MR2 Roadster Owners Club

The Workshop => Maintenance, Problems & Troubleshooting => Topic started by: Sam on December 20, 2003, 21:40

Title: MR2 just got LOUD!! - Update: CAT Failure
Post by: Sam on December 20, 2003, 21:40
Went shopping on Friday night - car running perfectly normal. On the way back the intake/exhaust note was louder than normal - it seemed to increase in volume on the motorway.  By the time I was close to home it was over twice as loud as normal. (Think TVR loud).

I managed to get out for another drive tonight and so far can say that the problem only occurs when the engine is under load - increasing acceleration = increasing volume. The car also appears noticeably slower accelerating. I have driven with the passenger seat forward and cubby hole cover open to get a better idea of where the noise is coming from and it does sound like the intake area.

I have had a strained look (in poor light) over the HKS Induction Kit - and everything appears normal - and firmly attached.

I havent had a chance to fully examine the car in daylight yet - which I will be able to do tomorrow - anyone got any ideas in the meantime?

I have only had the 2 back for a couple of weeks after it being with MR T for 31 days getting half the gearbox replaced and hoping this isn't a serious engine problem  s:roll: :roll: s:roll:
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Post by: zud on December 20, 2003, 22:18
I had something similar on a previous car... and it turned out to be just a loose bolt on the exhaust manifold.  Putting the engine under load opened up a gap.  The mechanic I used at the time just put in a new bolt and didn't even charge me anything!   Good luck with yours... I hope its something as simple!
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Post by: Slacey on December 21, 2003, 08:52
I agree, it sounds like the exhaust is blowing.
When you say TVR loud, are we talking TVR sound too? I'd be tempted to leave it...  s:wink: :wink: s:wink:
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Post by: Anonymous on December 21, 2003, 09:24
Boy racer you!
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Post by: Slacey on December 21, 2003, 12:22
Quote from: "cstevens"Boy racer you!
As I have said before, I think I'm becoming the club hooligan!  s:lol: :lol: s:lol:
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Post by: Sam on December 23, 2003, 12:20
So far have checked the exhaust and the intake - all in good condition - nothing obvious. I went down to Toyota garage and got the mechanic to take it for spin - he claimed the Intake filter was disintegrating! I had already checked this and it isn't. To be on the safe side I replaced it with a new one today and the noise is still there. Next up I have been advised to clean the MAF. Failing that I guess I 'll have to put the stock box on and then try it again.  s:roll: :roll: s:roll:
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Post by: Sam on December 31, 2003, 13:09
Things have taken a turn for the worse   s:cry: :cry: s:cry:  

I have cleaned the MAF (which was filthy) and reset the ECU.

I have now started to replace the HKS induction kit with the stock airbox. After I took the HKS kit out I noticed a scuff mark under the heatshield where it looks like something has been rubbing against it and actually worn a couple of millimetres into the shield. I looked inside the pipe connecting the filter head to the inlet manifold and it was also pretty dirty, I noticed some small lumps in with the general dirt build up and after getting one out I discovered it is a small piece of metal!

Oh no! I might just jump to the conclusion that the heatshield has been rubbing against something, disintegrating and flying straight through the filter and into the engine   s:cry: :cry: s:cry:  

Does this sound plausible? Could the metal sharpnel get through the filter? Could it have come from somewhere else? I dread to think if this is true what sort of damage it may have caused.

I will try to get some photos done tomorrow of it for all to see.

Help!!! Anyone got any ideas on this?
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Post by: Slacey on December 31, 2003, 13:11
Yes  s:( :( s:(  , it does sound plausible  s:shock: :shock: s:shock:  

I'm not sure what to suggest next though, one of the more technically minded members can jump in now....
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Post by: Anonymous on December 31, 2003, 14:06
wash the inside of the engine to slush the metal out !!!!

