Can Timing Belt Auto Spring Tensioner go bad??

super_cadet · Postby **super_cadet** » September 4th, 2013, 1:11 pm

So my timing failed awhile back. On inspection, i discovered the bolt holding on the swing tensioner arm sheared off and the belt just jumped off...2 Months before this happened,The mech told me that he put up the Auto Spring Tensioner and it will work but that it going bad. If that can go bad then it makes sense why my bolt broke, but how can i tell if it went bad...should bodyweight be able to push that spring all the way in??..I tried and i couldnt.

Postby **MISHI** » September 6th, 2013, 2:49 am

remember that tensioner is under a lot of pressure... more than you are able to move it. It has to hold the standard tension of the belt and also adjust for any changes in belt stretching and not to mention years of heat and cold cycles etc and If it was weakening then only a slight amount would be needed for the belt to have play that it would jump a few teeth and ruin the motor.

But in your case I would believe that the bolt holding it was already weakened over time from the same heat and cold cycles and failed causing the tensioner to come off. It's not uncommon: in 2010 a bolt holding my power steering idler pulley under tension from the one drive belt on the evo snapped clean off while driving. When I changed my Timing Belt in 2011 I decided to change most of my bolts while it was down just for that reason.

super_cadet · Postby **super_cadet** » September 6th, 2013, 11:44 am

Thanks for the reply.I replaced the broken bolt with a black steel bolt and timed back the engine.It's starting with what sounds like heavy tappet noise but i have to check the compression to verify that valves aren't bent, in which case, i'd be very very lucky

. Was just nervous about putting back the same tensioner.

Could bent valve noise be mistaken for tappet noise?? I've never actually heard an idling engine with bent valves to know, but i have a smoothe idle and easy start, and the engine was down awhile so i considered that to be the oil getting back into full circulation in the head. Any thoughts on that?

Postby **MISHI** » September 6th, 2013, 11:50 pm

I honestly would feel more comfortable getting a new OEM bolt. That Steel bolt may not have the tensile strength to hold up in th long run as well.

If valves are bent you will know. It has a constant sound with the revs that doesn't die out. Hydraulic lash adjusters (assuming it's the MIVEC we are talking about) are a common problem with ALL DOHC mitsu engines in time and it will sound like light ticking as tappets

best example I can describe is tappet noise being like drumsticks hitting each other... a light sorta sound. It should tend to come and go.

Bent valves sound like piston slap... almost like a drumstick hitting the metal rim of the drum. that noise will continue regardless and also continue to cause damage to head etc. The car will not idle smoothly at all.

super_cadet · Postby **super_cadet** » September 7th, 2013, 8:28 am

Thanks a lot. It's the mivec so hydraulic adjusters I was referring too. I'll see if I get that OEM bolt an replace the steel one.smoother idle and nothing that sounds like piston slap so I guess I'm a very lucky individual.

Postby **MISHI** » September 8th, 2013, 2:16 am

Well of course you will know for sure when you do the comp. test....

and broswe a few vids on youtube and you will hear the bent valve sound

super_cadet · Postby **super_cadet** » September 8th, 2013, 12:25 pm

Yea so finally checked the compression. #1-250
#2-100
#3-240
#4-250

So two's definitely bent. 3 is within range but how do I see if it's slightly bent when I take down the head??

Postby **MISHI** » September 9th, 2013, 8:49 am

have to remove them completely to see. Also to check the head for any damage as well when you remove em.

also check the piston and make sur it doesn't have impact marks

super_cadet · Postby **super_cadet** » June 22nd, 2014, 6:40 pm

So months pass and i'm now getting to fixing this car. CB Mivec 4g92 valves needed. Went by PT Parts in el socorro and he didnt have them but i got headgasket, timing belt Etc. He said he could order the valves for me if i had a chassis number for the engine, but since it's a conversion I should look about to see if i could get them before trying to order. Anyone knows where I can get the Valves?? need 2 intake 2 exhaust.

super_cadet · Postby **super_cadet** » June 24th, 2014, 7:04 pm

Any leads on where to get them appreciated

super_cadet · Postby **super_cadet** » June 25th, 2014, 9:52 am

UPDATE - After some research I found a list of part numbers for the engine.

https://partsouq.com/ru/catalog/mitsubi ... &group=230

Does anyone order their parts directly and know how to go about it. If I could cut out the middleman i could make out better. :lol: