When I start my car after it has been sitting for a while (ie overnight, all day when I am at work) the valves noise is scary. Even after the oil pressure has come up I still get the valve noise. It sounds like it is coming from the passanger upper side of the motor. Once the car get warmed up the noise will greatly diminish...about 90% quieter. Once the car is warm you hear a deep knock, knock, knock.

I am **** about my car oil changed every 3000, every maintenance has been done accordingly. I have 130K on the motor. To young for it to be making all this noise.

I have had a mechanic look and he says that I have a rod knock and valve issues....ie many $$$$.

Help my baby is sick.

 

Thats not a valve noise, but its the timing chain rattling. It happens because the hydrolic chain tensioner doesnt build up enough pressure to keep the chain tight, and it rattles. If you get it all replaced it will cost you big money. Do you use synthetic or dyno oil?

 

Started out with Dyno Castrol GTX now Synethic usually Mobil 1 or Valvoline

 

It's timing chain rattle, here's how to fix it, even though my mechanic told me that the chain had to be replaced:

- Buy the tensioner kit from Nissan
- Only replace the "plunger" part which can be done through the access plate on the timing chain cover. It's on the passenger side of the engine, of course. This plate is held my 4 10mm bolts. Keep the chain guide that comes in the kit, you can't change it using this method, the access hole is too small.
- The shop manual has a little write up on how to do it.
- Small hands help It was a PITA to do, but I got it done.
- Just make sure you don't let the little plunger fall out as you're taking the old one out (mine did and it's somewhere in the bottom of the timing case. Thank God it didn't wedge between the chain and the gear down there )
- The new plunger assembly prevents the drain of oil after the car has been sitting for awhlie. This was a design fault on the '95s and Sentra's also.

My car is a '95 with almost 200,000 miles on it & it's still purring. That ugly rattle is gone.

 

I have had this issue for awhile and have been wondering if there was a way around the entire replacemnt of the timing chain. I don't mind spending the money, but I would like to wait until I will have the car off road to do other work. Thanks for the advice on how to do it without going through the while replacement.

 

Thanks for the advise but what about the knocking when the engine is hot. If you put the car on a lift you can hear the knocking best from under the car.

I think that the tire/lube place started the car without oil. Since the problems started shortly after they changed the oil. But since I have on way to prove this.....I am stuck with fixing my self.

 

I have a little knocking sound just as you described coming from the engine bay on my 99 occasionally. As it turns out, it's just a noisey A/C system. If I throw it on Econo it completely goes away.

 

Did you have the a/c noise with the system off?

 

Hmmm. I can see it now. Cletus down at the Presto-Lube puts the drain plug back in the pan, lowers the car, slides his greasy butt into the driver's seat and starts it up. The oil pressure light is still glowing after several seconds, so he revs the engine up to build up oil pressure. Still doesn't go out. So he revs it up some more, up to 5000 rpm. Still doesn't go out. wtf? Oh yeah, forgot to put oil in, huh huh.

That's why I don't let anybody do anything on my car.

Anyway, I hope it turns it out to be something minor, but if it's a heavy knocking sound that you can hear best under the engine, it may very well be main or rod bearings.

 

Steve,

You are just about right...except that they "work" in teams. One "tech" is not paying attention and starts the car b4 the other puts the oil in.

The knocking is a deep tone that you can hear best from under the car.
Is that what you mean by heavy knocking?

Thanks
Chris

 

I'm not sure what you mean by deep tone, but an experienced mechanic will know the sound of con rod bearing knock. It will be louder when coming down from high rpm after you rev it up. A bad main bearing will be louder under load. If you don't trust your mechanic, get a second opinion, but don't ignore it.

 

Well, if it makes you feel any better, rods & main bearings don't seem to be a known issue with these cars. Since you change your oil so often, then it sounds like something else. Unless that car was run for an 'extended' period without oil. By the way, try using synthetic oil instead of that garbage the lube shops pump into your engine.

 

The drive belt pulley made a similar noise on my car. Probably you can check that also.

 

well i think you may both be right, there is a possibility that if the chain is loose or off, it can cause the valves to bend due to zero clearance, for a mechanic to change your timing chain is roughly 10 hours of labor. You may want to take it to someone, like Nissan, for a second opinion. Regardless, it sounds pricey.

 

Thanks for all the help. My mechanic has always been great. I was looking to pick the "brain" of the org and see if someone can but with some other diagnosis....a less expensive one.

Munji,
Great minds think alike already changed the belts.

So here are some options:
Re-man motor $3200 + labor
re-build existing $4500-5000
Get one from a smashed max/i30 with low mileage ??? + labor

 

So was this fixed for 96 and on?

 

I think so, I haven't heard post-'96 owners complain

 

I don't think that this is a common problem with any of the years. 95 was the first year for timing chain though.

 

lifters- our cars use hydrolic lifters and they get oil coking over time. the lifter (on new engines) rides in the camshaft at all times. after a while (60k) the lifters dont raise immediately and the cam lobe rotates and "smackes" the top of the lifter. oil additives and flushes might help for a little bit but it wont fix the problem.

 

The 4th gens don't use hydraulic lifters, they are adjustable by shims only.

 

I had this happen to me twice on my 97 early in the morning. Sounds really weird.