Ok here's the outcome of my situation,

A year ago I had an oil consumption issue on my 2003 G35 coupe and took it to the dealer and they replaced the short block but used the other stuff from the old engine. Now I originally took the car to the dealer because I was having a strong noise that lasted 1-2 secs when starting and the car was wasting 1 quart of oil every 2k miles. So once I got the car back the oil consumption thing was fixed BUT the cold noise wasn't, so I took the car to my bro which is an aircraft mechanic and he agreed to disassemble the engine and see what the problem really was.

Results,

1-The timing chain, had stretch out quite a bit. When we looked at the tensioner it had almost all it's teeth out which meant the chain was plastically deformed.

2-The oil pump, has two oil seal rings that seal it to the engine. Both of them were flattened out with the surface which meant that when the car was cranking almost no oil was going up to the tensioners and valve train.

3- Valve covers, they were leaking quite a bit on the edges and towards the bottom.




NOW THE FIX!!!


1- Replaced ALL the timing chains, now the tensioner is only using 2-3 teeth and the timing chain is very tight. In the past the tensioner was out 7 teeth

2- Oil seal rings were bought OEM new and believe me , THE DIFFERENCE IS A LOT, if you look from the side the oil seal sticks out from the surface which means that it is going to seal beautifully. New REVUP oil pump is now installed also.

3- Valve covers are known to leak on all VQ35 engines. The reason they leak is because of the bolts used. They go in the cylinder head edges but stop at a certain point because they don't want the valve covers to crack because of over tightened bolts. Unfortunately when the plastic valve covers age they tend to twist and therefore the adjustability of these bolts leave the seal not appropriately tight. You can fix this by putting very thin washers between the valve cover and the OEM bolt. What this does is provide a little more bolt thread area and therefore you can adjust it some more. You can also put some silicon on the edges to make sure nothing goes wrong.


THE ABOVE fixes have work for me I have now no noises on start ups and surely no leaking valve covers.

 

A HUGE thanks for taking the time to post this info, brother.
My last account was acting up, created a new account just to respond to this post - I'm due for a spark plug change and have been cringing at the amount of posts I have read, with people stating that they had to buy new valve covers.

I'm positive I'll have oil on at least one spark plug, so I will definitely try the remedy you suggested before going all out and buying 2 new valve covers that will ultimately develop the same leak as ones replaced.

Can you please tell me which silicone I should be purchasing to use to try this fix? I've read that it's something called RTV, but when I looked it up, there were so many different variations that my head started to spin.

I wonder if anyone else has tried this fix yet? Or has anyone else even read this thread yet?

Thanks again, brother. You may have just saved me several hundred - will post a follow up when I finally try this out in a week or so.

 

good info!!

 

Very good info. Can't believe no one has commented on this until now.

 

For some reason in the back of my head whenever I see that my engine eats oil for breakfast, lunch, and dinner every thousand or more miles the one thing that pops up before anything else is the oil pump seals and f/r crankshaft seals. Since I have done everything to stop this issue I'm going to get ***** deep and replace some of the oil seals starting with the oil pump. Also what creates oil consumption is the PCV (positive crankcase ventilation) system. If the lines are clogged, worn, torn or dryrotted ect. it can cause oil consumtion, idle problems and stalling. Many people are saying how their intake manifold has oil in it and others say their PCV lines have oil in them, ect. Well it's because of the PCV system not working correctly. There are tests that can be done to see the condition of the PCV system. Without the PCV system working correctly it can cause many major engine problems first being oil starvation leading to issues we should not talk about....
For a simple test to check your PCV system at your house you can first disconnect the hose (connecting to the PCV valve) going to the passenger side valve cover. Screw out the PCV valve and check the O-ring for tears, ect. and make sure the little ball is there and free moving when you shake it.
Another thing you can do is turn on the engine and let it warm up to operating temperature. Then disconnect that same hose I described from the PCV valve and plug it with your thumb to verify if there is vacuum present. If there is no vacuum look for a plugged/clogged pipe or hose or port. You also want to look for a collapsed hose when there is vacuum applied.
You can also remove the oil dipstick and install a vacuum gauge in the dipstick location. plug the PCV systems fresh air inlet hose which is the hose that connects to your z-tube or intake tube from the filter to throttle body. After you do that run the engine to 1500 RPM for 30 seconds then read the vacuum gauge while the engine is running at 1500 RPM. If there's vacuum present then the PCV system is working correctly. If there is no vacuum then there could be outside air being drawn into the system. The engine has to be completely sealed for the PCV system to work properly/correctly. This is where you would check the gaskets, seals, and everywhere else for leaks. If there is positive vacuum pressure on the gauge then look for plugged hoses or suspect engine blow-by.
Although if the PCV system is working correctly and the engine is still eating your oil and is in the throttle body or air induct system then it might be from excessive crankcase pressure. Thats when you go get a pressure test done on each cylinder. Also when i say blow-by i'm reffering to oil blowing by worn rings, pistons, and/or cylinders (or from constant heavy loads like driving hard at high RPM or something) into the intake manifold.
Anyways........i don't know what the VQ loves so much about the engine oil....it tastes like s**t....

