Shortly after I got my 2001 4Runner I joined this forum. I read that members ran longer than 90,000 miles on their belt before changing. First, they seem to last longer and second, the engine is a non-interference engine. Meaning if the belt breaks you will have a bad day, but your engine won't be toast.

Well, I planned on changing my belt @ 120,000, thinking I could go a little further. Of course life got in the way and before you know it, I had 150,000 miles on my 2001. Now, I have heard from a mechanic friend of mine told me that a double over head cam engine with 4 vavles even though they are non-interference, may under the right condition bend the valves. Well, I later saw a episode of Motorweek with Pat Goss and he said basically the same thing.

So, yesterday I got a tune up & my timing belt changed. Yes, I did change the water pump too along with almost everthing else. I had 150,995 miles on the odometer. My mechanic gives me the old parts back and I looked at the belt and the pump, they showed a little wear, but they still look very good. So my question is, has anyone suffered a timing belt breakage on their 3rd generation 4Runner? My feeling is that someone has gone longer than me. So if you have a original belt with a lot of miles or had one break, I would be interested to know how long that was. I was just wondering if I could of gone 200,000 miles on it?

My feeling is that my son is getting the 2001 when he graduates from college next July and I would like everything to be in working order. I am thinking he can drive it to 300,000 before changing the belt again. (And by that time, the price of changing the belt may be more than the car is worth.)

I threw a new belt on mine around the same mileage as you and it still looked really good. Thing to really check is the actual amount of stretch that it has suffered. Now as for water pump belt tensioner and the rest of those "should do" items, well I know they will last at least to 201k.

Got 236k on mine. My brother changed his at 347k only because the water pump was leaking...

The timing belt on my current engine which either has 220k or 160k if the engine was actually replaced as the previous previous previous owner claims. It has small cracks visible in it and I wouldn't call it "pretty good".

Are you guys looking at the belt after removing them? They will look MUCH worse under tension than they will once removed. Many of the cracks that are visible when the belt is under tension will dissapear once the tension is removed.

It's the same deal as when you stretch an old ruber band. It looks new, but add tension and all of a sudden you got cracked rubber everywhere.

YT has a 13-page mega thread on this.


http://www.yotatech.com/f2/how-many-...ng-belt-55233/

I read the whole thing before I decided to change mine when it got to 120k, and then change everything that touches the belt except the crank and the cam sprockets. I now have only 30k on my timing components and I like the feeling.

If you read the thread, the stories of breakage are very rare, and most are related to a coolant leak or a water pump seizure. I honestly would not expect a TB to fail all on its own before 200k absent extreme heat; I could not feel the same way about a trouble-free water pump for the same mileage. While inspection might alert you to a leak, a bearing failure might occur without warning.

A TB failure can certainly lead to damage to other components in its vicinity when it lets go, but I have never seen a report of bent valves due to a TB failure on this engine. I would not consider it as other than a theoretical risk.

correctly stated, toyota's factory recommendation is 90,000 miles. i had mine break at 176,000. no other damages. i replaced both idlers the tensioner and the water pump. "bad day" by the way is an understatement about that day. i was doing 80 in the passing lane on a 4 lane highway when it broke. the condition of the belt at 176k was extreme. cracks to the internal fibers the whole way around. the thing was smoked. and furthermore i'm surprised it hadn't broken sooner. i was actually lied to by the used car dealer that sold me my truck. he said that it was done already. i was PISSED.

I've got almost 14 years (102,000 miles) on the original one. The water pump, however, is starting to lose its mojo so everything (minus cam seals) is going to get changed before Turkey Day.

Not much to add, other than another owner whose water pump went out before the timing belt. Happened in the summer of 2010, at around 80k'. It was 105* out too. Lucky (or hella good design) that the motor wasn't otherwise damaged.

I replaced the pump, TB, and all the pulleys and incidentals.

I have 407,000 miles on my 1998 4runner
and still have the original timing belt.

I always thought you had to change them every 100K

Good thing for you the 3.4L is a non-interference engine. lol

How about the water pump? And what's your coolant and change interval?

It seem the problem is not the belt lasting but the water pump. Then the coolant leaking and causing the problem. I believe the problem comes in when the belt stretches or slips an throws the timing off rather than breaking. Had a Mazda do that. a non interference engine. Mechanic says that works about 75% of the time. To me around changing around 100000 miles is cheap insurance.

Zactly! Just hit 300K on the Desert Dune 99, I had ordered the timing belt kit a few months ago so I was ready. This past saturday I went ahead on bought a Denso radiator, Toyota red coolant and new hoses then got started. The belt was definitely stretched, but it wasn't splitting or cracking at all. I don't know how long it was there since I've only had the truck a year or so. What was obviously bad were the cam and crank seals. No telling if they were a/m or Toyota but the crank seal was not even all the way in and all 3 cam out ridiculously easily. It was pukin' oil out of the crank seal, that was my real motivation to do the timing belt. In the process I got a new water pump, idlers and tensioner, and new acc drive belts. I feel like I should have done valve cover gaskets too but I wanted to be done in one day, and I was. I'll do plugs wires and valve cover gaskets another day!

When I changed mine, it had a cheap aftermarket belt and I didn't know when it was done last.

The water pump was done in 2002 and it had about 160k miles on it. There was evidence that a timing belt had broke in the past because the timing covers were full of cemented rubber dust and there were 3 or 4 ribs stuck in the bottom of it.

I'm going to change mine at the 100k mile mark.