Tapping/Rattle at tickover

mr-ed_smt · May 25, 2011, 10:00

Thought it might be best to put this here rather than create a new thread.

MY engine has started making a rattling/ticking noise at tickover s:? :? s:? . It seems to be getting worse (although that could be my paranoia!), and definitely seems to originate from the right hand side of the engine (timing chain). The rattle frequency increases with revs (up to 1.5-2k), but seems to disappear completely over that.

I made a video of it last night - if anything the noise naturally sounds worse in the vid! Excuse the weird aspect ratio - stupid phone.

http://youtu.be/SZpVU4_H6zE

The car is as per sig, '53 post-facefift. Its done about 64k. Uses some oil, but not an alarming amount. I use fully synth 5-40.

Would I be right in thinking the noise is something to do with the timing chain? What would the next step be? I do most of my own work to the car but am not really confident touching the chain myself.

Many thanks in advance s:bowdown: :bowdown: s:bowdown: !

mr-ed_smt · May 26, 2011, 11:06

Bump...

Anonymous · May 26, 2011, 11:19

you can always check the chain and measure the links at the top without any worry of screwing things up just undo the bolts holding the rocker cover on and your away. if the chain fine you might be looking at something on the bottom end.

Smeggers · May 30, 2011, 11:49

I have exactly the same noise from my 2002. It's starting to get a little worrying. s:(

s:(

The accessory tensioner has been changed recently, to remove one potential cause of the noise but to no effect. An oil change (to fully synth) and ECU reset recently alleviated the problem for a short period time, but after a spirited drive later on that day (in which the car felt great) the noise was back.

It sounds like it is coming from the head/cam area and i am wondering if it could be the tappets or possibly the cams are not getting a good covering of oil during normal operation.

Any additional ideas?

Smeggers · June 14, 2011, 19:51

Could a blocked VVT OCV valve seive contribute to this issue?

Been having a look at the celica forums which have similar sounding engine rattles ....

Anonymous · June 14, 2011, 20:35

Quote from: "Smeggers"Could a blocked VVT OCV valve seive contribute to this issue?

Been having a look at the celica forums which have similar sounding engine rattles ....

if yout talking about the filter. i dont think it would as its plastic and if blocked the vvt would just not work. have you checked the chain for stretch.

Smeggers · June 15, 2011, 22:01

Chain 'looks' all right, although i will be changing the tensioner soon to narrow down further the source of this issue.

Bum dyno feels that there is a distinct loss of low and mid range torque ( it sometimes disappears, leading to one or two 'o-sh*t' moments when you suddenly start moving faster than expected s:(

s:( ), which is a symptom of a failing VVT system iirc, although i have no CEL on the dash. During the weekend I decided to pull the OCV connector to see if any difference was made. The car felt like it had gained torque from 4000rpm onwards but, i'm aware that this may just be the effect of the natural torque curve minus the VVT system. CEL lit up correctly.

The previous owner looks to have used some ancient grade of tar or possibly liquorice for oil btw when i emptied the oil during the service. Its this that got me leaning toward a blockage with the sieve.

Still open to ideas though. s:)

s:)

Anonymous · June 16, 2011, 05:10

ok so its been on a dyno. well to start i like you thought that the vvt made it rev better over 4k rpm. wrong. the vvt actualy works the other way and turns off at 4k rpm. what it actually does is to make the engine more effecient at low rpm so less emisions. now to test the ocv properly ie best way you need to leave it in but put a 12v accros it whilst the engine is ticking over. if it works the engine will be close if not stall. the other thing is the actuator on the cam, maybe if you can upload the dyno printout we can all see what its doing. also on another note a chain can look ok however be stretched. only way to check is messure.

Smeggers · June 17, 2011, 21:39

Quote from: "rbuckingham"ok so its been on a dyno. well to start i like you thought that the vvt made it rev better over 4k rpm. wrong. the vvt actualy works the other way and turns off at 4k rpm. what it actually does is to make the engine more effecient at low rpm so less emisions. now to test the ocv properly ie best way you need to leave it in but put a 12v accros it whilst the engine is ticking over. if it works the engine will be close if not stall. the other thing is the actuator on the cam, maybe if you can upload the dyno printout we can all see what its doing. also on another note a chain can look ok however be stretched. only way to check is messure.

