I just bought a 30 year old Nissan 300zx with very low miles. The miles on the odometer jibe with the Carfax report. It spent all of it’s life until this year in California and was taken in for inspection annually where the odometer reading was recorded.
According to info on the written on the timing cover, the belt was changed just over 10,000 miles ago. Good news, right? Maybe. See, it took 15 years for the previous owner to log those 10k miles. So here is the question - does time degrade a timing belt if the car was driven a little along the whole time? There is no sign of dry rot, but one can’t always tell by looking.
I agree. I have a 20 year old car and had the timing belt changed in 2003 at 60,000 miles. Ten years later, I had cut my driving drastically, but had the belt changed again a couple of years ago at about 80,000 miles on my mechanic’s advice. The car still starts and runs great. I credit good preventative maintenance for its running condition. Changing the timing belt is cheaper than writing off a damaged engine. Also, it would be a good time to replace your water pump if it’s necessary to remove the timing belt in your car to get at it. It will save labor at another time if your water pump does go out.
Made of rubber and (I think) nylon threads. Rubber ages with time, and age is not kind to rubber. So low mileage is unlikely to be able to compensate for what time has done to the belt. It may last longer than the manual suggests, but likely not by much.
Check with a Nissan mechanic and determine whether you’ve got an “interference” engine (which will be damaged if the belt breaks), or a “non-interference” engine, which will simply shut off when the belt breaks.
If it’s interference, just suck up and replace it right now.
If it’s not, you can replace it after it breaks for no more cost than doing it voluntarily. As long as you’re ok with your car shutting itself off with no regard to what time it is, where you are, what traffic is like, or whether you need the power steering, brake assist, and all the other goodies that come with a running engine.
Apart from anything else, it’s one of those peace of mind things. You clearly know it’s a bit iffy, otherwise you wouldn’t be asking the question. If you choose not to change it, you’ll be worrying about it failing on you every time you drive it (at least, I would).
Change the belt, then it’s done and you don’t have to think about it any more. You can then spend your driving time [del]enjoying the car[/del] worrying about all the other weird noises.
Since your engine is an interference engine, YES! Replace the timing belt.
IIRC, Nissan recommends that the belt be replaced every 8 years. You rig is at 15 years, almost double the recommended time. I would replace it NOW, TODAY, not tomorrow, today!
Of course, it is your car, do with it as you please.
Of course, there’s not much harm in popping the belt and smashing up some valves. Gives one a good excuse to do some deep maintenance on the head, replace some seals, adjust valves, etc. I mean, it’s not like the car will explode, and you effectively get a brand new engine out of the deal.
Out of curiosity, where did you find that info? I can only find Nissan’s recommendation for mileage replacement (60,000), not elapsed time. I know the “abundance of caution” thing to do would be to change it, but I hate spending $1,000 (timing belt, water pump, tensioner, seals, etc.) if it’s not really needed.
I asked for opinions, and I appreciate those given so far. Here it’s running 100% replace (but y’all don’t have to foot the bill ). IRL, I’m getting conflicting opinions - about 50/50. Anyone got hard data?
I’ve been fixing cars professionally for over 40 years and have never seen a time recommendation on timing belt replacement in the repair information I use (printed manuals years ago, online subscription now). I’ve heard people say things like ten years, but like you I wonder where that comes from. I haven’t seen it in print from an authoritative source.
Specifically in this case, I can’t see how the fiberglass reinforcement strands could deteriorate over time. The worry would be the possibility of the ribs separating from the body of the belt. I just don’t know how likely that is.
All that said, it’s an interference engine and noticeably more expensive to repair than most Japanese engine/body combinations. Even timing belt replacement is going to cost more than average. I doubt you need worry about the water pump and front engine oil seals, as I’m pretty sure they’re affected by use (heat/cool cycles) rather than by time.
). IRL, I’m getting conflicting opinions - about 50/50. Anyone got hard data?