Here we go again!!!!!!!!

[87TurboGirl]

Ok I have a fresh rebuild on my engine, the only thing I am lacking is my turbo is on its way out. For the rebuild we replaced main and rod bearings (Clevite 77), rings, head gaskets, all other gaskets, cam, lifters, had the crank turned and engine looked at and cleaned.

Well we have about 1000 miles on it and my loud knock sound is back. We originally thought it was the bearings but now we aren't quite sure.

I was getting off of the highway and then the knock sound just appeared. Literally...... All I have is a scanmaster and the only thing that looked way way off is my o2 readings they shot up to 15.0 plus.

Oil Pressure is fine hot and cold.

The knock sounds like it is coming from the passangers side.

Any ideas on where to start looking again? Or is it possible the bearings are out AGAIN? Or did we use the wrong bearings?

 

[Maximumwarp]

Lifter or rocker arm maybe?

Piston wrist pin? I have chased a ghost before and it was a wrist pin.

HTH, & good luck.

 

[87TurboGirl]

OK i think this will be some help these are my scanmaster readings.....

PARK AND AT IDLE.......

O2'S ------- 330-480 ZERO RETARD DEGREES

AF ---------- 05-06

L8 ---------- 37-38

INT --------- 128

BL ---------- 115

IAC --------- 32

MAL --------- 23 (I'VE HAD THIS CODE FOR 4 MONTHS)

OIL PRESSURE 62 ABOUT 50 DEGREES OUTSIDE AND JUST STARTED.....



DRIVE AND AT 2000 RPM


O2'S -------- 135-781 RETARD DEGREES 4.9 - 12.7

AF ------------ 34

L8 ------------ 104-108

INT ----------- 126

BL ------------ 126

ATS ----------- 58

IAC ----------- 77

OIL PRESSURE 48 ENGINE TEMP AROUND 150 DEGREES.

 

[turbo buicks]

12.7* of KR at 2000 RPM??? id look for false knock before anything. what was your CR after the rebuild? what TPS/boost level was the 12.7 * of KR at?

 

[87TurboGirl]

There is no boost with these readings.......

 

[b231v6]

Disconnect serpentine belt and listen? Flex plate, bellhousing. What do your plugs look like. I don't think it's anything in the valve train anyway. The only # that was off if any would be the IAC. Engine mounts?

 

[87TurboGirl]

There is no difference when we take off the serpintine belt either.

 

[ChrisCairns]

Oh oh.

I once had lotsa knock when slightly blipping the throttle. I "assumed" false knock. Next pass I went past the finish line but the crank didn't.

 

[turbo buicks]

Originally posted by ChrisCairns
Oh oh.

I once had lotsa knock when slightly blipping the throttle. I "assumed" false knock. Next pass I went past the finish line but the crank didn't.

my friends GN gets some transitional knock (~7*) when he gets into it but then it goes away. could this be whats happening?

 

[87TurboGirl]

This is happening at all times highway city etc...... The knock is very loud too.

 

[Chris Taylor]

What was the rod and main bearing clearance? What p/n bearings did you use?

 

[87TurboGirl]

When we put the bearings in they were within spec.

Don't remember the part number but they were P series and .20 over.

 

[WFO]

did you use loctite on the convertor/flexplate bolts?

 

[8UWITH6]

Dont drive it or start it if your getting 12.7* of KR without being into the boost. There is definately something wrong. If you can hear a knocking noise while its at idle, or even 2000 rpms, then you have a problem. Looks like you will probably have to pull the motor out again??? Did you break in the cam and engine properly? ~2000 rpms for 20-25 mins, blipping the throttle every few minutes or so........thats what we did on my GN, and its been fine for 5K miles. Ttype had new bearings, tchain and gear, no cam change, new valve springs, its been fine for almost 10K miles now.........

 

[NJTurbo]

Take the inspection cover off, is the noise coming from the flywheel area?

 

[325DR]

Pull the oil dipstick, and CLOSELY INSPECT THE OIL UNDER A BRIGHT LIGHT to see if there is any shiny metallic in the oil. I hope not, but this happened to me. Check that first, it will take you literally 1 minute and if it is clean, then you car pretty much rule out a bad engine bearing.

 

[87TurboGirl]

The noise isn't coming from the flywheel area more like the front passangers side. We pulled the oil dipstick and didn't see anything on the dipstick. But we are going to change the oil soon for a better look.

The car has been parked since this started the only time we started it was to get the scanmaster numbers.

 

[GN87Mike]

If it knocks at idle disconnect one spark plug wire at a time and listen for a change in the sound. Sometimes you can find the cylinder that has the problem this way.

 

[PaulRV6]

It doesn't sound like bearings to me but I would remove oil filter and cut open and look at the paper element, if you wiped any brgs it will show up, I know from expierience. If it is that loud I would pull the engine and start investigating. Remove valve covers to check rockers, then oil pan to check brgs and then front cover to check timing system.

paul

 

[87TurboGirl]

I don't know if this might be a clue to my problem, but before my problem started up we had just changed the oil about 300 miles prior and when we went to drain the oil the oil is BLACK as night. We always use Mobile 1 Syn. Any ideas or is this even a problem?

We checked the dipstick very closely for small pieces of metal didn't see anything but we are still going to pull off the pan to check the bearings.