Fairys good for grease   s:wink: :wink: s:wink:  

Na realy try taking the rocker cover and cleaning it by hand
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Post by: markiii on December 31, 2003, 14:39
not sure about the metal, but the HKS is iknown to be the worse one on the market for filtration so I wouldn't be surprised if stuff gets past it, I'd have thought shrapnel would be too biug to make it past though, un;ess we're talkign about filings here?
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Post by: Sam on January 1, 2004, 16:20
Yes it is shavings although there are a couple of larger pieces in there ( I guess a couple of mm across). I will borrow a digital camera and get some pictures done tomorrow.

I am in the process of putting the stock airbox back on but have managed to lose the top cover - so once I get a new one I'll try the engine again. Maybe it is nothing to do with the metal shavings altogether - does seem a bit of a coincidence though.

I am wondering what sort of damage they could do if they did get sucked into the inlet manifold?
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Post by: Anonymous on January 1, 2004, 16:31
Quote from: "Sam"I am wondering what sort of damage they could do if they did get sucked into the inlet manifold?

A lot, I hope you get things sorted ok   s:( :( s:(
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Post by: Sam on January 1, 2004, 16:36
Cheers WD - Me too!
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Post by: Tem on January 1, 2004, 17:21
Quote from: "markiii"not sure about the metal, but the HKS is iknown to be the worse one on the market for filtration so I wouldn't be surprised if stuff gets past it, I'd have thought shrapnel would be too biug to make it past though, un;ess we're talkign about filings here?

Yeah, you might wanna consider getting rid of the HKS...it might be good at sucking air and it might look nice, but it sucks at the main job of filtering.

Pictures say more than words, so here goes:
 m http://www.mkiv.com/techarticles/filter ... index.html (http://www.mkiv.com/techarticles/filters_test/2/index.html) m
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Post by: Sam on January 2, 2004, 13:18
Yeah I have seen that article before Tem (after I got the HKS). I think what has happened here though is not really down to the filter itself (although it does let more dust in than others) - but the fact that when Toyota last had the car for a gearbox problem and belt tensioner noise. For some reason they decided they needed to install a stock box to eliminate the fact the noise wasn't coming from the HKS kit. They did this and found it wasnt the HKS and was in fact the V-Belt Tensioner (as I had suggested to them). I think that when they re-installed the HKS they didn't do it correctly and hence the vibration and heatshield eroding away. I was hanging on with the HKS becasue it did sound great and I thought it was only a matter of time before I got a turbo installed and ditched the current intake system anyway.

Now I am stuck because Toyota wouldn't look at this latest problem until I had the stock airbox back on, and I havent got all the parts! Anyone want to part with their old stock box?
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Post by: Slacey on January 2, 2004, 14:15
Quote from: "Sam"Anyone want to part with their old stock box?
If no-one wants to part with theirs, maybe someone local to you could lend you one?
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Post by: Sam on January 2, 2004, 14:35
Quote from: "Slacey"If no-one wants to part with theirs, maybe someone local to you could lend you one?

Sure that would be great also - I just need to a) try it with the stock box to see if that cures the problem, or b) if the problem isnt cured just present the car to Toyota with a stock box on.

Anyone up for that?

I have been phoning around breakers/Jap spares places and have had no luck so far. I phoned a local Toyota and they were insisting that the Air Box cover comes with the MAF and cant be sold seperately which bumps the price up a lot. I then spoke to my original Toyota garage and they recognised the part numbers I provided from the Spyderchat parts list but wont be able to give a price till Monday.
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Post by: Liz on January 2, 2004, 14:45
I have got a stock box in my garage for a lend, I am in Essex so not too far away to travel? I am around most of this weekend and also off on Monday. Maybe if you came down you could clean my MAF for me as I don't poke around in engines!
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Post by: Sam on January 2, 2004, 15:03
 s:D :D s:D   Thanks Liz - you have PM!
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Post by: Anonymous on January 6, 2004, 14:13
Depending on how loud this sounds exactly like my car, eventually this was tracked to blockage in the lower exhaust, possibly bits of pre-cat (manifold replaced 18th Nov). The dealer changed the vvti gear and exhaust and problem is now resolved. I believe vvti gear was secondary damage, as initially power was OK just noisy, but it very quickly got worse.

