Miltb

Well following up my other thread .... I now know how to do a tensioner replacement (THANKS TO ALL WHO HELPED ON THAT).

BUT NOW it turns out I need to replace my timing chain because a guide is broken right where that bolt usually breaks on LNF blocks.

1 - Will this bolt (access port bolt) give me any trouble removing it??

2 - How do I change my timing chain??

3 - does my engine need to be TDC when changing the chain??

​​​​​​4 - is there a guide (manual or other) I could to make this simple??

5 - any DIYs I missed on how to do this?? I assume it's the same for all Cobalt ecotecs??

Please post your thoughts and help.

jdbaugh1

iTrader: (1)

ProfDNS

I've watched those videos a few times, it's easy to do, location is pain in the ass.

jdbaugh1

iTrader: (1)

True story. Having to remove the engine mount brackets and everything in the way is harder than the timing chain and guides themselves. One thing not covered in these videos is when you do it with the engine in the car you will want to have a hydraulic jack supporting the front end of the engine. I say hydraulic and not regular jack stand because if I am thinking correctly I had to move the front of the engine up or down slightly to get good access to a couple of the bolts.

C0balts5

This is the first I've actually heard of the lnf motors having chain issues. Is this a pretty common thing to be concerned about? I'm pretty easy on mine and don't beat on it allot and change the oil at 3k on the dot.

ProfDNS

Like anything else, they break down over time. However with them being chains, they just last a lot longer than timing belts (although the balancer and the pump are belt driven as well).

I ordered a new belt for my car when it gets warm enough I'm replacing it. Timing chain has never been done but I don't have issues either. I may end up replacing it anyways in the summer as preventative maintenance. I mean, might as well spend the $125 now, and not damage your pistons/valves later.

C0balts5

Gotcha. I use to work for nissan for 5 years, I've done more timing chains on nissans than I can shake a stick at. The one major variable with chains is how well you maintain your engine. Hit or miss type of thing.

Miltb

Why I'm changing my chain and guides is because there's a crack in the guide thats nearer the front of the engine, held on by the bolt that shears sometimes.

And on that point, should I get upgraded guide bolts???

OTTP sells some upgraded guide bolts.
OTTP offers ARP and regular high strength (just as strong as ARP)

​​​​​​Also another brand offers ARP upgraded bolts.

Thoughts??

ProfDNS

You could go grade 8 or higher bolts (similar to HSS), but you're holding in plastic on an aluminum block.

C0balts5

I would just put the factory bolt back in with some blue lock tight on the threads and maybe give it a lil bit more torque, obviously not the old German torque spec "goot an tight" and snap it off.

Miltb

Ya I think the ottp bolts are 10 or higher ....

The reason for upgrading is to allow gutentight torqueing .... Not to hold the plastic guide tighter ....

Basically so it wouldn't be possible to shear the bolt.

Miltb

​​​​​Know what the torque spec is??

I could find some blue.

Anything wrong with upgraded bolts?

C0balts5

Has anyone ever seen a bolt sheer off? Or are the just known for working loose and causing failure

WICobaltSS

The upper bolt on my daughter's Ion sheared off. Fortunately it was caught in time before the plastic guide disintegrated. I had to jack up the motor and drill a hole in what was left of the bolt using an angle drill. Came out pretty easy with an EZ out, My son's Cavalier was not so lucky. Bolt actually came loose, destroying the guide and causing the chain to flop around. Working on dropping a different motor in his car now.

Slowbalt2000

iTrader: (1)

Dorman makes a repair bolt so you dont have to throw away the whole engine just from one broken bolt.

Slowbalt2000

iTrader: (1)

https://www.dormanproducts.com/p-86802-917-954.aspx

Miltb

Nice that's an awesome find ....

Thankfully mines not sheared .....

Just want to never have the shearing issue.

Miltb

Sooooo here's the link to the OTTP bolts .... I think I should get them.

http://www.ottperformance.com/store/pc/viewPrd.asp?idproduct=1825&idcategory=339

The ARP version though. I don't like Allen setups.

ProfDNS

The head of the bolt does warp inward, but never sheered - for this section of the car anyways. I've had one bolt head "twist" off when I was replacing a sensor. It only took 120 in-lbs of force.

cobaltssdude420

Dude. I told you to pm me for a how to on timing. It's so easy lol.

Miltb

sorry I did pm you .... Must have not gone through .... I pm'ed my number too.

ProfDNS

You lie like a rug. Pics of GTFO

Miltb

Dude I'm a good lier .... I tell ya

Miltb