Jump to content
SAU Community

M35 VQ25DET rocker cover leak

admS15

By admS15,
in Four Door Family & Wagoneers

 Share

Recommended Posts

admS15 Grand Master

admS15

Posted
Posted

M35 VQ25DET rocker cover leak

 

Hey guys, got an interesting one here. Popped the bonnet the other day as something didn't sound right, could hear a hissing sound like a boost or vacuum leak. Pulled the compressor out and did a boost leak test. Couldn't pinpoint the spot until I put a small hose line into my ear and fished around, turns out the air leak was coming from below a coil pack. Obviously it is coming from the rocker cover seal, the funny thing is that there is no oil passing through, just air, spark plug well was dry as a bone.

 

Has anyone experienced this before?

 

Would this be considered a boost or vacuum leak?

 

Im wondering if in fact it is a shagged seal or maybe the pcv has shit itself and is causing this. As most of us know the seals are non serviceable and new rocker covers are around $300 each. I managed to find a passenger side for 180 brand new but it is the drivers side I require and cheapest I cold find was $318 delivered. I have simply put some 3 bond onto the coil pack seal to try and temporarily seal it up, haven't started it yet, letting it properly cure.

 

Has anyone successfully changed seals of an existing rocker cover. You tube methods look uninspiring, lol.

 

Thoughts and experiences please.

Link to comment
https://www.sau.com.au/forums/topic/469211-m35-vq25det-rocker-cover-leak/
Share on other sites
admS15 Grand Master

admS15

Posted
  • Author
Posted

Nissan quoted me 355. Anyhow, just pulled the rocker cover off and it looks fine, the seals are all intact and in good nick. I'll post pics when I've cleaned it up. Also checked pcv, seems to operate as intended as a one way valve. I'm at a loss to explain why this is happening. Anyone have any other ideas?

admS15 Grand Master

admS15

Posted
  • Author
Posted

I think I've figured out whats happening. I noticed the bolt securing the coil pack that was leaking was longer than the others. It had penetrated through the cover. I think the air was getting between the threads and leaking out. When I was spraying soapy water it was bubbling at the bolt area. I have put some silicon in the hole now and on the threads of a correctly sized bolt. Will see tomorrow afternoon when I start her up if I am correct. I did also fill the seal up with silicon before I worked out what was happening with the cp bolt. Pictured below.

 

 

 

 

 

 

admS15 Grand Master

admS15

Posted
  • Author
Posted

Yep, luckily the plastic was still hanging on for its life and didn't fall into the valve train. I saw it while I was cleaning the cover and flicked it off but I didn't click till I was putting it all back together. Old mate I bought this car off had ultra tune do a service and plug change a few months before I bought it. Probably happened then or possibly in japland. Who knows. Hopefully this is what was causing the tiny leak. Will find out tomorrow.

  • 2 weeks later...
admS15 Grand Master

admS15

Posted
  • Author
Posted

Leak still persists. Im not going to worry about it for now as there is no oil leaking into the spark plug chamber. The car drives perfectly fine and when i did a boost leak test it was taking a long time for the boost to bleed out of the system. I have ordered a new pcv valve in a last ditch effort before i ignore this. Im not totally convinced that it's the rocker cover seal and don't want to buy a new cover and find i still have the same issue. Im wondering if there is something else going on in the background that im missing, is that pressure meant to be inside the engine? Im sure that time will tell all, till then i'll just keep driving.

Leroy Peterson Grand Master

Leroy Peterson

Posted
Posted

I've got a bit of oil on my spark plug on cyl 6 (passenger side), do you have a link to that rocker cover for $180? I've replaced the rocker cover gasket already, which stopped oil weep onto the turbo.

Super strange with that long bolt piercing through...

admS15 Grand Master

admS15

Posted
  • Author
Posted
I've got a bit of oil on my spark plug on cyl 6 (passenger side), do you have a link to that rocker cover for $180? I've replaced the rocker cover gasket already, which stopped oil weep onto the turbo.
Super strange with that long bolt piercing through...

I'm not at a pc right now but the rocker cover was from amayama uae. Is the vq30det the same though? Shouldn't be hard to find with the part number.

Some bright spark obviously drove that bolt through but it wasn't the source of the air leak in the end. The air is now weeping through the seal around the plug but strangely no oil.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • hypergear
      Hypergear Turbochargers and High flow Services Development thread

      By hypergear · Posted

      Result of another R35GTR build. Similar specs as above except this is running our bigger size SS-2 profile option. Made similar power except this car runs on Pump 98 fuel. Build specs are: Nissan R35 GTR 2015 model stock engine and box. ETS street intercooler boost logi intercooler piping with tial bov, boost logi turbo inlet pipe ID 1050 injector DW 300C fuel pump Decatted oem down pipe and y pipe& HKS exaust 3inch intake pipe Upgraded actautors HyperGear SS-2 high flow option Final result is 639whp / 477wkws hubs, Ron 93 / P98 fuel at 20psi.  
    • Therry
      Left & Right Window Regulators for 2013 Skyline V36 Coupe

      By Therry · Posted

      Duncan:- it affect both sides.  Driver side is worse.
    • Duncan
      Left & Right Window Regulators for 2013 Skyline V36 Coupe

      By Duncan · Posted

      That seems like a very special issue!  Does it affect both sides? Either way, I would disconnect the driver's side switch and see if it still happens, noting that might require removal of the whole door card which is a bit of a pain (it does on V37 and HY51)  
    • Therry
      Left & Right Window Regulators for 2013 Skyline V36 Coupe

      By Therry · Posted

      MBS206:- The windows start to slowly open themselves. GTSBoy:- Battery is new since Dec. 
    • Vee37
      Brake pad Compound suggestion

      By Vee37 · Posted

      I currently have a 2008 370GT Coupe, with the big brakes (Akebeno if I'm correct), and Its coming time to get new pads. Previously, I had a 2003 350GT Coupe with the stock sized brakes, not Brembos. I had custom wheels on it that were pretty open to the brakes, and when I first put the wheels on it, the rims where completely coated with brake dust. A few years after adding the new rims, I needed to change to pads on that car. I didn't do any research, but I told the mechanic of the problem with the brake dust. I also told him I didn't track the car or even drive around the streets harshley. But the dust was an issue. The mechanics changed the pads to a different compound, and the dust was GONE! The other change I noted was that when coming to a complete stop, instead of having to press harder on the pedal as I approached 0kph, I had to actually lift off a little to not come to a hard jerky stop.( My unfounded explanation is they became stickier as they heated by stopping ) Since I got my 370gt with big brakes, I noticed that that as I came closer to stopping, I had to press harder and harder to reach a full stop. I am not talking about hard, just harder. I brought the car in from another state, so when I had a blue slip done, I asked the mechanic what he thought of the brakes, and he thought they were brilliant. The only negative of these pads on the 350GT, was that they squealed when cold. So driving out of a shopping center carpark, it was a little embarrassing, as the brakes squealed, and I am sure people thought that I needed new brakes, when they were actually fresh. I have no idea of what type of compound they were on the 350gt, but whatever it was, I want to get the exact same on my 370GT. They weren't ridiculously expensive, and were replaced at the local JAX (which is no longer open), so I am certain they would be a pretty common big brand, off the shelf type/brand. My current mechanic suggested I need top get the rear pads changed soonish, but he suggested standard Brembo pads. Which I expect to behave the same as the current ones and not like the ones on the 350GT.  I don't think dust will be an issue on the 370GT. With the behaviour I describe above on the 360GT, does anyone have a suggestion of pad material that will act like the change I had done on the 350GT?
×
×
  • Create New...