Friend brought her 1990 Camry to the shop to get the broken timing belt replaced. They did the belt and water pump but then discovered it has a bent valve. They want to charge her full price for the belt/pump and recommend she ditch the car because its not worth doing a valve job.
A. Since it is (I’m pretty sure) a non-interference engine, Is it plausible that it somehow bent a valve when the belt broke?
B. Is it reasonable for them to charge for the belt and pump replacement then give her back a busted car?
I need to ask them how they know its a bent valve. Maybe the Crank Angle Sensor got whacked?
Your thoughts appreciated, Thanks!
Jeff
This is a tough one. How can you expect the shop to know there is a bent valve? The car wasn’t running when it was brought to the shop and apparently the belt was broken.
Did the work order say replace the belt, or did it say evaluate the motor and report findings to owner for direction on what to fix? If she told the shop to replace the belt, they did that and should be paid. If she asked for an evaluation of the motor perhaps she has some argument.
From what I’m reading the shop did the work and should be paid. It seems to be a non-interference motor (according to Gates.com) so perhaps there it is not a bent valve. Perhaps a valve out of adjustment could get bent, but finding out what is going on is going to cost more money. If she doesn’t want to pay for the work done so far, I can understand the shop not wanting to do more work on the car until they see some money.
I think both engine options for this year Camry are non-interference engines. It is possible for a non-interference engine to bend a valve(s) under the right circumstances but it would be a real freakish event.
Try to find out how the shop determined a valve is bent, if that scenario is even correct. Ask if there is any noise present because if a valve is bent this means the valve lash will be way loose and this in turn will cause a loud rattle.
Compression test run? A bent valve problem will show up usually as a zero reading.
Just my opinion, but many shops and mechanics go about timing belt repairs in the wrong way. Determining whether a bent valve(s) exists is something that should be done BEFORE any work is performed and it’s simple to do. It is utter stupidity to run up a timing belt replacement bill and then determine after the fact the engine has damage.
Just offhand, I’m not convinced this car has a bent valve at all and caution should be used before making any decisions. Something for consideration could be that the shop is unethical and someone may be assuming they could pick themselves up a daily driver Camry with a new belt on the cheap by convincing the owner the car should be dumped.
What if your roof were leaking and you called in a roofer who replaced it but before you paid him you found that the floor was buckling up and even caving in in some rooms and would cost more to repair than the roof. Is the roofer responsible for the damage caused by waiting to call him?
I must agree that being presented with a running car and asked to change the timimg belt and being presented with a non-running car (because the belt broke)and asked to put a belt on it are two different things. I think it is part of a mechanics job to say to the customer something along the lines of “there is still some danger that your engine has been damage due to the belt breakage even though your engine is listed as non-interference”. Right at this moment I would say a "lets just put the belt on (meaning no water pump or new tensioner parts yet) and check compression and see if checking the valve adjustment gives me a clue as to if something else is wrong.
What I am trying to find is a middle ground between totaly completing the job or not doing the job at all before you announce that the job should not have been started in the first place. Perhaps a better idea how to do this comes to me in a few hours.
How does the mechanic know that it is a bent valve and not a burned valve? If the engine runs and sounds OK then drive on.
That’s an interesting view, that a crooked mechanic could advise a gullible customer that the engine has a big problem that is not so. In a smaller populated area the mechanic could tip off a friend to watch the paper for a Camry with a low price and a bent valve. For a 20 year old 1990 model, I can hardly think that the scam would be worth the trouble but such a scam for a newer model could be lucrative. Perhaps this is a practice run or possibly some poor college student needs a good but old car at a good price.
I’ve had one experience with a failed timing belt while driving (which is supposedly critical). I was driving a recently purchased (used) 1998 Eagle Talon. I had AAA tow it to the local shop that owned the tow truck. The mechanic called me after two days and told me the valves were wrecked. So then I called the dealer and told him to come get the car and deal with it, since it was still under warranty.
It turned out the valves were fine. The dealer told me that his mechanic told him that the AAA mechanic failed to remove a piece of the failed timing belt that was stuck to the timing pulley. This supposedly threw off the timing of the the replaced belt,and prevented the car from starting, resulting in the incorrect diagnosis that I needed to replace my valves.
Well. First of all with a piece of timing belt stuck to the timing pulley there was no way the AAA mechanic ever fit a new timing belt onto the pulley. I’ve replaced timing belts. I would have replaced this one rather pay to have it done except that I intended to go back to the dealer with the bill.
A new timing belt fits on the timing pulley like a wet leather glove. There is no way the AAA mechanic got a new timing belt onto the timing pulley if there was a piece of old belt left on the pulley.
So I was lied to, by both the original mechanic and by the dealer’s mechanic.
Draw your own conclusions.
If a mechanic can’t determine whether or not valve damage exists before installing a new timing belt then he should find another line of work.
This should take no more than 5-10 minutes, all depending on the method.
enlighten us all on how this would be done.
If the valve was so bent that there was 1/4" play in the adjustment that would be pretty simple to see. Just roll the cam around as if the valves should be in the closed position and give the clearance a check. This method will find the gross failure but you could be let down if the valve just barely got nicked. I saw this happen when a 4 cam BMW V-8 had some head work done on one side and my BMW buddy got the timing just ever so slightly out and only one intake got nicked. It caused the slightest misfire that was very hard to figure out why. We went over and over an ignition and fuel cause but it turned out to be a valve not sealing, bad day at work.
Other methods of determining whether a valve is bent or not, other than the excess lash mentioned by oldschool:
Bringing the No. 1 cylinder up to TDC on the compression stroke, removing the spark plug on No. 1, and then applying air to that cylinder. If it hisses out the intake, bent valve. This can be carried over to all cylinders.
Starting or cranking the engine and listen for a valve lash ratttle; a bad one.
It can also be stated that an engine with bent valves will turn over much more easily with the starter motor than an undamaged engine. It’s very noticeable.
Since both engine applications for this Camry show to be free-wheelers I’d like to know how and why this bent valve (singular) was arrived at.
We had a car in the shop once that was diagnosed as needing a valve job due to its running so poorly, and with only 30k miles on the car. Cause? One bad plug wire. Replaced that and it ran like a Swiss watch.
The car is 20 years old with in all likelihood over 200K miles…The OP has never posted back…Bent valves?? Everything is bent…If it’s a non-interference engine, then the belt breaking did not cause any valves to bend…When it died by the side of the road, that’s where it should have stayed…Road kill…
Not gonna be able to start an engine with a broken timing belt. How’s number 1 gonna get to TDC? Can’t turn the cam, belt’s broke. Gonna have to do some dissassembly. I’m thinking maybe an hour or so to take a look. By then, the belt’s on.
A tool that works good to turn the cam when the belt is broken is a strap wrench. I would not advise trying to turn the cam with the bolt that holds the gear on, you may just twist this bolt off, or you may get away with it.
Wow, thanks for all the ideas.
I forgot to mention that it is the four cylinder with 180k miles.
I agree its ambiguous whether the shop should have checked for valve trouble before doing the belt. Its a non-interference so I can forgive them for not checking i guess. My friend (the customer) is not mechanically literate, and did not give any instructions about “replacing the belt”, she said something more like: Fix it.
I talked to the shop spokes-babe who says that the mechanic says that actually 4 VALVES ARE BENT cuz it wont start and besides, there is no compression in ANY cylinder. She wont let me talk to the mechanic on the phone.
Huh?! I’m not buyin it.
What could cause no compression in any cyl?
- 4 crushed values? - I guess.
- Blown head gasket - Doesn’t seem likely.
- Cracked block from freezing - I s’pose
- 50 cal. round from a black-hawk at just the right spot - That might do it.
- Putting the belt on 180 degrees out - Could that do it?
- Not knowing how to test compression
So I’m gonna go to the shop and look for myself.
- try to make sure he didn’t put the belt on 180 degrees out
- Check the compression myself with my own gauge.
Why does it matter?
I guess the only reason it matters is cuz if it really needs the head rebuilt, then its not worth it. But if its something else simpler, then it might be worth fixing.
Any other ideas?
Get the car back from them and pull the head yourself. We will walk you through the process. This is just an idea. My feelings on how a non-interference engine bends valves is that there is a large amount of carbon built up on the top of the pistons. This would be a great project. Perhaps you negoiate and get them to pull the head with payment inclusive in the bill already paid. So three jobs for you, negoiate a better price for the work done, try to get them to pull the head inclusive in the bill you will be paying (or already paid), then if head is salvageable, get the head rebuilt and reinstall.Let them know that if it comes down to no price reduction and no help getting the head off that their diagnosis better be correct because you are going to pull the head yourself and check.
My point is that an engine with bent valves is going to crank over very very easily. Whether the cam is turning or not is irrelevant.
Rotate the mark on the crank balancer to TDC, rotate the cam lobes on that cylinder to where both valves should be closed, and blow some air into the spark plug hole.
None of this is difficult and I’ve never in my life had to install a timing belt just of find out if there’s damage or not.
At this point, I’m skeptical of the bent valve diagnosis and not buying any of it either. If there is no compression in any cylinder then maybe it’s simply a matter of camshaft timing being off and some clueless tech is saying bent valves because he doesn’t know any better.