MR2 Roadster Owners Club

The Workshop => Maintenance, Problems & Troubleshooting => Topic started by: Anonymous on December 19, 2003, 09:46

Title: Diesel Noise under acceleration - anyone had this fixed ?
Post by: Anonymous on December 19, 2003, 09:46
2000 car 21k miles, noise since September, dealer has changed belt tensioner and manifold, with no improvement.

After a month of deliberation with Toyota, this week they have been stripping engine down.

Big end shells were missing some white metal (which I found a bit alarming) so they have changed big and small end bearings, they are also changing the vvti gear (not sure if they mean gear as in the drive pulley with vane gubbins, or the entire vvti setup, which I guess includes camshaft(s)). They are also going to check/adjust valve clearances.

Hopefully they will finish this today so I can have my car back, and hopefully this will now be fixed.

Noise characteristics:
Fairly quiet when cold, after a few minutes changes to a loud diesel like clatter under acceleration audible from idle up to at least 5k revs, when engine is hot (ie after 10-15 mins running) the noise suddenly goes quieter, less like diesel clatter and more like rough running and a fluttering noise.

I don't think this is belt tensioner as it has been changed
I don't think this is chain tensioner as it doesn't stop at 3.5k revs.
I don't think this is pre-cat problems as manifold changed.

Has anyone else had big end problems on such a low milage engine ? I check oil level religously, and top up with Shell Helix 10/40 (as used by dealer), so there seems no reason other than manufacturing faults or oilway blockages for this ??

If anyone has had a similar problem fixed, can they let me know what was done to fix it.

James.
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Post by: markiii on December 19, 2003, 10:06
I seem to remember Little rocket on SC reporting that his first engine that blew when stripped showed signs of oil starvation at the head if that helps.
Title: Re: Diesel Noise under acceleration - anyone had this fixed
Post by: Tem on December 19, 2003, 10:06
Quote from: "jblackmore"2000 car 21k miles, noise since September, dealer has changed belt tensioner and manifold, with no improvement.

2000 with about 20k miles, similar noise and first guess was belt tensioner:
 m http://www.mr2roc.org/viewtopic.php?t=1250 (http://www.mr2roc.org/viewtopic.php?t=1250) m
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Post by: Anonymous on December 19, 2003, 14:02
Just picked up car, noise still there, they have ordered vvti oil control valve and pulley to change in new year, but don't seem too sure this is it.

Tem do you know what caused your engine to fail ? My oil is always clean, and I check/top up weekly, it has used about half a litre since service, which I assume was mostly initial settling/filter absorbtion.

Mechanic did re-assure me they will not stop until they fix this, so don't worry about being fobbed off, and they can clearly hear the noise, so I am not going mad.

Car is under ext warranty for 2 more years, and I will extend 2 after that, so hopefully that is enough time for them to resolve this !

Fingers crossed.
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Post by: Tem on December 21, 2003, 18:32
Quote from: "jblackmore"Tem do you know what caused your engine to fail ? My oil is always clean

The precat failure is the most likely cause, you can find more of it here:
 m http://www.spyderchat.com/phpBB/viewforum.php?f=6 (http://www.spyderchat.com/phpBB/viewforum.php?f=6) m

Check at least the first two topics for familiar symptoms...

FWIW, my oil was always and it didn't consume any...not even when the noise first appeared, but only right before the major failure...keep your eye on the oil level till they found the fault.

PS. It's pretty easy to take the O2 sensors off and check the precats. You should ask your dealer to do this, if they are clueless...
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Post by: Anonymous on December 22, 2003, 15:34
Quote from: "Tem"
Quote from: "jblackmore"Tem do you know what caused your engine to fail ? My oil is always clean

The precat failure is the most likely cause, you can find more of it here:
 m http://www.spyderchat.com/phpBB/viewforum.php?f=6 (http://www.spyderchat.com/phpBB/viewforum.php?f=6) m

The manifold (incl precats) was replaced on 18th November, and the car has only been driven a few hundred miles since then, so I would hope this cannot be the cause of the noise, as it was unaffected by the change.

The noise is now so bad I am not happy to drive the car, so am in the process of trying to arrange a loan car from the dealer until they can sort this out.
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Post by: Tem on December 23, 2003, 07:51
Quote from: "jblackmore"The manifold (incl precats) was replaced on 18th November, and the car has only been driven a few hundred miles since then, so I would hope this cannot be the cause of the noise, as it was unaffected by the change.

The noise is now so bad I am not happy to drive the car, so am in the process of trying to arrange a loan car from the dealer until they can sort this out.

So if I understood this correctly...the precats were broken and replaced? And nothing else?? The broken precats mean there is most likely a lot more severe damage than just the cats.

You really should read at least the "A documented case of precat failure" thread from the above link...
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Post by: markiii on December 23, 2003, 08:24
nope they did it as a precaution, nothing wrong wioth the original manifold if I remember correctly.