How much to fix timing belt?

Recently my car has been making a clunking kind of sound in relation to the RPMs. I drive an Nissan Sentra SE-R, so the engine is actually an Altima's (QR25DE) and i've had two mechanics take a brief look at my car. One told me it was the top camshaft that might be messed up, but he's only a mechanic that works on little things like brakes and oil changes but he's one we can trust. We then went to another place that's new to us and the mechanic told us that it was actually the timing chain that was making the noise. He said he get's the problem all the time with Altima's and it's more in his nature to do these bigger jobs in comparison to my mechanic, so he sounds more convincing on that part. However, he said that it'd be about a 12-16 hour job and the total cost with parts and labor would be about 600-800$. I have yet to get a second opinion on the price so that's why im here to ask if that's a legitimate price for what is wrong with the car? However he did say the parts by itself would be around $200 and i've looked it up and its about right.How much to fix timing belt?I wish I could find a mechanic to work for 16 hours for $800. The guys that replaced my transmission charged me $600 for 7 hours.



There should be a cover that you can pull off and look at it. I would take the cover off, and start it up and watch it to see if it's lose and slapping around. I can't imagine that the chain would make a %26quot;clunking%26quot; sound. Think of the motor turning 3K, 4K, 5K rpms that chain is going to be seriously moving. If something is wrong with it, it's going to break ... not clunk. I never have had a chain go bad on me, so I'm not sure what kind of noise it makes (if any noise at all).



I have a strong, strong feeling that the last mechanic is trying to take you for a ride ... like most mechanics do. Plus 16 hours to replace it!!!! Good lord, he must take naps while he works. It took me 1 1/2 hours to replace my timing belt and water pump on my Civic, and I'm a jack leg. But that was a belt, and not a chain.



Let's assume for a moment that he's right tough and it is your chain. You should notice something along the lines of sluggish performance, no-start conditions, rough idle, a sudden change in performance, a chattering noise (not clunking). Imagine a bike cycle chain when it gets ready to slip off ... the noise it makes going over top the gear. It's a higher pitched noise.



The reason you would notice these things is because your chain is wearing down, and it's changing your timing. If you notice those things he may be right ... other than that ... move on to someone else.



On a side note, I've never heard of a cam-shaft being messed up either. It's a moving part, and all moving parts are subject to break, but it's highly, highly, highly, unlikely.



Also is your car a manual or automatic? A clunking noise that matches your engine speed might be a sign of the transmission going bad.
How much to fix timing belt?
Those numbers don't make any sense. It wouldn't take 12 hours unless he's incompetent, and if it did, it would cost more than that. Take it to someone who knows what they're talking about.
How much to fix timing belt?
HERE IS WHAT TO DO!!!! Try to understand this. THe oil galleys in Asian cars are a wee bit smaller than in most engines. This engine is complicated with camshaft adjusters, and other items. These things are regulated, like your valve lifters, with OIL PRESSURE!! IF you have been using a really cheap quicky lube bulk oil, sludge forms, and the timing chain tensioners and camshaft adjusters get sludged up, and cannot do their job correctly!! It is kind of like engine cholesterol!! THE ANSWER, FIRST, is to use a nice safe, gentle engins sludge removing chemical, like AMSOIL CRANKCASE CLEANER. It is made of butyl cellosolve. When in use, the heat from your engine activates the ingredients, and it washes the varnish and sludge from all the vital engine passageways. Your tensioners and camshaft adjusters CAN NOW WORK CORRECTLY!! NOW%26gt;%26gt;%26gt;%26gt; Change the oil using a GREAT synthetic oil, like Mobil One or Pennzoil Ultra. These oils will continue to clean things out as you drive, and prevent the formation of unwanted %26quot;cholesterol%26quot; that ruins engines. PERHAPS, you do NOT need new timing chain and tensioners now. I owned a Nissan Maxima that lasted to 180,0000 before the cam adjusting sprocket self destructed. TRY MY WAY FIRST before you spend spend spend on parts. Asian cars will take a good cleaning better than most. This procedure will cost about $100 for fresh oil, filter, and cleaner. Until you get the junk out of the engine, more problems will occur, anyways!!