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Please Help - 86 Corolla 4AC Oil Leak - strange issue with timing belt cover

Hi folks,

I appreciate any help from the Toyota repair guru's out there ... I'm far from a guru so please excuse any wrong words/descriptions. Thanks for your help!!.

I'm working on a 1986 Corolla Sedan, Auto 3spd, power steering, 4ac engine with 205,000 miles, unknown history, and a severe oil leak.

I traced the leak down to the the lower timining chain cover and area around the harmonic balancer. When I removed the balancer, I was shocked to find that it was litterally scraping and creating a gouge in the timing chain cover (it's plastic, and this caused an entire side of it to break off) and also found the balancer rubbing along the oil pan edge (amazing it didn't catch fire or something).

I have no idea how this could happen as I'm not familiar with Toyota engines. Were spacers left off at some time in the past, or has this well used engine simply worn internally so severely that it's beyond tolerance/clearance? The funny thing is, other then the oil leak, the car runs really well.

So, I'd appreciate some advice. Should I replace the lower timing chain cover and let the balancer rub in again? Are there shims I can use somehow? I'm worried that if I pull the timing chain cover in it's damaged condition, it wont be replaceable unless i use a new one, so i want to be sure I'm doing the right thing.....help!!

Zac

Reply to
ZacInAus
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The oil leak will continue if all you do is replace the lower timing chain cover and let the balancer rub it again.

Some possible causes are a worn or damaged front seal, worn or damaged thrust washers, and worn or damaged crank shaft bearing, in that order of likelihood. Any of those items, left in worn or damaged condition, could lead to accelerated wear.

If you have an oil pressure gauge and oil pressure is low at idle, worn or damaged crank shaft bearings could be the cause. If there is fore-aft play on the crankshaft/balancer, then worn or damaged thrust washers could be the cause. If the crank bearings and thrust washers are Ok, then the front seal is the likely culprit. I have never heard of parts left out of an engine at the factory. I have heard of thrust washers falling out, but that was on a different engine series.

If you are going to spend money, then fix the root cause of the problem. The timing cover is more of a dust cover - it doesn't hold pressure so you may be able to get away with silicone, epoxy, cement, or duct tape to hold the timing cover in place if you do not want to replace it with a new one.

Reply to
Ray O

Ray, thank you so much. I'll continue work on it in the morning and let you know what I find. This is a huge help.

Z
Reply to
ZacInAus

You're welcome and good luck!

Reply to
Ray O

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