Audi 2.5 TFSI DAZA Rebuild, common faults & everything you need to know
Complete guide to Audi's inline-five in aluminium form. The engine that gave the RS3 and TT RS 400 hp, with plasma-coated cylinder bores, a fracture-split con-rod and camshaft bearings machined straight into the cylinder head. Technical data taken from Audi's own self-study programme SSP 661.
The DAZA is the inline-five that went lightweight. When Audi developed the EA855 evo, the cast iron block was swapped for an aluminium block and the engine shed almost 19 kg in the crankcase alone. The result is a 2.5-litre five-cylinder turbo engine with 400 hp and 480 Nm, fitted to the RS3 8V facelift and the TT RS. It sounds fantastic and it works hard, but it is built with production methods that place completely different demands on an engine rebuilder than an old cast iron engine: the cylinder bores are plasma-coated instead of lined, the con-rods are fracture-split and have no small-end bush, and the camshafts run in bearings machined straight into the cylinder head. A DAZA rebuilds perfectly well, but it has to be done under the right conditions. We carry out everything from cylinder head reconditioning to complete engine reconditioning with our own machine shop and a 12-month warranty.
The DAZA at a glance
All the values below are taken from Audi's self-study programme SSP 661, The Audi 2.5l TFSI Engine EA855 EVO series, page 5. We have read the page both as text and as a rendered image and got the same values both times.
| Engine code | Block | Model | Power | Particulate filter |
|---|---|---|---|---|
| CEPA | Cast iron | TT RS (8J) | 340 hk | No |
| CEPB | Cast iron | TT RS Plus, RS3 8P | 360 hk | No |
| CZGB | Cast iron | RS3 8V (pre-facelift) | 367 hk | No |
| DAZA EA855 evo | Aluminium | RS3 8V facelift, TT RS 8S | 400 hk | No |
| DNWA | Aluminium | RS3 8V facelift (later) | 400 hk | Yes |
| DNWC | Aluminium | RS3 8Y, RS Q3 F3 | 400 hk | Yes |
The variant table is based on specialist workshops' compilations, not on Audi's own documentation. SSP 661 confirms that the EA855 evo was launched in the TT RS and that the engine was planned for more models in the group. Always check the engine code on the car before ordering parts. The code is on the timing chain cover on the left-hand side of the engine.
Design features that affect the rebuild
These are the details in the DAZA that govern what can and cannot be done in an engine rebuild. All the information comes from SSP 661.
Block & bottom end
Pistons & con-rods
Cylinder head & valvetrain
Cam drive & fuel system
Service and intervals (factory figures)
Note - The intermediate shaft cannot always be removed: the intermediate shaft that drives the camshafts, the high-pressure pump and the vacuum pump is pressed and bolted into the crankcase. Audi distinguishes between two versions. The early shaft with a threaded end (before 2017) is listed as non-removable. The later shaft without a threaded end can be removed from above, but then the cylinder head has to come off. That is something to find out before planning a build, because it determines how far the engine needs to be stripped.
Note - The cam drive is on the gearbox side: unlike most engines we have on the bench, the chain drive sits at the rear towards the gearbox, not at the front. The camshafts are locked with Audi's tool T40264/2A when the valve timing is set, and the pistons are fitted with a special funnel (T40347) whose job is to protect the three-piece oil ring during insertion. That says something about how sensitive the ring pack is on this engine.
Note - Plasma-coated cylinder bores: the DAZA has no cylinder liners. The bores are coated with a thin plasma-sprayed coating straight onto the aluminium. The coating is typically around 0,14 to 0,20 mm thick, which means there is no material to bore into. An ordinary oversize bore removes the entire coating and exposes the aluminium. The coating hones very well, however, which is how it is finish-machined at the factory, but only with the right tools and minimal material removal. If the bore is scored or damaged, sleeving is the answer, that is, boring out the block and fitting proper liners.
Note - Con-rod without a bush: the small end has no bush and the gudgeon pin runs directly against the con-rod. Wear in the gudgeon pin bore therefore cannot be fixed with a bush replacement as on an older engine. The con-rods are also fracture-split, which means each cap only fits its own rod and must never be mixed up or machined flat.
Note - Camshaft bearings in the cylinder head: the camshafts run in roller bearings in the cam cover, but the cylinder head itself forms the mating bearing shell. Audi states in SSP 661 that the whole cylinder head must be replaced if the bearing surface is damaged. It is one of the most important things to check before deciding whether or not a DAZA is worth rebuilding.
Note - We do not publish torque specs for the DAZA: we only list torque figures we have been able to read on an actual factory page. Audi's workshop data for the DAZA sits behind a paywall in ElsaWeb and erWin, and SSP 661 is a self-study programme that is expressly not a repair manual. We never guess, and we never borrow torque figures from the older cast iron engine CEPA or CEPB, because the block is completely redesigned. If you need the figures for a build, get in touch and we will look them up in Audi's system for you.
