Timing Belt ... How critical is 100K ?

[caffa]

The 4JG2 is 250 k's of 300,000 so I will see the horrid amber light Friday afternoon on my way home from work. Havent got time to get it done before I go. My question is, should I consider alternative transport? I have run over a little before, maybe 1 or 2 thousand k's without any real fear. This trip is about 4500 k's in a week and a half of which about 4000 k's is at 100-110 on the highways. It still sounds okay. The first belt change at 100,000 k's made a huge difference with regards to idle and engine noise etc. Got a factory belt for the second change and it still sounds good, not noisy and no difference to idle or anything.
Should it do the trip or is it an unnecessary risk ?
What's everyones thoughts ?

[justin]

A dilema! I had my light come on at 71K, (which no doubt equates to 286,000,000 Km's in wind back terms) and I never changed it till around 74K. So it is just an indication of when it should be changed. So what you need to consider is if the belt does go in motion then, as I am led to believe, the damage can be not good, How high is that risk? Well I think you'd be pretty unlucky if that happened... Saying that if it were me and I said 'okay I'll take the risk' my car would detonate on the freeway, (the main reason why I don't gamble on anything as it is an imediate curse). So do you feel lucky?

[geeves]

3 issues can kill belts Age,Milage,and oil leakage. If you do high miles so youve done the last 100k in only a couple of years your probably ok if the rest of the engine is good but dont leave it too long after you get back There is a safty margin built into the change interval
Ive just changed my belt at 6 years and 80k It looked brand new still
A belt change on its own shouldnt affect the running of the engine But if it breaks your valves hit pistons =new engine

[Len]

My local mechanic tells me that Isuzu's aren't known for breaking timing belts, and you're quite safe going a few thou over the change interval. When mine was changed at 100,000 it looked in perfect condition, as if it could have gone another 100,000.... ;D

[caffa]

Thanks for the input guys. Another question, It clocked over on Friday as I anticipated but I have yet to see the t-belt light. Now I may be wrong but I thought I had seen it the same time every 100,000 k's. I am guessing the speedo was molested as is with alot of caryard cars because the light came on at 40,000 ..... then 140,000 ..... I was presuming it was wound back 60,000, all was fine and I was going to see the light again at 240,000. Does the light come on every 100,000 kilometers or 100,000 kilometers afer it is reset under the dash ?

[James W]

"I was presuming it was wound back 60,000"

or 160,000 or 260,000.....

My engine was completly shot on it's second set of rings at supposidly 184,000 Km. Timming belt was at 145,000, hence it was clocked 55,000 or 155,000... I suspect at least the latter

[Bruce]

Hi Caffa, interesting subject, when I sold my 1988 Nissan Skyline, R 31 3 litre 6 cyclinder motor, to a mate, cheap $1000, he asked me when I last changed the timing belt, ye well never I said, the old girl had done 450,000 k's. But another story was my Lada Niva (great truck off road) had a chain drive and a manual adjuster which I use to adjust often, but should have changed the adjusting thing earlier. So what happened, put all the valves through the tops of the pistons, motor U.S. So what would I do now change the belt every 100,000 k's cause I hate seeing that light on all the time.
Cheers Bruce.

[Bruce]

Forgot to say the Skyline did not have a light.
Cheers Bruce