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My 1992 3000GT VR-4 Rebuild.

200K views 2K replies 62 participants last post by  AdamVR4 
#1 · (Edited)
This was my first engine rebuild. As of now, I am about 1750 miles into the rebuild the car is running strong.

The rebuild is more or less BPU. My mods are a K&N intake, DN precat deletes, ESP downpipe, test pipe, 3SX lightweight aluminum crank pulley, Blitz BOV, and a boost controller set to 13psi.



I'd like to say thanks to the people here that answered my many questions throughout the build. Your help was GREATLY appreciated.
 
#69 ·
I'm guessing that if you changed the bearings that you plastiguaged and verified you bearing clearances. With the shim in the oil pump I'm guessing you have not put a new one in. Just an educated guess that you oil pump may be worn. There is a way to pull it and check the tolerances but I don't know it, I'd search on how to. I ran 20 w 50 Mobile 1 in my base model the entire time. Never had a problem but it was not a turbo and it did turn into some mean lifter tick which I found out years later was caused by that high an oil. I wouldn't change what you are running until you can check the tolerances of that oil pump. With the ranges of pressure you are getting I couldn't think it would be anything else and with the oil pressure warning light coming on at hot idle that points to it even more since you have taken accurate PSI readings. Since you have hard numbers I am going to assume you are no longer running the crap stock gauge.
 
#70 ·
I have an aftermarket gauge. Here's where it gets weird. The crank clearances checked out fine when I assembled it on the engine stand. They checked out fine when I replaced the bearings after the first oil change. The oil pump was new OEM when I assembled it and I even checked clearances on the internals of the pump. It checked out fine. When I pulled the pan I swapped it out with another OEM oil pump I had with 2500 miles. I checked the clearances on that one also and it was fine. I have checked the clearances on the cams and those are okay also. I have no clue what the problem is.
 
#71 ·
wow, me either. I would send you to check you oil lines but that wouldn't make any sense, it would either be too high or too low, not both. Well, it's beyond me. I can't think of anything else that would be worn if all of that was within spec.....I'm scratching my head and steadily thinking. Hopefully someone else speaks up that knows better than me......and I don't think crank case pressure is going to have that much of an adverse effect on oil pressure coming from the top end even if your PCV system is totally plugged......can't be a sender, you are reading mechanical....maybe the flux capacitor, try resetting the samo-flange under the mocodulator valve.....ok, that last line was just me laughing at myself trying to figure this out having all book knowledge and no wrench time
 
#72 ·
Lol. Well I had a huge thread about my oil pressure and with all the help from everybody on here I never found the solution. My dad and a few others said I should just drive the thing and so that is what I have been doing for the past few months.
 
#73 ·
No doubt! Freaky
 
#75 ·
From what I have been reading, 20w-50 will have a higher oil pressure at operating temp than a straight 30 though. I was thinking something like a 10w-50 or a 5w-50 if I can find them. That will lower my cold start pressure and keep my hot oil pressure where it is. Or am I wrong about the straight 30 vs 20w-50?
 
#77 ·
Like I said, multi grades break down so fast in our climate that they no longer have the multi grade properties when they were new. Your engine really does not get cold here in the South (I am talking about start ups in below freezing temperatures). Multi grades are like This Old House, great to watch but not very relevant to the way we do things down here. You are better off with the stability of a straight weight. Its better for your engine, long term.

You have to remember, oil pressure is really only relevant to maintain an oil film. Oil creates a film that the metal parts ride on so that even at start up, there is enough oil film left from the previous run to prevent excess wear. As long as their is adequate oil pressure to maintain that film, damage is unlikely on a well tuned engine.

Oil pressure will almost always increase with RPM. Its just the way most oil pumps are designed. Oil pump speed is pretty much linear to engine speed. Viscosity is what causes non linear changes in oil pressure, for the most part. And that is a factor most affected by oil\engine temperature.

Oil pressure consistency\stability at different RPMs while the engine is at normal operating temperature should be your primary gauge of engine health.
 
#78 · (Edited)
Okay. So straight 30 it is then. What brand do you recommend? My dad swears by Castrol GTX, but I am not sure they have a straight 30 (not that I looked for it or anything).

Edit: Again with another question of oil choice. When I ran 10w-40 for the first oil change or so, my oil pressure light was flickering at idle. Would a straight 40 be a better choice?
 
#79 · (Edited)
one more thing to totally confuse the issue, as if we need one.
oil pressure hen you stop to think about it, is actually back pressure, or that is to say, pressure between the pump and whatever is being oiled. a restriction just before a bearing will yeild a higher pressure. This includes the thickness of the oil as part of that restriction. Thinner oils penetrate better, thicker oils stay better so what you need to find is the balance point to suit your purpose.

My thoughts on that are, thicker for seals, blowby and bottom end, thinner for break in, top end.

BTW, did you know they removed the zinc additive from oil?
Bad news for new engines, lifters/rockers, et al.
 
#81 ·
I've heard a lot of good things about the Brad Penn. Maybe I will have to try it out in the future. For now, I got Castrol straight 30 and a K&N filter (as always). I bought one of the nifty handheld torches. I'm eating lunch now waiting for the car to cool down a bit. I decided I am going to do the turbo swap, SS oil lines (at least the rear), and change the oil today instead of waiting for the weekend:) I'll probably update with pictures of everything tonight or tomorrow.
 
#84 ·
Apart in about 30 minutes. All I have to do is drain the oil, take the precat off, oil lines, then the turbo.

