What did I get myself into

After realizing I blew a head gasket in my new to me 2010 Prius, I realized all the money I saved in gas was now going into a repair. Is it worth it?

 

I do, unfortunately most of the time it’s me

Seriously though I’d like to give a shout out to the contributors to this forum, for a wealth of information. Especially thanks to all who posted Toyota service manual pages!

I purchased a Haynes manual, which is about as clear as mud. Between that manual, the many links to the Toyota manuals on here, and reading many posts here, I decided to tackle the blown head gasket myself.

If I would have known of the egr cooler issues, I possibly could have avoided the blown head gasket at 157,000 miles. My egr cooler was plugged. The intake egr orifices were plugged. It all went downhill from cylinder 2 misfire.

I replaced the spark plugs, two days ran like new, no misfire. Then misfire again, no coolant loss. Replaced the #2 coil pack, again two days like new, no coolant loss.

Misfire #2 again, knock at cold start. Next morning checked it out, coolant loss. Then I knew, head gasket .

Well now I know I can add a 1.8 Prius motor to my rebuilt list.

I learned about this motor the hard way. It took three days of soaking in Dawn dish soap, pressure washing, oven cleaner, parts cleaner, and a stainless tig rod to clean the egr cooler black coke tar out.

I replaced the head gasket, head bolts, egr valve, and electric water pump. The head went to the machine shop for complete rework.

Parts, and machine work $750, labor priceless
So far my gas mileage is climbing so the jury is still out on worth it or not?

 

Judging from the 1/4 quart of oil that was in the intake manifold, the wet carbon tar crud plugging the egr cooler, the coal black piston tops, and valves I figured it surely wouldn’t hurt to possibly cut down the excess oil on the intake side?

 

It was a learning experience, so in essence if I get another 50k+ miles I’ll consider it a success.

I did read quite a few threads and on other blogs, folks having issues with the timing chain skipping a link on them.

I noticed going back on with my chain there appeared to be more slack in the long side, exhaust, side of the chain. I played around with the chain to see how easy it would be to get a link or tooth off in the timing.

Having read the Toyota timing chain instructions, especially on the release of the chain tensioner, I saw it would be real easy for the slack in the chain to drop down below the crankshaft timing sprocket and fall off the sprocket. Without the tensioner in place to keep the slack out. I actually had the chain skip a link on two out of three tries.

So I hit the Internet and YouTube to see if I could find any ideas on keeping the chain in place and releasing the tensioner without using the method Toyota recommended, placing the chain in the guides, then install timing cover, then tensioner, then turn the crankshaft counterclockwise slightly to force the tensioner to release.

With the amount of slack in the chain on the exhaust side, it could easily fall off the crank sprocket and possibly skip a link before the tensioner released.

I dreaded the thought of the chain skipping a link after installing a FIPG timing cover. Also after speaking with a local Toyota technician, who said, Good Luck with the timing chain. I watched a guy in YouTube show how he installed a tensioner on a 1.8 and then released it by reaching down in the timing cover with a long screwdriver and pushing the tensioner guide shoe back towards the exhaust side. You could hear the ratchet mechanism release as the tensioner tightened the guide shoe and chain.

From there I came up with a idea to secure the chain in place on the crankshaft timing sprocket and then release the installed tensioner without turning the crankshaft counterclockwise and risk the slack in the chain falling off the crankshaft sprocket.

I wanted to get the chain right the first time. I took a piece of 90 lb. nylon coated braided stainless leader material about 18 inches long. I then held the chain tight to the crank sprocket and slipped the leader material through a chain link on each side of the chain then doubled it together and placed a small cable tie around the two loose ends. I then fed the doubled leader string out through the timing cover crankshaft seal which I lubed with a little grease.

I then installed the timing cover dry with a few bolts hand tight and the chain tensioner. I taped up the end of a long heavy screwdriver, then reached in and pushed back towards the exhaust on the chain and guide shoe. This released the tensioner and took the slack out of the chain.

I knew the success of my idea depended on being able to remove my temporary leader material, that held the slack out of the chain, from the crankshaft sprocket. I cut the cable tie holding the two steel leader string ends together, and just as I expected the nylon coated steel braided string gently slipped out by releasing one end and gently pulling the other.

After the successful dry run, I installed the new o rings, slipped my leader material back in place with a new cable tie, put the Toyota brand FIPG seal packing on the timing cover fed the two loose string ends though the crank balancer seal and installed the timing cover.

I then properly installed the timing chain tensioner and released it with a screwdriver. Then I gently slipped my leader string out of the chain and cover between the balancer seal and crankshaft. All three of my main timing chain marks never moved. The tensioner released maybe a quarter of its normal range and properly tightened the chain.

I lubed everything real well and cycled the chain through its complete rotation, aligning the exhaust cam and timing mark at 12 o’clock, the intake cam and it’s dual marks at 2 o’clock, and the crankshaft timing sprocket at 3 o’clock and the crankshaft Key way at 12 o’clock.

Anyone feel free to try my hack, but if you forget to remove the string and destroy your timing chain, it’s not my fault.