Leaking VTC Cam Gear/ Sprockets repaired?

[DeeZX]

I had some leaking vtc cam sprocket/ gears. I got it tig-welded around the seam by a buddy of mine.

I haven't put the car back together to see how it runs. When the gears were leaking, they never made that horrible tick and humming sound on some of the others I've heard before. I hope the heat from tig-welding didn't cause any problems or cause it to tick/hum.

I got the idea from a timing belt technical article on zhome.com
http://www.zhome.com/ZCMnL/PICS/timingB ... gBelt.html (Scroll down to subtitle "Intake Cam sprockets")

Has anyone else ever tried this? And with what results?

In any event, I'll let you guys know my results when I'm done.

Below are some pics of the tig-welded cam gears/ sprockets.

[xclusivez32]

if they were leaking it was probably the seal behind the sproket or the valve covers in the front. these sprokets are balanced so adding metal you might throw off the balance and make for some issues. if i was you i would reseal the valve covers with rvt copper and buy new cam seals and get some different sprokets. just my 2 cents

[DeeZX]

if they were leaking it was probably the seal behind the sproket or the valve covers in the front. these sprokets are balanced so adding metal you might throw off the balance and make for some issues. if i was you i would reseal the valve covers with rvt copper and buy new cam seals and get some different sprokets. just my 2 cents

It can only be the VTCs. I could turn the back plate with my hand when I took them off the camshaft, and oil was seeping through the seem, so they definitely were leaking. I had already changed the cam oil seals and did a valve cover job with the RTV on the exhaust and the new rubber seals on the intake valve covers a few months ago; All of which are now leak free.

I understand what you mean about it being a balance part, and I took that into consideration, but can't afford the BDE VTC cam gears as yet ($625.00), This will be only temporary, about 2 to 3 weeks, until I can afford the BDE VTC cam gears. But if it doesn't run good when I fire it up, I'll have to bite the bullet and get them immediately.

[xclusivez32]

I see where your coming from, be careful i had to replace the heads on my engine due to timing belt issues i would hate to see someone else deal with doing that. good luck

[DeeZX]

Well... I started it up last night and ran it for about 30 minutes and so far so good. No leaking oil, vibrations, ticking or humming. I'll see how it goes after about a week of driving.

[itsa300zx]

Please keep us updated, mine is starting to leak also.

[DeeZX]

After about 6 days of driving (regular and High Speed), all is well with the VTCs. It's great to look in my engine and not see oil every where, except for the old hard to clean oil.

[xlpbodily]

Ok so i have a similar problem. I just got done rebuilding my 90 300zx na motor due to the fact that it spun rod #5 (thank you oil pressure relief valves behind the oil filter adapter) anyway put the motor together installed in the car. Cranks and run's great. After about 10 minutes i notice oil dripping out from behind the balancer (note not from the oil pan but from the actual oil pump like where the front seal would leak) so i decided ok, front seal isn't from nissan so i'll get one from the local dealership. Installed and still leaking. So i tear it back down again and just put the harmonic balancer back on to crank it up with the covers off. No oil leaks noted til about 5 minutes in and i see that the oil is coming from around the intake cam gears, so another trip to nissan to grab 4 camseals. installed and fully put back together and still leaking. then after some research i find this thread and said oh my cam gears must be bad. pulled them out sure enough they was. so i brazed them since i don't have the money for the bde's installed them earlier today and it is still leaking from the same area around the intake camgears any other suggestions that i might need to look at. Because like I said the oil only seems to be getting slung from around the camgears, and after time running down the timing covers to the oil pump which would explain the 10 minute wait before leaking. I've had the front of this motor apart so many times i can have it all torn down in roughly 30 minutes now. I just need another idea or opinion.

[BigTDogg (MA)]

Ok so i have a similar problem.

Your other problem is the wall of text. Paragraphs please

[xlpbodily]

sorry its been a very hard and rough day... saying i've torn the front of this motor apart i know 4 times today...

[BigTDogg (MA)]

If you brazed them around entirely, they should not be leaking. The brazing to stop motion will only prevent the inner from rotating relative to the outer, it will not seal up unless you do the entire circumfrence.

