KenCoupe

Hey guys,

Looking for some advice here or personal experience:

I posted earlier regarding the bent valves on my Coupe 2.8 V6(AAH 12v) .

I’ve shopped around and if I don't DIY, I'm looking at around ZAR15 000 for a complete head recon, water pump and cam belt change, etc. For a bit less I could buy an imported motor of the same spec(AAH 2.8 V6, 12valve). My coupe has just clocked 300 000km and given no engine issues till now. With high mileage though, my concern(shared by a few others) is if I redo the heads, the bottom end may start playing up in the not too distant future-smoking, etc.

Do I then consider a straight swap for an import motor with lower km’s? The car is neat, I’m the second owner and I’d like to keep it as original as possible. So personally I’m not that keen to swap the motor.

Alternatively, is it worth chucking ZAR28 000+ and having the entire motor redone?

The car is otherwise really neat and I would like to hang onto it long term.

Budget is a concern but I’d also hate to go cheap and then have to spend more money a month or 2 down the road(mind the pun).

Thoughts?

Thanks,
Ken.

hubturn

Converting from South African Rand to dollars, you're talking $2000+ for the reconditioning to $4000 for a rebuild. Seems like you could online some U.S. junk yard for a set of heads and take a chance. I realize shipping will be steep.

Lago Blue

At your location, I'd suspect there's likely little salt damage to your car, and with some TLC, you might be able to keep this probably mint, and very interesting car to drive; a very long time.

Do you need the car back on the road ASAP? Are you at all mechanically inclined? Would you consider this a possible in-part DIY project? Do you have time and place to do some of the work yourself?

With either a replacement motor or strictly a non-DIY repair, you will get none of the preventative maintenance items done that have been so well documented here, that could be performed during repairs of this depth. These items may serve you well in terms of maintenance and operating costs, reliability and performance, and certainly enjoyment and satisfaction, if you plan to keep the car; long-term.

I might find a shop to re-do the heads, after a little bit of DIY (see below). Meanwhile, I would then research and do the following:

- send your injectors to RC Engineering for re-conditioning;
- replace all the soft vacuum lines;
- relocate the vacuum reservoir and ignition coil wires;
- the valley-pan cover flattening and re-seal procedure:
- the Intake-Manifold surface flattening and re-seal procedures;
- perhaps you don't have an EGR system, so the EGR passage polish procedure may not be needed?;
- the head intake port-matching procedure, & then have heads redone;
- farm-out the head replacement if you have to.

The above does look like a long list, but if you could do even some of them, you won't regret it. Everything up to head replacement is just plain grunt work. This method may be the most cost-friendly, and even though it will take some time and requires you to get dirty, it will also get you a more satisfying result down the road.

Either way, I'd bet the bottom-end would be fine for years to come.

KenCoupe

Thanks Lago Blue.

After some thought, with the help of some mates I decided to take heads off and have a look 2 weeks ago. . .














The Culprit:






Head and manifolds at engineer for reconditioning and polish and porting. I've been flirting with the ideas of bigger throttle and cams but apart from price, I'd like to keep her close to stock, neat and reliable.

My DIY is average I guess-only rebuilt my Golf MKII 1800 8v-also kept stock but I'd be lying if I said the Audi bigger motor and more costly parts didn't intimidate me.

I'll certainly look into this list, thanks! Please see my comments below and excuse my ignorance .

- send injectors to RC Engineering for re-conditioning- does this make a big difference? As good as replacing them? I'll have to find a local supplier here in Cape Town.

- replace all the soft vacuum lines-I assume, the hoses?

- relocate the vacuum reservoir and ignition coil wires-is this just aesthetic. have you got an illustration of this procedure?

- the valley-pan cover flattening and re-seal procedure-just removal and refitting with new Gasket? Mines pretty covered in oil as you might see in the images.

- the Intake-Manifold surface flattening and re-seal procedures-surface flattening? Is that the gasket surface?

