Timing chain problems 2.7 liter 3RZ-FE

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May 26, 2006
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Ecuador
Balance shaft bearing failure: Prado 3RZ-FE engine (2.7 liter)

I live in Ecuador and recently purchased a very clean and smooth running 2006 Prado with a 2.7 liter gas (2693cc) 3RZ-FE, with just 50,000 miles on it. Recently, after some 3,000 miles of easy driving with my new truck, I decided to make a road trip to the coast. After about five hours of easy highly driving I began to hear a rattling in the engine. It sounded like marbles towards to front of the engine, near the timing chain. With the limited tools I had on hand, I took off the valve cover, but could not find anything unusual. The lifters and guides appeared to be in tact; the chain and tensioner looked in good order, the bearings from the alternator and oil pump were good. To be safe, I called in a platform and had the truck towed to the nearest city -- some five hours away. After careful inspection, the mechanic informed that the timing chain and tensioners had to be replaced, but he did not find any other problems. Further inspection identified a balance shaft bearing failure.

My concern is what could have caused this problem in the first place? Have others experienced this sort of problem with the 2.7 liter engines (also common in Hilux and Runners)? Should I be worried about past mistreatment of the engine? I have two 70-series LC (3F and 22R engines) and have never had this sort of engine problem...

Thanks in advance for any advice or thoughts you might be willing to share.
 
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Joined
May 26, 2006
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I wrote too fast. The mechanic I am working with just completed the tear down. We found that the seal from one of the oil circulators at the base of the block had disintegrated, blocking the oil pump and leading to the damage of the timing chain.

When I contacted an engine shop in Quito, the folks there told me they had made at least 15 of these sort of repairs to Prado in the last two years. Oddly, I have not seen related comments at this site or elsewhere on the internet. Maybe this is limited to a motor sold in the Andes. My opinion of Toyota LC just dropped a half dozen notches! Will post a few images tomorrow.
 
Joined
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balance shaft failure

As promised, I am sending attached a foto report in a pdf document. This provide further details. I have three questions:

-- Do you foresee a problem in eliminating the balance shafts and weld up the holes in the block?
-- Has anyone experienced this sort of problem before in a 3RZ-FE motor (or anything similar)? The local machine shop believes its a design flaw...
-- Any other thoughts or advice? Should I be looking for a new block?

Thanks!
 

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Hola Shuma!!

I have a 2007 90 series Prado 3RZ FE like yours!

That's a rare problem.

On the contrary, I have read many good things about 3RZ engine.

I read that you can remove the balance shafts.

The 2.7L, 3RZ-FE petrol engine has a cast-iron block and aluminium cylinder head.
The valves in this engine can be prone to burn damage. This is generally caused by the valves wearing and not contacting the cylinder head properly, which leads them to overheat.

It is essential to ensure that regular servicing has included valve clearance checks to reduce the risk of getting stung for the cost of replacing valves. Compression testing can help show up faults.

PRADO PERFECTION | Australian 4WD Action

One of my favorites websites!

Other links that may interest you:

http://www.customtacos.com/forum/showthread.php?t=143039

http://www.tacomaworld.com/forum/4-cylinder/64499-3rz-balance-shaft-delete.html

http://board.marlincrawler.com/index.php?topic=54964.0

http://www.toyotacatalog.net/M1WebG...UniqueID=8BBEF063-67CB-49BC-B322-290943276929

http://www.google.com/url?sa=t&rct=...sg=AFQjCNFWxA2Fx68DQdiC7gzxwvVQHyg5mg&cad=rja

Saludos
 
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Joined
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Messages
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Ecuador
Consider removing your balance shafts!

After a few days of research on the internet and consultation with mechanics and engineers, I found a large number of cases of balance shaft bearing failures in Ecuador, the US and beyond. My machine shop in Quito has serviced 15 of these in the last ten years. This is occurring in the 3RZ engines as well as similar in-line four cylinder engines that suffer from inherent vibration problems, such as those found in Mitsubishi's and KIA/Hyundai's. It is so common in the 3RZ that folks have an acronym for it (Balance Shaft Elimination or BSE) and LC Engineering in Arizona sells a balance shaft elimination kit for helping people correct the problem, as well as for racers who seek BSE as a means of increasing horsepower.

Believe me, a balance shaft bearing failure can be expensive. Not only did it strand my family (including a two-year old child) and me in the middle of nowhere on the Ecuadorian coast, I have had to remove the engine and machine parts of the block and rebuild my engine (the valves were not affected).

