Rebuilding AU 6Cyl engine...

kingham3689 · 01-10-2009, 09:17 AM

Hey everyone,

Im new to the forums here (as you can probably tell

) And Im after a bit of advice...

OK so heres the story, Im being given a '99 AU series 1, which has had the front bumpers and the front-side panels removed (The car was bought to pull the front bumpers off to repair a friends AU ute). And im looking at doing a full tear-down of the motor, as a project and so I can learn a bit more about car engines (Ive been around bike engines mostly). The engine has about 170,000k's on it, and according to when it was run last week, it was a 'bit rough'. I know that means bugger all for diagnosis, but its a start. Ive also got my workshop manual, and ive read thru it a couple of times (Thanks guys!)

Basically, I want to know whilst putting it all back together, what is best to replace in these motors? Ill being doing all the basics, such as all bearings, gaskets, piston rings, etc...

How well do the heads and valves wear in these engines?

I wont know exactly how much work will be required until I rip the thing apart, but just a bit of general info about peoples experiences with these motors would be great.

Also, (in your opinions) is it worth things like the valve springs? What kind of performance gains could I get while I have it apart?

I basically want to recondition the whole engine.

If I can finish the engine and get it running well, Ill look at turning the whole car into a project... But the engine is first...

Mr Hardware · 01-10-2009, 12:24 PM

hi there kingham3689,

Reconditioning a motor is a really good idea, but i wouldn't recommend it on an AU I6, it'd be an extremely large waste of time and money.

I could almost guarantee you that the 'bit rough' would be external to the motor itself - opening the motor will almost certainly not fix your problem. It'll be the usual suspects that will be causing it - plugs, leads, coil, dirty ISC, dirty throttle body, air filter, fuel pump etc etc. Fortunately or unfortunately, 170k on an AU I6 is peanuts and wouldn't even really start to being any sort of worn. Cabs regularly return up to a bit over a million kays out of an unopened motor.
Hope this helps!

kingham3689 · 01-10-2009, 01:34 PM

I see, thanks for the info! Thats why Im asking

I havent gone thru the parts manual and priced parts, but what would I be looking at for say a set of piston rings, bearings and gaskets? The main idea of this is so I can learn more about car engines and such, and I figured that this would be a good opportunity to do so... Since im getting it all given to me.

Basically every part for an AU falcon seems to be cheaply avaliable (thanks ebay) apart from any of the major engine parts, which makes sense as they dont seem to wear out.

So perhaps reconditioning the whole engine is not such a good idea, but reconditioning all the other parts associated with engine (power steering puump, water pump, throttle body, etc...) is a better idea? And if I get really curious, I can rip the rocker cover off and have a look-see perhaps.

I know there are better project cars out there, but I cant really go and sink $5k into a partially started project car. I have about 4 months before I go to start uni, and I want to be able to do as many things as I want to do beforehand, and this is one of the things I want to learn about. And if I get a driveable car at the end of it, then awesome, and if not, its not like I spent heaps to buy the car in the first place.

What does everyone else rekon?

Mr Hardware · 01-10-2009, 03:16 PM

Yeah, i see what you're saying. I'd be heaps more keen to look after my suspension and interior and paint & panelwork though. Clean your motor and engine bay, and just plain service everything. Oil, Oil filter, Air filter, clean throttle body, plugs, leads, coil, maybe battery, trans fluid, diff oil, brake fluid, power steer fluid, coolant, brake pads, maybe a new thermostat, fuel filter. Then i'd move on to replacing all the bushes in your suspension. Go to the wreckers, have a look at all the interior things you're missing out on in the AU range, spec it up as high as you can without being silly. Spend ages on paint and panel, have it shining. I think you'll find bringing the car up to schmick will be far more rewarding than tearing down a perfectly okay motor. Oh and i'd intend to get the car driveable asap, take it to a mechanic, get him to tell you all the things that are wrong with it that won't make it pass roadworthy, and spend all your time focussing on that. And drive it as much as you can - that's the real way to have a top-notch car, to know it intimately.

frd906 · 01-10-2009, 03:33 PM

what are your plans in the future, cam? turbo? supercharger?

just so you no au i6 na enigne will hold up to about 7 psi on boost,

AMB · 01-10-2009, 08:21 PM

Like Mr H. said. At 160,000 km, its done hardly anything. You'll get a lot more valuable experience getting the engine running smoothly - cleaning up all the external parts, finding out how it all works together, finding out why the engine is running rough. There's bugger all inside the engine, and it hasn't changed much in 100 years -crank, piston, rods, bearings, oil pump, not much more. Its all the peripherals that's getting complicated.

mik · 01-10-2009, 10:26 PM

give or take a few k`s from 170 k`s the odd oil leak(at timing case area) seems to be the only gripe on these engines other than general maintenance items, ignition parts filters, plugs etc .

kingham3689 · 02-10-2009, 07:07 AM

That sounds like its the ticket, engines are engines hey, they all work the same way.

Ive heard about the oil leaks around the case aswell, it must be a fairly severe problem, but its only a gasket, isnt it?