 

Thanks for that lil tidbit Winter, but...
Back to the original topic... need to find out what type of RTV to use, and am curious if anyone else is up for trying fix #3.

 

well tdotdizzle you can use almost any silicone adhesive RTV sealant. heres a link since nobody can search instead of ask.....

http://horsepowerperformance.com/i-1...ne-sealer.html

also you said you want to fix the #3 cylinder....im assuming your sparkplug in that cylinder has engine oil on it?

if so then your gonna have to replace the tube seal for that cylinder or replace the valve cover like i did for my #5 cylinder. if you want a good price for the valve cover then ill sell you my extra one thats brand new still in the box.

another thing you can do is look at my posts in the leaking valve cover thread which you would of found already if you used the search option. if you have oil consumption issues then again look at my previous posts on here or on my350z.com.

 

Thanks bro.
I actually did search, but came up with a crapload of diff types... was looking for one that clearly stated it was for high heat applications.

I think you misunderstood what I was saying by "fix #3" though. I wasn't referring to my #3 cylinder, was referring to the "fixes" listed at the bottom of the OP.

I've been following the posts on 350z too, but couldn't really find anything conclusive besides the OP here to show this could really work.

 

BTW thanks for the offer on the valve cover... if this doesn't turn out to be a viable repair option then I will def consider taking it off your hands.

 

hi!
i would like to have more info about the cold start noise...my car start to make a weird noise too last week.I would like to know if it sound like this guy:

https://g35driver.com/forums/engine-...upe-video.html

mine make the same noise(first start up in the video)
I have a 04 with 45k miles and it doesn't consume oil at all!!
it does'nt make it every day but always when cold...
-how many miles did you have on your G?
-was it making it every time you was starting?
I want to have some opinion because my car is no more warranty

 

Apparently different people has this noise issue for different reasons. Lucky me I found what was causing it but some people might fight with it until the time they sell the car.

The FIX 3 has been running strong for some time now. So far no oil is leaking on the valve covers and I check the bolts to see if they were still tight and they are alright. I really recommend this fix to anyone changing their spark plugs or cleaning your engine it sounds stupid but it really works. I have the money to replace both valve covers but it seems to me that if these washers that cost me less than 2 $ are doing the job I will give em a try. I mean for 2$ you have nothing to loose.

 

that noise freak me a bit...I just want to be sure that is not too serious

do you think that those washer will work for oil that goes on top of the spark plug?because if I understand your cover was leaking on the outside right?

 

Can you please list part numbers for the Oil seal ring as my number 6 tube has oil in it. I have checked PCV valve and its fine but will do all other suggestions made by winterdevilg35.

Do i need to all 6 seals or just the one? and i read not to change tube a its a massive job?

And i can just check the left valve cover and if seals are fine then use washer trick? what size washers??

Thanks guys

 

I'd suggest being very careful when tightening the valve cover bolts and/or using washers to increase torque. The valve covers bolt holes are reinforced with brass to handle torque loads and displace torque. The OEM bolts are designed for minimal torque and will snap if you over torque them. If you're luck, the bolt will break off with enough length to get it out of the head. If you're unlucky, the bolt could break off inside the head. Have fun with that one.

The valve cover leaks on the VQ, like most any car, are common. I've never owned a car that doesn't eventually have weeping or leaking valve covers. It doesn't seem to matter if the valve covers are plastic or metal. They all seem to leak. Subarus and Porsches are notorious for this because of their boxer design. The leaks on the VQ valve covers usually come from the areas that require RTV sealant per the FSM. These areas are typically the lower corners of the valve cover and/or the front cam lobe crevices.

As for the tensioner and a stretching chain, this is the first I've ever heard of a such a thing on VQ motor. The timing chain should not be super tight. The tenisoner is designed to keep the right amount of tension on the chain. Too much tension and you'll wear out the tensioner or the chain itself. Hopefully the guy that "fixed" this VQ had the FSM because there is a very specific procedure to setting chain tension. Additionally, the last I heard, the tensioner was spring loaded and not adjustable. Tensioners on the VQ's, especially the VQ30s (95-01 Maximas), have a history of wearing out and getting noisy as the miles pile on. The VQ35 tensioner is beefier and tends to last longer. However, they can get noisy. The fix is simple, replace the $50 tensioner which is accessible through an opening in the timing chain cover. The common tensioner noise is a rolling metallic sound right at start up. It tends to last about 1 second until the chain is fully lubricrated. It's more of an annoyance than an real issue.

I can't really comment on the oil pump issue because I can't really follow what the exact issue is he's describing. The oil pump is a super simple device and they rarely fail unless you try to wind the VQ30/35DE past 7500rpms.

 

So is it safer to use stronger bolts if going to use washers on the cover or just take it off and if not too bad use rtv to seal it up again? U still need to replace the oil ring seal right?