Rocker Cover Tapping...

[HZRDIZ]

Can't seem to cut a break with the ol' Levin at the moment...
Had her out yesterday and she was running perfect-the best shes ever run... Take her up north today and felt a bbit on the shady side but didnt worry to much about it cause it seemed to go away after the engine warmed up. Turn her on to go down the road and the next thing I hear is this very loud tapping noise. Give it some gas and it just gets louder. At first i thought it mite be noise from the valves lifting but it just kept getting louder louder. Went 2 a garage up north and he said that it could be the driveshaft rattling. Rang my dad and he aid it could be the water pumps rooted and then my mates dad says that theres something loose inside.
Anyone had a similar problem? Im wondering if this has something to do with the other prob I've been having...

[JasonZE]

Could be just about anything without seeing it,
Does it do it when not moving if so rules out driveshaft, water pumps dont tap usually a metallic rumble, check that a spark plug hasnt come loose.
Got oil in it??
Take it to a decent garage for a listen if you dont find it soon..

[HZRDIZ]

It makes the loud tapping sound will idling and in motion. And i think its made louder by echoing... Sounds like it is coming from underneath the cover... Will get it checked out cause its gotta be fixed. Not driving it at the moment so will have to get it sorted ASAP

[HZRDIZ]

On closer inspection I have discovered that it sounds like its coming from the cam/cambelt cover. Put my hand on the cover and rev it and there is definate vibration there. im wondering if maybe a cam has come loose? Anyone else had this problem?

[jondee86]

Hiya.... had a noise like that once. Not really noticeable when the car was moving, but pull up at the lights, and there it was.... the death rattle !!! Not so loud the first time I noticed it, but kept getting a bit louder each day !!

I would have swore it was a big end or a main bearing. Isolated it as coming from the front of the engine, and when the cover was pulled, we found it was coming from the idler on the cam belt tensioner.

Put a new idler on and good as new Worth noting that the old idler still spun nice and smooth, but the bearing was sloppy with a bit of angular play. Worth checking.... and a good time to chuck on a new cam belt if it hasn't been done for a while.

jondee86

[HZRDIZ]

Hiya.... had a noise like that once. Not really noticeable when the car was moving, but pull up at the lights, and there it was.... the death rattle !!! Not so loud the first time I noticed it, but kept getting a bit louder each day !!

I would have swore it was a big end or a main bearing. Isolated it as coming from the front of the engine, and when the cover was pulled, we found it was coming from the idler on the cam belt tensioner.

Put a new idler on and good as new Worth noting that the old idler still spun nice and smooth, but the bearing was sloppy with a bit of angular play. Worth checking.... and a good time to chuck on a new cam belt if it hasn't been done for a while.

jondee86

Thanks dude that helps. Guess if that is the problem thou theyre gonna charge an arm and a leg just to take the cam cover off dammit...
Do you know if its safe to drive round in with this problem?

[Ae92typeX]

Guess if that is the problem thou theyre gonna charge an arm and a leg just to take the cam cover off dammit...
Do you know if its safe to drive round in with this problem?

Easy enough to get the cover off and check before ya spend the money on getting it fixed, just give it a go.

[jondee86]

Hiya.... If it is a little noise only heard at idle, and it pretty much disappears when you are driving at 50 kph, you should be safe to drive around (quietly) for a while.

If it is like you said in your first post (I hear is this very loud tapping noise. Give it some gas and it just gets louder), then it is more likely that you have run a bearing (ugly) and it is only going to get uglier !!! The noise will be like a knocking sound... like someone was inside the engine block tapping real fast with a hammer.

If you have run (= melted) a big end or a main bearing, your oil pressure will usually be down, and if you dump the oil while it is hot, you will see shiney metallic powder in the bottom of the tray.

Problem with tapping sounds in an engine is that they can sound like they are coming from anywhere, as sound travels real well through metal. I'd pull the timing belt covers and check out the cam pulleys and idler first... anything that makes a loud noise in there should be easy enough to spot.

jondee86

[HZRDIZ]

OK finally found out what was wrong. This is basic laymans terms which was explained to me-so half technical and half layman.
The key that holds the cog/bearing that is connected to the crankshaft under the cam cover. It had come loose and thats what had been making the tapping sound. So now the pulley and the actual cam/bearing/cog (or whatever) has to be replaced. That plus 5 hours labour and goodbye $425.
But hey my car will be up and running tomorrow. Took it to Boosted Performance in Howick. Good guys their. Im sure that if I took it to Toyota id be looking at another $200 +

[jondee86]

Ha !! I should have thought of that.... common thing with 4AGE's. Happened to me once but it didn't make any noise. The bolt that holds the crankshaft pulley onto the end of the crankshaft loosens off, then the pulley flogs on the little half-round key that is embedded into the end of the crankshaft.

If you are lucky only the pulley and the key need replacing. If you get unlucky the crank has to come out so it can be built up and re-machined. Otherwise, yup... new pulley and away ya go The toothed pulley/gear that drives the cam belt, sits behind the crankshaft pulley and shares the same key. Mine was OK, but I guess it could get damaged if it rattled around enough.

So, on 4AGE's it is very important to torque the bolt holding the crankshaft pulley to the correct specs (101 ft-lb or 137 Nm for a 16 valve). BTW that was a pretty good price, as I was quoted $350 just for the pulley on a RWD 4AGE !!!

jondee86