Noisy Engine / Oil Leak / Misfires

[rfdgn1209]

I hate to thread jack someone else's thread, but a few threads on here seem to be very similar to my problem.

I was given a 1999 Corolla VE with 140k miles on it, from a friend in March. Ever since I had it the check engine light has been on. I've been driving it more, so I decided to fix the CEL. The codes were for Engine Misfire / Cylinder #1: P0300/P0301 and another for the exhaust gas detected by the O2 sensor (I can read the code again) which I believe was being cause by incomplete combustion.

So I bought new spark plug and wires (NGK BKR5EKB-11's & TE64's). Upon popping the hood I noticed that the alternator was cover in oil, but there was no obvious oil leak. Sure enough checking the oil, it was very low. I drained the current oil which was less than 3000 miles old (according to the windshield sticker) with Mobil1 10w-30 Full Syn High Mileage and a new Mobil1 filter. Oil was all over the left side of the engine and serpentine belt, so I degreased all the parts that I could and replaced the belt with a new Gatorback one, and changed the plugs and wires. One plug had a little oil on it.

I let the engine run for awhile in the garage with the hood up, and noticed a rattling, non-cylindrical sound from the engine bay that was loud at idle and gone after 2.5-3K RPM or so. I realized the noise has been there since I got the car but I could never pinpoint it, now I can tell its coming from the engine on the passenger side. Thanks to some other threads I believe this to now be a problem with the Timing Chain Tensioner. Which could also explain the oil leak all over the power steering pump. The sludge would have traveled and splattered anywhere the serpentine belt traveled. I drove the car on Friday and it was hesitant to accelerate but once it got up to speed it was fine. This was probably caused by resetting the ECU, since by Sunday it now accelerates properly from stop lights, but the 3-speed Tranny sucks. The car used to shake at anything over 55 MPH, which I thought was just a bad alignment/tires. It was partially the tires (they were replaced this week) and the engine. The car seemed solid up to about 65-70 MPH, at which point it began to vibrate, and CEL started to flash, but wouldn't stay on after I dropped below 65 MPH. So I tested it again, and got it to 75 MPH at which point the CEL stayed on after dropping below 65 MPH.

1. Rattle sound seems to be a bad timing chain tensioner. How much work is this to fix?
   The price of the part is cheap enough, and another forum member Huangxin noticed that after replacing the tensioner his spark knock went away. I'm thinking the misfire codes are being thrown because the timing is off at high speeds, but that's just a guess.
2. If the Alternator wasn't putting out the proper voltage would it cause problems with the ignition only at high speeds/RPMs?
   I have no other electrical problems with the car, it starts fine, and there is never any dimming
3. The initial acceleration/hesitation I had once all the repairs were done is gone. I have a steady idle but its very loud, and at high speeds I'm getting misfires. Thoughts?

[fishexpo101]

Tensioner is not that expensive - but labor is going to get you. If you took it in to get fixed, might be a couple hundred dollars easy.

If the alternator is not putting out clean juice, it could cause all sorts of problems. When you replaced the oil slicked belt - did you clean the pulleys as well? A slipping belt could cause some problems at higher speeds. Alternator - just pull it off and have it tested to be sure.

Make sure your sparkplugs are gapped correctly. Even off several to tens of hundreths of an inch can cause a misfire.

Also keep in mind that the misfires could be from something completely unrelated. Since they have been on so long - there might be a bad sensor (crank, cam sensor) or electrical issue (ground loops, poor chassis ground) or even electro-mechancial (bad injector or bad coil) or even mechanical (bad valve, heavy deposits in engine).

A flashing CEL is a bad sign - that only happens when there is a serious problem that could affect proper drivability or engine health.

[johnoh]

What is the check engine code you are getting on the highway now - still getting misfires with new plugs?

Your leak is probably the timing chain tensioner, but your rattle is probably the serpentine belt tensioner.

The timing chain tensioner ($30 part) is an easy remove/replace if you have the right tool - a small pivotable stub ratchet. It is just two 10mm bolts back there. Its a tough job for some because they can't get at the bolts.

To r/r the serp belt tensioner ($100 part) remove the plastic shield underneath the belt area and do as much as you can from under the car. Things are harder to get to from up top.

[rfdgn1209]

I'll check the codes again tonight. Along with the belt tensioner, and order the timing chain tensioner, possibly belt tensioner.

So far it seems the change from 10w-40 dino oil to 10w-30 full syn hasn't revealed more oil leaks, the belt is clean and the alternator looks like its drying up.

I should have all the proper tools to do the job myself.

Question what do you guys recommend as far as gasket manufacturers for these engines?

[fishexpo101]

Most of the gaskets on the car are FIPG type of materials (form in place gaskets). A few use o-rings type gaskets - like the valvecover gasket.

For the O-ring type gaskets, can't go wrong with OEM gaskets - cost difference is only a couple of bucks, and you know it will fit right the first time around. The Toyota FIPG stuff cost about $13 a tube, Permatex has ones that are very similar to the Toyota OEM, but runs about the same price.

[huangxin]

the timing chain tensioner is very easy to replace. it's held into the block by 2 10 mm nuts.

the tensioner itself cost 17 dollars from the dealer if i remembered it correctly.

[rfdgn1209]

Upon further diagnosis tonight, I found that the belt tensioner is making noise but not much, it seems that the click, clanging sound is coming from within the timing cover.

I saw on here before the a member pulled the serp belt off and started the engine to check which one of the two tensioners was causing the noise. How do you run the engine without the alternator hooked up?

No more oil leak as far as I can tell, and its been in the same spot since Sunday night.

The codes were P0300/P0301 again, which is Cylinder #1 Misfire. The other code P0420, Catalyst Efficiency Below Threshold (Bank 1) is gone. Now that I think about it, I recall one of the plugs had some oil around the threads, and I believe that was cylinder 1's plug. The rest had some carbon deposits.

Other than the noisy idle and the misfires over 70-75MPH the car is running MUCH better than before.

I'll check the plugs again this weekend, as the car isn't moving again until then anyway.

[fishexpo101]

Car will run without the alternator - atleast for a limited time - it will suck all the juice it needs from the battery, so don't run it too long.