MR2 Roadster Owners Club

The Workshop => Maintenance, Problems & Troubleshooting => Topic started by: Anonymous on October 13, 2005, 08:36

Title: Mechanics View
Post by: Anonymous on October 13, 2005, 08:36
Hi guys,  i know there is other posts on pre cats but couple things i wanted to mention.

Spoke with an old friend yesterday who is been a mechanic longer than ive been alive. mentioned to him about maybe removin my pre-cats and advised why. he advised me not to. said the chances of the pre-cats breaking up and going faulty are very slim as i use the car for everyday use and not a track or something, also said if this did happen the chances of it coming foward and killing the engine were not likly as it wold just get kicked out the back.  and lastly he said doing this would make my car fail MOT as he normally does mine.

He is going to speak to a friend of his who is at toyota to clarify with them and get back to me
Title: Re: Mechanics View
Post by: aaronjb on October 13, 2005, 08:41
Quote from: "reddi"also said if this did happen the chances of it coming foward and killing the engine were not likly as it wold just get kicked out the back.

 s:roll: :roll: s:roll:  Frankly. He's wrong. Plain and simple.

Perhaps you should get him to come on here for a quick lesson on how this particular engine works, in particular, the exhaust gas recirculation system.  s:roll: :roll: s:roll:  

Still, it's your choice.. I'd have thought the evidence on here was pretty clear, really, and I'd trust that over someone who has no idea about the workings of the 1ZZ-FE - this isn't some old CVH Ford engine, you know..

QuoteHe is going to speak to a friend of his who is at toyota to clarify with them and get back to me

Why? The offical line from Toyota is that this does not happen. There are no problems with these engines. It's all in your mind. So why ask? The chances of getting them to say "Yes, we see this all the time" are slim - although, reading recent posts, Stu (kanujunkie) did get exactly that answer from a Toyota mechanic, including how many they'd done that month!
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Post by: Anonymous on October 13, 2005, 08:46
On most other cars I would agree with him, however on the 1zz-fe engine (ie in mr2s, avensis etc) it seems to occur without any trends or signs eg mileage or usage.

Personally I would say using the car for everyday use puts a slightly higher load on the function of the precats as you generally use the car when the engine is cold, particuarly if you do a lot of short journeys in it.

As for the precat getting into the engine: rather than escape out the exhaust most of it blocks the Catalytic convertor creating far more backpressure in the exhaust and therefore bits can get sucked into the engine during valve overlap.

Finally, I think out of everybody who is on this site that has already gutted their precats that not one person has failed an MoT based on that.

hope this helps u mate,

Richie
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Post by: Anonymous on October 13, 2005, 08:48
yeah i do see what you mean and rekon your right and im just gona need to take the plunge

its not actually mr t he is going to speak to, its a friend of his and he will tell him honestly "off the record" not as a toyota mechanic
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Post by: SimonC_Here on October 13, 2005, 08:50
Oh and I just passed my MOT perfectly happily without the precats, including with the Unichip.

Simon
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Post by: aaronjb on October 13, 2005, 08:51
Quote from: "reddi"its not actually mr t he is going to speak to, its a friend of his and he will tell him honestly "off the record" not as a toyota mechanic

Then you might get a straight answer - fingers crossed, anyway  s;) ;) s;)  I'm sure Toyota do keep statistics on engine failures, it's just they're never released..

C'mon.. Whip 'em out! (And if that doesn't sound suspect, I don't know what will!  s;) ;) s;) )
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Post by: Anonymous on October 13, 2005, 08:55
LOL  think ive found someone in my area that can do it so ill give them a call and see what price they wanting
Title: Re: Mechanics View
Post by: Tem on October 13, 2005, 09:27
Quote from: "reddi"who is been a mechanic longer than ive been alive

No offense, but guys who knew everything about carburettors in the 50's might not know a thing about 1ZZ-FE in the '2. Experience is a great thing, but it doesn't make them experts on things they don't know. Especially on a subject like this, which just doesn't happen on most cars.
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Post by: spit on October 13, 2005, 10:33
I can understand where your friend is coming from Reddi. My Dad has been a proud and skilled engineer all his life, and would tend to leave well alone until he has unequivocal ratified evidence that preventative measures are necessary.

I can see the logic of his views - but in his hayday an individual piece of machinery was built to outlive the machine! He is starting to chill a little since retirement though (which is handy for me when discussing things like C2 Turbo  s:lol: :lol: s:lol:  )

I don't think that any of the gutted crowd have failed a UK MOT on warm-engine emissions. My readings before and after gutting didn't alter one iota, and were miles below the legal limits.

Aside from the inconvenience of doing it/having it done, there seem to be no downsides.
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Post by: heathstimpson on October 14, 2005, 09:27
My dads got his own garage and has been in the trade all his life. He agrees with the thoughts on this forum regarding the precats  s:wink: :wink: s:wink: