The car is a 2003 Misubishi Eclipse. Now they are telling me that it is a hydraulic tensioner adjuster and that the bolt that broke on the bracket is what caused the belt to break. They said they only changed the timing belt because it got antifreeze on it during the water pump/coolant pipe install. They said the tensioner looked new so they didn’t think it needed to be changed. They said this even though they have said that other work done previously on the car did not seem to be done to a very high standard. So now, somehow the bolt that holds the tensioner onto the bracket was apparently over tightened by previous mechanic and they never removed this bolt until the belt broke because the belt just slipped on over it, but that it was just snapped in two. If the bolt broke how did the belt snap from being too tight? Would the belt have not become more loose if this were the case?
It almost sounds to me as the new belt caused the bolt to break.
How does an overly tightened bolt holding the tensioner to the bracket just break?
How do they know it was overtightened?
Sadly, you’re now paying the price for slipshod mechanical work. And the people that did it are BSing you. Morally the mechanic is responsible for the subsequent damage. Legally it might be tough to get a recovery. Keep all your paperwork and consider small claims court. Maybe you’ll get lucky and the judge will be familiar with that shop.
As I said in another thread, I’m the luckiest guy in town. I made it to 190,000 miles without timing belt problems. The dealer that bought the car said the engine ran better than they thought it might at that mileage. I sold it because I didn’t want to do the 210,000 mile timing belt service which almost certainly would have included oil seal, tensioner, and pulley replacement. With all the extra work, I imagine the price would push $2000. That’s more than I was interested in putting into the car.
I think there’s different style of timing belt tensioners used, varies by make/model/year. Some types (usually the ones on newer cars) require no adjustment, others like on my 25 year old Corolla do require adjustment. I have to loosen the tension on tensioner to get the belt on and off, then after the new belt is installed I have to tighten it back up again to get the proper belt tension.
I’m guessing in OP’s car’s case the tensioner is the non-adjustable type, but what happened is one of the bolts that holds it on to its bracket broke, presumably b/c that bolt was over-torqued during the belt install. Then it finally gave way, the tensioner came loose w/the engine running, didn’t provide enough tension to keep the timing belt on the pulley’s, and the belt entirely slipped off its path. Crankshaft turning, camshaft not turning. Big, bang , boom, valve damage.
The timing belt tension on my Corolla is checked by pressing on the belt, it should deflect 5 - 6 mm with a 20 N force. If it tests incorrect during the install the tensioner has to be re-adjusted, then the timing marks re-checked. The tensioner on the 4AFE engine is a fairly simple device, really just an idler pulley with an offset cam to make it adjustable, and a spring that pulls it towards the belt path.
The engine in your car has an auto adjuster. Different from the link above that is for the older Mitsubishi’s with the Chrysler engines. When replacing the timing belt the auto adjuster is placed in a vise to compress the piston before reassembly.
The reason things break after a timing belt replacement is because mechanics use air tools and over tighten, cross thread and break bolts while working on vehicles. We replace hundreds of timing belts each year and do not need to replace tensioners or pulleys, they just do not fail.
It would likely make no difference if a new tensioner was installed, people break bolts with new or used parts.
Sorry to bump this thread but I literally have the same car (2003, 3.0L, 5-spd), went in for the same reason (coolant leak from water pump), and have a similar problem, but my tensioners were changed, and thankfully I was at very low rpms and I don’t believe (at this point in time) that the belt actually snapped. The shop I took it to has been very dismissive of recent complaints, they seem to try and talk you out the door before you can tell them anything, and they’ve already charged me twice for a minor repair they never completed. They suddenly seem to want to talk now that I’ve posted bad reviews on Google, Yelp, Carfax, complained to the BBB, and contacted NAPA because they’re franchised by NAPA. Was there ever a satisfactory resolution to this?
A coolant leak from the water pump on a 19 year old vehicle is an expected problem. Not an unusual thing. If you feel there are remaining problems,. suggest to post them here under a new top post. If you aren’t satisfied with how your shop treats you, and a chat w/the manager doesn’t resolve it, find a different shop.
Get real. The timing belt failed less than two weeks later–meaning that the car had probably traveled less than 200 miles since the timing belt job was (allegedly) done. It didn’t fail 6 months later or a year later, or two years later, which might very well offer a plausible “out” for the mechanic.
Any tensioner or idler pulley which was in such bad shape that it would break apart or seize up within the span of 200 miles would have had such worn bearings that it would have been painfully obvious to even the most dim-witted mechanic upon spinning the pulley by hand and checking for play in the bearings. Regardless, the customer is not expected to be savvy enough to understand and request that the incidental parts be replaced along with the timing belt. Most end-users take their car to a professional mechanic for this service, and a reasonable mechanic would replace the entire timing belt kit–which includes the tensioner, idler pulley, water pump (if driven by the timing belt), and so on.
Personally, I think one of two things happened here. Either the work which you paid for was not done, and the mechanic gambled that your existing timing belt would last for several more years, or alternatively some mistake was made during the procedure. Many engines require that the belt be installed with the tensioner set to maximum tension, then the engine is rotated several revolutions by hand, and then the tensioner is relaxed to some position (typically indicated by a notch or arrow) in which the optimal tension is exerted on the belt. Sometimes this step is omitted, which would cause the belt to fail prematurely although I would still expect it to last longer than it did.
I remember when I owned a 1995 Dodge Caravan with the 3.0L engine–which is non-interference. I paid to have the timing belt changed at around 100,000 miles–at a Chrysler dealer nonetheless, and again at around 200,000 miles. At around 208,000 miles the timing belt failed, and being low on funds I had the van towed home and decided to tackle it myself. I discovered that the timing belt which I paid for at around 200,000 miles was never replaced–based on the date code on the old belt, and that the water pump was original with a 1995 date code cast into the housing. That was when I made the decision to DIY from that point forward, so that I could be certain that whatever work needed to be done would actually get done. And of course, that engine ran fine once I changed the timing belt kit, coolant crossover pipe, several hoses, etc.
I can make a post and let people know how it goes with the shop if you want. As @bcohen2010 has pointed out though, it’s getting hard to trust mechanics to even do what they say they’re going to now, and sadly with the previous manager at this particular shop I felt taken care of, now I feel like they blow me off and make excuses, the change is really sad.