I wouldn't recommend the welding and reinstall without a balancing of somekind, but apparently it's working for the OP, so good for him. Usually the easiest thing to do is to swap them out for a known set of good, non-leaking gears.

[xlpbodily]

mkay. Bought the BDE camgears. installed them with new nissan seals again (just for good measure) as soon as i crank the car i can see oil gettin slung from the intake camgear area again. This is really begining to piss me off now. cause there's $500 down the drain with no improvement. Begining to wonder if the camgears are defective from BDE

[es.biggs]

the seal area isn't scratched is it? No scratches at all on the cam or the recess the seal sits in?

[DeeZX]

Hope your camshaft isn't scratched. Did you change the o-ring on the cam cover that retains the spring tensioner?

[nissanfreak12]

Are you sure when you installed the seal, that stupid spring that tighens it down on the cam didnt come off? It has happened, all it takes is a little roughness. Make sure you add a little lube so you don't rape it dry, no on likes that!!!

[xlpbodily]

No the seal area on the camgear isn't worn. like i said new camgears from BDE. Seals were properly lubricated so no dry rapage happened. and the retaining spring is still intact on this set and the previous 3 sets that i've tried. It only slings oil from the Intake cam's. The o-ring that goes on the cover that retains the VVT spring is also brand new and isn't leaking from there. I can crank the car with no timing covers on and actually see the oil being slung from those gears. no if's and's or but's about it.

Anybody local sell dynamite by any chance?

[nissanfreak12]

Are you sure the diameter isnt to small and just have a loose fitting? By chance, are you sure its not coming from the cam cover and leaking just enough to be on the gear to get flung around?

[xlpbodily]

i've taken a micrometer to everything i can think of. The seal fits in like it is supposed to as well as the camgear into the cam seal. The valve cover gaskets are not leaking because i've even second guessed myself and checked those. Only place i find oil is where the camgear has thrown it around. I've even showed the local nissan master tech and he's scratching his head. Pretty bad when a Master Kia Technician (me) and a Nissan Master Tech cant figure the problem out. Oh and just to mention something also when the factory nissan cam seals outside diameter is 51.8mm and some of the aftermarket brands are 52.1mm when i mic'd them. I have tried both kinds. Seems kinda weird to me, but figured i'd throw that information out there.

[marty1mc]

Have you tried a different set of stock gears? Also, is it slinging oil from where the cam seals are located?

[GerryO]

I followed these steps when installing my new camshaft and crankshaft oil seals:
1) wipe the seal installation locations and shaft surfaces free of all grease, oil and debris with a clean alcohol wetted cloth
2) wipe the inner and outer surfaces of the oil seals with a clean alcohol wetted cloth
3) lightly lubricate the inner lip-seal ring of the oil seals with white grease
4) VERY lightly coat ONLY the outer perimeter and outer rear surface of the oil seals with black RTV
5) carefully align seals and PRESS into place
6) wipe off excess RTV, while not allowing it to contact shaft and
7) allow the RTV to cure
8) turn the engine by hand a few complete rotations, after timing belt installation and before starting

I'm also using Castrol 20-50 synthetic blend oil.

And then there is this:

http://bobhooversblog.blogspot.com/2006 ... -seal.html

[es.biggs]

I never use RTV or alcohol when I do cam seals, and I coat the inside with some motor oil, no grease. Never a problem with mine, and never had a comeback for oil leaks.

[GerryO]

I never use RTV or alcohol when I do cam seals, and I coat the inside with some motor oil, no grease. Never a problem with mine, and never had a comeback for oil leaks.

Did the alcohol/RTV/grease thing after helping my son with several of his 4AGE engines, with their sort of split cups for holding the camshaft oil seals. RTV sticks better to clean, dry surfaces and grease stays put much better than oil. Very little and just enough of both is good.

[es.biggs]

How are you pressing the seals into place? Is the seal sitting deep enough into the recess? I can't remember if they are supposed to bottom out against the inner "cup" part.

Oh and can you tell if it's leaking out of the seal or out of the gear?