[Landrover]

Same here, wife's vehicle is 2005 vintage Mercury Mariner with 208K miles and we're watching the Bronco with great interest. I'm hesitant to buy the first year of any vehicle model (especially a Ford), however...

Yeah, I am hesitant to buy first year too after the issues with my FJ, but if I'm not mistaken, the two available engines on the Bronco have both been around for quite some time now. Not so sure about the transmission.

Landrover -

If I am reading your posts correctly, you have been having P0016 issues since ~40K miles.

Did you purchase this vehicle new, or as a used vehicle?

If used, was there a complete service history available covering the period prior to your purchase?

Finally, have you pulled the inspection plate over the chain tensioner and confirmed that the chain is elongated by the distance that the tensioner plunger is extended?

If your plunger is NOT grossly extended, your timing chain is NOT excessively worn, and there are other conditions that can erroneously trigger the P0016 code, like cracked or very slightly bent reluctors on the cam phasers.

Certainly 40K miles (or 100K miles) is an unacceptable life for a timing chain IF the specified oil change intervals were
followed using the correct oil.

The fact that many 1GR-FE engines achieve 300-400K miles with their original chains indicates that there isn't a fundamental design flaw in the engine.

Since 80K actually. Purchased new and did all the maintenance on it as per schedule myself. Have NOT pulled the plate, but everything points to this exact issue. Changed out cam sensors and crankshaft sensor (what a waste of money) with no change.

 

[FJtest]

Yeah, I am hesitant to buy first year too after the issues with my FJ, but if I'm not mistaken, the two available engines on the Bronco have both been around for quite some time now. Not so sure about the transmission.



Since 80K actually. Purchased new and did all the maintenance on it as per schedule myself. Have NOT pulled the plate, but everything points to this exact issue. Changed out cam sensors and crankshaft sensor (what a waste of money) with no change.

Would it be possible to pull the little inspection cover and take a look at the tensioner position?

If you've actually performed oil changes per the maintenance schedule, the chain should should not be elongated enough at 80K miles to exhibit the P0016 fault unless there is truly some defect in the timing chain.

Pulling the little cover will reveal the truth ...

When you replaced the crank and cam sensors, did you also pull and inspect the oil control valves, and the oil filter screens? If the engine oil was actually changed per schedule that engine should be absolutely pristine inside, but just confirming that the oil control valves and screens are in perfect condition is another thing you should check before 'giving up' on the vehicle.

 

[Bushav8er]

Awesome write up! Thanks!!


Sent from my iPhone using Tapatalk

 

[Landrover]

Would it be possible to pull the little inspection cover and take a look at the tensioner position?

If you've actually performed oil changes per the maintenance schedule, the chain should should not be elongated enough at 80K miles to exhibit the P0016 fault unless there is truly some defect in the timing chain.

Well that's just the thing isn't it? The chain should NOT stretch so much that the tensioner moves all the way out, but as you can see in Waypoints posts, his tensioner was fully extended as well and he has surmized that the issue was caused by a bad batch of chains:

"I really believe that Toyota got a defective batch of timing chains, given every case I find is a 2007 or 08 1GRFE. I haven't found a single instance of 2003-2006 4Runners, or 2009 FJ/4Runners, having this problem. The original manufacturer of these chains is unknown, as the manufacturer ID mark on the endplates doesn't seem to be traceable."

I have no doubt that this was a chain issue and that it was most likely only in the very earliest of models (I bought my 2007 FJ in July of 2006).

 

[FJtest]

Well that's just the thing isn't it? The chain should NOT stretch so much that the tensioner moves all the way out, but as you can see in Waypoints posts, his tensioner was fully extended as well and he has surmized that the issue was caused by a bad batch of chains:

"I really believe that Toyota got a defective batch of timing chains, given every case I find is a 2007 or 08 1GRFE. I haven't found a single instance of 2003-2006 4Runners, or 2009 FJ/4Runners, having this problem. The original manufacturer of these chains is unknown, as the manufacturer ID mark on the endplates doesn't seem to be traceable."

I have no doubt that this was a chain issue and that it was most likely only in the very earliest of models (I bought my 2007 FJ in July of 2006).

Yes on every point, but as we have seen on this forum, there are a few other conditions that can occasionally trigger the P0016 other than an elongated chain.

If you have maintained your engine 'by the book', you should not have sludge or an elongated chain at your mileage.

I was just asking if it was feasible for you to pull the inspection cover and take a quick phone photo of the tensioner's extension. This would be a useful datapoint in confirming that a properly maintained 1GR-FE CAN experience an elongated chain at relatively low mileage.

There are quite a few '07's and '08's on this forum with fully documented oil change histories that are at 250K or 300K miles (or some with far more than that) still running their original timing chains with no issues. What would REALLY be interesting is to look at the timing chain manufacturer's mark on the side plates and see if there was MORE than one chain supplier, and if there is, if there's a higher incidence of P0016 problems with one supplier than the other.

Looking at one very dirty chain removed from a sludged '07 with "timing chain problems", it's marked "UZ", "JAPAN", and "390".

 

[Landrover]

I suppose that's something I can do, but if I recall they did that when I first brought it to Toyota for diagnosis. Maybe if I get a chance, I'll pop it off and take a photo and post it up on here.

And yes I did all the maintenance at the required intervals which should have alleviated any chance of "sludge" building up and causing issues such as a clogged oil intake screen. 5W-30 at LEAST every 4500 Miles as per the dash cluster reminder. Then again, as has been pointed out, there have been plenty of instances of engines with sludge build up and no chain stretch/P0016 code, so between that and my maintenance I still see this as a bad chain, albeit limited to only some '07's and '08's.

