Timing chain stretch.

Hi Tundra owners:

I have a 2010 Tundra 5.7L with ~60k miles. The engine (symbol) warning light just came on (called the "malfunction indicator lamp"), also low oil pressure (instrument panel pressure gage). The (independent) shop is telling me the problem is the timing chains have stretched and they need to be replaced at a cost of $5k! They say Toyota is quoting about the same price. They are saying "could be caused by not changing the oil often enough", which isn't the case here. I meticulously change the filter and oil at the recommended 7,500 miles or less (don't use E85).

I occasionally tow a small (7,000 lb) 5th wheel and usually don't use the Tow-Haul mode, but downshift on grades. Maybe that is a mistake (not using Tow-Haul).

Has anyone had experience with this? Is this really a $5,000 job? Any idea how much the parts would be for this?

Thanks in advance for any thoughts,

ParagonSteve

 

Maybe it’s just worn out tensioner‘s

 

I'd have Toyota verify that as in drive/tow it to them. I've NEVER heard of a UZ or UR motor needing a TC that soon....EVER

 

sounds like a ton of BS to me. The entire point of timing chains is that they don't stretch. I mean, they will, everything will, but the stretch factor will be next to inconsequential in terms of the issues you're experiencing.

As for the tow/haul... i'd start using that if i were you, I didn't and nuked my lockout in the torque converter in a Toyota 4runner

 

I'm not a mechanic. The chains are/were designed for the life of the engine and are internally lubricated. It would be highly irregular for this to occur. I'd be suspect of your mechanic. Do you have MIL/Code? That would be the ideal place to start.
These VVT engines are pretty sophisticated, I'd choose my mechanic wisely.
Any other symptoms? Backfires, loss of power, etc?

 

Belt = stretch
Chain = break

 

I think they’re full of shit. Maybe it’s just an electrical issue somewhere. Check for chewed wires. Maybe your oil pressure sending unit is bad or the wires got messed up. I think that’s pretty low miles for any type of issue like that. $5000!

 

Do our trucks change the lock out on the converter when in tow haul mode? I thought it just changed the throttle sensitivity and shift points.

 

honestly, i'm not sure, but after my last experience, i press the button if i'm towing... or in a bad mood and just need to hoon it for a while

 

Hahahahaha me too. I always use tow/haul when I’m towing. I mean that’s what it’s for right? I know it doesn’t give you more horsepower but it tricks my mind into thinking it does!

 

So I am by no means an expert But I believe that the oil pump on your motor is driven by the crankshaft. So the timing chains would not cause low oil pressure. Also The 5.7 has a great reputation for not having any timing chain issues. I would Highly advise you to find another shop to give you a second opinion.

 

Have you checked your oil level? The chain tensioner works by oil pressure. If the oil pressure is truly low that would explain the loose chain.

 

Yes, it is highly irregular that a timing chain would stretch or break (they're made to outlast the life of the truck, as others have stated), but I'm here to tell you it can happen. Because it did happen to my 08 Tundra 5.7L 3URFE engine at 146k miles. Here's the sequence of events. The Check Engine light came on. The local Toyota dealer ran extensive diagnostics and said my timing chain was stretched. They said they'd fix it to the tune of $6700 parts and labor. Ouch! Because the truck was running perfectly, I was naturally a little suspicious of their diagnosis. I said to the service rep "but it's running perfectly!". And he responded "well, I'd just keep driving it then." And so that's just what I did, thinking to myself "well, if it IS the timing chain, I'll certainly know it once it breaks or skips a tooth, and THEN I'll get it fixed." Little did I know it was a ticking time bomb due to the fact (unbeknownst to me at the time) that this engine is what they call an "interference" engine. This basically means that if the timing chain breaks or skips a tooth, congratulations you just instantly ruined your engine. Google "interference engine" and you'll understand why. That little piece of information would have been very helpful had the dealer's service rep bothered to warn me about the consequences of continuing to drive it with a stretched chain.

I'm telling this story with the hope others will not make the same critical mistake I did. If you are told your Tundra's timing chain is stretched, and you are told this from a trusted service department or other mechanic, bite the bullet and get it fixed ASAP!!! Yes it's frustrating because it's not supposed to happen, and yes it's an expensive repair, but it pales in comparison to the cost of an entire engine replacement or a rebuild. So unfortunately I'm now looking at a $10,000-$12,000 expense for another engine. And sadly, that's more than the dang vehicle is worth on a trade.

