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Discussion Starter · #1 ·
For those of you who don't know about the Auto-tensioner (aka idler pulley) and how to check on it, read up...

I ran into a problem this past weekend after road racing my car. Actually, it stems back from when I did my intial install and I'd like to share this info with all of you just so some of you don't do what I did.

I never checked the serpentine belt auto-tensioner indicator when I dropped my K20 into my EG, which freekin retard! (live & lean I guess!). I shoulda read the RSX helms manual before doing my install.....I guess I was just too excited about the whole swap and let it blow by me.

Anyways, after having an awesome track day at Buttonwillow this past weekend, on my way home and as soon as I got on the freeway, my battery light decided to turn on and stay on (because of the alternator). Thought that was weird. Shut my car off and turned it back on. Then my check engine light came on. "WTF" I thought. Then shut the car off and back on one last time. Then my TEMP gauge shot up to HOT. I tripped out thinking wtf is happening??? Steam started to emmit from my hood. I immediately shut my car off and coasted into 'rest stop' exit. Popped my hood, jumped out, took a deep breath before opening my hood to see what hellish delights fate had brought to me.....

Coolant was EVERYWHERE. Which looks like it escaped from my coolant resivour tank. I looked around some more and noticed that my idler pulley (or auto-tensioner pulley) was not attached to the motor anymore and neither was the serpentine belt!!!! The bolts that held the auto-tensioner pulley to the motor were sheared right off. Here's a pic of it:



So, being that the serp belt came off meant the water pump wasn't pumping and the alternator wasn't alternating, hence the reason behind the idiot lights turning on. :eek:

Tho, a little bit of luck was in my favor that day because a fellow hybrids.jp friend of mine was able to tow me home (God bless the chap!)



Anywhoo, I found that if I would've checked on the auto-tensioner indicator before hand, this would have never happened :eek: . My serpentine belt was set waaay too tight which led to the bolts breaking! Check it out, the arrow should be pointing to the middle of the 2 squares




So, for those that don't know about this, here's a scan of the Helm's RSX-S auto-tension inspection:
http://www.ff-squad.com/tech/k20stuff/autotensioner.jpg

Hope this helps out fellow K20 hybriders who forget to overlook important things like this :D

PS: I haven't gotten my car running again just yet, but I'm betting it'll be ok and hopefully I didn't blow my headgasket or warp my head from overheating. :cry:

[ BELATED UPDATE ]

Would be nice if I followed up eh?

Well, I fixed this problem about a week later.
I wound up buying a brand new auto-tensioner ($75) from an EP Civic thinking the one I had was bad. It wasn't. How & why? Because with the new tensioner installed, the auto-tensioner indictor is still pointing in the same place as shown above. I'm saving the old tensioner as backup if the new tensioner bolts decide to break again.

I also upgraded the auto-tensioner mounting bolts to that of air-craft grade allen head studs as added strength:



Finally, as an added bonus, I upgraded my alternator pulley to an AEM RSX pulley. What fun this install was :rolleyes:. I had the assumption the 5070505 belt would be too short and bought a slighly larger belt....nope...belt had too much slack. Took it back and bought a slightly shorter belt....nope...belt was too small. Wasted all that time when all I did was slap back on the 5070505 belt and it fit perfect :hammer:. I didn't notice this right away, but the tensioner indicator arrow is now pointing on the opposite end:



Personally, I think the belt tension indicator becomes useless for hybriders who are going with a 5-pulley (or less) setup and not with an OEM 6-pulley configuration. Without that 6th (a/c) pulley, the indicator goes wacky and just becomes a false positive.

I've been running on this updated setup for about a year now without any problems. I've also been to about 3 track events too without issues :up:



 

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Re: Auto-tensioner Warning!

So if you are running P/S is this still an issue?

Sorry to here but hopefully everything turns out alright...
 

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Re: Auto-tensioner Warning!

katman,

i notice this too when putting my EP3 Pulley on the k20r engine. Did you have the ep3 pulley setup? if so i don't think there is anyway around the markings.

they aren't gonna line up with a different pulley on there.

what cha think?

chad

chad who remembers the old days of honda.hybrids.jp
 

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Discussion Starter · #5 ·
Re: Auto-tensioner Warning!

jon v said:
So if you are running P/S is this still an issue?

Sorry to here but hopefully everything turns out alright...
I'm not sure, I dont' run P/S, but you should definitly keep an eye on the indicator! it should be within range as the Helms manual says per the diagram I posted.
Thanks for the condolenses Jon :cool:



chad said:
katman,
i notice this too when putting my EP3 Pulley on the k20r engine. Did you have the ep3 pulley setup? if so i don't think there is anyway around the markings.

they aren't gonna line up with a different pulley on there.

what cha think?

chad

chad who remembers the old days of honda.hybrids.jp
Sup chad...
Well I have an EP3-R engine, so my engine came with the EP pully's etc. Thing is I never checked the marker when I dropped my motor in :rolleyes:. I took off the pully assembly last nite, brought it to work today to extract the studs and to realign the pully marker to its proper position following the Helm's instructions.



SBE said:
Damn Kat....thanks for sharing the info...

so you at least got to run the car right?
Oh hellz yeah I did! Ran my fastests time at BW (2:09 config #13)! I'm glad the pully didn't break off during a race sesh ....it would've been a waste of $130 if it did break during the main part of the day!
 

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Re: Auto-tensioner Warning!