Sorry dude. You misread my post. Bum dyno (ie my backside) tells me that low to mid range torque is down. It hasn't been on a dyno. s:)

s:)

The increased feel in torque when i pulled the ocv socket would be the natural torque curve of the engine kicking in (MINUS the VVT, which i know increases low to mid end torque making the normal torque curve rather flat with a correctly working engine) beyond 4Krpm (where VVT doesn't effect the engine). Note the engine felt almost the same at lower rpm on that jaunt no matter if the ocv was plugged in or not, which would indicate that the VVT system isn't working normally (and not just the ocv) but this should throw a cel as far as i am aware.

I'm starting to wonder if the timing is out. If the chain has slipped at any point on the VVT sprocket (or on any sprocket come to think of it), the intake timing would be off making any adjustment to intake cam by the VVT system moot depending on direction of slip. So the VVT system is hitting its maximum advance point (as far as the timing is concerned) without getting the correct valve timing (or vice versa depending on direction of slip).

Over the last couple of days the engine really is starting to sound like a diesel which is worrying. Bearing in mid that the oil was change a short time ago..... s:(

s:(

New chain tensioner has arrived with new guides. Will be fitting when the weather decides to brighten up a little .... maybe next april if the rain carries on like it has been for the last couple of days. s:evil: :evil: s:evil:

Anonymous · June 17, 2011, 21:59

getcha well before you change that with the engine ticking over put a a 12v accross the two pins and see if it tries to stall. however i still think the rattle is still somewhere on the chain.

Smeggers · June 19, 2011, 19:09

Managed to get a break in the weather long enough to change the timing chain tensioner, clean the OCV sieve and the OCV itself.

Both the sieve and the OCV valve were caked in the gunk that the previous owner considered oil. The sieve looked very badly coated, but after a bit of carb cleaner and a once over with a tooth brush, it came up rather nice. The OCV valve itself didn't look too horrific, but the spring looked just as badly caked as the sieve. Getting the ocv and the sieve out and back in again was a lesson in patience. Doing it all blind in a very tight space made the job a bit of a pig. I fully recommend stuffing a rag between the head and the alternator as you will drop the sieve a couple of times before it gets into the hole correctly and loosing something quite small like that would be a pain to try and retrieve.

Results are positive. The engine is now running an awful lot smoother and the low to mid range torque is up but i still have and the rattle. Now that some of the other engine noises have been ironed out, the rattling sounds like its coming from the inlet side of the head/cam cover, not quite where the inlet manifold is, but very close, possibly somewhere between the inlets of valves 1 and 2.

When the weather clears, the cam cover will be taken off again and the tappet/lifter clearances will be checked. I also forgot to check to see if the inlet cam had slipped a tooth or timing when i looked at the chain tension. Oh well. s:? :? s:?

Smeggers · July 8, 2011, 20:56

Since is tried to diagnose the knocking issue, the engine has started running like a bag of spanners, without me touching it at all.

Very recently, when the car is started the revs drop immediately to almost stall and after a minute they rise back to normal for a cold engine. Torque feels like its dropped off a cliff, throttle response is laggy. It's like i have nothing below 4Krpm. On top of all of this i'm starting to get a knocking from the engine under acceleration at around 3Krpm.

I'm wondering if oval bore syndrome may have kicked in and is spitting oil over the o2 sensor (which was replaced earlier this year) causing the sensor to misread. The 3krpm knock could also be the big ends going as well ...

.... needless to say i'm getting a little worried. s:scared: :scared: s:scared:

Any advice or alternatives would be welcome.

Anonymous · July 8, 2011, 21:09

Timing chain could have slipped a tooth,were the symptoms there straight after changing the chain tensioner?

Smeggers · July 8, 2011, 21:52

Car was running fine. Back to normal as it were.

.... not sure why the car has suddenly started trying to imitate a herd of elephants in tap shoes. s:(

s:(

Anonymous · July 8, 2011, 21:55

Sounds like you engine has had it I'm afraid but difficult to diagnose over the internet and I'm no mechanic but it sounds like a lot of other engine failures posted on here.