Timing CHAIN

[manp0899]

My T4R survived Hurricane Irma barely. As soon as I got back to FL my car started acting weird. Check engine light with VSC off and such. I went to the mechanic to take a look at it, on the way there the car stalled. the engine light was no longer there and they figured it was throttle body and cleaned it out. Next day I had a similar issue the car was idling rough but no extra sounds. I whipped out my OBD2 and collected to codes myself. Found P011 and P0016. VSC wasnt on but the ABS light was blinking. Mechanic said it's the chain and has to be replaced and it would be over $1500 job. We figured the sensors got messed up from the water/moisture, tons of cars in FL are having weird car trouble, moisture messed up the sensors which then possibly messed up the chain.

I am probably going to take it to toyota dealership tom to do a diagnostic again and distinguish between the chain and sensors. Someone suggested to check the tensioner plunger, if it is pushed then the chain is stressed, if not then sensors need to be changed.

The car has high mileage but never even idled off until right after the hurricane. One person said I should just get a used engine and out it into my truck..to be honest I rather fix my engine and take the hit but I hope its not that steep in price. This job is way out of my expertise.

 

[lbhsbz]

Hard for the chains to jump time unless the guides broke...and you'd hear a whole lot of clanking if that were the case.

How's the oil look?

Those codes generally mean the VVT isn't getting the expected results...sticky actuator or clogged screens in the oil pressure circuit.

I'd start with an oil change...if there is sludge in the actuators, that sometimes loosens things up.

With a real scan tool, you can actuate the VVT solenoids and watch the cam timing change to confirm that the system is mechanically capable of working correctly.

 

[4Reak Show]

You can also add about 1/2 quart of high quality ATF (Honda brand is really nice) in place of engine oil. It has strong detergents and breaks loose deposits. Used this method a few times on other vehicles with good results.

 

[manp0899]

I actually did get an oil change when I wanted to get this problem evaluated initially.

I don't think it made any difference. The odd thing I cant really explain, other than failed sensors, is why the ABS starting blinking and the VSC lights turned off while the check engine light is still on. The mechanic at Firestone is pretty helpful but in this case just said its a lengthen chain and did not bother diagnosing it.

Hopefully my insurance for the hurricane can cover it since I believe it to be a failed sensor.

 

[lbhsbz]

Whenever an engine trouble code is set, ABS and VSC are disabled...those lights always come on (mostly always) whenever the check engine light comes on...and will go away on their own once the fault is addressed. You can ignore them for now.

 

[waypoint]

I'm battling a stretched timing chain in my '07 that causes an intermittent P0016 under very specific conditions...cold engine, low RPM high load.

I know it's stretched because the #1 tensioner piston is extended nearly 3/4", whereas on pics I'm finding they are usually around 1/4". The piston has varnish discoloration on the first 1/4", the rest of the exposed piston surface was shiny metal.

The original owner wasn't a fan of oil changes as shown by CarFax records and the amount of sludge inside the passenger side valve cover. The soot in degraded oil is known to accelerate timing chain wear and elongation (stretch). I'm not inclined to spend $400 in Toyota timing kit parts and a weekend disassembling the front of the engine given the condition it's in...but it runs very well apart from the intermittent P0016. I'm running Shell Rotella T6 0W-40 diesel truck oil in it to gently clean out sludge...turns black after around 700 miles at which time I change it and repeat.

In your case...did the truck get submerged in water? What does the oil dipstick look like immediately after shutting down the engine? Amber motor oil, or chocolate milk (emulsified with water)? Is there water under the carpeting?

 

[084RUNNAH]

You will need new timing chains, guides and tensioners. The timing chain has stretched due to wear. I've done 3 where I work ( two FJs and one Tacoma).

Sometimes, on cold start, you will initially hear a rattle which would last 1-2 second.

 

[BlackWorksInc]

Most likely stretched timing chain, seen it on a couple FJ motors. You'll need new hardware like the person above mentioned.

 

[nevada]

Most likely stretched timing chain, seen it on a couple FJ motors. You'll need new hardware like the person above mentioned.

but wait, I thought these chains were a non-serviced part. "good for the life of the engine". or at least that is what a lot of people on the site are saying...

 

[4Reak Show]

but wait, I thought these chains were a non-serviced part. "good for the life of the engine". or at least that is what a lot of people on the site are saying...

Under perfect instances, you are correct. I've replaced a handful of chains on various makes/models due to poor maintenance. Generally the guides which are plastic wear out first and then eventually the tensioners run out of room to tension and max out. Then the chain either jumps or is out of whack enough to throw off cam/crank timing. Stretching isn't as common from what I've seen, but without lubrication the chains can give out too.

Let this be a reminder to change your oil!

 

[BlackWorksInc]

but wait, I thought these chains were a non-serviced part. "good for the life of the engine". or at least that is what a lot of people on the site are saying...

I mean they're right... when the chain breaks it usually breaks the timing cover and other bits.. by the time you price it out you might as well replace the engine or rebuild it... Yes it lasts the life of the engine up until it doesn't.