Mechanics and engineers familiar with this technology inform that the balance shafts play no role in decreasing engine vibration. The in-line 4 cylinders inherently suffer from vibration problems. All the balance shafts spin in reverse directions to the camshaft at twice the rate of the engine RPMs, which generates considerable force on the bearings. All they do is dissipate the already generated vibration for rider comfort. They play no particular lubrication function (other than a small jet that sometimes exists at the pinion for lubricating the timing chain; LC Engineering sells a replacement jet).

Yes, you can feel the difference when standing still and revving the engine at 3,000 RPMs, but it quickly disappears once you get started. My All Terrain tires easily generate a greater degree of vibration in the pilot cabin. In addition, driven directly by the camshaft, the balance shafts consume horsepower (between 5-15 hp, depending on how you measure and who you believe). The only potential concern may be increased oil pressure, but no one I communicated with has experienced associated problems.

I would recommend that folks keep an eye on their balance shaft bearings (how without removal of the engine, I don't know!), but keep your ears open for the earlier described marbles... By removing the oil pan, you can reach the balance shafts which lie just above and to either side of the camshaft. If you feel any movement in the shafts, you may have a serious problem in the making... In the event of needing to remove your engine for other purposes, I'd recommend a BSE. I'll report if I have any problems down the road, but from the multiple experiences out there, I do not expect any.

For a nice summary on the issues at hand with regard to BSE (from a Mitsubishi technical forum), see:

Eclipse Balance Shaft Removal

If you are interested in obtaining a balance shaft removal kit for the 3RZ engine from LC Engineering, see:

http://www.toyotacatalog.net/M1WebG...UniqueID=8BBEF063-67CB-49BC-B322-290943276929
 
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Estimado MDST,

Yes, I've opted for getting rid of them. The machining and replace of the shafts would have cost about $400, and I would continue to run the risk of another failed bearing in the future.

The LC Engineering kit is not really necessary if you have a good machine shop, but I like it for the small oil jet that it provides for lubricating the timing chain (see the attached instructions). A BSE involves removing the old shafts and bearings (a handy tool is provided for that purpose) and then a re-install of the front two bearings on each side, thereby plugging oil holes in the block. You then need to plug an external hole. You cut the shafts and replace the pinion gears that are part of the timing chain circuit. That's it.

Espero que te sea util.

Con muchos saludos,
Steve
 

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Regarding the balance shaft elimination. Of note, I did not cut the shafts. I just eliminated them and the pinion gears and chain and installed the LCE BSE kit. I used freeze plugs to block the remaining shaft holes in the block. I'll be starting the engine on Monday. Will let you know how it turns out.
 
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Nice to hear that shuma!!

I can`t wait to read your impressions about the balance shaft mod, like vibrations in the engine, in the cabin, some more power. etc.

I still think you should use 15w40 engine synthetic blend oil instead of 20W50.

Saludos
 
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MDST,

I am open to suggestions on oil viscosity for the 3RZ-FE in the highland Andes. I live on the equator near Quito at about 2,500 meters above sea level, where daily temperatures fluctuate between 5-25 degrees C (40-80 F). To be honest, I use 20W50 because that is what mechanics generally recommend here. I also own two '86 three-door LC 70s (an FJ70 with an in-line six 3F engine; the other an RJ70 with an in-line 4 22R) and use 20W-50 for those. I buy 5 gallon buckets of Pennzoil Long Life Gold 15W-40 for my diesel tractor, so could save some money shifting everything to 15W-40. When do you change your oil -- every 5,000 kms? Do you have a recommendation on oil filters?
 
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MDST,

I am open to suggestions on oil viscosity for the 3RZ-FE in the highland Andes. I live on the equator near Quito at about 2,500 meters above sea level, where daily temperatures fluctuate between 5-25 degrees C (40-80 F). To be honest, I use 20W50 because that is what mechanics generally recommend here. I also own two '86 three-door LC 70s (an FJ70 with an in-line six 3F engine; the other an RJ70 with an in-line 4 22R) and use 20W-50 for those. I buy 5 gallon buckets of Pennzoil Long Life Gold 15W-40 for my diesel tractor, so could save some money shifting everything to 15W-40. When do you change your oil -- every 5,000 kms? Do you have a recommendation on oil filters?
I change myself the engine oil and filter every 5000 kms. The brand of the oil filter is Millard ( is a good filter here ).

