Poorly RS2 :(

[Bowie69]

WEll, seems you found part of the solution anyways, and unsurprising given the ago of the engine, HGs tend to be more age than mileage related after all.

[Harvester]

I really can not understand what is the reason of your issues , even when you have so low mileage . This 5 cylinder engines should make huge amount of kilometers. I hope you you will be back on the road soon . Btw : Normal pressure on cylinders is about 130-150 psi ?

[K Simmonds]

Sounds to me like the exhaust valves aren't seating all that well due crap on or damage to the seats combined with a bad head gasket leak. I would be fairly surprised to find it's a problem with the bottom end, it should all become clear once the heads off. Good luck!

[UrS4boy]

. Btw : Normal pressure on cylinders is about 130-150 psi ?

Compression pressures
New: 9-14 bar (131-203 psi)
Wear limit: 7.5 bar (109 psi)
Max. permissible pressure difference between all cylinders: 3 bar (44 psi)

This is from the AAN engine manual but it applies to the ABY and ADU equally well:

[Ducky]

I'll run a comp test again when I have a second pair of hands (the engine was warm but not up to 80C as indicated above) just to be sure.

cheers
Chris

[Rusty]

Aye, sounds like something is amiss. Best of luck getting it sorted. Mine's approaching the factory compression limit on cylinder 4, so 10-11 Bar on 1,2,3&5 and 8-9 on 4. Bit lumpy at idle but runs well enough and doesn't burn much oil

Head gasket isn't too bad. Take the chance to replace what's necessary, inspect what you can and maybe fit some ARPs. If you do have the head rebuilt the consider having multi angle valve seats an some port matching as a little treat to the old girl

[Harvester]

But in my opinion , its strange that only 3 and 4 cylinder is problem . There is not any higher temperature , or cooling issue as on fifth cylinder could be .( I remeber that bmw straight six cylinder engines has often problem with the ,,last,,cylinder because of heat and head gaskets are often cracked .) There is not any speciall effort on 3 and 4 cylinder .

[driftin jo]

When you did the comp test did you have the throttle open ?
Was the engine warm?
What make is the comp tester,I had a cheep one that read 50psi down as it wasn't calibrated, I didn't believe how low and even the numbers were so checked it, at 150psi it was showing 100!

you could be looking at valves no seating properly rather than head gasket gone, although it makes no difference as the head has to come off anyway, this is a classic symptom of a car not being driven enough, 80k miles could be it's down fall.

[Ducky]

Round #2!

Albeit it makes no difference. I borrowed another gauge off a mate, engine warmed up and throttle open, I get roughly 120 to 140psi on 1,2+5 and 70 on 3+4, so better but still not great and means my gauge is probably crap (Ebay).

So looking into options at the moment with JP.

[UrS4boy]

Round #2!Albeit it makes no difference. I borrowed another gauge off a mate, engine warmed up and throttle open, I get roughly 120 to 140psi on 1,2+5 and 70 on 3+4, so better but still not great and means my gauge is probably crap (Ebay).So looking into options at the moment with JP.

Based on those numbers, where even the good ones are quite low, you might want to consider a good used replacement engine. At the minimum for your engine, you are looking at a headgasket (and timing belt job) but you'd also want to refresh the head (valve guides and seals and relapping the valves to the seats).

AAN or ABY engines are good candidates for replacements, not just ADUs.

IMO

[Fat Audi 80]

Based on those numbers, where even the good ones are quite low, you might want to consider a good used replacement engine. At the minimum for your engine, you are looking at a headgasket (and timing belt job) but you'd also want to refresh the head (valve guides and seals and relapping the valves to the seats).

AAN or ABY engines are good candidates for replacements, not just ADUs.

IMO

Are you serious? A replacement engine will kill the heritage of an RS2, head off refurb and the car is s good as new and retains its value.

Cheers

Steve

[UrS4boy]

Are you serious? A replacement engine will kill the heritage of an RS2, head off refurb and the car is s good as new and retains its value. Cheers Steve

Show me where the external differences are between an AAN/ABY and an ADU. (there are none on the block or the head, except the exhaust cam and sprocket). Internally, the only difference was rod bearings.

So what if he does the valves and the head gasket and the compression is still low? ADU engine out for rings?

[Monkeymagic]

Sounds like poorly seated exhaust valves. But all 5 cylinders cpmps seem low to me.
Id be amazed if there was ring wear unless its got borewash etc.
At that miles a top end refresh should transform it. Easy enough.job but maybe a bit much including moving house...