Rebuilding a 4.6 V8

[racing snake]

this is exactly why i have gone and bought all my own equipment to build my own exhaust systems as there are simply too many horror stories out there. also why i used to stay with the vehicle at the exhaust shop for as long as it took to ensure that i give my customers the best possible quality. i have had many business dealing with sanjeev from powerflow and have never had an issue in the past and if this happened at his shop i would try and give the man the benifit of the doubt as there must be a good reason as to why this happened... and im sure he will sort it out.

as for the viscous fan - there are warning signs that the fan is going to commit suicide most of the time and if caught on time can prevent the damage that happens as a result.

 

[Peter@AEW]

Fan and viscous new with no stress marks or damaged blades

 

[racing snake]

Fan and viscous new with no stress marks or damaged blades

perhaps the guys damaged it while doing the exhaust... some of them are really not firing on all cylinders if you know what i mean:fencelook:

 

[Sankekur]

as for the viscous fan - there are warning signs that the fan is going to commit suicide most of the time and if caught on time can prevent the damage that happens as a result.

Such as?

 

[Fordkoppie]

as for the viscous fan - there are warning signs that the fan is going to commit suicide most of the time and if caught on time can prevent the damage that happens as a result.

Such as?

Yeah - no warnings usually.

It is a ticking time bomb of which the counter display went dead

 

[Peter@AEW]

As predicted shop management determined that it was the "mechanic's" fault.
I must say that the response was not unexpected.

 

[racing snake]

as for the viscous fan - there are warning signs that the fan is going to commit suicide most of the time and if caught on time can prevent the damage that happens as a result.

Such as?

the clutch is designed to start to slip as the motor increases in rpm. most of the time when the viscous packs up it will either get tighter or looser... this is also temperature sensitive of course and will generate more drag as the motor reaches running temp.

looser: symptoms are the temp will go higher than it should when you hit traffic or are driving in a stop start manner, the fan might also appear not to be turning at the same speed as the water pump pulley at running temp on idle

tighter: the motor starts developing a fan type noise heard on the older type bakkies where the noise of the fan increases with the rpm of the motor. this is usually the 1 that results in the fan exploding and destroying many parts in the immediate area. this also pulls on the water pump shaft and causes the bearings to expire as the load is directional in design for the belt pulling down and not forwards.

another way is to check the fan for free play when the motor is off... and when the viscous is rotated try to feel for a loose and then tight operation when turning the fan, it is normal to have a little but not too much... it should even out after giving it a few rotations.

 

[Peter@AEW]

Also when first starting the engine the viscous engages and makes an audible sound.

 

[DieselFan]

As predicted shop management determined that it was the "mechanic's" fault.
I must say that the response was not unexpected.

You or the owner of the car should post in vendor complaints about this. Let the people know. Not everyone comes browsing the advertisers section.

This is disgusting. We all know you'd never do that to a car.

 

[Peter@AEW]

As predicted shop management determined that it was the "mechanic's" fault.
I must say that the response was not unexpected.

You or the owner of the car should post in vendor complaints about this. Let the people know. Not everyone comes browsing the advertisers section.

This is disgusting. We all know you'd never do that to a car.

This is something that the owner needs to do.

They have equally connected the cat and O2 sensors incorrectly and wires are mixed up.

I am sure that all people make mistakes and it is not out of the ordinary.

What I find frustrating is when a mistake is made and rectifying it, is not important or acknowledged.

Clearly that exhaust shop is manned by perfectionists living in a Utopian world.

Disgusting!

Should I ever post that I visited Edenvale exhaust shop please kick me in the head with steel capped boots for surely I shall deserve it.

 

[DieselFan]

Yes I fully agree, things happen and mistakes are made. But the shop not acknowledging the damage they caused is disgusting.

 

[Peter@AEW]

I did the camshaft timing again on the V8 as I used the left bank cam bridge on the right bank and the right bank on the left.
This led to inlet cams being over advanced as opposed to the exhaust cams.

In the process I marked the vanos gears to show you the full extent of the inlet cam movement.

This is the left bank(passenger side) fully retarde with engine at top dead center.

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Again left bank fully advanced with engine at TDC
Effectively this is the movement of the inlet cam once the engine is operational and vanos active.
The exhaust cam also moves an equal amount as the inlet cam as it is gear driven and connected to the back of the inlet cam sprocket.

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Taken from a different angle

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When cams are locked with the bridge the vanos is fully retarded and the cam sensor wheels are located with the special tool.

---

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Left bank bridge is sloped on one side.

The grooves for the exhaust cam are roughly 2 degrees off 90 degrees.

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Right bank bridge.

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Car is going back to Shaun and will be taken for the exhaust shop to sort out the welds and location of cat and O2 sensors.

 

[moranor@axis]

estimate of how many Deg the Vanos can change on this engine

 

[Peter@AEW]

estimate of how many Deg the Vanos can change on this engine

Roughly 10 to 15 degrees on the inlet and the exhaust is already advanced by roughly 2 degrees so I would anticipate the exhaust at full advance to be at inlet advance +2 degrees

 

[Sankekur]

as for the viscous fan - there are warning signs that the fan is going to commit suicide most of the time and if caught on time can prevent the damage that happens as a result.

