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Anyone ever heard of a bad vtc on a ga16de?

11K views 8 replies 4 participants last post by  b13er 
#1 ·
1994 sentra ga16de

I'm hearing lots of noise between 1000 and 3500 RPM's. It seams to come and go depending on exactly how much gas I'm giving it.

Normally people would shout "timing chain tensioner", but I just did a complete timing chain job, which cleaned up most of the noises my engine was making.

At first I thought it was a bad valve and I prayed it wasn't rod knock. After some research I found out rod knock gets even worse at high RPM's and my car doesn't do that.

I put my ear up to the valve cover and I swear it's coming from the back left corner if you are facing the engine, which is right where the vtc is.

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I know the sr20de engine is plagued with bad vtc sprockets, just google it or youtube it, but I'm not sure about the ga16de.

Has anyone ever heard of a vtc sprocket going bad and making noise in a ga16de?

Also, does anyone know if the vtc sprocket in a ga16de is the same design as the sr20de vtc sprocket?
 
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#2 ·
I've never heard of a VTC sprocket going bad. I assume by your username that you have a B13 GA16. Does your engine still have the guide above the upper timing chain, because I have heard of those breaking off and causing all sorts of issues / damage. As far as I know, the actual VTC sprocket is just a weight that changes the duration of the camshaft at certain RPMS. How that can go bad I do not know, as there are no bearings or other components involved save the teeth of the sprocket itself.
 
#3 · (Edited)
As I mentioned in my previous post I just did a timing chain job, and the noise was there the second I finished the job. I suspect it was there the whole time, but since my broken lower timing chain guide was making twice as much noise, I just couldn't hear it.

I saw some comments on the SR20DE videos that suggested it might also be a valve lifter, I'm hoping that's not the problem.

IMPORTANT: I forgot to mention that I only hear the noise when the completely engine warms up.

My dad said that is a symptom of it being a bad valve lifter, but it sounds like it's coming from the vtc, and considering the vtc uses oil, and the oil gets thinner when it's hot, it would also make sense that it could be the vtc.
 
#4 ·
the upper chain tensioner is also oil-driven...maybe you have an oil pump issue...have you checked the oil pressure when hot? maybe try a thicker oil next time you do your oil change. as for bad VTCs, I changed the entire timing kit last year, but I didn't change the VTC cause honestly, it's expensive as hell. and after approx. 250K kilometers, the vtc sprocket didn't seem too beat up. never heard of one going bad. and here in mexico you can only find replacements at the dealership.

I see that it has been over a month since your last comment on this thread, hope you fixed your problem.
 
#5 · (Edited)
Thanks for your input, and no it's still there. I replaced most of my timing chain stuff recently, but I didn't do the lower tensioner. So just the other day I replaced the lower tensioner and the noise is still there.

If you listen everywhere on the engine, I swear it's coming from the VTC sprocket. Either that of the valves right next to it, but that upper tensioner is located under the VTC, so it could be that too.

I too suspected that maybe I needed thicker oil and it was oil pump related too. I wish I had replaced the oil pump when I did my timing chain job, but it was an extra $100 a genuine oil gear set.

Now the noise is there even when the engine is cold, so I no longer suspect it's thin oil. And if my oil pressure was that low, wouldn't it kick on an oil light? I just replaced that sensor too a couple of months ago. It was leaking oil and I thought maybe my oil pressure was bad and the sensor was too broke to tell me. Well still no oil light.

Since I suspect maybe it's the upper tensioner, I might try and return it to the dealership and get a new one. I also plan on going to the junk yard and getting a different VTC sprocket.

I'm really hoping it's not the valves, so I'm going to do everything I can to try and avoid a head job. I measured the valve clearances just recently and they were all in perfect spec. Still I wonder how worn my valve guides are, but what a pain to replace those.

This video reminds me of my car, only my car doesn't do it at idle, just ever so slightly higher than idle, which is the complete opposite of this video, but then this video is for a sr20de not a ga16de. It seams to stop making noise at about 6000 RPMs.
 