5 to 25 degrees I think you can use 15w40 synthetic blend oil. Most 4x4 web forums use 5w30.

Here the temp fluctuate between 18 to 35 degrees.

Check this:

3Rz-fe Engine Oil Grades - TTORA Forum

Saludos
 
Joined
May 26, 2006
Messages
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MDST,

By the way, there is a nice study on oil filters at:

Oil Filters Revealed - MiniMopar Resources

The Fram ExtraGuard (ubiquitous in the Andes) did not perform well. The Millards were not evaluated. Nevertheless, the Millards looked like a good alternative, so I shifted to it (ML-3614) for both my Landcruiser Prado 2.7 3RZ-FE and Landcruiser RJ70 22R. Am trying 15W-40 (Gulf Super Duty Extra Plus) for the 22R and will be breaking in the 3RZ-FE with 10W-30. Will let you know how the 15W-40 does at high altitude. I decided to change the clutch on the 3RZ-FE, so won't start up the rebuilt for a few more days. Am curious to check out the engine without the balancing shafts. The mechanic is optimistic. Will report.

Saludos,
 
Joined
Jun 10, 2010
Messages
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MDST,

By the way, there is a nice study on oil filters at:

Oil Filters Revealed - MiniMopar Resources

The Fram ExtraGuard (ubiquitous in the Andes) did not perform well. The Millards were not evaluated. Nevertheless, the Millards looked like a good alternative, so I shifted to it (ML-3614) for both my Landcruiser Prado 2.7 3RZ-FE and Landcruiser RJ70 22R. Am trying 15W-40 (Gulf Super Duty Extra Plus) for the 22R and will be breaking in the 3RZ-FE with 10W-30. Will let you know how the 15W-40 does at high altitude. I decided to change the clutch on the 3RZ-FE, so won't start up the rebuilt for a few more days. Am curious to check out the engine without the balancing shafts. The mechanic is optimistic. Will report.

Saludos,
Excellent study about filters. Thank you!

You'll be fine with the Millard filter, you will not regret!

Read you soon!!

Saludos
 
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Yes, the balance shaft removal has been on engines from multiple vehicles. In addition to the Toyota 3RZ-FE, I've seen that folks have similarly removed balance shafts from Mitsubishi's and KIA/Hyundai's. For further information, see: Eclipse Balance Shaft Removal
 
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I now have 3,000 kms on my rebuilt engine, with balance shafts removed. There is a noticeable increase in horsepower with no noticeable vibration from the driver's seat -- certainly not noticeable beyond the noise generated by my AT tires... I cannot be sure how much of the power increase is due to improved compression from the rebuild or gains from removal of the balance shafts. I don't have access to a dyno, but the estimated 3-5 HP increase from balance shaft removal suggested in the literature seems reasonable. Right now, I would not have any difficulty recommending a balance shaft removal, but let's see what happens over the long haul! Since balance shafts don't actually affect the actual vibration generated by an engine, I don't expect any particular problems. At the very least, I have eliminated the cause of an earlier, very serious engine failure.
 
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I now have 3,000 kms on my rebuilt engine, with balance shafts removed. There is a noticeable increase in horsepower with no noticeable vibration from the driver's seat -- certainly not noticeable beyond the noise generated by my AT tires... I cannot be sure how much of the power increase is due to improved compression from the rebuild or gains from removal of the balance shafts. I don't have access to a dyno, but the estimated 3-5 HP increase from balance shaft removal suggested in the literature seems reasonable. Right now, I would not have any difficulty recommending a balance shaft removal, but let's see what happens over the long haul! Since balance shafts don't actually affect the actual vibration generated by an engine, I don't expect any particular problems. At the very least, I have eliminated the cause of an earlier, very serious engine failure.
Hello amigo!!

That's a good news. I'm going to do the balance shaft removal soon to prevent failure. Maybe going with LC kit.

Now you need to solve or be aware of another problem common in the 3RZ:

" The valves in this engine can be prone to burn damage. This is generally caused by the valves wearing and not contacting the cylinder head properly, which leads them to overheat "

" It is essential to ensure that regular servicing has included valve clearance checks to reduce the risk of getting stung for the cost of replacing valves. Compression testing can help show up faults "

Cheers
 
Joined
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Vermont, USA
Hello!

How did your engine hold up after the repair? I know this is an ancient thread and you may not hang around here any more, but I figure if you are still around you would have gotten a pretty good idea of the longevity of the engine!

Thanks
 
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