the pre tensioner leaves the motor when I do the job is when I replace that as well.

While Gates in general is a great product, I have seen many of the pre tensioners fail like yours has, this is why I harp on about using the genuine unit only. My timing belt wholesaler who has tried almost every unit on the market only sell genuine units as an example and they have over the years sold far more than I have and were sick of returns

If you are handy with a spanner I can tell you over the phone how to change the pre tensioner without taking the belt off, you will need to re tension the belt to do this properly but it can easily be done and I have done this myself many many times

Got to agree with Mal.
Pretensioner stays on engine, doesn't get replaced unless its leaking. Plunger pushed in slowly by putting tension on the rear cam belt run, slip pin in before taking old belt off. Avoids the plunger reaching the end of its travel and then stressing it by putting it in a vice.

Done it that way twice now without any problems down the track at 25,000 km on my TJ and 10,000 km on my TL.
I have an aftermarket hydraulic tensioner as part of a kit sitting around, but I doubt I will use it if the need ever arises. lol Genuine will be obtained.

Neighbour has a TW that sometimes hammers badly on startup, he just gives it a big rev to shut it up. lol I'm just waiting for that swing arm pivot bolt to break and leave him stranded. I should tell him, but then he will probably expect me to fix it . . .

(I personally prefer the system of a big spring providing the initial belt tension as on the 3.0L second gen engine and 2.0L Lancer, much easier to set up.)

Thanks Mal. Reasonably handy with a spanner. Do most things but not timing belt replacements but would be happy to do the tensioner. Not something I'm going to get to for a few weeks (car not a daily driver). I assume drivers side engine mount comes off to be able to remove timing belt covers? Then car on jack stands for access?

Steve

I'm going to order a genuine one in the meantime.

Not at all, give me a call during the week and will step you through the process

I can supply genuine units much cheaper than a dealer as well BTW

Thanks Mal. Reasonably handy with a spanner. Do most things but not timing belt replacements but would be happy to do the tensioner. Not something I'm going to get to for a few weeks (car not a daily driver). I assume drivers side engine mount comes off to be able to remove timing belt covers? Then car on jack stands for access?

Steve

Jack front driver's side wheel up, axle stand, remove wheel, splash guard, remove ancillary belts, remove crank pulley, support engine, remove engine mount, remove cam belt covers.
Change hydraulic tensioner, set up cam belt tension.
Reassemble.

(Perhaps Mal will suggest some shortcuts there.)

Good luck.
In the meantime, don't drive the car too much. If something is going to break, it will be at startup.

Thanks Mal and Max. Mal, I couldn't see one in your store. What is the best way to order one?

I think the mechanic in question doesn't know the Magna too well as I remember him saying he always replaces the pretensioner as they tend to fail. Obviously he is wrong.

Steve

No need to remove mount or jack up engine.

Best to call me as I have them here on the shelf, I have not had time to list too much in my store at the moment as too much work to contend with.

No need to remove mount or jack up engine.

Good point, this is only needed when changing the belt.

Check though that the tensioner is leaking or other wise defective, it may still be an adjustment problem. If the plunger is fully extended and there is movement possible in the idler pulley on the swivel mount, then it probably wasn't set up correctly.
Worthwhile having a new tensioner on hand when you do this job though.

Thanks Mal. Will call during the week.

Steve

As this has been with the mechanic 3 times, I'm not taking any risks with the Gates tensioner, especially as it was quiet for 10000km and then started playing up. It is already going to be an $800 timing belt change by the time I've finished. Oh well. It's been good otherwise and is in pristine condition, only 98000km. Would hate to stuff the engine as want to keep it original.

lol If you do the tensioner change yourself, you are well on the way to knowing how to do a belt change yourself, saving that $800 cost, so it's worth having a go at doing.

Nice of the mechanic to have 3 goes at it, and still not getting it right. lol

(Perhaps he didn't use a torque wrench, and under tightened that bolt, or overtightened and stretched it so now it has slowly let go its tension, allowing the idler to move? Worthwhile to have a look at that bolt - the one that goes through the adjustable idler pulley. Probably ok, but I'm grasping at straws to work out why he got it wrong. lol I'm in the habit of questioning and checking everything a mechanic does to my cars, hence I keep them away from mechanics and do DIY. lol)