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SR20 Rattles

12029 Views 18 Replies 10 Participants Last post by  lshadoff
Has anyone here had any problem with persistant timing chain rattles on cold start, or after several hours sitting? My father has a 98 Pulsar SSS, which has a fairly bad timing chain rattle, which Nissan are trying to avoid fixing. The car has 50,000 miles on it, and the problem was reported just after he bought the car, which was just inside factory warranty. The car has the correct grade Nissan oil, and genuine oil filter.

I think the most likely culprit is a faulty timing chain tensioner, with the ratchet allowing the tension to come off when the motor is first cranked. Nissan attempted to fix it, and the car was quiet, with the noise returning after two days and about 100 miles use. I think they have unbolted the tensioner, and slid it out until the ratchet clicked up a notch and then put it back together.

Has anyone else had similar problems? And if so, how was it fixed? I have trouble seeing this as a common problem, with the SR20 fitted to various sporting models. Sports car owners are unlikely to put up with this sort of trouble.
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Timing tensioner.

OK. Now having inspected internally, the ratchet on the SR20 timing tensioner seems very corse, with my fathers car having not quite gone over the point of the ratchet dropping to the next tooth. In this condition, the rear timing guide could be moved about 1/2" before the ratchet stopped it, this was enough for the chain to brush the inside of the cam cover. We were able to sort the problem out by releasing the nuts which hold the tensioner, and sliding it back until the ratchet dropped into the next tooth, then bolting it all up again. The chain still had enough slack for it not to have a problem with over tightness of the chain.

I know the tensioners have had at least one revision in the life of the SR20. What was the revision? Is there a tensioner out there with finer teeth? If so, where do I get one?

Thanks all for any help anyone can give.
This a common problem on the sr20 motors. I think the tensioner has had two revisions. Don't quote me on that. I know mine with 169k miles sure can do it and it's on it's 3rd one.
Remember - SR20s have hydralic(sp) lifters - they always rattle on start up
SR20 rattles.

My Fathers car has no rattles from the lifters on start up, so that is not a problem. However, he managed to talk a new timing chain and tensioner out of Nissan:) (The car was just out of factory warranty) The new tensioner has about three times as many teeth as the old one, so it should not much before the tensioner drops into the next tooth.
what are you talking about teeth? There are no teeth on the tensioner. I know when I changed my cams and removed the tensioner that there was no teeth on them
He is speaking of the teeth which the "catch" grabs on to - the same teeth that you must pull back the catch to push the tensioner in before you can loop it.

Well. The new tensioner has been in the car for two weeks, and no sign of a rattle at any time since it went in.
I always have a rattling sound on cold days with my b12, and now that I read this post it is probably the timing chain. The guide on my old chain broke and the chain tore through my engine, but I have a new one now and it still makes the rattling sound on cold mornings....oh well. I use synthetic oil too, well semi synth.

The new tensioner is fairly easy to tell from the old one, the original had about 15 teeth, and the new one about double that. But you obviously need to have it out of the car to check that. Apart from the teeth, it is identical.
SR20 rattle

I have pulsar SSS N14. My timing chain rattles mostly on cold starts or when the car has been standin for some time. Although it does go away for a bit every time I change the oil. Doesn't seem to affect the performance though. I've left mine alone.
You will probably find that the rattle will slowly get worse and them improve suddenly as the tensioner goes over the next tooth.
Also, I have personally seen 3 different revisions of the tensioner, and had them all on my car. The first was the original. The second had the same number of teeth but the outside of it looked different (larger oil chamber?). The third was the one that has been working the best, and its like the second except the teeth are much finer, allowing for smaller adjustments.

sorry to bring up an old thread... but has someone got more info on these tensioners.

I have a 98 model SR20 and it rattles on startup and its definatly timing chain related.

Does anyonehave a specific part number that I need to order from Nissan?

Thanks for your help.
That rattling you are hearing is most likely the infamous cold start rattle. All the oil drops back down after awhile so when you start the car it has to lubricate again, which is why it goes away seconds later and why when its still warm it doesnt do it. Thats how my car is. Nissan oil filters have an anti drain back feature which helps, but ive noticed that after awhile it ends up doing it again.

BTW they dont like bringing back old threads around here.
But bringing back old threads is better then starting a new thread and getting flamed because you didn't search..he obviously searched and read the forum rules and that is what separates him from the standard newb. :)
I have cured my rattle. I replaced the tensioner with a updated model from nissan and all is fixed.
nizzan4u2nv said:
BTW they dont like bringing back old threads around here.
If by "they" you mean NissanForums Administrators or Moderators, that is ABSOLUTELY WRONG! There is no rule against posting in any open thread.

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