Mr2 mk3 ticking noise

Started by 2000mr2, November 3, 2022, 17:55

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2000mr2

Hi, I'm kinda new to having an mr2 I love it, I took it to the track the other day and about halfway through the day I hear a ticking noise coming from the engine and have no clue what it is. It sounds like it's top end. I took off the rocker cam head and unplugged injectors and coil packs and then turned it over and then I can't hear the noise? Any help is appreciated.

Carolyn

How does it sound when the engine is running?
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Iain

Manifold gasket is first guess for a ticking noise.

2000mr2

That shoes there is no noise turning over with cam cover off
That's the ticking noise I'm scared to rev it but when I drove it home it sounded awful and a lot worse than that and louder

2000mr2

Quote from: Iain on November  3, 2022, 18:10Manifold gasket is first guess for a ticking noise.
The exhaust is brand new I only just replaced the manifold gasket and manifold.

Carolyn

Take a small 'flap' of tissue, and tape it to the end of a long screwdriver.

Start the engine and pass the tissue around the manifold, both at the cylinder head and at the flange between the manifold and the cat.  It will flap when it's near a leak.  Those compound gaskets that come with those exhausts can fail pretty quick.

If you do have a leak, put a steel manifold gasket on and use OEM crush rings gaskets at the flange.

If there's no leak, rev the engine and see if it gets louder or harsher....
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shnazzle

If idle is about 800rpm then to my untrained ear that sounds like about 400rpm, making it a cam noise. So that's good news I guess.
If my ear is wrong then perhaps you spun yourself a pretty little bearing ,as it happened on the track, where long right-handers LOVE to destroy these engines.

It's doing it only when the valve cover is under pressure (i.e. cover on) it seems.

1st question; the little pipe that goes into the blue valve on the airbox, is it connected? That can pop off sometimes (or you forgot to put it back) and it sounds like a top-end ticking. It's hard to tell from the video.
...neutiquam erro.

Dev

History of racing where the sound appears during the event.
Loud hammering noise consistent with idle from the video.
I would place my bets on rod knock.

Probably best to inspect the oil as a first step and then drop the pan.


Carolyn

I tend to agree that it's a probably a spun bearing.  BUT.. Might as well rule out the exhaust leak before taking the sump off.

If there's shiny metal in the oil, it's a bearing.
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maffiozo1234

I have, what im guessing is the same issue. I have a tapping noise, its been diagnosed as top end but not sure what yet. It only taps when the engine is either under no load or when its rpm is stable, at all rev ranges. Its 100% not knocking or spun bearings, thats how my first engine died and its not even close to that sound.

If the engine is increasing or decreasing in rpm, no noise, if its being held at a constant rpm it will tap and rattle. I originally thought it was chain slap, but ive just changed the chain and the sound is still lingering. Ill get a video for audio to help.

TIA

shnazzle

Quote from: maffiozo1234 on December  5, 2022, 14:09I have, what im guessing is the same issue. I have a tapping noise, its been diagnosed as top end but not sure what yet. It only taps when the engine is either under no load or when its rpm is stable, at all rev ranges. Its 100% not knocking or spun bearings, thats how my first engine died and its not even close to that sound.

If the engine is increasing or decreasing in rpm, no noise, if its being held at a constant rpm it will tap and rattle. I originally thought it was chain slap, but ive just changed the chain and the sound is still lingering. Ill get a video for audio to help.

TIA
rattle at a specific rev range (frequency) is usually the exhaust heat shield
...neutiquam erro.

Carolyn

Quote from: shnazzle on December  5, 2022, 14:14rattle at a specific rev range (frequency) is usually the exhaust heat shield

Quote from: maffiozo1234 on December  5, 2022, 14:09I have, what im guessing is the same issue. I have a tapping noise, its been diagnosed as top end but not sure what yet. It only taps when the engine is either under no load or when its rpm is stable, at all rev ranges. Its 100% not knocking or spun bearings, thats how my first engine died and its not even close to that sound.

If the engine is increasing or decreasing in rpm, no noise, if its being held at a constant rpm it will tap and rattle. I originally thought it was chain slap, but ive just changed the chain and the sound is still lingering. Ill get a video for audio to help.

TIA

Did it get a new chain tensioner?  It does soiund like the symptoms of chain slap.
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maffiozo1234

Heat shield removed, full timing replacement kit, gears, guides, chain, and tensioner. Its 100% in the engine but not sure what it is exactly, visual inspection of cams, tappets etc doesn't show anything obvious. Its at any rev range just only when the engine is either unloaded at held at an rpm or when steady cruising at a set rpm

Carolyn

#13
You might have got sealant in the oilway to the tensioner?...it does sound as though the tensioner is not working properly.

You might be better able to pin it down with the aid of a stethoscope before you start tearing back into it.
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maffiozo1234

We checked the chain, it is definitely tight, its sounds like its coming from either cylinder 3/4 but cant say for sure. the oil way was checked.

Carolyn

Have you checked the valve clearances?
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maffiozo1234

as in the gap between cam lobe and tappet? if so then no, that will likely be my next step, ive done a compression test ( which i know isnt of much use) which came back very healthy

Carolyn

There's a 'how to.

https://www.mr2roc.org/index.php?topic=65009.0

@jonbill has the bucket bank at the moment.  I can arrange for you to get the buckets you need.
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maffiozo1234

Excellent link, thanks. I am currently rebuilding a head to put on this engine so that will be very useful. Where are the buckets available from?

Carolyn

#19
I'll get the bucket bank from Jonbill, so you can get them from me.

Are you planning on changing the head with the engine in the car?  I've done it and I would not recommend it.  Best to drop the engine.
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maffiozo1234

It will be a summer project, as its my daily and i dont fancy the odds of getting it done, in the garden, in a weekend.