 

While it's possible that a defective TC made it into a vehicle it's more likely that there's another problem that caused the TC to stretch. My 4.7 had a timing belt that had to be changed roughly every 100k. It wasn't optional. To do it you had to pull the front of the truck apart so most people would change the idler pulleys and the water pump. And the belt would dry rot and crack so the mileage wasn't the only determining factor. Most brands have gone away from them because chains just last much longer. If it was me I wouldn't just change out the chain and call it good as you can expect that it's most likely going to fail again and much quicker.

As for $10k to $12k to replace the motor? Are they replacing it with a brand new motor? A used one can be had for $3500 and a reman one for about twice that.

 

Found this post doing a search for self-diagnosing a timing chain or belt issue on my 2014 Platinum with roughly 160,000 miles. Just a quick bit of information. I used to have a B7 Audi S4 that had a 4.2L V8 ran by a timing chain. The timing chain service for it was anywhere between $12,500 and $15,000. Required the engine to be pulled because the timing chain was at the back of the engine, and the parts alone were outrageously priced. So the quote for your Tundra's timing chain service doesn't seem too far fetched to me. As previously stated, the timing chains are SUPPOSED to be designed to outlast the engine. Was also SUPPOSED to be the case with the Audi.

 

As above I found this listing when I was searching for Timing Chain issues. I have a 2010 5.7L. I was running rough at start up and sounding like dieseling until it warmed up. It gave now lights or codes, a month and a half later I was driving home from town, got on the free way going up hill and when I reached 65 MPH, I heard a snap and the truck started running like crap. I pulled over and shut it down. I checked the codes, the only one shown was the Cam Shaft Sensor, I replaced that and it still wouldn't start. Had it towed to a reliable shop, after two weeks and numerous test they were afraid it had jumped time or other worse scenario internal to the engine. The shop owner did not want to go any deeper as it would possibly require a full engine re-build. I had the truck towed to the closest Toyota dealership, after a week sitting they checked it, pulled the timing chain cover and found that the Timing Chain had snapped. They said they had never seen this nor heard of it. I am still waiting for the repair to finish, but looking at over 6K in expenses and repairs.
This is not the only forum that is displaying issues with the 5.7 engine having intermittent issues with the Timing Chains or Tensioners.

 

A failing tensioner may of been the cause to your chain breaking. That noise you described is the normal tensioner issue. Did they mention which chain broke? I’m guessing the driver side chain did.


That being said working at the dealer for 7 years now I’ve yet to see a 5.7, 4.6, or 4.0 fail

 

PARAGONSTEVE, sorry for your unfortunate situation. It can stress one out big time.

You could say I’m from the old school. You could also say this is a rare problem. My personal opinion is to let the engine run for at least 3 minutes at first start up of the day. Drive easy until the water temperature starts to climb. This will ensure good oil circulation before unleashing the engines power. I say this because a lot of folks at work start their engines drop it into drive and go instantly. Also in my opinion, give the engine oil a chance to pressurize the engine. Oil pressure does not come instantly. The 0W20 helps the oil to travel through the engine much faster then a 10W30. The shear point on the 0W20 is much better then the 10W30. The 0W20 supposed to help with the fuel mileage as well. If you do a lot of towing the oil should be changed every 5,000 miles, I would use a 5W20. This comes from a lubrication engineer from Mobil 1. Hope I brought some light to this topic.

 

Something else I’d like to add. At least once a year I have a engine oil sampled by Blackstone Laboratories. So far so good thank goodness. It’s like a blood sample to see what’s going on inside. Like anything else, early detection of any issues helps prevent big problems. Happy motoring.

 

I've extensively researched high speed chain technology. They get longer due to wear rather than the side plates actually elongating.

The additional length is realized when the pin-to-bushing interface begins to wear. You can detect that kind of wear by pulling the chain taut and measuring the length of two distant pins... say 50 links on a silent timing chain.

Another mode of apparent lengthening that has nothing to do with the chain links at all is sprocket wear. As the sprockets wear they become smaller in diameter. This is mis-diagnosed as the chain getting longer or stretching.

