R33 GTR - ticking sound on revvnig (cold start) and turbo pushing air out of the MAFs

[judasentinel]

Now that I have the front CV boot issue figured out, I wanted to ask experts about the three issues I have recently started to observe:

1. A few days ago, I started hearing a slight medium-pitched ticking sound when I start the car. First of all, the car is taking a bit of time starting up. The starter cranks but not at a consistent speed. And once it starts (which it always does), it idles at around 1200 rpm. At this point, if I suddenly give a little bit of gas, I hear a faint tick tick tick, which goes away after a few seconds. If I rev the engine slowly, all the way to over 5000 rpm or even more, the sound is gone. Let go of gas, give it a bit again, and the sound is back again, and then goes away as the revs climb. I know the first thought would be the lifters ticking but i know that sound, which is different. This one feels to be from not the top of the engine. After the car is warmed up, you cant hear it anymore if if you give gas, but when I start to drive it again and give gas to move, I hear it again and then it is gone. I am not sure what this could be. This happened after driving the car hard last Saturday for a few minutes. Is it possible that it is an exhaust leak from the manifold or around there? Will that go away after the car has warmed up? Or could it be the turbo wheel/fins touching the housing intermittently? Or a transmission issue, as the CV boot tore after running the car hard for a few minutes?

2. The cold start and idle are a bit rough, especially after I rev the car a few times. I unplugged each coil to see if one of the cylinders was misfiring, but the revs drop on each coil's disconnection.

3. After the car has warmed up, and I rev the engine, there is no BOV sound. Instead, I hear two sequential whoosh whoosh sounds from the around the turbos and can see air/dust flowing out of the MAF filters.

The car boosts all the way up to 1.1 bar and even more if I keep going. I have NO idea what kind of turbos it has, as I bought the car as it is. What do I need to remove to identify the turbos? Since it came directly from Japan and I am the first owner in Canada, it has quite a few visual upgrades. I am not too sure mechanically, though. When I bought the car in January, it ran great and none of these problems were there. It's a different story now.

Can anyone give ideas as to what's goin' on? What should I check? I hope these are not very dangerous signs or symptoms of some catastrophic failure lurking in the shadows.

Please help me as these issues have me totally stumped.

Thank you.

[caliber676]

Your bovs are most likely still recirculating and releasing the air pressure back into the intake is likely coming back out the intake because your not needing that air as you would when shifting to the next gear on load. I would take a looks at your turbos to see if they are causing issues if you believe the noise is from there. Also take a look at things like accessories. Air con, ps, water pump and the belt idlers all have bearings that can wear out. Stethoscope on the housing of each suspected component while running is a method of isolating the issue

[judasentinel]

the sound seems to be louder with the hood up and closer to the exhaust side. But there is no smell of exhaust in the area. Also, I noticed a bit of oil in the pipe that runs from the rear MAF to the turbo. I removed the MAF and revved the engine and saw a bit of oil in the pipe. It was black and a bit thin, which seems to suggest an oil leak in the turbo. How bad is that? Or is a little bit of oil normal? I doubt it.

If I am to remove all piping around the turbos to look at them, what else should I check? I can see that the BOVs are recirculating the air back to the turbos, but am not sure where it connects - between the turbos and the twin turbo pipe or is there a separate Y pipe that joins the two turbos? Assuming the recirc is working as it should, what would cause the car to stall? Could MAFs themselves be throwing wrong readings out to cause this issue?

I also noticed today that the starter is having a bit of a hard time starting the car. Hope the grease from the broken CV boot didnt mess it up.

Does anyone have any solutions for me? Is it better for me to just dump the twin setup and go big single? Or will I lose bottom end power/torque curve due to that? Guess I will also have to change the MAFs and ECU?

[judasentinel]

Update:

I checked the twin BOVs and they are connected as they should recirculating air back to the Y-pipe between the turbo and the MAFs. I assume that is correct.

Next, I disconnected the MAFs from the turbos. I found oil on the rear MAF. Had to clean it up. I have a PCV pipe running from the top of the exhaust cam cover into the rear turbo pipe between the MAF and the turbo. Could this be causing the oil to to slosh into the line? Why is it connected that way, because the vapors of oil from the valve covers would go into the turbos and into the engine?

I also found that the coil number 4 had no spring in it anymore. The whole coil inside was covered in some white stuff. It was spotless a month ago when I put new BKR7E plugs in. The terminal of the plug was also green, possibly oxidization. I also noticed that the side electrodes on all plugs were green in color - oxidization? What does it indicate? The car is running massively rich, which I attribute to wrong MAF signal being generated for the ECU and the BOVs recirculating air back into the turbos, with the rear turbo not working up to capacity.

What is the solution?

[caliber676]

Oil in your intake piping is normal, it's from the pcv system. Your ignition system sounds like it needs some attention. White can indicate corrosion or spark arcing, the green is usually Oxidation and should be addressed Asap. Has the car been sitting for a while? You ticking could quite possibly be your ignition arcing to the head instead of the plug. It sounds like your chasing multiple issues and it may be easier and cheaper in the long run to bite the bullet and take it to a shop

[judasentinel]

I think the green is oxidation. However, I dont know what it means. As far as the ticking is concerned, I think it is coming from the rear turbo area. I checked., The car has been a daily driver for a few months now, so it wasnt sitting. The plugs are fine otherwise, no signs of detonation or running rich/lack of combustion.

Interesting that the coil could be arcing to the head itself. I never thought of that. I just bought some sandpaper and will clean up the inside of the coilpack hole, as well as the spark plug. I did find a spring from a spare older coilpack. Quick question - do the hole inside the coilpack need to be spoteless clean or could some corrosion still be there without it arcing away from the spark plug? And now that the spring is in, I feel it might be a bit better.

There is no reliable mechanic that I know of, in St Cathartines area. I have always worked on my Skylines myself in the past, but never had to deal with this issue.

Without removing the turbo itself, is there any way I can check the rear one for issues? What specifically am I looking for other than shaft play?

[NoLimit0596]

Your ticking sound coming from the turbo can be just bad exhaust gasket between the manifold and the turbo..

[judasentinel]

if only were it constant and got louder in that area with the revs, would I say it was the exhaust leak. There is no smell or smoke in that area either. I just cleaned up the coil that was messed up, sanded it down with a dremel tool and put it back on....will see what it shows.

I am strongly contemplating if it is just better to dump the twin turbo setup and go a slightly bigger single. My budget is tight, so I will have to be very careful with it. What all do I need? A GTX35 with a top mount exhaust manifold, plus a different down pipe, a different dump pipe, and ditch the twin BOV setup (use one of the blitz BOVs I have on)....and perhaps find new fittings for oil and coolant lines. I'd appreciate anyone who has done a budget single turbo setup on his/her GTR to share the experience.

I will update here again tomorrow after I find out how she is running. I am also suspecting that the the green color on the plug is due to the quality of gasoline. Esso recently started something called synergy fuel in our area, and it seems that green color on plugs is usually the result of fuel additives, ethanol, and sometimes meth/NOS.