And for another noob question. Wescott, I have oil in my intake again and my rear valve cover is leaking. My PCV is fine. It is about 1/2 overfilled. When I change the oil I SWEAR I don't overfill it. I fill it up to the full line, crank it and let it run for about 5 seconds or so to circulate the oil, turn it off, wait about 5 minutes to let the oil come down from the heads to the crankcase, check it and it is still at full. I have tried filling it to about 1/2 quart low, crank, wait, check and add oil, repeat, repeat, etc to ensure I am not overfilling. I can check it the next day and it is 1/2 quart overfilled. There is no coolant in the oil and there is no fuel. It is just oil. WHAT AM I DOING WRONG? Am I not compensating for something? I feel like such an idiot.

Now I have to spend a couple more hours cleaning the oil out of my intake and fixing my leaks. Great.
 
#85 ·
while you have it down that far it's a good dea to pull the valve covers (wich you are going to do anyway) and run some pipe cleaners or something behind the baffles inside.

Over the years crud can build up inhibiting the free return of any oil that gets splashed up in there.
^^^major contributor to oil being sucked thru the vent and PCV.
 
#87 · (Edited)
Okay so I hit a major hold up. The 13g exhaust wheel won't fit in the 9b housing that I planned to use. I thought it would fit since it isn't an "L" or "HL" wheel. I don't know how I didn't notice, but it turns out that the exhaust housings are different. The 13g housing won't fit in the back turbo position. I have it clocked and the housing hits the head and won't mount to the manifold because of it. I will either have to put it all back together the way it was before or get my 9b housings bored out tomorrow.

Edit: Or I can take the front turbo, clock it and put it on the rear and put the 13g on the front. It was in the front before I took it off the spare engine I have so it will fit.
 
#88 ·
You must be bummed. At least you found out early and you still have time to fix it before the end of the weekend.

Swapping turbo positions sounds like a real pain but it won't cost you anything but time. I know you are itching to finish the upgrades.

Glad the torch made your job easier.

I still have not gotten my oil pan. I called today to check on the status.



Wish I could be there to help. I have to take my male blue ticked beagle in for a splenectomy on Friday morning. He has been fighting a bad infection for over a month. We are hoping this will fix him. The ultra sound seems to point to a growth on it. We have switched his antibiotics twice already. (Could have bought my Megan's and new paint for the cost of surgery!!!)

Anyway, keep us posted and stay calm. I know the rear turbo can really cause your blood pressure to rise so be patient. You will get it handled.
 
#89 ·
I'm so pissed. I spend almost 4 hours removing the front turbo. The last time I took off the precat I broke a bolt so I got a smaller bolt, a nut, and some washers and used that going through the precat to the turbo. It worked great. Until I tried to take the damn thing off. It was in the absolute worst spot out of the 4 bolts that holds the precat to the turbo. I had no room at all and it seized, and would absolutely NOT move at all, leaving the precat and turbo stick together. I tried bringing the whole thing out of the bottom. Didn't work. Tried to break the bolt loose. Didn't work. Tried unbolting the radiator and shifting it. No go. Tried breaking the bolt loose again. Nope. I wound up being able to shift it sideways. I grabbed my impact to try and get the bolt loose. STRIPPED THE DAMN THING. I was finally able to take the lower radiator hose off of the water housing and bring the whole turbo assembly out by the air filter. I had to clamp vice-grips on the bolt and a breaker bar to finally break the bolt when it was out of the car. So stupid. Today's project failed miserably.

I decided to take the front turbo off, clock it and put it on the rear and put the 13g on the front for a couple of reasons. I have an exhaust leak by the front O2 where the precat connects to the turbo because of a broken bolt and it is messing with my O2 voltage and don't have another 9b exhaust housing to put on the front to fix it so the 13g can go there. Both turbos will be out of the way and I can install the front and rear solid mounts I have easier. My front 9b is fairly new (rebuilt) and my rear has lots of shaft play (they were rebuilt at the same time but something hit the rear compressor wheel). I was already halfway there and I didn't want to have pulled the rear turbo for nothing. Turbo clocking is free whereas machining the turbo housings to fit the 13g isn't. The 13g will give me more powa:) It isn't the easiest option but I feel it is the best option. Hopefully it will be back on the road tomorrow.
 
#90 ·
Man that sux! I looked at my front one while I was changing out the radiator and O2 sensor. The sensor was bad enough, took me weeks to change. Broke an O2 socket, bent a ratchet and screamed a lot. Finally dumped 2 cans of liquid wrench on it over 4 days and bought a heat gun and sat there with it on high for an hour. The entire time I was looking at that turbo saying " One day I have to take you off.....I know it won't go well and bolts are going to snap off". I dread it more than most things on my car. The only things that top is are spinning a bearing and toasting a tranny.
 
#91 ·
I'M FUCKING PISSED.

While trying to clock the turbos, my pliers broke. NOBODY has a set of ring pliers or 90 degree needle nose pliers big enough to take the clips off. I went to Autozone, O'reilly's, Advance Auto Parts, and Sears. So what I basically spent 20 hours doing was taking both damn turbos off to put them right back on. I have to get it running tonight or mid-tomorrow as this is my DD so I can't order any. Fuck my life.
 
#95 ·
That's the 28 or so mm ones I found. Still just a tad too small. Thank you very much though. I'm putting it back to stock so I can drive it and then I'll line everything out so I can do all of this again with the proper tools and resources. Now that I know what I need it won't be such a pain in the ass
 
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