Blew turbo, found knock

[dekansnowman]

Ok so I blew an S13 SR T25/28 hybrid drifting and figured I would quickly shut it down and trailer it back home. After spending a couple weeks deciding the fate of the CA I bought an S15 GT28R-4, (With the incanel fins, etc) and sent the car in for paint and got new hood.. I had it back at the shop and turned it back on to make sure what I thought the problem was is in fact right. I let it idle, sounded fine, except the scratching obviously coming from the turbo. Took the intake elbow off and you can easily move the shaft around like a 360 joystick. It was awesome. No point in revving because I don't want pieces of that junk going anywhere so about about 10 seconds of idle I kill it. Well, Friday night me and a good friend take on the task of removing old turbo and installing new turbo. Notice the size difference!

So 15 hours later, no rush mind you, and some good tunes we get everything on, sealed, checked, and double checked before we start motor to break in the turbo. Following the instructions from Garrett to a T we spend 7 mins idling the turbo and checking for any leaks, and flow of oil and coolant. Everything checks out great and we are ready to take it out for a short, low speed cruise. Well, we start it up again and check fluid levels and then give it a slight increase in throttle.. Damn, I notice rod knock. WTF..... Now it only happens during a rev, and sounds perfect on idle. Can bearings be a "simple" fix? Please help me get this newly dolled up car back on the road.

[float_6969]

Are you sure it's rod knock? If so, I know for a fact it's possible to change the main and rod bearings by just dropping the oil pan. This only works if the crank is still in good shape and you get the bearings from Nissan based on the numbers stamped on the crank and block.

[rico05]

Sure it is bearings? I had a bad lifter that sounded good at idle, but got all nasty at speed.

[jt15833]

ah nice to see another CA s14 on the road!+1 for color, i love it.

sorry i can't actually help but hopefully my comments will indirectly help by making you feel better.

[zmannz]

I second the bad lifter. think rod knock usually occurs in throttle let-off too.

[boost_boy]

Lifters don't just go bad all of a sudden. If you heard a rattling noise prior to blowing your old snail, then it's more than likely bad lifters. But if your engine is quiet at idle and light throttling you start hearing the noise the knocking noise, you should try and pin point the cylinde that you suspect is making the noise. Once you have made that assumption, kill the ignition to that cylinder by removing the coilpack connector from the coil. Rev it up again and if the noise is not present, you have worn rod bearings for that cylinder. This noise should be heard at or around 2800 rpm. Good luck with this and don't drive the car until you've done the necessary tests. An d like float says, it can be as simple as just changing the rod bearings if replaced with the same bearings.

Dee

[dekansnowman]

First, thanks guys for the compliments.

I will do the tests you speak of and report back what I find. Please allow the thread to stay open for a couple days so I can have some online help from the most knowledgeable CA guys this side of the net!

[rico05]

My bad lifter started as a very quiet tapping. Then got worse. Way worse. It would clack at cold start, then go away until full hot. It would do it on throttle anywhere above 1000RPM to redline, and never get louder or anything. Super annoying. And FYI: go to the dealer and get the lifters. $33/each. Get a new cam seal too. They are cheaper there than at a parts store.

[dekansnowman]

Are you sure it's rod knock? If so, I know for a fact it's possible to change the main and rod bearings by just dropping the oil pan. This only works if the crank is still in good shape and you get the bearings from Nissan based on the numbers stamped on the crank and block.

I just ordered and received ACL Race Series Rod and Main Bearings with extra oil clearance. The guys recommended this for my application so we will start with this since it isn't a bad idea to go ahead and do this anyway. The motor was rebuilt apparently before I purchased it but I doubt bearings were ever replaced. Oh well, at least after this bearings hopefully won't be a problem. I'll try to remember to take pics during work to show my findings. If it's a lifter after I wind up replacing all the bearings then I'll tackle that. But 70.00 for all the bearings is a solid deal. It will be a learning experience for me!

[Rin5]

..the hell man... lol i almost got in trouble at work for those legs...my supervisor said no p0rn and im like ahh no its a turbo...better than p0rn but he though it was nudity

[dekansnowman]

Lol thats awesome..

Ok, so if any of you have done bearings, how did you attack it? Did you just suck it up and pull the motor? Any advice? I wouldn't mind some time/anger saving tips. I'm gonna start it in the next couple days..

[dekansnowman]

Ok, so bearings were replaced and the number four piston was the one knocking. Once we dropped the oil pan you could slightly wiggle the rod while everything was still tightened down. We replaced all with ACL Race Series bearings with a bit extra clearance for oil and in the process of torquing everything down, broke on of the rod cap bolts. No big deal, ordered a couple spares from the local Nissan shop who has become familiar with a friend and me ordering old CA stuff.. Just waiting for the bolt to come in which should be tomorrow and I will put the new one in and put the motor back together. The only problem will be connecting all those plugs back together once the motor is in...

[dekansnowman]

Sure it is bearings? I had a bad lifter that sounded good at idle, but got all nasty at speed.

And yes, after seeing the bearing first hand and noticing copper in the oil pan, it was bearings.. Hopefully hopefully hopefully when I start em up again everything will be smooth..