#6 · (Edited)
I've heard local mechanics say that by the time the oil pressure light comes on on B13s, your engine is already boned. Something about those sensors not being very accurate about their readings or whatever. only way to be sure is connecting an oil pressure gauge right into where the sensor screws into the engine...

did you buy a timing chain kit or did you buy the components separately? I ask cause maybe you neglected to change the lower chain tensioner
here's a pic of mine before it went into the engine:


you also changed both lower chain guides, right?


your description related to the video leads me to believe the issue might be related to the lower chain, since it sounds exactly like what caused me to do my timing kit.

my engine would rattle at around 1500-2000 rpm. not at idle and not above 2000. I also thought the problem was related to the upper tensioner, but the noise didn't go away after I changed it. so I resigned myself and got ready for the PITA job of changing the entire kit.

when we finally took off the timing cover/oil pump, this was what was making all the noise:

one of the lower chain guides had broken off from the bolt. looked like the previous owner had used the cheapest possible plastic POS replacement he could buy


here's the POS plastic guide next to the badass steel-reinforced OEM guide:


sorry, kinda went off topic, I got a little nostalgic :D

anyway, yeah. just wanna make sure you changed both lower guides and the lower chain tensioner.

maybe the little channels/pipes that drive oil up to the tensioners are blocked with sludge. that would cause the tensioner to not have enough strength to push against the chain properly. that would explain why you don't have an oil pressure problem, since the low pressure would specifically affect the tensioner, and not the rest of the engine... if you're planning on pulling the upper tensioner, you might wanna try forcing some wd40 down through the hole that feeds oil into the upper tensioner. just an idea.

EDIT: here are a couple of videos of GA16 engines with the tell-tale timing chain noise, for reference purposes:
https://www.youtube.com/watch?v=pxgUOid3OSA

https://www.youtube.com/watch?v=JQ25avUEa-4
 
#7 · (Edited)
Ya I never told my whole story either, that exact same guide was broken on my car as well, in the exact same place also. Replacing that broken guide cut the noise my engine was making in half, but it's still noisy. I replaced everything except for the sprockets, they all appeared to be in 100% perfect condition. I bought most of the stuff from Nissanpartzone.com, which is all genuine nissan stuff. I thought the lower tensioner was going to be fine since it didn't have any plastic that could wear on it, but actually a tiny bit of the metal did wear on a corner. I just replaced that last weekend to no avail.

Also I forgot to mention that I already tried cleaning out that hole, only I used a 14 gauge power wire and fed it through the hole until it stopped. Honestly I knew it wouldn't be clogged; you remove my valve cover and everything looks spotless besides the oil all over the place which is obviously normal.

I suspect the upper tensioner still because despite someone advise on here, and the fsm, I went ahead and used some rtv on it. It might have clogged a passage. I did this because I bought a cheap one from autozone and it made tons of noise like a ball bearing in a spray paint can rattling around, and I suspect the flaw is in the mating surface. So I read on here that two other forum members had the same problem, and both of their solutions were to buy an oem tensioner. Well I went and got an oem tensioner, and out of paranoia, I added some rtv to it. With the oem tensioner the ball bearing in a spray paint can noise disappeared.

Really the order of operations went like this:

1. put autozone tensioner on: engine at idle sounded like a ball bearing in a spraypaint can shaking around very loudly.
2. put oem tensioner on: that ball bearing noise disappeared, but at 2000 rpms and above it sounded like the chain was rubbing like crazy, very loud.
3. replaced broken lower guide, the other lower guide that the lower tensioner pushes on, and both chains: the engine sounded 50% better, but still very noisy.
4. replaced lower tensioner: no change.

Thanks again for the advice, I'm going to get an oil pressure gauge thanks to your tip.
 
#9 ·
Ya I pulled the pin, I'm 100% sure on that. I didn't replace the gears because like I said, they all appeared to be in perfect condition. I took the valve cover off the other day just to check the chains tension, and it was super tight.

I wish I had put new gears on, but I just don't trust the cheap aftermarket ones. I suspect the genuine Nissan ones are much stronger, but they cost a lot of money.
 
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