Every measurement is checked against factory tolerances with our own machine shop.
Common faults on the DAZA
This is the picture that specialist workshops in Europe report on the DAZA. It is workshop experience, not information from Audi, and we present it as exactly that.
Injector that sticks open
Known fault • Critical- Symptoms
- Rough running, a misfire on one cylinder, a smell of fuel and a sudden loss of power. It often goes quickly from the first symptom to serious damage.
- Cause
- The engine has both direct injection and port injection. The FSI injectors sit in the cylinder head, work at up to 250 bar and are controlled with up to 65 volts to manage multiple injections per combustion cycle. If one of them sticks open, fuel is injected uncontrolled and the flame gets a cutting-torch effect against the piston crown. This is the fault that specialist workshops single out as the most dangerous on the DAZA, because it can melt a piston before the driver has time to react. At the first suspicion, the injection must be checked straight away.
Damaged cylinder bore in the plasma coating
Design-related • Critical- Symptoms
- Oil consumption, poor compression on one cylinder, blue smoke and metal particles in the oil. Often a secondary fault after a melted or damaged piston.
- Cause
- The coating is thin and sits straight on the aluminium. If it is damaged there is no liner underneath to fall back on, and an ordinary oversize bore is not possible. The block is saved by sleeving, where we bore out the cylinder and fit a liner. It is entirely doable, but it needs to be in the calculation from the start.
Water pump and thermostat housing
Common • High- Symptoms
- Coolant leaks, a falling level in the expansion tank and a smell of coolant after driving.
- Cause
- The plastic housing cracks from repeated heat cycles. Audi has developed an updated version. It is a peripheral fault rather than an engine fault, but worth fixing before the engine overheats, because an aluminium block is more sensitive to overheating than cast iron.
Play in the turbo wastegate
High mileage • Medium- Symptoms
- A metallic rattle on acceleration and engine braking, uneven boost pressure and, in worse cases, a fault code for boost pressure control.
- Cause
- The wastegate shaft and linkage develop play over time. It is described as common on the evo engines. We fault-find the boost system and recondition or replace the turbo.
Big-end and main bearing wear
Tuned cars • High- Symptoms
- A knock from the lower engine under load, falling oil pressure and metal shavings at oil changes.
- Cause
- Audi reduced the main bearing journal from 58 to 52 mm to lower friction, and compensated with Irox-coated bearing shells. The design is made for the standard engine. If you raise the power substantially, the ignition pressure and the load on those very bearings increase. During a rebuild the crankshaft is ground and new bearings are fitted to factory tolerances.
Damage to the camshaft bearings
Costly • Critical- Symptoms
- A bad noise from the cam side, shavings in the oil and, in the worst case, a camshaft that seizes.
- Cause
- The camshafts run in roller bearings, but the bearing race is machined straight into the cylinder head. If it is damaged, the bearing shell cannot be replaced. Audi states in SSP 661 that the whole cylinder head must be replaced. We always check the bearings during disassembly before we quote for a rebuild, so that the verdict comes before the work and not after.
DAZA rebuild prices
Prices based on the DAZA specification: 5 cyl inline, 82,5 mm bore, 20 valves, 6 main bearings and 5 big-end bearings, aluminium block with plasma-coated bores. We carry out cylinder boring and sleeving, crankshaft grinding and cylinder head resurfacing with our own machine shop. All prices exclude VAT and parts.
Cylinder head reconditioning
Bottom end
Sleeving the block
Full rebuild
The price covers machining work only. Parts and assembly/disassembly labour are charged separately.
