Nissan Altima, Presage, Sentra QR25 Belt Tensioner replacement

Reason to replace : High pitch squeak recurs few months after new belt replacement . The tensioner spring lost its tension and will eventually causing belt slippage and high pitch squeak intermittently. There are 2 12mm screw on the tensioner. However, the upper one is very difficult to reach as the  space is tight between the chasis and the pulley. The job takes me 1.5 hours to complete. 

Step 1: loosen the belt ( You should be familiar with belt change) by using a 14mm wrench.

Once the belt is loosened, the lower 12mm bolt showed up.

 The upper tensioner bolt is very difficult to reach and very difficult to insert a 12mm bolt wrench, because of tight space .

The new tensioner is made by the same OEM Bangdo. The old pulley itself is still in shape. 

Nissan ( Altima Similar ), Presage , TU31 Front Engine Mount replacement

This is one of the toughest DIY job I have done. The Nissan engine mount 17mm nut is crimped and not to be replaceable by an average DIYer. With a 600Nm torque wrench, I can bearly loosened the crimped nut. There is not enough space for an impact wrench and using an angled adapter will reduce its torque. It takes me almost 3 hours as I have no  idea how to do it as there is not much information on the internet or the workshop manual. 

 This is taken under the car. The 1st  front mount 17mm nut is loosened with impact wrench.

 The rest of the 2 17mm nut is loosened from above. The fan is better to be removed to allow more working space.

 The tranny is jacked. Here is the wrong illustration without a piece of wood.  Don't jack too far 1-2 inches is enough to loosen all 3 screws.

 This is the hardest part to think out how to remove the mount. Finally I get it from above, easily once the engine is jacked up  enough. The front mount can be slide forward easily.

The mount is removed, showing the space. Remember, the mount can only by slide forward ( towards to radiator)

 Left old mount with compressed rubber and some cracks.

 New mount is slide into space with some leverage.

17mm nuts and screw can be easily inserted ( with appropriate engine jacked up sequentially) and then tightened with.

Replacing Presage TU31 rear brake pad

Sqeaking noise was heard recently at high speed. It will disappear on braking briefly. Inspection revealed rear pad wear to limit of less than 2mm.

The top 14mm screw of the clamp is removed. The  clamp is flipped open and the cylinder is pressed inward gently. The old pad is removed and the back plate is priced out. New pads are dropped in and the clamp is flipped back. The 14mm screw is put into place. Note there is some grease at the screw tip. I put some blue loctite at the socket end as some corrosion is noted.

Nissan QR25DE Camshaft position sensor recall

from http://www.b15u.com/troubleshooting-support/20302-0340-ways-fail.html

Replacing Nissan Presage / Altima TU31 QR25 Engine mount

 Above is old damaged engine mount. The right sided (from compartment view) (near pulley/ engine belt side) is most prone to be torn apart.

 There are 3 hex nuts on the engine side mount. Two above and 1 at the bottom. You need long socket to loosen it as seen here the center pin is long.

 A long hex socket extender > 12 inches will make life easier.

 This is the second most difficult nut to be removed. I need two socket extender ( total length of 15 inches) to reach the chasis mount at the back. The regridgerant lines will obstruct you access.

 You can see the hex nut at the back of the chasis engine mount.

 This is the most difficult hex nut to be removed because the difficult access. Taking away the Relay mount/ bracket, I still cannot reach it with wrench or hex socket from above. The belt and pulley is obstructing all movement here. Finally, it took me 30 mins just to loosen this nut. I have to jack up the car (not engine) and insert the long long hex socket from below.

 The Relay box/ bracket needs to be loosened in order to reach the front chasis engine mount nut.

All hex nuts are loosened but are not taken away yet. The engine is jacked with a foot long hard wood under the tranny. How much is needed to jack the engine? I jack it up till I can observe the engine mount rubber edge  rising up by about 1 inch and the whole mount can be shaken loose by hand.

 The engine mount can be removed now. You need to lift the water reservior out.

The damaged engine mount with the center strut completelt torn apart from the rubber mount. The central strut kicking around and create clunking that is very obvious in the passenger compartment, whenever over bumppy road.