Timing Chain Idler Sprocket bolts
Good Morning everyone,
Been a long time since I posted, long story short. I'm doing my timing chains for the second time. The first time was around 100k and they lasted close to 70k, so I did the teardown for the second set. I believe my issue was related to the oil pump I could see my oil pressure dipping lower than normal for the past couple of months until the timing codes popped up again. After the first set, I was very religious about changing every 3 months or 5k miles on Pennzoil HM FS. I believe the Pennzoil made a difference as the first time I took the timing cover off the varnish and burnt oil build-up was horrible. This time around it was not too bad, some light varnish buildup with no chunks of burnt oil that I could see. Could be from the increased oil change intervals I honestly can't tell. The problem was in the process of replacing everything with a new timing kit from cloyes, I was torquing the timing idler sprockets I didn't even get to 30 ft-lbs. 1 bolt on the left bank seemed to have slipped slightly, I got nervous and thought I stripped the threads but looking at the bolt I seem to have twisted it as I could see the breaks in the metal but didn't shear it off completely. So I'm replacing those 2 bolts, went to the dealership to get a set of replacements and they were incorrect. They said that's what their system shows and they can't deviate from that. does anyone have the dimensions of the bolts? I feel dumb I didn't measure them before I tossed them in the trash. https://i.ibb.co/V3z42SQ/1.jpg |
I can't help you with the bolt sizes but I can tell you those bolts included in the Cloyes kit are known to break off completely while the engine is running. Be glad you never got that far.
Take the bad bolts to your local Fastenal store, they can help you. Good Luck What chain kit did you use @100k the 1st time you changed them? One more thing, be sure to soak those new chains in oil before installing them. By the time they get fully lubed from the vapor-splash oil in they engine they will be be worn hard. I also highly recommend you switch to a full synthetic oil and keep it full. You should have gotten easily 150k from a set of chains. The problem in these engines is they use oil. This in turn causes the chains to run dry because the only lube the chains get is from oil vapor and splash. Lower oil level = less lube on the chains. I keep my oil level 1/4qt above full, as it uses oil and gets to the full mark I add 1/4 qt. This works out to about 1/4 qt every 1k miles. I expect to get 200k before the chains need changing. |
First replacement chain set was Cloyes, it didn't come with any bolts at all. I was able to source the correct bolts from a better chevy dealer that knew what they were doing. Cost 12 bucks each but better for peace of mind. New Cloyes set looks exactly the same as the first also no bolts came with the kit, made sure I checked idlers before installing to make sure they weren't rusted out or damaged. I know Cloyes had issues with their idlers in the past I called the service number and they acknowledged this. They just told me to make sure it had 2 blue marks on the idlers and I should be good. Used all new gaskets but I did tear one of the vvt solenoid gaskets while installing the solenoid. I have placed an order for another set so I silicone this one in place until then. total job was about 15 hours from start to finish 2 days, I also cleaned the intake valves on both sides. Car runs way better than before didn't realize how bad it had gotten driving day to day.
|
Ok , update:
New Cloyes set made it 15k miles before the tensioner failed on bank 1. POS, I have several valves on bank 1 bent as well. have to take head to a machinest to check the valve guides and seats. I am having to order all new parts for the head and a new set of chains from a different vendor. Before everyone starts with the oil issue, I can tell you without a doubt I never ran low on oil. Oil was checked religiously on every full tank of gas and topped up when needed. Chains are fine from what I can tell, just the tensioner failed. Will be replacing with ac delco chains and tensioners, as this is my second cloyes chain kit failure and they refuse to warranty. |
What failed in the tensioner?
|
ok, I spoke a little too soon, Tensioner did not fail as far as I can tell. what broke was the crappy yellow plastic timing chain guide the puts pressure on the bank 1 timing chain. I ordered a leak-down tester to check how bad the valves are on that bank. I checked with a borescope camera and only saw contact on cylinder 1 exhaust valves but the valves seat all the way up. My hope is that the timing chain falling off the cam allowed the valve to roll the cam lobe out of the way before it seated itself. posting some pictures.
https://ibb.co/JnmdBTK https://ibb.co/fCSr51y https://ibb.co/DgcqKCy https://ibb.co/JF5f3g8 |
Thats a odd thing to happen.
|
Quote:
|
any update on your case? I replaced my chains with cloyes but still DTC P0008 remains.. I am suspecting from not using ACDelco chains.. What do you think?
|
Quote:
|
Quote:
|
Is your oil filter cap anti drainback valve working ? If not the pump has to re-fill the filter housing every time you start which might be starving other things.
|
Quote:
|
I don’t know how to check it as when you remove the cap the anti drain back valve gets released and the oil drains.
You might try pushing the valve by hand and add some oil to see if it drains or not. Holding the valve down should stop the oil from leaving the canister |
All times are GMT -5. The time now is 01:20 AM. |
Powered by vBulletin® Version 3.8.9 Beta 4
Copyright ©2000 - 2024, vBulletin Solutions, Inc.