Depending on how loose/rattly the debris is you might be able to check this by removing the exhaust and shaking it, failing that not sure how you could check this other than trying another exhaust which is a load of hassle.
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Post by: Sam on January 7, 2004, 10:06
Yeah to be honest I have now started to suspect the precats causing some trouble. Well I should soon find out - the car is disappearing to Toyota again on Friday (Lets hope for not as long as last time - 31 days!).
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Post by: Sam on January 15, 2004, 17:39
Update:

I collected my car today. The problem was pre-cats disintegrating and blocking the main cat. All 3 cats have been changed although I am still waiting for the copy of the claim put into Toyota by the garage to confirm this was all that was changed.
They tried to blame the HKS induction kit - saying that fitting this altered the compression ratio! (I can't see how this could be true in any way at all).
I said that other MR2 owners had had problems with the pre-cats failing and they said this was the first case they had seen or heard of.

Anyway car is running perfectly now so I think I'll keep the stock airbox in place and extend the warranty. Just have to be patient now and wait for the TTE turbo   s:roll: :roll: s:roll:
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Post by: aaronjb on January 15, 2004, 18:29
Quote from: "Sam"They tried to blame the HKS induction kit - saying that fitting this altered the compression ratio! (I can't see how this could be true in any way at all).

PMSL! You're right to disbelieve them... Given that compression ratio is a function of bore size/piston stroke/squish area etc (basically engine internals), there's no way an induction kit could alter compression ratio..

If by some miracle you managed to create enough of a ram air effect, you might raise cylinder pressure a tiny weeny bit - but no more than driving on a cold day increases the density of oxygen in the cylinder.

Just another example of a garage saying anything that comes to mind to try and get rid of you, I'm afraid...

(Someone correct me if I'm wrong!)

Aaron
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Post by: Anonymous on January 15, 2004, 18:35
Quotesaying that fitting this altered the compression ratio!

I would agree with your sentiment on that although I can't say why the fault occured. I thought compression ratio was a fixed aspect i.e. the ratio of the space above the piston from when it is at it highest point of its travel, to the space above it when at the bottom of its descent. To change it you would need to alter the head, piston or connector rod in some way I would have thought.

Some of the turbo owners can probably give us a more experienced view.

They didn't say why the pre-cats had fallen apart? Was it age? Overheating?
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Post by: aaronjb on January 15, 2004, 18:38
Thinking on it a bit more (you're right on the definition of compression ratio btw Lusaka), the only reason I can think that an induction kit could cause the cats to fail is this (and it's a very slim chance);

If the induction kit pipework modifies the crankcase breather arrangement, it could increase the ingestion of oil fumes to an extent that the oil content contaminates, and then breaks down, the CAT element.

But that really is a slim chance, and purely conjecture until someone comes along who knows the ins and outs of the 1zz-fe breather arrangement (I don't, but I've seen similar problems on other engines).
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Post by: mph on January 15, 2004, 18:48
Quote from: "Lusaka"Some of the turbo owners can probably give us a more experienced view.
Compression ratio - you're quite right with your explanation.

Quote from: "Lusaka"They didn't say why the pre-cats had fallen apart? Was it age? Overheating?
I've heard an authoritive expert comment that the Toyota CATs are of 'questionable quality', 'cheap' and 'prone to failure'.

My interpretation is that cheap CATs can't tolerate as high temperatures as quality ones, and that overheating a CAT will cause it disintegrate.
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Post by: filcee on January 15, 2004, 18:58
Quote from: "mph"My interpretation is that cheap CATs can't tolerate as high temperatures as quality ones, and that overheating a CAT will cause it disintegrate.

