I have a 86 n/a and there is an awful squeaking noise coming from my engine. I decided to remove all the v-belts to find out if the squeaking was coming from them. I removed all the v-belts and fan and started the engine. My engine was still squeaking. It sounds like it is coming from the timing belt case. Remember the water pump, fan, alternator, idler pulley, and power steering are disconnected. So what could be causing this squeaking sound?

 

About all that's left to squeak is the bearing in the timing belt tension pulley.

 

Yeah that's what I figured. It's about time for the timing belt to get changed anyway. Now I've been driving around with this problem, can anything bad happen until I fix it?

 

Someone more knowledgeable can chime in and correct me. But if I remember correctly these engines are interference. Meaning if the timing belt breaks the engine goes boom, bend valves, break pistons, that sort of thing. I am not sure if a slip could have the same effect, but I would assume it's possible.

 

I believe you're right man. I wouldn't drive it unless you want a nice explosion

 

All VG30 engines are true interference designs. Any loss of timing by a broken or slipped timing belt with the engine running at speed will result in extensive damage. Park the car until you have time to change the belt and tension pulley.

http://xenonzcar.com/z31/timingbelt.html

 

The squeaking has gone away, but I don't trust it. Thanks for the advice guys!

 

Purchase a complete timing belt kit on E/bay which sometimes include a water pump along with tensioner pulley etc cost approx $200.00. Great price too.

 

I've been looking at the timing belt replacing directions in my haynes book. Are all the steps in the manual necessary? Removal of the rocker arm covers, intake plenum, and the camshaft bolts?
Correct me if I am wrong, but basically to change a timing belt all I need to do is:

Remove:
Radiator hose
fan
v-belts
timing belt covers
crankshaft pulley

Fix the engine to TDC, mark cam pulleys, loosen the timing belt tensioner pulley, pull old belt off, and put new belt on lining it up with all the proper markings and arrows, and tighten the tensioner pulley.

I'm an amateur mechanic and the whole process seems overwhelming but simple at the same time. My "tool box" isn't that extensive either. I do have access to a good air impact gun.

Is there a good brand of timing belt I should buy? I found a kit on ebay for $88.80. Should I go for it? (Picture shows: NPW Water Pump & NSK Bears)

 

When I've replaced my timing belt, I used the same basic approach as you describe. I've never loosened up the cam saddles and retorqued them as indicated in the FSM. I do remove the spark plugs to eliminate compression before I align the timing marks, and it makes the engine easier to turn by hand after the new belt and tension pulley are installed. Make sure you turn the crank two full turns to check for any binding. Complications you might find once the covers are off are leaking cam bearing seals, a leaking crankshaft seal and/or a heavily corroded stud that holds the tension pulley. The tension pulley spring also can rust quite badly. The upper radiator hose connects to a short piece of pipe that is connected to the water pump by another short piece of hose. I hate dealing with hose ruptures, so I replace them all (including the lower hose). Brands? I either use the OEM brand or kits manufactured by Gates Rubber Company. The last belt I replaced was in the Z31. The Gates kit with belt, tension pulley, water pump and wp gasket was $63 from Amazon.

 

Great! That's a relief. I found the Gates kit on amazon at $63. It doesn't have a really good product description. Does it come with a tensioner spring and cam seals? I don't recall seeing any leaking from the camshaft pulleys when I removed the covers to replace the CHTS. Should I still replace the seals anyway?

 

No, this kit does not supply cam seals, tension spring or tension pulley stud. To be honest, I'm not sure what good the spring does. Once the nut on the tension pulley is tightened, the spring serves no purpose from what I can tell.

That is up to you. I put 200K on a 93 Maxima with the same VG30 engine and never replaced a cam seal. I don't know the cam seal history of my Z31, but the existing seals were dry. Of course I'm the sort of guy that checks oil levels at every fill up and usually notice when oil is being lost.

 

Gotcha. I spring is only $4 on Amazon so I'll just put one on for consistency sake. I'm also going to pick up a torque wrench while I'm ordering parts. I usually tight things on until they "feel good", which is probably a bad mechanic practice. Last thing I need is for the tensioner pulley to fly off because I didn't tighten it on properly.

How about the tensioner pulley stud...should I get it?

 

How do I set the correct tension on the timing belt? The FSM doesn't really say anything except turning the tensioner pulley clockwise and counter-clockwise 2 or 3 times with a hex wrench.

 

Using a torque wrench is smart, if not a necessity.

It's a relative inexpensive item, so sure. You might also consider replacing the thermostat since you are installing a new water pump. Even if you do not change out the thermostat, you will need to swap the old thermostat housing over to the new water pump. Get a new thermostat housing gasket, which you can get at almost any auto parts store.

Tension instructions come with the Gates kits. Be mindful that there are arrows printed on the timing belt indicating the proper orientation on the engine. The belt is designed to install only one way, and the instructions explain this as well.

Also, buy a can of penentrating oil. Use it liberally on all bolts before loosening them, especially on those associate with the alternator and power steering pump brackets. Buy a small tube of Loctite, Permatex or similar medium strength thread locker. Apply to the timing belt tension pulley lock nut before you properly torque it down. Buy a tube of RPV Silicon sealant. Smear a thin layer (it does not take much) on both sides of the water pump gasket and fill the the threads of the bolts that secure the water pump to the block. The threaded bolt holes penetrate to the water jacket and you don't need coolant seeping back through the bolt holes.

If you have not done this before on any car, I advise you to read all the pertinent information regarding timing belt replacement on the ZBUM and XenonZ31 web sites. This is a great job for developing mechanical skills, but you don't need surprises either.

Good luck.

 

I order a torque wrench with all the rest of the parts I need.

I went to Napa and they couldn't find a tensioner stud in their computer system. Any ideas? Actually, I replaced the thermostat when I first bought the car. I had to make that gasket too.

Unfortunately, I had to order an AC Delco timing belt because that was the only one I could get shipped to me intime for a 400 mile drive I have to take in a week. So I hope it comes with tension instructions. All I need is Loctite.

I have been on the Xenonz31 timing belt page quite a few times. I will have the FSM, my Haynes book, and Xenon z31 at my side for the entire project. I'll have to check out ZBUM.

Thanks for the help Ken99!

 

Update:

On tuesday I replaced my timing belt, tensioner pulley, tensioner spring, camshaft seal, water pump, and put a new gasket on the thermostat house. The tensioner pulley was coming apart while it was bolted on and once I removed it, it fell apart in my hands. The spring was so coated in dirt and oil that is looked a like a sold piece of pipe. During the tear down I found that one of the camshaft seals was leaking. The thermostat housing was leaking around the bolts.

I started the project at 1 pm and finished at 11:45 pm. There is no squealing sound, the idle is smooth, and the performance has gotten better. Not to mention all the leaks I mentioned are fixed.

Things I realized I need once I started: Pulley puller and seal puller. Luckily the garage I was working in has a pulley puller and I picked up a seal puller later in the job.

Thank you guys for all your help!