# 00' VG33 engine timing belt oil leak??



## elaric (Aug 9, 2009)

Hi everyone --

I have an 00' Frontier with the 6 cyl engine/AT
Without going into details, it has developed a very serious oil
leak at the front end. 
Both the front main seal _and_ a silver-ish "case" with the largest pulley on the front lower end of the engine are pretty much 'fast dripping' oil.

Looking at the PDF repair manuals, I am confused-
The engine has a timing belt, so what is that assembly the main pulley is located on? 
Based on position, I'd say it's the lower timing belt cover.
But I wouldn't have thought that the timing belt cover assembly
would have had oil inside it and the sort of seals 
that a timing CHAIN cover would have?

I hope that setting up the timing and aligning/adjusting the belt isn't too complicated, since I'll be pulling off that lower pulley to get at the front seal, won't I??


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## rogoman (Dec 16, 2004)

The main pulley is bolted to the crankshaft end which protrudes through the lower timing belt cover; the cover has no seals. The presence of oil is due to the leaking front crankshaft seal. If the timing belt has oil on it, replace the belt. Also replace the tensioner and spring.

Prior to removing the timing belt, set No. 1 piston at TDC on its compression stroke by rotating crankshaft.

INSTALLING TIMING BELT
1.  Align punchmark on LH camshaft sprocket with punchmark on timing belt rear cover.
2. Align punchmark on crankshaft sprocket with alignment mark on oil pump housing.

TENSION ADJUSTMENT AFTER BELT REPLACEMENT
If the timing belt was replaced (or to adjust tension on a used belt),
follow the steps below:
1. Loosen tensioner lock nut, then turn tensioner clockwise and counterclockwise with hexagon wrench at least 2 times.
2. Tighten tensioner lock nut.
3. Turn crankshaft clockwise at least 2 times, then slowly set No. 1 piston at TDC on its compression stroke.
4. Measure deflection of timing belt midway between camshaft pulleys while pushing with 98 N (10 kg, 22 lb) force.
Belt deflection when engine is cold (Reference value): 13 - 15 mm (0.51 - 0.59 in)/98 N (10 kg, 22 lb)
5. If belt deflection is not within specification, return to step 1 and repeat procedure.


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## elaric (Aug 9, 2009)

Thanks much!

Based on your description, I have oil dripping from the joint what is evidently the lower timing belt cover where it meets the engine block, as well as from behind the main pulley.

So I imagine that there is oil all over the belt and the tensioner and spring, basically the entire inside of the 
timing belt cover, at least the lower one.
I'll plan to replace all of that, in addition to the main crankshaft seal.

I gather from your response that there's really nothing else on the lower end of the engine that could be leaking oil; 
it's just that the seal is behind the timing belt enclosure that means that oil can be coming from multiple places.

I don't think the valve cover end above all this is leaking, so I don't think there's oil coming from there.


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## smj999smj (Jan 1, 2006)

Whenever I replace a VG timing belt, I replace the belt, tensioner pulley, water pump, thermostat, front crank seal and front cam seals. I usually get a Gates Timing Belt Component Kit w/ Water Pump from Rockauto.com, which supplies the timing belt, water pump, and tensioner pulley for around $100. I'll get the seals and thermostat from Nissan. One has to keep in mind that the service interval of the VG33 timing belt is 105,000 miles, so you have to ask yourself: "Will the other components under the timing belt cover last that long if I don't replace them now?" There is usually a pretty good chance they won't, especially if they are original. 
One nice feature about the VG timing belts is that they come with alignment marks on the belt to match up with the marks on the sprockets, which makes it easy to get the cams and crank in time (don't rely on the marks on the rear cover because they are a little bit off). As far as the tension of the belt, I have a simpler method that works just as well: Once the belt is installed on the sprockets, loosen the 14MM nut on the tensioner pulley and let the spring pull the slack out of the belt. Turn the right bank cam sprocket (the one on the passenger side) counter-clockwise about three teeth to pull any additional slack out of the belt and tighten the tensioner nut to 35 ft/lbs. Turn the right sprocket counterclockwise about two or three teeth. With your thumb and forefinger placed on the belt midway between the two cam sprockets, twist the belt 90 degrees. If you can't, the belt is too tight and will likely make noise from the distributor when you start the vehicle. If you can twist it more than 90 degrees, it's too loose. If you do it the way I say, most of the time it will be just right the first time. It's also a good time to replace any hoses or drive belts, which I recommend you stick with Nissan parts.