Now I'm worried  s:roll: :roll: s:roll:

How much evidence do we have for this, collectively?  The reason I ask is that the exhaust on my '03 is noticeably throatier than it was when brand new.  I thought this was down to it being properly run in now, and the added 'bean can' tuning the sound slightly.  However, given that I spent most of the summer bashing up and down the motorway in that glorious weather, I'm now thinking that the noise might be due to a combination of long runs at speed and hot weather warming everything up just a little too much.  Oh, dear!  I hope I'm being paranoid, and there's really nothing to worry about  s:? :? s:?
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Post by: Sam on January 15, 2004, 19:41
I wouldn't have thought the hot weather would be anything to worry about, given the temperature of the exhaust gases would be a good few hundred degrees centigrade.

I had been worried about the pre-CATs, but other than put a TRD header in or similar I dont know what can be done to avoid this problem.

Lusaka/MPH/aaronjb - Thanks for clearing the compression point up - it was what I thought and I did say it at the time in the garage.

I am going back in next week to collect the paperwork so I will ask a few more questions as to why the cat broke down - I did wonder if it was anything to do with the original particles of metal I found in the air intake pipe...who knows?
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Post by: Anonymous on January 15, 2004, 21:03
Quote from: "filcee"
Quote from: "mph"My interpretation is that cheap CATs can't tolerate as high temperatures as quality ones, and that overheating a CAT will cause it disintegrate.

Now I'm worried  s:roll: :roll: s:roll:

How much evidence do we have for this, collectively?  The reason I ask is that the exhaust on my '03 is noticeably throatier than it was when brand new.   s:? :? s:?

I wouldn't worry to much about this, unless its gotten REALLY loud...?
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Post by: Anonymous on January 15, 2004, 21:26
Like mine lol - all with 7000 miles and 7 months of ownership, i aint giving it to them until she pop's though, i'd miss her too bad.
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Post by: GSB on January 16, 2004, 08:09
Quote from: "bigun007"Like mine lol - all with 7000 miles and 7 months of ownership, i aint giving it to them until she pop's though, i'd miss her too bad.

You mean to say you still havent had anyone look over your car?

You do realise that you are obliged to report any fault as soon as possible so that the damage (and consequently the size of the repair bill that Toyota have to pay) can be minimised?

It wouldnt be the first time a manufacturer has refused to honour a warranty in these circumstances...
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Post by: Anonymous on January 16, 2004, 09:21
Quote from: "Sam"I had been worried about the pre-CATs, but other than put a TRD header in or similar I dont know what can be done to avoid this problem.

Indeed, and given the cost of the TRD header (even with a good $ exchange rate), I'm giving serious consideration to gutting the cats from my existing header.

How practical is this? I realise it'd be a permanent thing, but would screwdrivers/chisels/drills get the cats out?
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Post by: filcee on January 16, 2004, 09:22
Quote from: "WoodenDummy"I wouldn't worry to much about this, unless its gotten REALLY loud...?

I can still hear the radio  s:) :) s:)   I'm guessing that this means it's not loud enough.
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Post by: markiii on January 16, 2004, 09:29
Quote from: "pmdye"
Quote from: "Sam"I had been worried about the pre-CATs, but other than put a TRD header in or similar I dont know what can be done to avoid this problem.

Indeed, and given the cost of the TRD header (even with a good $ exchange rate), I'm giving serious consideration to gutting the cats from my existing header.

How practical is this? I realise it'd be a permanent thing, but would screwdrivers/chisels/drills get the cats out?

Phil,

take a look on C for gutting the pre-cats, someone just documented it, seems easy enough. I'd do mine now but I'm worried about the warranty. Though since Martins manifold is still in my garage I could always stick that on if it had to go in.
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Post by: GSB on January 16, 2004, 09:59
Quote from: "markiii"Phil,

take a look on C for gutting the pre-cats, someone just documented it, seems easy enough. I'd do mine now but I'm worried about the warranty. Though since Martins manifold is still in my garage I could always stick that on if it had to go in.

The guy on SC (hotkoala) who documented the procedure took it down as technically it was an illegal act. (In the states it is an offense to interfere in anyway with any part of a cars emmision control system - even to the point of changing the silencer...)

I did in fact ask him to send me a link to it, which I'll share with any member who wants to PM me...