Parts for AU's seem to be extremely common, if im to take whats avaliable on ebay as what parts avaliability is like generally, I should easily be able to get any part I need. I guess there are tonnes of cabs wrecked cabs around for parts hey lol. People even seem to have service kits for sale.

Ill need a few random pipes and a radiator, as I found the mate has also pilfered those (radiator and pipes, and power steering pipes, as well as the steering pump, i think). Though again those parts are easily avaliable.

What are wreckers like for the cost of parts? Or am i just better off looking on ebay and buying parts of people who dont know what their worth? For example, the random pipes and steering pump...

@frd906, thanks for the info, I was curious about how many psi theyd be able to handle. I think if im going to spend $4k on a turbo kit, ill spend it on a car thats worth it. Although you never know.

Although I will be focusing on making it driveable again, what power mods are avaliable, short of sticking a turbo in it? Ill do a bit of research, and if anyone has any info, thatd also be great.

Ill find out a lot more when I actually have it sitting in my back yard, so I cant really make too many guesses as of yet... Which is still a couple of weeks away...

Rob · 02-10-2009, 07:32 AM

Quote:

Originally Posted by kingham3689

Ive heard about the oil leaks around the case aswell, it must be a fairly severe problem, but its only a gasket, isnt it?

It's not a big problem, you'll find 99% of 4 litres have a weep around the timing case. Don't worry about it.
.

Quote:

Originally Posted by kingham3689

Although I will be focusing on making it driveable again, what power mods are avaliable, short of sticking a turbo in it? Ill do a bit of research, and if anyone has any info, thatd also be great.

Extractors, exhaust and a higher flow panel filter will give you a good power increase. Presumably it's an auto, so a 3.45/3.73 diff ratio will help overcome the BTR's looooong 1st gear. It'll also help with acceleration and economy.

au11futura · 02-10-2009, 07:13 PM

Quote:

Originally Posted by Mr Hardware

Yeah, i see what you're saying. I'd be heaps more keen to look after my suspension and interior and paint & panelwork though. Clean your motor and engine bay, and just plain service everything. Oil, Oil filter, Air filter, clean throttle body, plugs, leads, coil, maybe battery, trans fluid, diff oil, brake fluid, power steer fluid, coolant, brake pads, maybe a new thermostat, fuel filter. Then i'd move on to replacing all the bushes in your suspension. Go to the wreckers, have a look at all the interior things you're missing out on in the AU range, spec it up as high as you can without being silly. Spend ages on paint and panel, have it shining. I think you'll find bringing the car up to schmick will be far more rewarding than tearing down a perfectly okay motor. Oh and i'd intend to get the car driveable asap, take it to a mechanic, get him to tell you all the things that are wrong with it that won't make it pass roadworthy, and spend all your time focussing on that. And drive it as much as you can - that's the real way to have a top-notch car, to know it intimately.

on the ball.

These motors are the ultimate workhorses and with a little tlc around it make them go even further.

yeh take the rocker cover off and take it to a plisher for crome work.

kingham3689 · 03-10-2009, 12:12 PM

Again thanks for the info guys. Ok, so lets say for shits and giggles, what would be involved in turboing it? What needs to be bought apart from a turbo, piping, ecu and manifold? Are turbo manifolds avaliable? Im just curious, and im a newbie to it. But from what im reading, it doesnt seem terribly worth it.

kingham3689 · 04-10-2009, 02:58 PM

Anyway, getting off the turbo thing, and I guess this is a more general question.

1. If/when I finish the car, and go to get it registered, what hoops will I have to jump thru to get it registered? Is there a checklist of things that will be checked (anything apart from the obvious ones like lights, brakes, etc).

2. And, if for what ever reason i decide to turbo it before I get it on the road, will that affect anything when getting it re-registered?

3. Also, will changing the color of the car affect anything much with registration?

I would really hate to spend money on it and get it all working great, and then be told I cant register it because of some stupid reason.

Mr Hardware · 04-10-2009, 03:03 PM

Hi there kingham3689,
To answer your questions with a queensland flavour, because i don't know where you are and they're the only answers i know:
1. All you need is a safety certificate. Yes it is a checklist of how well all the mechanical and safety aspects of your car work, whilst they don't care whether you've got diff howl or noisy tappets, they do care if you've got oil leaks or frayed seatbelts etc.
2. No, provided you get it engineered/machinery plated or whatever they call those things
3. No, just tell DOT you changed the colour, they walk outside and look, and they update your rego and give you a new sticker.

kingham3689 · 04-10-2009, 06:13 PM

Ah yes i forgot to mention im in nsw

Mr Hardware · 04-10-2009, 11:52 PM

put it in your forum profile!

kcej · 05-10-2009, 12:17 AM

Five years back my EL Fairmont broke the bolt that holds the cam gear on, resulting in new cam, reco head, 2 new valves etc.
I asked my mechanic for a price on new rings, bearings etc while it was off the road and "open".
His reply was......

"Its only done 200,000ks, it's still like new inside, don't waste your money"

As others have said, HUGE chance the rough running is due to external stuff that controls spark and fuel.