Such as?

the clutch is designed to start to slip as the motor increases in rpm. most of the time when the viscous packs up it will either get tighter or looser... this is also temperature sensitive of course and will generate more drag as the motor reaches running temp.

looser: symptoms are the temp will go higher than it should when you hit traffic or are driving in a stop start manner, the fan might also appear not to be turning at the same speed as the water pump pulley at running temp on idle

tighter: the motor starts developing a fan type noise heard on the older type bakkies where the noise of the fan increases with the rpm of the motor. this is usually the 1 that results in the fan exploding and destroying many parts in the immediate area. this also pulls on the water pump shaft and causes the bearings to expire as the load is directional in design for the belt pulling down and not forwards.

another way is to check the fan for free play when the motor is off... and when the viscous is rotated try to feel for a loose and then tight operation when turning the fan, it is normal to have a little but not too much... it should even out after giving it a few rotations.

But it is not the viscous coupling that fails that is the problem, as this is pretty easy to spot, it is the fan itself that just randomly explodes that is the problem.

---

Also when first starting the engine the viscous engages and makes an audible sound.

This sounds normal. A working viscous clutch should be engaged the moment the motor is started and should stay like that for around 30 seconds then it should be quiet until the motor heats up.
Once the clutch has engaged it should disengage when the motor revs to around 3k rpm (this will depend on the pulley ratios I believe) or once the clutch has cooled down sufficiently.

 

[Peter@AEW]

Car is back with me as we are getting O2 sensor errors on the 1-4 bank.

Powerflow who fitted the sensors saw fit to re route the wires as they pleased and we now have some of them being rubbed by the front prop shaft and some of them cooking on the exhaust pipes.

The sensors that were supplied take a square fitting and the wires are "screwed" into the fitting individually unlike the old fittings which are a press in.

I shall try and get some pics of what I mean for you to see.

On the 1-4 bank we are getting a "short" error or "low voltage" which leads me to believe that they did not wire the sensor correctly.
I shall see once I get underneath the car.

Alexander's M Coupe needs to go for mid pipes and guess where it will not be going..........

 

[gavsadler]

Our skilled artisans are really keeping the backyard mechanics busy lol.

Shocking. Keen to see the pics of the damage.

Sent from my GT-I9100 using Tapatalk

 

[Peter@AEW]

The replacement sensors have the following coloured wires
Balck-Grey-White-White

Black is power
Grey is negative
Whites are heat wires

The car has the following colour wires

Black-power
Brown negative
Yellow
Green

with yellow and green being the heat wires.

Right bank wires were wired correctly
Left bank were incorrectly wired in as much as they connected the yellow wire as negative to both sensors.

So the car now idles ok and is not throwing up errors and multiple misfires.

In the process it has lost it throttle adaptations and the accelerator pedal is not communicating with the throttle body so it is now in limp mode and will not respond to throttle inputs.

Next chapter..............................

Anyone know how to reset the throttle and pedal please let me know as google is not your friend in this instance.....

 

[Ralf*]

The replacement sensors have the following coloured wires
Balck-Grey-White-White

Black is power
Grey is negative
Whites are heat wires

The car has the following colour wires

Black-power
Brown negative
Yellow
Green

with yellow and green being the heat wires.

Right bank wires were wired correctly
Left bank were incorrectly wired in as much as they connected the yellow wire as negative to both sensors.

So the car now idles ok and is not throwing up errors and multiple misfires.

In the process it has lost it throttle adaptations and the accelerator pedal is not communicating with the throttle body so it is now in limp mode and will not respond to throttle inputs.

Next chapter..............................

Anyone know how to reset the throttle and pedal please let me know as google is not your friend in this instance.....

OUCH OUCH OUCH !!

This sounds like the learning experience I had in my shop last year
to summarize
1)VW Polo with cracked manifold casting, new manifold from agents R5000+
2)Elected to rather do branches (Viper)
3)Supplied branches didn't have the same o2 sensor fitting as the probe, only discovered by technician after the entire system had been installed
4)Ever willing exhaust technician trying "to please" cut off the O2 probe, and walked over to Goldwagen, to purchase a new probe, but with a different thread and taper, to match the new branches
5)as it turns out it was a Toyota probe we purchased
6)Wire colour coding was different to the existing wires
7)lack of technical knowledge in this respect, attempted to re-wire the probe and installed.
8)once the work was completed, customer left the shop, but drove about 1KM then the car went into "limp" mode, so he "limped back to the shop.
9)I then was made aware of the problem. told them to remove the branch and return to Viper to get a branch with the correct VW adaptation for the O2 sensor
10)remove and re-fit the correct branch
11)remove the toyota O2 sensor and re-install the VW O2 sensor
12)Car still in "limp" mode, accelerator pedal not communicating with the throttle
13)Install brand new VW O2 sensor......problem persists
14)relocate vehicle to the VW CLINIC behind us
15)New computor box fitted, errors cleared, ..car OK

it turns out that during the crossed wires when fitting Toyota O2 sensor, it blew some delicate circuitry, according to the owner at VW CLINIC, 5 volt and 7 volt circuits blown within the computor

Cost of Branches +/- R1500
Cost of sensor (times 2) +/- R500
Cost of repairs at VW CLINIC R3800
Customer charged R3200 initially--rectification was on our cost

Loss R2800

so I learnt, so we learnt

Hope you get your issues sorted soon

 

[gavsadler]

I seem to remember something along the lines of- press accelerator pedal to the floor, insert key to switch on ignition. Keep pedal pressed for 15seconds odd, then kill ignition and release pedal.

Or what about disconnecting the battery for an hour or so?

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