 

[7TH_SIGN]

2008 model year with 120k miles. Just purchased and P0016 CEL came on the day after taking ownership. The dealership knew about the CEL and thought they repaired the issue by replacing the crank sensor. Tomorrow they are replacing the camshaft and crankshaft sensor (again) and checking the harness to ensure there is no damage. They are also replacing bank 1 OCVs under my request.

I have researched this P0016 religiously and I personally believe its the timing chain needing to be replaced.

 

[ZoSoIV]

2008 model year with 120k miles. Just purchased and P0016 CEL came on the day after taking ownership. The dealership knew about the CEL and thought they repaired the issue by replacing the crank sensor. Tomorrow they are replacing the camshaft and crankshaft sensor (again) and checking the harness to ensure there is no damage. They are also replacing bank 1 OCVs under my request.

I have researched this P0016 religiously and I personally believe its the timing chain needing to be replaced.

yeah I’d bet it’s the timing chain , that’s a $3000 repair everything has to come off to get to the chain

 

[7TH_SIGN]

yeah I’d bet it’s the timing chain , that’s a $3000 repair everything has to come off to get to the chain

What I find strange is the check engine light will come on for a day or two then go away on its own for as long as a week before returning.

I was really hoping it wasn't the timing chain however after reading all the P0016 threads, both here and on other 1GRFE sites, it seems to be the cause 9 times out of 10. Sucks as it only appears to be 2007-2008 vehicles mostly.

We will see if the dealership pays for the timing chain replacement as they said they would. I honestly rather pay a couple thousand now then have years of car notes. I was hoping to take the FJ from 120k to 500k miles. I really enjoy the driving it.

 

[ZoSoIV]

I seen more 2008s have trouble

 

[7TH_SIGN]

Crank sensor, Cam sensor, and bank 1 Intake OCV replaced today. If the P0016 comes back the dealership has agreed to replace the timing chain.

 

[ZoSoIV]

Good deal

 

[7TH_SIGN]

So I’ve put 170 miles on it, so far no check engine light, however I’m still not certain it won’t return. Need to drive it more.

I did notice something after the Bank 1 Intake OCV and Camshaft Position Sensor were replaced. The engine is much more quieter now. Prior to these two components being replaced you could hear a prominent “ticking” sound coming from the valve train once the engine reached normal operating temperature (could not hear it when the engine was cold). That’s now gone. Not sure why though.

Any thoughts?

 

[ZoSoIV]

The sensors corrects the timing ,… hopefully it holds up

 

[7TH_SIGN]

P0016 Solved Finally!!!

After months of chasing this damn code it’s finally over and fixed. I changed out the OCV, Crank and Cam Sensors only for the P0016 to come back.

Measured and checked timing chain which was within spec. No sign of stretch or damage.

Upon close examination of the wiring harness to the sensor found it to be damaged, causing the code.

FJtest called it out in another P0016 thread. He was correct. Check your wires! Thank you FJtest!

 

[norm356]

186k miles vehicle with chain wear, pic of the factory tensioner showing the discoloration rings.

Question: Does anyone know what the design nominal chain tensioner extension length, and its service limit are?

I've been all through this forum, and through the shop manuals, but have not been able to find a value.
This photo of the one from a badly worn chain engine (with tragic amounts of sludge in) shows how far out it had got to (the final dark ring):

This is a photo of mine today, 120k miles, 15 years old, 5k miles oil change intervals.

It is hard to measure precisely because of the angle, but let's say 8mm:

Comparing the first dark line on the tragic one above, with mine, the plunger in mine looks like maybe mine hasn't worn yet (or if original was, say, 6mm, the wear is small, compared to the worn one).

I'd decided to check it today after reading this thread in which it was suggested '07s and '08s had premature wear. My June built '08 seems to be doing well.

Norm

 

[FJtest]

The FSM does have a timing chain elongation spec, but measuring it requires that the chain be removed from the engine, hung vertically with a XX kilogram weight at the bottom, and the distance between YY links measured with a caliper.

(I can't find the reference right now for the specified weight and number of links to be measured, but I have it archived on my laptop at home.)

Ridiculous in my opinion, as I can't imagine anyone going to the effort to remove a used chain and not replacing it with a brand new chain as SOP.

 

[waypoint]

That's my old factory tensioner from the 2018 chain project. Yours is in excellent condition, I didn't measure my plunger length when I reassembled the timing system with new Toyota parts, but that looks exactly where the plunger set itself after two crank rotations.

Yours is a big win for good maintenance practice. What oil do you use?

Question: Does anyone know what the design nominal chain tensioner extension length, and its service limit are?

This is a photo of mine today, 120k miles, 15 years old, 5k miles oil change intervals.
...
It is hard to measure precisely because of the angle, but let's say 8mm:
View attachment 1215765

 

[FJtest]

Found it - measurement of timing chain wear (elongation).

This description shows a spring force gauge used to apply tension to the chain for measurement ... I'm pretty sure an earlier manual said to hang the chain vertically with an XX Kg weight at the bottom during measurement.

This covers both the primary chain, and the two secondary chains (#2 chain).

 

[norm356]

"What oil do you use?" - I've only owned this for 40k miles, or 1/3 of its life so can only say Mobil 1 5w30 since then. The service record showed the original owner had been changing it every 5k, so that's probably as much the reason why its so clean, as much as brand.

Someone asked Jerry Lee Lewis's manager, "does he ever sleep?", and his manager said, "Well, I've only represented him for two years, so can't say for sure how much beyond that."


Norm