2003 Toyota Corolla S, 1ZZ-FE ENGINE:
The engine has a tapping sound. When accelerated to 2000rpm it turns into a ring that goes in and out. Over 2500rpm it goes to tapping again. Some say its the lifters. Others say its the timing chain. Yet others say its the oil pump. I've changed spark plugs, used oil additive(Sea Foam). Now I'm being told to use Restone. Any comments please.
I don't believe that oil additives are going to help here. The only real solution is determining the source of the problem. How many miles are on the engine?
118000 MILES. That's my dilema. Determining the source. I want to raise the valve cover, but then what am I looking for? I will also see part of the timing chain. Is this recommended?
You wouldn't be able to visually tell if the valve lash is off...you'd need a set of feeler gauges to measure the lash. You would be able to see the timing chain and the top gears, yes. But you may be able to tell if the chain has a lot of slack in it. It may be that the tensioner needs replacing. That doesn't seem to be a common problem, but that's not to say that it couldn't happen.
I saw an example of a chain tensioner, but I'm unsure about its location. I checked where the manual said it should be, but all I saw was a blank plate right next to the serpentine belt tensioner pulley. Is it inside this blank plate?
It is the "blank plate". If you have decent mechanical skills, it is not hard to take the tensioner out and inspect it. If it was not holding the proper tension on the chain it could cause some strange noises. Ditto on the oil additive, not gonna help this. If you have an automotive stethiscope, you could listen to the "blank plate" and other areas to try and pinpoint the location. This sounds like it will be a tough one. Good luck.
I've been all over the internet and found some very good info on timing chain on 1zz-fe engines. It read- chain wear will cause multiple noises. Chain slap and valve tapping due to the slack in the chain. This explains my frustration trying to pinpoint the noise location. I was brave enough to open the valve cover. I found some slack in the chain. Since the vehicle has 118000 miles, I think it's safe to say that having the timing chain, guides, gears and tensioner changed is a good thing. As for the Oil pump, I hear that you should have it changed also. Is this truly necessary. Why change the gears? Why is the outer gear thicker than the inner gear? About removing the tensioner- is there any danger in removing the tensioner. Is there the possibilty that the chain could skip a groove or possibly not seat correctly. Isn't the purpose for the hook on the tensioner to relieve pressure while removing and installing the tensioner, surely this requires removing the right motor mount, serpentine belt, pulleys and covers. Any shortcuts to any of this?
i've never done it on a 9th gen before, but timing chain shouldn't need to be replaced at that early
the reason the intake gear is bigger is because the VVT-i, it adjust the intake timing from that cam.
as far as replacing the tensioner, if it's same as 8th gen, then it's very easy, the tensioner is located on the passenger side of the exhaust manifold. just two nuts and it's out. the hook is just for reinstalling.
the timing chain tensioner needs oil pressure, so with the engine off there's no oil, it will have slacks and appear that it's stretched out. as soon as oil reaches the tensioner, the chain will tighten up.
as far as i know, the only way to measure slacks in timing chain is to take it out and measure the distance between links, but at your mileage, i'm almost positive that the chain is fine.
since your had the valve cover off, how do your lifters look? sometimes a sticky lifter will cause a tap noise
If you know the timing chain has slack in it, I'd just start with replacing the chain tensioner. The chain should still be good. The timing chain system SHOULD effectively be good for the life of the engine. 120,000 miles is too early to be replacing stuff, but there could be a defect or premature problem in anything I suppose. I'd start with the tensioner. It's pretty easy to replace, and doesn't requiring disassembly of the front of the engine like many designs do.
The tensioner depends on the oil pressure
I have seen illustrations of what the tensioner looks like and can't image how oil pressure causes the tensioner to tighten the chain. Please explain. This is better than "How they make that".
There is "ticking" coming from the vacuum switching valve. Is this normal?
Huangxin - That's some great info.
My most important question now is: Can I safely remove the tensioner without fear of timing chain slipping of the gear. Then how do I reinstall the tensioner since I can't use the hook without removing the timing cover? And one last thing: How do I determine that I have a bad tensioner? Any obvious signs?
If you have a FACTORY TOYOTA repair manual, Follow the steps in it exactly. If you do not have the Factory repair manual, get one. The Facotry Toyota manuals are great, they explain procedures very well, with pictures and have a troubleshooting section that is very helpful.
The verdict is out.
Took the Corolla to the local dealer for a free diagnostic.
The Master Mechanic says 9 out of 10-the problem is a push rod.
$200 to drop the oil pan. $500 to change all 4 push rods.
NO CAN DO.
I'll have to shop around for a Mechanic.
No way I can spend that kind of money during Christmas.
I'm a bit skeptical about that diagnosis. I would think the car would run worse to not at all with that verdict.
I mean, really, the car runs great. It just has this tapping sound!
Does push rods sound too far fetched?
Is this a normal occurence with only 118000 miles?
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Tapping Sound.
Linear Mode