Since in 5.7 application the chain and sprockets are liberally lubricated I'm inclined to suspect the plastic guides or the hydraulically assisted tensioner.

Regarding the reported instance of a snapped chain I'm wagering the chain was put into a bind after jumping off a cam sprocket and yanked apart directly after.

 

Hagrid
I’m inclined in every aspect to what you’ve mentioned. Today there’s oils that lubricate, and oils that really lubricate. I believe that what you made clear has a lot to do with oil lubrication. Being slippery is the key to longevity. As far as I’m concerned the oil that Toyota uses is not the best oils. They just do the job, it’s not the best. Today a lot of folks are in a hurry, and that also takes a toll on the chains, sprockets and everything else the oil passes through.
There’s an old saying.
The dearest is the cheapest in the end.
Thank you for a very good input. I bought a Toyota Corolla new in 1998, I’ve always used Mobil 1 from the first oil change. I sold it a year ago and it’s still running as strong as ever. Never ran it hot either. It still has the original clutch in it.

 

The tensioner on the driver's side of the 5.7 is half way down the guide due to packaging issues (there is a coolant passage further up). these means the tensioner doesn't have nearly as much leverage and has to work a lot harder.

I got my truck dirt cheap because the tensioner had failed and the chain was extremely noisy. on disassembly it had broken the far driver's plastic guide and was wearing away the steel backing plate. It was also eating into both the block side and the cover side from whipping around so much. I was very lucky to be able to save the engine.

Timing chains on 5.7s are a fairly common issue if you search around for it, mostly due to the driver's side tensioner.

Not all timing chains are created equal, there are some that will far outlast engines, and then there are others with design flaws like the 5.7 that aren't quite as lucky.

 

Wow! I’m assuming you did this all yourself from what I read. Good on you. I’m happy the engine was saved along with you, that’s awesome!

Friday I get to see what kind of shape the inside of my transfer case is looking like. I got flakes of aluminum out of it when I drained the oil. I have a bearing growling, I’m not liking it too much.

 

I haven’t read all the replies on this thread so if I repeat what anyone else said, I’m sorry. I’m a Toyota Master Technician and I believe the timing chain story is incorrect. If the oil pressure is low it is probably causing camshaft/crankshaft correlation codes because the VVT-i system uses oil pressure to adjust the camshaft timing. Find the source of low oil pressure. I have seen the center support tube for the oil filter missing (oil change done incorrectly) resulting in the filter collapsing and causing low oil pressure.

 

Hello Brian, I have a question for you. In your opinion, pulling a 6,300 lb. RV using regular gasoline (87 octane) I feel the low octane fuel is not the best to use. I’ve been using 92, or 93 octane since day one feeling it’s better for the VVT-I ( I know the VVT-I has to do with valve timing). I’m not a 100% sure what the VVT-I does, or is. I’d like to hear you opinion. Thanking you in advance,
Anthony C

 

I have tested the tow/Haul mode with my trailer to see what the difference is. When driving with the switch on the throttle is more sensitive and will shift down much quicker. It does not let the truck get behind the power curve. With the switch off you have to mash the throttle down way more for it to down shift. That is about all there is to it. Plus you get worse MPG when the switch on but you won't loose the power.

 

Hi Anthony, good question. Octane is basically a fuel’s resistance to detonation. The higher the octane level, the more even the burn. The 5.7 has a compression ratio of 10.2:1 and the VVT-i allows the computer to adjust when the valves open and close within a given set of parameters. This allows the engine’s volumetric efficiency to be adjusted depending on load and demand (how hard you are pushing on the accelerator). This is also why the 5.7 does not require an EGR system as the engine can accomplish the same basic result by varying the amount of overlap (time that both the intake and exhaust valves are open simultaneously). I’m not sure why but the 4.6 version does have a dedicated EGR system. On the fuel, I’ve tried 93 and 87 and my rig seems to run the same with either. That being said, there is probably a bit of performance (in theory) to be gained as the higher octane fuel would allow the engine to have the ignition timing a bit more advanced.

 

Thank you Brian. In my mind I felt the 93 octane would allow a little more power, and allow the timing to advance at the upper RPM’s. I just couldn’t put it the way you did. Thanks again.
Anthony C