How to diagnose possible detonation/ spark knock T-Sport

[dennis10]

Hi guys,

I've been chasing a rattle on my 2005 Corolla T-Sport for quite a long time, which I ended up firing the parts cannon at (New aux belt tensioner, engine mounts, PCV valve amongst others) but still have this issue.  It can be described as a kind of juddering at take off in 1st gear (that is better if I keep the revs above 2krpm when pulling away) and then a loose sort of rattle when under load in 2nd, 3rd, 4th etc at low rpms (1500-2500rpm ish) - Above this rpm it seems to clear and it revs really cleanly through to 8200rpm.  It is also seems much less noticeable once the engine is up to temperature.  I can slightly hear this rattle sometimes when revving out of gear from idle (previously thought it was only when in gear, which led me down the path of thinking it might be a gearbox issue, but the car engages all gears nicely)

I then watched a video (of another car) where somebody was showing the detonation/spark knock/pinking/pinging their car was experiencing (at similar rpms to mine) - And it sounded very much like what I am experiencing. 

How best to diagnose if this is the issue?  I have no warning lights or engine management codes on the reader.  Are there specific things that could cause pre-detonation on this vehicle?  Could the knock sensor be faulty without a warning and be causing this problem?

Many thanks - really want to get to the bottom of this on-running issue. 🙏

[oldcodger]

You could try one of the Octane Booster addatives eg Redex, and see if that reduces the noise if it is Pinking/Pinging ?

Are you on standard petrol or Shell V power with its higher octane rating ?

[flash22]

Has it had spark plugs ? Has it had the lift bolts done ? Sounds like a weak cam chain tensioner to me and/or worn guides, use a stethoscope or long screwdriver to listen to the front cover

What is the mileage and what oil is in the car ?

 

Any knock will be picked up by the knock sensor and either throw a code or pull timing and or fuel it will be very noticeable at higher rpm, non Denso plugs or fake plugs can give issues

[dennis10]

16 hours ago, oldcodger said:

You could try one of the Octane Booster addatives eg Redex, and see if that reduces the noise if it is Pinking/Pinging ?

Are you on standard petrol or Shell V power with its higher octane rating ?

I've not tried octane boosters, but I only put Momentum99 or Shell V-power in, so they should be enough.

 

 

15 hours ago, flash22 said:

Has it had spark plugs ? Has it had the lift bolts done ? Sounds like a weak cam chain tensioner to me and/or worn guides, use a stethoscope or long screwdriver to listen to the front cover

What is the mileage and what oil is in the car ?

 

Any knock will be picked up by the knock sensor and either throw a code or pull timing and or fuel it will be very noticeable at higher rpm, non Denso plugs or fake plugs can give issues

Yes, I replaced the spark plugs earlier in the year - I chose Denso IK20TT - I got them from a reputable online seller, so I've got no reason to suspect they might be counterfeit.  I don't think there should be any issue with these plugs on the 2ZZ-GE engine should there?

I had a replacement engine about 9 months ago, the rattle wasn't immediately apparent, but the juddering was there when engaging the clutch.  I was told the engine was a low mileage one, was provided with compression results and I have no reason to disbelieve this, but I guess I don't have any real proof.  The timing chain tensioner was replaced with an FAI aftermarket one - Is there a way to diagnose this as being the issue before aiming the parts cannon once again - I do still have the old tensioner, so I guess I could clean that up and reinstall?  Lift bolts were replaced, but it engages lift perfectly.  Really reluctant to just throw more money at it, without diagnosing the issue.  Apart from this low rpm rattle and the slight judder on clutch engagement, it drives perfectly.  I wouldn't say it is down on power at all, especially not at high rpm, where it pulls hard.  I've even had 41mpg out of it on a 130mile round trip!

I use Millers Motorsport CFS NT+ 5w40 oil in the engine - am in the UK

[flash22]

Can you post a clip of the sound, is the sound constant at low rpm or does it come and go ?

[dennis10]

1 hour ago, flash22 said:

Can you post a clip of the sound, is the sound constant at low rpm or does it come and go ?

I'll try and get a clip at the weekend - It's a kind of marbles in a can rattle, loose sounding but also seems to increase with revs.  It is constant at low rpm, until I get above about 2500rpm.  

Does anyone know of any trusted specialists in the UK that could diagnose this?  I've been to two garages and they're clueless unless it's a 2023 model

[flash22]

Does in sound like this

 

[APS]

Did you inspect the state of the clutch (disc springs, fork, release bearing) when you put the replacement engine in?  Although, you did say it's only noticeable under load, which should exclude the clutch.

Clearly, clutching at straws here.

[dennis10]

8 hours ago, flash22 said:

Does in sound like this

 

Yes and no - I only really hear it when under load at low rpm and it's alot more obvious and rhythmic, not just a random sort of ticking like in that video - but the sound of it probably isn't far off.

 

7 hours ago, APS said:

Did you inspect the state of the clutch (disc springs, fork, release bearing) when you put the replacement engine in?  Although, you did say it's only noticeable under load, which should exclude the clutch.