- perhaps you don't have an EGR system, so the EGR passage polish procedure may not be needed?-EGR?

- the head intake port-matching procedure, & then have heads redone; Check

- farm-out the head replacement if you have to.

What about replacing rings while heads are off-an easy procedure?

Hope I remember how to put this thing back together! Can't find a technical manual for this motor . . .

Thanks for the advice,
Ken.

grillage

I am in the midst of a head swap and may be able to help a little with lago's suggestions.

- send your injectors to RC Engineering for re-conditioning;

You might get as lucky as I was. I found that there was a recall from 1999 or so that applied to my 1993 AAH engine. The injectors and fuel rail were replaced by Audi for free about two months ago.

- replace all the soft vacuum lines;

You can get 3mm vac line in silicone from a bunch of places but many here swear by the vac line sold by BMW. I know I first bought some that was a little flimsy and prome to kinks. You are bound to find some broken or even chewed on vac lines

- the valley-pan cover flattening and re-seal procedure:

Search the archive here for this one. It's actually what I'm waiting for to put the heads back.

- perhaps you don't have an EGR system, so the EGR passage polish procedure may not be needed?;
I would bet you don't have an EGR. If your drivers side exhaust manifold has a hard pipe that goes to the throttle body you do have one.

Hopefully this helps! Have fun

KenCoupe

Thanks Grillage,

I’ll have to source a local supplier here in Cape Town for the injectors and will look into the valley pan procedure.

I don’t seem to have EGR.

Heads should be done today and look like new . My only concern now is with 300K on the clock-whether I change the rings. I kinda feel, if it aint broke don’t fix it. I’m not really in a position to take block out, re-hone/give a slight rebore so I’m worried if I put new rings in a slightly worn bore(even though it look good) it may be more likely to smoke than if I just left it.

Will keep you guys posted.

Thanks,
Ken.

hubturn

Would you post a picture of what your heads look like after they come back from the shop? Are they installing new valves etc? Thanks.

Lago Blue

If you aren't as lucky as Grillage, I've had good success with simply a set of used injectors from the wreckers that I sent to RC Eng. and swapped in. The price was very reasonable and the service was fast.

The vacuum reservoir and low-tension ignition coil wires suffer heat damage as they are in the valley. Search and find in the archives. The wires become brittle. oil soaked and short out. The installed res. and ancillaries must pass your leak-down checks.

The Valley Pan casting; and the Intake Manifold castings require flattening on every mating surface. Obviously, the pan's lower side, you will see the high-spots around the bolt-holes as you proceed. The Int. Man. has about 13 surfaces, none of which will be true. The pursuit of as high as possible engine vacuum at idle is the immediate goal of truing all these; and the indirect goal of this work is better low-end response and fuel mileage.

The pictures may be gone for many of the old articles, but they are worth mining. Here's my attempt at a to-do list for the intake:

https://www.audiworld.com/forums/sho...highlight=tour

It's an article that attempts to capture and detail the work required to more properly maintain a stock system. It may be wise to incorporate this material as a base-line, prior to considering other major part substitutions, since there will be little joy in operating a motor that consumes oil, makes little vacuum, has poor fuel mileage and responds poorly to throttle inputs at low speed. For most folks, I suspect they would be better served by high engine vacuum at idle, and low oil consumption vs. whatever throttle-body or camshaft etc. they could possibly have.

Although it's too late to measure your compression now, many of the low power and oil consumption issues found by other people here are other than rings, and may be just stuck rings, not a lot of talk around ring replacement, so you may be fine in that regard. Perhaps you've done this already - make sure you remove any stray coolant that may be laying in the cylinder bores on the rings, after head removal to help keep the compression you started with.

Keep the questions coming as you go. Use the above topics as search terms. Some of the older articles will make more sense as you move through the subject ares. Please keep us posted, there are many who are contemplating, are treading across, or have been on; similar paths.