Hey Katman, sorry to hear your situation. I've already dropped my K20A2 in my EG, but I'm running a 3-pulley setup(crank, w/p, alternator). Do you think I might encounter your same problem?
 

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Re: Auto-tensioner Warning!

That sucks man. But like you said, at least it didn't happen in the middle of the event. :cool:

First off, my belt was a bitch to even get on. So i'm kinda having the opposite problem i guess.

My tensioner indicator is all the way to the "loose" side and i can't get it to rest in the middle no matter what i try. I assume the only real problem that could bring would be belt slippage?
 

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Re: Auto-tensioner Warning!

my belt started cracking damit :down:

motor was brand new also :confused:
 

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Discussion Starter · #10 ·
Re: Auto-tensioner Warning!

TrueZen said:
Hey Katman, sorry to hear your situation. I've already dropped my K20A2 in my EG, but I'm running a 3-pulley setup(crank, w/p, alternator). Do you think I might encounter your same problem?
I dont think you'll have any issues since you're deleting the complete auto-tensioner assembly as a whole.

I'm thinking about going the 3 pully route myself too...but somethings telling me not to. I wanna figure out if my auto-tensioner needs replacing of if I need to get a slightly shorter belt.

btw, I got the studs out this weekend and was able to put everything back together. Problem is, when I turn my car on, the auto-adjuster is suppose self adjust and bring back the tensioner indicator to the center, which its not doing... :(

I'm going to purchase a new auto-tensioner this week and see if that'll fix the problem...
 

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Discussion Starter · #11 ·
Re: Auto-tensioner Warning!

#2 said:
That sucks man. But like you said, at least it didn't happen in the middle of the event. :cool:

First off, my belt was a bitch to even get on. So i'm kinda having the opposite problem i guess.

My tensioner indicator is all the way to the "loose" side and i can't get it to rest in the middle no matter what i try. I assume the only real problem that could bring would be belt slippage?

#2
did you use a 14mm box wrench/or socket (as shown in the helms diagram) to help put on the serp.belt??
http://www.ff-squad.com/tech/k20stuff/autotensioner.jpg
:cool:
 

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Re: Auto-tensioner Warning!

katman said:
#2
did you use a 14mm box wrench/or socket (as shown in the helms diagram) to help put on the serp.belt??
http://www.ff-squad.com/tech/k20stuff/autotensioner.jpg
:cool:
You know this meng. Had the helms right next to me the whole time. It actually got to the point that the pulley bolt was starting to come loose from trying to push it to the center of the marks. I'm using a Dayco poly-cog belt, part# 5070505.

Any advice?
 

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Discussion Starter · #13 ·
Re: Auto-tensioner Warning!

#2 said:
You know this meng. Had the helms right next to me the whole time. It actually got to the point that the pulley bolt was starting to come loose from trying to push it to the center of the marks. I'm using a Dayco poly-cog belt, part# 5070505.

Any advice?
whoa..trippy...
well, you can try what I originally did...
on the auto-adjuster pulley, you see how there's two 12mm bolts holding the pulley to the auto-adjuster assembly? (ie. the same damn 2 bolts that broke off on my engine!)....yeah, loosen the lower right bolt first, then completely remove the top left bolt, then swing the pulley forward, fit the belt on, then snap back the pulley into place and reinstall the 12mm bolt and tigten both down. This should help fit the belt on...but make sure to check the auto-adjuster indicator before you turn your engine on and after you turn your engine on to see where the indicator points to...
:cool:
 

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Re: Auto-tensioner Warning!

katman said:
whoa..trippy...
well, you can try what I originally did...
on the auto-adjuster pulley, you see how there's two 12mm bolts holding the pulley to the auto-adjuster assembly? (ie. the same damn 2 bolts that broke off on my engine!)....yeah, loosen the lower right bolt first, then completely remove the top left bolt, then swing the pulley forward, fit the belt on, then snap back the pulley into place and reinstall the 12mm bolt and tigten both down. This should help fit the belt on...but make sure to check the auto-adjuster indicator before you turn your engine on and after you turn your engine on to see where the indicator points to...
:cool:
Ahhh, i just friggin wrestled with the thing till it finally slid on. Seriously took me about 45 minutes just to install that damn belt. Your way sounds easier.

I'll keep an eye on the indicator. Hopefully it'll settle in the center after she cranks. We'll see y0!
 

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Discussion Starter · #15 ·
Re: Auto-tensioner Warning!

#2 said:
Ahhh, i just friggin wrestled with the thing till it finally slid on. Seriously took me about 45 minutes just to install that damn belt. Your way sounds easier.

I'll keep an eye on the indicator. Hopefully it'll settle in the center after she cranks. We'll see y0!
yeah lemme know!
'cuz I kept an eye on my indicator after reinstalling my auto-tensioner & belt, and the indicator arrow isn't going back to its center position...the pointer is staying just like this, before I started my car and after I started my car....



:(
 

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Re: Auto-tensioner Warning!

katman said:
yeah lemme know!
'cuz I kept an eye on my indicator after reinstalling my auto-tensioner & belt, and the indicator arrow isn't going back to its center position...the pointer is staying just like this, before I started my car and after I started my car....
:(
Will do. So weird, mine is the exact opposite of how yours is right now. Hopefully it won't snap on ya again.
 

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Re: Auto-tensioner Warning!

hybrid racing said:
Someone should make this a sticky!
Hybrid you guys haven't seen any of these problems?
 
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