Clearly, clutching at straws here.

Clutch was replaced as I saw no reason to re-use an old clutch assembly.

 

I think I'm going to try a decent 0w40 oil in place of the 5w40 I'm currently using.  I've been doing alot of reading and some people seem to have had a similar issue which was caused by too thick an oil when cold, meaning it didn't flow properly to where it needs to - and as the engine is somewhat unknown, it could have a build up of sludge making the oil passageways harder to flow well when the oil is cold and thick - I don't seem to have an issue at higher rpms and when the engine is warm it seems much less prevalent, which also would suggest oil.

What do you guys think?

[flash22]

Input shaft bearing on the gearbox ?, when was the gearbox fluid checked/replaced last

[APS]

Things get noisier as fluids heat up and get thinner - both in the engine and the gearbox. Rattle under load is most likely external to the engine. So your first ideas about engine mounts and tensioner are probable. Other things to check would be exhaust (shields, manifold coupling), intake pipes. Chances are it is something quite benign.

[dennis10]

On 10/18/2023 at 9:33 AM, flash22 said:

Input shaft bearing on the gearbox ?, when was the gearbox fluid checked/replaced last

I can't discount it - but it is so difficult to get somebody to take a look at it and reliably diagnose.  Even tried to get a gearbox place nearby to just drive it for 5 mins and give me a verdict - not interested.  First of all he said he had no availability for 6 weeks, then when those 6 weeks were up, I messaged again, this time he can't do my gearbox anyway because he doesn't have the tools.  I've also approached other garages and even had my clutch redone months ago, which gave a mild improvement, I've kind of given up on finding anyone knowledgeable and reliable, so I've resorted to internet research and forum opinion.

I've replaced the gearbox oil twice, first was Redline, but it didn't feel nice and still had a synchro grind when cold, the 2nd lot, currently in the box is Millers Motorsport CRX NT+ 75w - and it's fantastic.  Completely cured my 3rd gear graunch when cold (2nd into 3rd or sometimes 4th down to 3rd)  The box changes faultlessly.

If anyone knows somebody who could help me diagnose down in the Bucks/ South of UK area, please, please let me know!

On 10/18/2023 at 9:49 AM, APS said:

Things get noisier as fluids heat up and get thinner - both in the engine and the gearbox. Rattle under load is most likely external to the engine. So your first ideas about engine mounts and tensioner are probable. Other things to check would be exhaust (shields, manifold coupling), intake pipes. Chances are it is something quite benign.

That's the thing, it isn't noisier when hot, I'd say it's alot quieter - hence why I'm now looking at oil grades.

I've spent hours checking all the heat shields etc.  I might swap back to the stock airbox jus to rule out that area.

[dennis10]

Hi guys,

This weekend I replaced a bolt in the downpipe to mid pipe to rule out the 2 faces not being properly situated, also checked the exhaust manifold gasket to make sure it wasn't blowing. All seems good in this area.

Ive attached a video of the rattle, it's doing it at idle now, and sounds like this also when in low rev take off situations, then disappears at high revs and when warm. Any ideas?

 

 

[dennis10]

Anybody able to diagnose the noise in my video?!

[Gerg]

Some random thoughts:

Is it worth running the tank low and putting a couple of gallons of regular fuel (95), and then seeing if the noise gets any worse?

On eBay/AliExpress etc., mechanic-style stethoscopes are quite cheap and might possibly help you find the origin of this noise.  But the 'normal' noises you find with a stethoscope, at least initially, are sometimes disturbing/overwhelming! 

Of course, you can improvise with a slender, long, piece of wood or a long screwdriver, pressed against your head, around the area of your ear, but extra care is necessary, especially when poking near the serpentine belt!

[Roker]

On 10/16/2023 at 3:22 PM, dennis10 said:

Hi guys,

I've been chasing a rattle on my 2005 Corolla T-Sport for quite a long time, which I ended up firing the parts cannon at (New aux belt tensioner, engine mounts, PCV valve amongst others) but still have this issue.  It can be described as a kind of juddering at take off in 1st gear (that is better if I keep the revs above 2krpm when pulling away) and then a loose sort of rattle when under load in 2nd, 3rd, 4th etc at low rpms (1500-2500rpm ish) - Above this rpm it seems to clear and it revs really cleanly through to 8200rpm.  It is also seems much less noticeable once the engine is up to temperature.  I can slightly hear this rattle sometimes when revving out of gear from idle (previously thought it was only when in gear, which led me down the path of thinking it might be a gearbox issue, but the car engages all gears nicely)

I then watched a video (of another car) where somebody was showing the detonation/spark knock/pinking/pinging their car was experiencing (at similar rpms to mine) - And it sounded very much like what I am experiencing. 

How best to diagnose if this is the issue?  I have no warning lights or engine management codes on the reader.  Are there specific things that could cause pre-detonation on this vehicle?  Could the knock sensor be faulty without a warning and be causing this problem?

Many thanks - really want to get to the bottom of this on-running issue. 🙏

Pre ignition sounds like stones in your engine. To me it sounds like clutch problem,assuming it is not a hybrid