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## elaric (Aug 9, 2009)

Thanks SMJ! 

A friend who is a mechanic mentioned the possibility that there's no oil on the 
belt, even with a serious leak.

However, I don't know how familiar he is with the VG33 engine in particular.

Along with the idea that no oil might be on the belt, he was thinking that I could conceivably change the seal without removing the timing belt all the way.

I can't see how you'd be able to avoid pulling the lower crankshaft timing gear though, right??
I guess he's talking about just removing the belt in position without removing it from the cam pulleys and then just having to retension it afterwards. 

If it does somehow turn out that the lower gear is clean and there's no oil on the belt,
would it even be possible to replace the crank seal on the VG33 without fully removing the timing belt and all it's parts?



I'm not trying to skimp on doing the right thing here- 

But the timing belt, water pump, etc were all replaced about 15k ago or so 
So if they all just happen to be clean, is there any point in replacing them all
if I don't have to disassemble the entire timing belt area anyway?


If I do have to take the entire timing belt area apart, then it's certainly cheap enough to replace all - but I don't want to do twice the work I need to in order to get to just the seal?


I will certainly get the Gates kit if I do need to disassemble the entire thing.
I'm not opposed to replacing anything I should while in there - just don't want to go taking things apart that I don't have to.


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## smj999smj (Jan 1, 2006)

You'll have to remove both upper and lower covers. At that point, you mind as well just loosen the tensioner and give yourself enough slack to remove and install the belt normally. If the parts have only 15,000 miles on them, then there is no need to replace them. Obviously, if the belt is oil contaminated, you'll want to replace it. Usually the hardest part of the job for most people is removal and installing of the crank bolt. If you have access to a shop with air tools, it's not bad at all. However, without access to air tools, one needs to find a way to keep the crank from turning.


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## elaric (Aug 9, 2009)

Thanks SMJ -

Sounds very much like I should replace as much stuff as I can while I'm in there, then.

I know I had the shop replace the timing belt not long ago, but I'll have to check on the water pump, etc.
If any of that is more than 20k miles or 2 years, I'll probably just go ahead and replace with that $100 kit from Gates. 

And yeah, if _anything_ is oil contaminated, it's going to go.


This all started when the engine hit critical mass of being sludged and the oil light came on. 
I think you posted in another thread of mine about this truck recently.

Part of the reason it's pouring out oil is because the current oil has a quart of
Gunk's Motor Flush in there - 

But it was leaking oil badly even before I changed the oil and put the motor flush in.
The oil light had come on while I was driving, and by the time I got it 2 miles home,
the sludge had broken loose and probably had stopped up the filter.

I changed the filter and oil and added some motor flush and the oil started circulating normally, and the engine now sounds perfectly normal, so I don't think any harm was done.
Of course, the leak is much worse with the flush in there since it's thinner.
I had been running the engine for just a couple of minutes at a time, and was planning on draining the flush this weekend anyway.
Now, I'll combine that with changing the seal.

When I drained the original oil, the filter appeared to have blown oil out the engine side of the filter gasket, the timing case cover was leaking at one side, along with the bottom of the main pulley (all the oil is coming from the same crank seal, from what you guys say)
and the entire bottom of the engine was wet with oil.

I thought I could just get it to seal back up again, but I've come to realise from researching this, that the leak is bad enough that I need to fix it, and check the timing belt for oil along the way and replace if needed.

And then we'll get back to de-sludging the engine
by pulling the valve covers and cleaning out what I can get at.


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## elaric (Aug 9, 2009)

By the way, is it necessary to drain the radiator and remove the fan, or does that
depend on one's skill set and tools?

