Valve Guides

[mrred]

Looking for some info from you Toyota tech guys. I am not familiar with Toyotas, I'm doing some research for a friend.

Vehicle in question is a '02 Rav4, 2.0.

She got a call from her mechanic saying a valve guide(s) need replacement. What labor is involved with this?

Did a quick search, found guides need to be machined out, pressed in. Is this true?

How many hours would this take? Mechanics see a girl walk into a shop knowing nothing about cars and see nothing but dollar signs.

Parts aren't expensive, but it looks like the labor will be.

Thanks in advance.

[toyomoho]

What was happening with the engine/car when you took it to the shop? What reason did the mechanic state for requiring new valve guides? Where does it state the guides must be machined out?

This type of repair is common. Often when people do a valve job, new guides are installed. Depending on how the shop is set up, they may send out the head for repairs to a machine shop. Removing/installing the guides is a straightforward job.

The shop will also do a valve job, install new valve seals, and may need to resurface the head if warped (not a big deal).

As you state the major cost is this job is labor. Thought Toyota had lined out 6-7 hours for a head gasket, this engine has about the same design. Might do a TN search, as valve jobs are a common topic.

Also again what led the shop to state the guide are bad?

[mrred]

At a cold start, white-ish smoke would come out of the exhaust for about 20 seconds or so. I initially thought transmission, as it had that color and smell.

Lately, the smoke was more blue, so the oil burning would make sense. She's been unable to speak to the mechanic yet (a family friend of hers, free diagnosis of the problem). I told her to ask him what led him to that conclusion.

He doesn't have the appropiate tools to do the job. I suggested she take it to the dealer she bought it from, as it has an extended warranty. Don't know if this would be covered.

Always good to have an idea of the work involved before handing it over, I appreciate your response.

[toyomoho]

Suggest you see if the extended warranty covers this repair! Being a 2002, unless this engine model has a history of wearing out valve guides prematurely, it is unusual for this to happen until the miles get up to say 130K or more.

If the smoke is just at startup and the car is not burning oil (keep checking the dipstick), the problem may be bad valve seals. These are the seals that go over the guide and around the valve stem to control oil flow in the guide (and into engine). On other engine models, often just changing the seals stops the smoking issue. This can be done with the head on the engine, but it takes more skill and maybe more effort. The mechanic gets paid one way or the other and will go for the easiest fix for them.

This said, how did the shop determine if the guides were the problem and not just the seals? Does this engine model have a history of wearing out guides prematurely? Did they shop actually check the play between the valve stem and guide?

Again, I would strongly pursue getting the extended warranty to pay for this job. That is one reason it was purchased. How many miles on this car? Did the car ever sit for a length of time, as in months without being driven? How was the maintenance, regular oil changes?

[Hook]

to my knowledge, the 2002 model hasn't had a history of premature valve seal failure, so before u go trying to remedy a problem that may not exist while the real probel is still there, consider this

At a cold start, white-ish smoke would come out of the exhaust for about 20 seconds or so. I initially thought transmission, as it had that color and smell.

not necessarily...could be water/coolant, ie. indication of head gasket failure and the smell might be just the rich cold-start mixture or the antifreeze (it has an almost sweet-ish smell)

the leak might not be a big enough to have you blowing smoke out the yin-yang, but enough for water to seep from the cooling channels into the cylinders slowly overnight

Lately, the smoke was more blue, so the oil burning would make sense.

prolly getting worse...breach widening to the oil channel closest to it causing oil to seep into the cylinders along with the water, hence the bluish colour

my advice is to perform a compression test on the motor to rule this out before starting any kind of repair work

[timebuilder]

Yes, it could be more than one problem.

The puff of smoke at startup is classic failed valve seal behavior. Many techs like to do the guides at the same time, because valve seal wear is often related to valve guide wear.

Did the car have to go to the dealer? Not really. But it's not bad, since most shops will send the head out for a thorough once-over because of the specialized tools involved. In five dealerships, not one where I worked was set up to do automotive machine work. One had a dusty old valve grinder in a corner, and one shop didn't even have a working brake lathe. New rotors, only.

A compression check is good, and so is a cylinder leakdown test. I also like to draw gasses into a test bulb with CO2 sensitive fluid to look for combustion gases in the cooling system. Of course, neither you, nor I, nor anyone else here in the thread was there at the dealership to hear the entire conversation, explanation, and justification for this course of action.

It is possible that the cheap fix might be to replace the valve seals, or even to add a head gasket if further testing reveals its warranted to do that. It's also possible that failing to replace the guides on this vehicle would mean only doing part of what is really necessary.

You can call an automotive machine shop and get prices and further insight. Chances are, that's the shop that will do a part of the work, anyway.