Engine Compatibility

[aragorn]

So lets say the engine in our A4 was to die, (it hasnt, but its not the most healthy sounding of motors and i like to be prepared incase the worst happens)

Clearly there are a whole pile of 1.8T's fitted across a range of motors, so which ones can be used to replace an AEB? Clearly i'd have all the parts of the AEB to swap over should be be a different motor, but i'd like to know wether its only longitudinal motors i can use (or even only certain longitudinal motors), or if i can install a transverse motor as long as i use the longitudinal manifolds etc?

I notice the transverse engines have a different waterpump/thermostat system, is this interchangable with the AEB's external waterpump?

Cheers

 

[Broken Byzan]

aeb/apu/ajl should work but you would need to swap in your throttle body and some of the engine switches as the later onse have them silly little black plugs instead of spade etc used on the AEB

I have an APU botton end and an AEB head for instance

HTH

 

[aragorn]

so sticking to the longitudinal engines is a better bet?

Its odd there is such a wide variation in prices too, a quick scan of ebay shows a couple around the £300 mark (which is what i expected) but some of the breakers on there are wanting £800+

 

[Broken Byzan]

When i needed one the going rate was around 500-600

Longitudinal would be my preference, they are also less sought after as they cannot easily be used for conversions on FWD cars. Best way to find one is from a VW, they seem to go for less money despite them being the same unit

 

[jcb]

any 20v, you just have more work to do the further away from the B5 platform you go.
some have internal water pumps some don't.

if it is just the bottom end that is dead you should be able to swap over any ancillaries from your dead one.

if it was mine I would be dropping in a new metal impellered water pump (instead of teh shitey plastic one!) and new oil pump and doing the cam belt as a matter of course before it goes in

 

[aragorn]

well as it stands the timing chain/valve gear seems quite noisey, it seems to burn a litre of oil every 2k or so, and if the oil level is below about half way it starts to tick quite loudly if left idling when hot for more than a few minutes.

The latter point is probably the oil pump, and the first one is probably the chain tensioner, both of which could be changed, but it means i'd be throwing 2-300quid + time at an engine thats done interstellar mileage and could self destruct anyway even with the parts changed. I keep the oil topped up which will hopefully keep the oil pump issue at bay for now, not sure what the deal with the timing chain tensioners are, but i doubt its worth the effort to change it on that engine.

TBH i'm probably just scaremongering myself, it'll likely rattle on for another 50k by which point we'll likely have sold it on, i just like to know the score if it does self destruct! It drives perfectly fine and doesnt sound obviously knackered (unless its low on oil, when it sounds pretty shagged, but i shouldnt really be letting it get low on oil in the first place!), its just a close ear picks up the chain noise and i thaught i'd look into it to be sure

 

[jcb]

tensioner probably just requires another nylon block and you can get new oil pumps from the states for a lot less than here.
www.qedpower.com $179.00 (£120 no tax)

 

[aragorn]

Can you buy just the nylon block? If so and if its not too much work to fit i might throw another one in it.

Is there any way to check the parts for wear? can i look at the tensioner/chain and say "ok thats humped" or is it tiny tolerances?

ECP has the oil pump for £100, but again its a fair amount of work for an engine that's a bit ****** anyway...

 

[jcb]

tensioner is driven by oil pressure IIRC so your problem may nto be the block. you would be able to see if it was shagged but a good servcie and oil pump replacement might do the trick

 

[aragorn]

i think the oil pressure is fine, bar at idle while the level is low.

I keep meaning to get a proper gauge onto it and see what the pressure actually reads, but i've not bothered.

Before we baught it it looks like its missed an oil change or two, there was a bit of sludgey gunk in the rocker cover and i gave it a good flush and got a lot of the crap out, but i guess the tensioner could still be gunked up inside. Its done 20k since then though and had oil changes every 4-5k

I dont think the block itself is gubbed, bar perhaps the rings being a bit leaky leading to it using the oil, but there comes a point were you have to consider the economics of trying to breath life back into an engine thats done 174k, or just waiting until it dies and replacing it.