I do have a small compressor and an 3/8" side air ratchet, so maybe that'll break free the crank bolt. 
If not, time for the PVC breaker bar ;-)


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## smj999smj (Jan 1, 2006)

Drain the antifreeze, remove the plastic panel from the bottom of the fan shroud that will allow the shroud to clear the fan, disconnect the cooler hoses (A/T models) and radiator hoses, remove the upper radiator support brackets (two 10MM nuts), remove the radiator vent hose (to reservoir), and pull the radiator straight up and out. There will be four 10mm nuts holding the fan to the water pump; loosen them up before loosening the drive belts and be careful not to drop the washers when you take off the nuts. Remove the drive belts and then remove the fan and pulley. 
Torque spec on the crank bolt is 150 ft/lbs. A 3/8" air ratchet isn't going to cut it. If you have a manual trans, you can put the vehicle in gear and set the parking brake. If you have an auto trans, it's a little harder. The rope trick is one method, where rope is stuffed into one of the cylinders so when the engine is turned, it'll compress the rope and lock the engine. There is another tool that threads into the spark plug and extends far enough into the cylinder to lock the piston in place, but last time I used one of these on a Toyota V6, it damaged the spark plug threads and created another problem, Not to many places have a ring gear stopper for VG engines, but that would be the best option. Still others jolt the bolt loose by cranking the engine with a breaker bar and socket on the crank bolt; the problem with this is it can be dangerous if the breaker bar goes flying and I have seen this method cause a starter housing to crack when done on a VG engine. Bar far the easiest and safest way is to use a short 1/2" drive impact gun.


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## elaric (Aug 9, 2009)

I saw a Youtube of a guy doing that tie-down-the-wrench and crank the engine up
method.

Looked like a real Darwin award to me, not to mention the prospect of damage to the car if the wrench slips.

I'll try to get the 1/2" impact gun and a short socket.
May have to borrow a larger air compressor, because I think my 60lb compressor
won't have enough power to be up to that task...


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## smj999smj (Jan 1, 2006)

Your compressor may be ok; remember you only a need a short jolt to break the bolt loose. I use an Ingersoll-Rand. You want to make sure the impact wrench is short enough to fit between the A/C condenser and crank pulley and still give you a little working room. Once you break it loose, remove the impact gun and spin the bolt out by hand if possible. You don't want to run the bolt so far out that it'll jam the gun against the condenser. A gear pulley comes in handy for removing the crank pulley, but two prybars can be used if you are careful, as the pulley is pretty brittle and can break easily. Sometimes you luck out and it'll slide right off...sometimes....


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## elaric (Aug 9, 2009)

Hi all -

After putting out a few fires at work requiring me to work weekends,
I'm now researching the parts I'll need --



I see the Gates kit (GATES Part # TCKWP249 ) at Rock Auto, and that's pretty straightforward looking, and I can see why people replace the water pump at the same time for that little extra money, considering the time involved.

But when I look at crankshaft front seals, I see the individual seals listed for $3-$5 AND I see FelPro's "front crankshaft seal kit" which appear to be the crank seal and several additional gaskets.
"FEL-PRO Part # TCS46034 More Info Crankshaft Front Seal Set
Front; Type: Crankshaft Front Seal Set; Must be used w/OS 30591"

OS30591 is the oilpan gasket. 

I don't understand entirely what the 'front crank seal set" is and how to figure out whether or not I need that entire kit?

Obviously if I do need that seal set, I have to get into the oilpan, which I'm hoping not to have to do... 

Just don't understand when or why I'd need the entire seal set as opposed to just the crank seal itself?


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## elaric (Aug 9, 2009)

Bump.....

;-)


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## RxRC (Nov 5, 2007)

I'm wondering now about my oil leak. My V6 is gushing pretty good but I've been assuming it's all from the drivers side valve cover. It really smells.


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## elaric (Aug 9, 2009)

RxRC said:


> I'm wondering now about my oil leak. My V6 is gushing pretty good but I've been assuming it's all from the drivers side valve cover. It really smells.


On mine, the leaks are from the bottom of the oil pump right behind the main crank pulley, and the side of the oil pump.

Here's a picture of the leak from the side of the oil pump
This is with the inside wheel well cover removed, you're looking from in front of the passenger side front wheel.The silverish part at the right is the oil pump with the lower part of the timing belt inside that, and the righthand darker part is the engine block.









Here's a view of the front main seal leak at the front of the oil pump 
right behind the main crank pulley.
This is from below, top of the picture is the oil pan, bottom is the pulley, and that triangular piece with oil on it is the bottom end of the oil pump.









Check your oil filter too, which is just to the drivers side of this area.
If your oil leaks are not coming from these areas, and are coming from higher up, then I think you're on the right track to be thinking of the valve covers.


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