How much longer will it last - Toyota Nation Forum : Toyota Car and Truck Forums

BeaterCorolla · 06-26-2006, 12:49 AM

My wife's Corolla has bad exhaust valves in cylinder 4. It sputters at idle, but seems fine on the highway. Fuel economy hasn't dropped either. What harm can continuing to drive the car cause? If the catalytic converter goes bad, will it choke the engine? I just want a few opinions so we can decide when to start looking for a new car. Tomorrow? 6 months?

Thanks

punter · 06-26-2006, 01:44 AM

Keep an eye on the oil level and you should have a fair while.

How did you determin it has bent valves?

ToyotaMan1281 · 06-26-2006, 02:40 AM

well on my old neon cylender 4 was going bad. I had to put some special oil stuff in with the engine oil to help seal it or something. It lasted for a little while until i got it up to trade in for the new rolla. You might want to start looking for a new car just in case.

BeaterCorolla · 06-26-2006, 11:58 AM

A compression test showed only 80-90 psi for cylinder 4. They may have done a leak down test too to identify the exhaust valves. I don't think any oil additive will help here since it's the valve and not the cylinder rings. Correct me if I'm wrong. It seems so odd for it to go bad with only 150k on it. I'm wondering if the timing belt work done back at 100k could have caused it.

ToyotaMan1281 · 06-26-2006, 02:44 PM

im not sure what the nortmal psi is. but my neon only had 50K most on it when cylender 4 went bad. Thats good american quality for ya. I know the car was a piece of junk lol. But at 150K it does seem odd. Can you have someone replace cylendr 4?

freakinbox · 06-26-2006, 05:22 PM

it's hard to say how long something will last after it's been damaged. Will depend how nice you are to the car and if you maintain it I guess.

punter · 06-26-2006, 06:02 PM

As above its impossible to tell, the head of that valve may fall off tomorrow or next year some time, or maybe never.

But from pervious experence as long as you keep oil in it you should have a few months.

Can you hear ticking?

freakinbox · 06-26-2006, 07:02 PM

what year corolla is this?

alltracman78 · 06-26-2006, 07:32 PM

BENT valve or BAD valve?
If it is only the valve seat to valve seal that is bad, it should last a while.
If it is an exhaust valve, it will have a hard time though, as touching the seat is the primary way it rids itself of heat...

If the cat get's clogged, it can choke the engine.
It will run, but it will run poorly.

freakinbox · 06-26-2006, 07:40 PM

it would burn more oil, no? oil would leak in through the bad valve should puff out smoke when started. I keep asking the year because you could always swap out the engine if it's a 4afe for next to nothing, or even just swap the head.

alltracman78 · 06-26-2006, 08:25 PM

Oil will leak only if
The seal is bad
The stem is bent, warping the seal.

freakinbox · 06-26-2006, 08:47 PM

well depending how badly it's bent would depend if it even seals :s

alltracman78 · 06-26-2006, 08:57 PM

Too badly bent and it won't slide in the guide.

punter · 06-26-2006, 10:33 PM

When I bent a valve in my mirage its lost alot of its oil because of crankcase pressure, so bending a valve can cause the seal to go bad.

BeaterCorolla · 06-27-2006, 02:20 AM

Thanks for the responses everyone. It's a '97 CE with the 1.6L engine and auto. When I did a vacuum test, it was shakey which my service manual said was bad valve guides. The shop I took it to only said that it was a problem related to the exhaust valves. Whether it was the valve or the valve seat, they wouldn't know until they took it apart. The engine doesn't seem to be burning oil, but it definately clunks when stopped in drive. You could say it ticks at idle, and the exhaust putters. Oh, and it stinks of unburned fuel... Ugh, I just hope it lasts until the Miata hardtop convertibles show up at dealers. That's what the wifey wants.