A documented case of precat failure (I think I'm done).

[silencery]

EDIT 04/11/05: Finally finished up the details today... haha. It's nearly 1 1/2 years and I've completely forgotten about this post. I hope it was useful to people around here!

EDIT 04/03/06: Last week, I finally got around to replacing the manifold with Che's stainless header. Over the course of the year, I've been pulling the O2 sensors periodically to check the condition of the precats. I'm glad to report that approximately 40,000 miles after the last incident, the precats are still in one piece. If you are intent on getting rid of your precats, here is a link for all the parts you might need, and here is a link with instructions on how to get it done.

I've decided to document my precat case to assist anybody who might need it in the future. I remember there was something similar in the old board, so if it turns out to be useful, perhaps the mods can make this post a sticky for reference. Hopefully both old and new members of spyderchat can take advantage of this information.

Please refer to existing posts found here and here for more information.

Here's what I've managed to garner so far from everybody else's experiences. Please correct me if I'm mistaken:

1. Engine oil blow by is caused by piston ring distortion from heat while running the motor in mid-high rpms (or just regular operation).

In addition, as kingspyder (thanks!) pointed out, there is another school of thought which believes the block has an overbore issue which is a result of poor factory quality. Effectively, this causes oil blow by during standard operation. If so, this would mean that blueprinting the 1ZZ might be a remedy. That would, however, be far too expensive as a practical solution.
2. Leaked oil is seeping into pre-catatalytic converters.
3. Exposure of precats to oil causes the material to break off.
4. Due to the close proximity of precats to engine, contaminated air with precat material is returned somehow (magically?).
5. Contaminated air (precat dust?) is sucked into the combustion chamber which causes engine failure to accelerate.
6. Repeat steps 1-5.
7. I haven't managed to find anyone claiming to know what the specific problem with the engine was, but I am assuming it has to do with rod bearings and low oil volume/pressure or even blown piston rings.

edit (thanks Racer x!): forgot to mention that there is speculation saying that the precats just start falling apart on their own which means that they cause the problems to begin with (excessive backpressure distorting the piston rings).

It would seem that the occurrence is fairly random; only a few unlucky souls have been inflicted by this problem. It hits people with low mileage and high mileage as well. There is, however, a theory which points the blame at using natural oil, and several others scapegoating the break-in process used.

As of right now, the only preventative measure Spyder owners can take is getting rid of the precats either by gutting them out w/ a screwdriver or by removing them completely by replacing the factory header with an aftermarket header; niether option is very appealing nor recommended since they require time/money and the car probably won't pass smog. At least, not in California.

The best way to make sure you're not affected is to check your oil consumption regularly. Toyota's standard allowance of consumption is 1qt/1,500mi. Additionally, you can check the cats visually by pulling the 02 sensors on the header. When doing so, make sure everything looks intact. A third way of checking is the "t-shirt" method. This is done by placing a black t-shirt directly under your exhaust pipe, and giving it a few revs. If specs of catalytic converter material are found on the shirt, then chances are, you've got pre-cat syndrome.

Here is a personal log of what has happened up to this point:

42,000 Mi. - Noticed that the oil happened to be a bit low right before taking it in to my local dealership (Macpherson Toyota) for my standard 3,000 mile oil change. At this point, it was about 1 cm higher than the "E" mark on the dipstick which equates to about 1.5 quarts. Took it in and commented to the tech that the oil level was a bit low and asked if they could possibly check. They did so, and did indeed confirm that oil levels were a bit abnormal; told me to that they needed more time w/ the car and recommended that I start an oil consumption test if it happened again.

45,000 Mi. 11/22/03 (Sat). - Checked oil levels periodically and they were still falling pretty quickly. Oil consumption seemed to be about 2.0 quarts/3,000 miles. Oil consumption test started by larger dealership close to work (Longo Toyota), which will hopefully have a better service center. At least they have wireless internet (and a $tarbuck$ too)!


45,917 Mi. 11/28/03 (Fri.) - While driving on the freeway and cruising at about 4K rpms, engine suddenly started making metallic knocking noises (similar to a loose timing chain but louder) and lost a severe amount of power. Pulled off, turned off the car, and restarted it. Revved to about 6K rpms, but takes a tremendous amount of throttle to get beyond 4K. At this point, the car is fine after restarting as long as throttle is kept under 3K rpms. After the car warms up, or goes beyond 3K, there is a severe loss of power and the metalic sound is fairly prevalent (spun bearing?).

46,051 Mi. - 11/29/03 (Sat.)- Took the car back to the dealership today, and confirmed that oil consumption was approximately 1.5 quarts for 1,051 miles. The service advisor who was handling my case, Danny LeBlanc, was pretty helpful, and says he has seen this once before in another Spyder. Hopefully, we can get everything sorted out without too much hassle. He claims that he must contact the corporate office on Monday and wait for them to advise what to do w/ the car. Service advisor lets me leave with the car since rental office is already closed for the weekend. Currently waiting for them to call back, and planning to take the car back in on Mon.

46,115 Mi. - 11/30/03 (Sun.) - Put another 64 miles on the car, and it has gotten SEVERELY worse. Engine will not rev beyond 4,800 rpms when in neutral, and under strain (5th gear), does not rev beyond 3,500 rpms. Taking the car back in to the dealership tomorrow because it is definitely undriveable this way.

46,215 Mi. - 12/01/03 (Mon.) - By the time I reach the dealership, top speed has been reduced to approximately 50mph. Car does not rev beyond 2,500 rpms, and under heavy strain, it is much worse.

46,215 Mi. - 12/02/03 (Tues.) - Spoke to the service advisor today after stopping in to rent a replacement, and he let me know that corporate has not yet responded to their inquiry; he then called the technician over to find out what was going on with the car. Technician who pulled the motor told me that they were probably going to have to replace the Piston Head in addition to the cats and shortblock.

While making small talk with the service advisor, he mentioned to me that this is the 3nd case him and his partner (I guess they work in pairs there?) have handled for Spyders in the past 1 1/2 years. I was trying to convince them to make sure they replaced the head in addition the shortblock and cats, but he told me he was already lobbying for that to happen. Apparently, the last car he did went through two blocks before it was finally fixed, much like everyone else here. He let me know that he thinks Toyota is documenting the problem, but he wasn't quite sure. Hopefully they'll have some good news for me on Thursday.

Driving the Corolla sucks!

46,215 Mi. - 12/05/03 (Fri.) - Called Danny, the SA, and he confirmed that everything we thought had happened, did indeed happen. They've sent the head out to a machine shop to get it checked, and everything should be ready by Tuesday. He mentioned that they were going to replace at least the cats and the engine block. Depending on what the machine shop reports back, they might end up replacing the entire engine.

Man, I still hate driving the Corolla...

46,215 Mi. - 12/09/03 (Tues.) - I receive a call from an operator at Longo Toyota telling me that my car is ready to go. I race over to the dealership (as quickly as the Corolla will take me at least) after work and pick up my car. Unfortunately, Danny wasn't in to give me any details. While looking over the invoice, however, I see that they've billed the warranty work for $4,000+. Apparently, the machine shop thought the head looked ok, so it wasn't replaced. They did replace all catalytic converters though, along with the block.

Epilogue:

66,000+ Mi. - 04/11/05 - Okidoki. So, I've put on significant mileage in the past year and a half, but everything still seems to be running strong. I go back to Longo Toyota occasionally, but I've been told that Danny LeBlanc, the service advisor I was working with, has moved onto working at a Honda dealership in Clairmont.

I was chatting with a Senior service advisor the other day, and I found out a little more about the warranty. Since I forgot to ask initially, I asked him what kind of guarantee was available for dealer repairs. He told me that if I ever exceed my factory warranty, which I have, Toyota will guarantee any work done by an authorized dealer for 12,000 miles or one year. These repairs can be done by any Toyota service center; I would not be forced to return to the same dealership. Unfortunately, this doesn't help my case.

I gotta remember to get off my ass and pull the O2 sensors to check the cats ASAP.

If I ever do gut them, I will probably do so after I get my first smog check. This way it will at least put off the headache I'd have to deal with w/ emissions.

Overall, I'm quite happy with the work they've done for me, and I hope anyone else who runs into this problem can at least get the same treatment. Except for the fact that I was stuck with a Corolla, everything was fairly painless, and it was taken care of professionally.

Engine modifications: None.
Gas used: 87.
Type of driving: Spirited.
Oil Type: Natural.
Mileage: 42,000 when noticable problems arose.

Please contact me if any of this information is incorrect or confusing and I will do my best to accomodate.

Long-term follow up
118,000+ Mi. - 05/26/09

My car is now almost at 120,000 miles and I haven't had any drivetrain problems yet *knock on wood.* Since getting the work done at Longo over 4 years ago (!!), quite a few things have changed, but the modifications are just bolt-ons. To eliminate the precats completely, I have been using che's header for a few years paired with a TRD exhaust.

We did a major service (by ourselves) late last year. This included mostly basics such as replacing a few seals, hoses, belts, gaskets, 02 sensors, etc.

Smogged the car last week. This was actually the second time I've smogged it in the last 3 years, and both times it passed with no problems. When I asked, the technician said it passed with flying colors. He did suggest replacing the third 02 sensor, but that's about it.

Happy driving!

[ekang315]

That was at Longo Toy. after the tea house meet? Im sure you'll end up with a new block, keep us posted.

[kingspyder]

You might want to add possible engine overbore as a contributing factor to blow by in some people's cases, but not necessarily in everyone's since we don't know because most people who have theirs replaced unfortunately do not bother to have the bores checked. There has been enough other evidence brought forth at this point from others though to know that this is an actual manufacturing defect with the older blocks.

I'm pretty sure the pre-cats on my car went first, blocking the exhaust flow and thus causing excessive back pressure that forced the rings to give.

[silencery]

eric,

Yeah, this was right after the meet. I had to limp my way over to the dealership :roll: . I'll be sure to let you know what happens.

king,
You're talking about overbore from the factory right? If so, I'm assuming you mean that the factory specs on the sleeves are sloppy to begin with? Please let me know, and I'll be sure to update the post.

Racer,
You're right, I do remember there being some discussion as to which came first. Thanks for reminding me!

[kingspyder]

Originally posted by silencery
king,
You're talking about overbore from the factory right? If so, I'm assuming you mean that the factory specs on the sleeves are sloppy to begin with? Please let me know, and I'll be sure to update the post.

Yes, that's what I meant.

[Mister 2]

This post is a keeper. Definitely library worthy...keep us posted.

[silencery]

Updated today. At least I got some people who seem like they know what they're doing...

[LittleRocket]

There is no egr on the spyder.

[silencery]

?? really?

haha, ok, thanks LR! I'll be sure to update to reflect that tomorrow.

[markiii]

Originally posted by Racer X
I'm pretty sure the pre-cats on my car went first, blocking the exhaust flow and thus causing excessive back pressure that forced the rings to give.

I know you guys are going to want me to justify this statement, and since I was told this in confidence I can't at present.

However for whats it's worth I have it on good authority that Toyota cats are not exactly known for their high quality compared to many others on the market.

Due to this this they are suceptible to the high temps caused by being so close to the engine, this causes them to disintegrate and the particles are then sucked back into the engine when valve overlap occurs, this scores the cylinder walls and generally starts stage 1 of the engine failure.

Now this bit is me speculating but I suspect this is what causes ring failure which allows the oil past which then excacerbates the cycle.

[MadMigMR2]

i allready posted my story in another post and is quite similar to yours.

What has been told to me is that the main problem in our car is the block.
Some blocks have a slight error (6 microns)

And after some miles that error grows and then all the chain reaction starts.

The baby cats don't like oil and start to deteriorate.
The main cat get's dirty with the particles that become loose from the baby cats, causing more back pressure

Because of the extra oil going trough the headers, the 2 sensors on the headers start to think that the mixture is rich and tell that to the ECU
The ECU lowers the gas values on the injectors, and you start to have a air/oil mixture instead of air/gas misture.

This was told me by an engineer from toyota that worked with waranty issues on this cars.

He also told me that only in midlle of 2002 they started to install an updated block on the MR2.

This was the story that this guy told me for all our engine problems.

My engine was gone at 60000KM.
- New block (updated version)
- New headers (that i have on my garage because i replaced the stock to the trd)
- New Main cat.

I'm now with 6000KM in the new block without a problem.

Next weekend i'm going to do my first long trip with the new block (around 2500KM)

Let's see if this time i reach my final destination.

That still doesn't discount the fact that the pre-cats are just badly manufactured or designed and disintigrate too quickly regardless of the engine itself.

[SpyderLust]

Originally posted by green
That still doesn't discount the fact that the pre-cats are just badly manufactured or designed and disintigrate too quickly regardless of the engine itself.

i must have missed something along the catalyticatastrophe path...fact? speculation?

Okay, I don't know it for myself. I've just heard it regarded as fact that Toyota does not use high-quality catalytic converters, from people in the trade. I'm sure there's someone who can confirm or deny that here.

It's true with a lot of cars that have blown up.

Toyota is not going to fess up. The facts are simple:

The precats are in the exhaust manifold that gets very hot and hotter once the precats block the passage for the exhaust to leave the tail pipe. Also, the precats are close enough to the head, that apart from causing excessive back pressure; the engine on the intake stroke sucks parts of the precat back into the engine 6,000 times a minute.

[myrtle spyder]

I am worried about my car, and was wondering what the very first sign of this oncoming catastrophe is? Unusual oil consumption? Knocking noise? Poor performance?

My car is a 2000 with 38,000 miles. I have noticed that it is using more oil than is normal. There is NO oil on the floor of my garage...therefore I have assumed the car is burning oil...not leaking it.

I took it to dealership and told them my problem...they looked it over...said it was leaking oil from somewhere and said they fixed it. But I can't possibly see how it could be leaking oil and not have a single drop on my garage floor. Any suggestions about what I should do?

[silencery]

The first typical sign is burning oil. If you're experiencing poor performance, chances are that your engine is already on its way out.

As I wrote in the original post, Toyota's normal allowance is 1qt/1,500 miles. A quart is approximately halfway down the dipstick. If your dealership is good, they should acknowledge the problem and diagnose it properly if your car is indeed losing that much oil.

They will probably start you on an oil consumption test, and gauge exactly how much oil you're losing from there.

Also mentioned in the original post, you can see what others have said about their personal experiences with toyota service centers around the U.S. by visiting this thread. Results are usually varied, so be sure you don't take crap from your dealership.

Make sure they change at least the shortblock, precats, and main cat if there is indeed something wrong with the engine. Some cases of complete motor replacements have also been reported.

Good luck!

[silencery]

By the way, my dealership did replace my shortblock, cats, and threw in new sparkplugs. I also asked them to do an alignment which they gladly did for me.

Once i get the chance, I'll finish up my log with complete details =p

[BSautner]

I'm currently dealing with something very simulare with my 2000 mr2 @ 54k - i've been getting a rattle in my engine when i'm at 3k-4k rpm and i'm losing oil rapidly - the dealer replaced O rings, timing change, tensioner trying to get rid of the rattle - also i'm on my third set of O2 sensors. I'm interested to hear why you are losing oil and if this is a sign of cat failure. I'd love a new engine before my car turns 60k.