Timing Chain P0018 P0302,304,306

Excellent write up and advice, only thing I can add as suggestion is take the extra time and remove the lower oil pan. If your replacing guides and other parts, those worn off bits of plastic are in the oil pan along with bits of removed FIPG. Not a whole lot of extra work and worth doing. If you build a wood jig to rest on the bellhousing, support the transmission, remove the transmission mount bolts, you can Jack up the engine using the wood jig, (DO NOT JACK UP ON THE TRANSMISSION OIL PAN) enough to get the upper oil pan out without removing the engine.

 

Buy the gasket kit, your going to need all the o-rings, valve cover gaskets, inspection plate gasket, intake gasketS (do not reuse those, they will leak, suck in air), etc... Even if you don't buy oem, I think in the end it would be alot cheaper than buying separate. And save alot of future headaches. If you do reuse intake gaskets, put a light coat of oil on them before install.

 

How did it get stretched so much? Guide or tensioner failed?

 

No, if it's been well maintained, guides and tensioners still look good, no sludge build up clogging journals, good oil flow to bank 2, chain shouldn't stretch. Especially on high miles 1GR-FE, change oil every 3,000 miles, inspect drained oil. Take a bright flashlight, look for tiny glitter fragments and obvious metal or plastic shavings or if you start hearing extra noises, notice missing oil, then start diag.

 

Short version: Oil contamination due to excessively-long change intervals killed this chain.

Long version: The original owner had the oil changed at average 22K mile intervals. It originally lit the Check Engine light at 96K miles with P0016 error code, Toyota records show the dealership quoted him a new engine. So he kept running it and changing the oil at stupid-long intervals until he couldn't get it through state inspection, then dumped it on Craigslist for cheap. Still had the factory mix of NGK and Denso spark plugs in it at 163K miles, and it ran well despite this.

I made a lowball offer and bought it last year as a project assuming I'd be swapping the engine for a junkyard replacement. But after removing bank 1 intake cam and cleaning out the VVT oil passages, replacing the VVT oil filter screen & #1 chain tensioner, and walking the chain back 1 link on bank 1...it ran very well. The bank 1 intake cam bearing gaps mic'd within service tolerance spec.

So I ran Pennzoil High Mileage 5W-30 in it through the Fall-Winter-Spring and changed it at 2000-2500 miles to slowly break up some of the sludge, had two Blackstone Lab used oil analysis runs to confirm the engine was otherwise in good shape, and then replaced the timing kit this Summer. I put over 12K miles on it before the timing job, only reason I opened it up was what I thought was off-idle "engine noise" which turned out to be 2 worn-out serp belt idler pulleys. These are remarkably tough engines.

EDIT: pics of one of the oil filters used over the Winter showing sludge it caught. Bottom pic is where I dumped the filter canister contents through a coffee filter:

 

Timing chains do elongate even if you perform proper maintenance. They're a wear part, like rings are, and eventually require replacement. I'm not saying improper maintenance didn't help here, but chains do elongate with use because of wear in the pins and bushings and this is natural.

 

Excellent approach, excellent job. Same as I would have done.

 

I like this statement. Means more than you think as to doing proper maintenance. Short of pads on the tensioners breaking up, as long as the engine stays clean and sludge doesn't interfere with the tensioners, they can take up some of the slack from ware on the chains.

 

Absolutely true, and great point. The engines have a useful service life limited by mechanical wear, and this can only be extended...not completely prevented. A properly-maintained engine should, and usually will, outlive the other components of the vehicle which fail and lead to the scrapyard.

While these 1GR-FE engines use port fuel injection and not direct injection, the growth in GDI and resulting problems with abrasive soot have led to a surge in timing chain elongation problems. GM seems to have taken a big hit even prior to GDI with their DOHC V6, likely a combination of weak chains and overly-optimistic oil life calculations in their monitoring software.

With the industry now focusing on timing chain elongation, e.g. GM's Dexos 1 Generation 2 oil spec, we all benefit from improved oil quality which should (again, in properly maintained vehicles) minimize timing chain problems...and allow us to focus on more interesting things like fixing dash lights.

 

They should go back to double-row chains! The chain on my old Celica's 20R is double-row, but the 22R-E on my pickup was single-row (disappointing). On my truck, I was sitting at 120K miles, had a mandatory 2 weeks off, and the clutch was getting a bit old. Decided that if I was going to do the clutch and rear main seal, might as well do the front as well and refresh the timing chain and sprockets while I was at it. Good thing I did, one of the plastic guides was almost completely gone, which I later learned was a common problem. Pad on the tensioner was pretty worn as well. The chain was probably fine, but I needed the guides and tensioner anyway. That truck is probably still carting people around in Mexico.

Interesting how direct injection would have that effect on timing chains. I did watch a video on what it does to the valves since there is no fuel to wash them off on the back side (and glad my '18 has both direct and port injection). Odd how that is related to timing chain wear, but if it is gunking up valves like that, it's not surprising it might cause other issues. Not really a fan of belts, but at least they are isolated from that.

I blame poor quality materials and craftmanship, and a general decline in pride in your work.

 

Interesting wear pattern on that engine at 120K. This 1GR-FE with the first 164K miles of poor oil change maintenance had very minimal wear on the guides and nylon damper surfaces...barely catch a fingernail. And I'm sure your 22R-E was maintained much better than this.

On the GDI thing, academic research articles studying this problem cite a "corrosive-abrasive effect" when both soot particles and zinc/phosphorous oil additives are present which accelerates wear. GDI engines tend to generate more of this soot than port injected versions. The findings suggest that high concentrations of soot in engine oil have been a significant cause of timing chain elongation in modern GDI engines.

Reference articles:

https://www.sciencedirect.com/science/article/pii/S0043164817308244
https://ac.els-cdn.com/S00431648130...t=1534457405_8a2f08ff57d0ba0ad73ccd31e7003d10

 

Castrol GTX every 3K miles, everything was pristine, I was surprised as well. I guess even back then they had supplier quality issues. Talking to a mechanic friend of mine, he said that it was a known issue. Not catastrophic for that motor, just a bit more noisy until it warms up. I think changing the timing chain was expected above about 120K or so back then as well. Tech and tolerance weren't as good as they are now, which certainly can contribute to wear even in a well-maintained engine. Reminds me, I need to get my '77 started up again, it hasn't run since we moved a year ago.

OP, any update? How are things?

 

I'm guessing he is cleaning the factory FIPG off the block and timing cover...that's a lengthy process. Don't forget to clean FIPG off the 4 inner bolt bosses on the block surface: 1 above the oil filter passage o-ring, and 3 above the crank sprocket.

 

Sorry for the delay just now got all the parts in. As far as putting the new chain back on, where do I need to line up the marked links on the chains themselves? And as far as the driver side, how far do I need to rotate camshaft and intake sprocket to be on set?

 

Timing marks are covered in the shop manual link I posted. Current marks are as effed up as a football bat, and you didn't show the crank. Pull up the shop manual, get all 5 sprockets lined up exactly right as shown, and then rotate the crank 2 full revolutions putting the crank reluctor wheel dot back on the block casting mark, and re-verify all sprockets are on the right marks.

Once again, the shop manual page w/ the timing marks: https://www.customtacos.com/tech.ol.../06toyrm/06toypdf/06rmsrc/rm2006ta/007003.pdf

 

Follow the manual (except for installing the #1 tensioner first, it goes on last after the idler sprocket) and they'll look like this with the new chains and color-coded endplates in the right places:

 

Ok It looks like I’ve got the cams lined up as they should be and I’m almost poster the crank is set at 0 degrees. It may have move a smidge but can’t tell with the timing cover and crank pulley off. Now I’m just struggling with chain placement

 

Looking much better, be sure to oil the new sprocket teeth and soak the chains in oil before you hang them. No dry parts.

Does your new chain have color-coded link plates for the cams and crank sprockets?

 

Yes sir they do have off colored links on them.

 

Then read the shop manual page I linked, it covers where the colored plates go. My pics also show placement.