Cylinder machining (5 cyl, 82,5 mm bore)
| Service | Price |
|---|---|
| Sleeving 5 cyl (with damaged plasma coating) | 7 364 kr |
| Boring straight cylinder block 5 cyl | 3 892 kr |
| Plateau honing, 5-cyl | 1 274 kr |
| Honing with stress plate 5 cyl | 2 926 kr |
| Replace dry cylinder liners 5 cyl | 4 452 kr |
| Decking cylinder block 5 cyl | 2 436 kr |
Crankshaft work (6 main + 5 big-end)
| Service | Price |
|---|---|
| Crankshaft grinding 5 big-end journals | 2 002 kr |
| Cleaning 5-cyl crankshaft | 1 008 kr |
| Grinding 5 cam bearing journals | 1 596 kr |
| Check and adjustment of main bearing bores, Linetouch | 2 940 kr |
| Line honing main bearing tunnel 5 pcs | 5 404 kr |
| Align-planing and line boring main bearing bores 5 cyl | 9 366 kr |
Valve reconditioning (20 valves)
| Service | Price |
|---|---|
| Removal and refitting of valves and springs, 5 cyl 20v | 1 358 kr |
| Cutting 20 valve seats | 1 831 kr |
| Cutting 20 valve seats (race) | 2 594 kr |
| Fitting valve seat, light alloy 5 pcs | 2 016 kr |
| Valve guide replacement 15 pcs (light alloy) | 2 156 kr |
| Reaming valve guides 15 pcs | 1 442 kr |
Resurfacing (I5, alloy cylinder head)
| Service | Price |
|---|---|
| Straightening and resurfacing cylinder head 5 cyl (standard) | 1 596 kr |
| Straightening and resurfacing cylinder head 5 cyl (large) | 1 820 kr |
| Straightening and resurfacing 5 cyl 0,5-1,5 mm (standard) | 1 848 kr |
| Decking cylinder block 5 cyl (standard) | 2 436 kr |
Con-rod work (5 pcs, small end without bush)
| Service | Price |
|---|---|
| Check and straighten con-rod, adjust big-end housing 5 pcs | 1 764 kr |
| Straightening, big-end housing adjustment and resizing 5 pcs | 2 814 kr |
| Full reconditioning, rod, 5 pcs | 3 738 kr |
| Shot peening, rods, 5 pcs | 2 828 kr |
| Replace piston rings and cleaning 5 pcs | 1 442 kr |
Pressure testing & balancing
| Service | Price |
|---|---|
| Pressure testing cylinder head, 5-cyl (small) | 2 156 kr |
| Pressure testing cylinder head, 5-cyl (large) | 3 108 kr |
| Balancing rotating assembly, straight engine 5 cyl | 4 066 kr |
| Balancing rotating assembly with bobweight 5 cyl | 8 232 kr |
| Weight matching, rods, 5 pcs | 1 554 kr |
Indicative prices for the DAZA configuration (5 cyl inline, 82,5 mm bore, 20 valves, alloy cylinder head, aluminium block with plasma-coated bores). Labour prices exclude VAT and parts. Note that the con-rod small ends have no bush, so a bush replacement does not apply on this engine, and that cylinder work requires sleeving because the plasma coating will not tolerate an oversize bore. Request a quote for an exact price after inspection.
Tuning the DAZA
The DAZA is a highly stressed 400 hp engine straight from the factory. There is plenty to gain, but durability is decided by the bottom end and by the fuel system keeping up.
- 1
Software tuning
A well-developed ECU remapping gives a clear lift on the standard setup. It assumes a healthy boost system, healthy spark plugs and that the injection has been checked. On this engine in particular, the injectors are what you have to keep an eye on before the power is raised.
450-480 hk - 2
Tuning + freer flow
A freer intake, a downpipe and better charge-air cooling together with matched software. This extracts most of what is available with the standard engine's parts and reasonable margins. A healthy turbo is a prerequisite.
500-520 hk - 3
Reinforced bottom end + boost
Forged pistons and stronger con-rods, checking and balancing the rotating assembly plus an upgraded turbo. Here you leave the standard parts behind, and this is also where the fuel system needs to be built out.
550-600 hk - 4
Full build
A gone-through bottom end with a sleeved block, port work in the cylinder head and a boost system sized for the power. We build the chain largely in-house with performance engine building and a focus on durability.
600+ hk
Questions & answers about the DAZA
What we hear most often from RS3 and TT RS owners.
Can a DAZA engine be rebored?
Not in the usual way. The block is aluminium and the cylinder bores are plasma-coated instead of lined. The coating is only a couple of tenths of a millimetre thick, so an oversize bore cuts straight through it and down into the aluminium. The bores can be honed gently, however, which is how they are finish-machined at the factory. If the bore is damaged, sleeving is the way forward, that is, we bore out the block and fit proper liners.
What does it cost to rebuild an Audi 2.5 TFSI DAZA?
A cylinder head reconditioning runs around 7 000 - 9 500 SEK in labour and a bottom end without cylinder work around 8 000 - 13 000 SEK. If the block needs sleeving, add around 12 500 - 16 000 SEK. A complete rebuild typically lands at 22 000 - 34 000 SEK in labour. Parts are always extra, and on this engine the pistons, bearings and stretch bolts are a significant item. We give a fixed quote after inspection.
Why don't you publish torque specs for the DAZA?
Because we have not been able to read them on an actual factory page. Audi's workshop data sits behind a paywall in ElsaWeb and erWin, and Audi SSP 661, from which we have taken the technical data, is a self-study programme that is expressly not a repair manual. We would rather publish nothing than a torque figure we have not been able to verify, and we never borrow values from the older cast iron engine. If you need them for a build, get in touch.
What is the difference between the DAZA and the DNWA?
Both are 2.5 TFSI engines of the EA855 evo type with an aluminium block and 400 hp. The DAZA is the earlier version without a particulate filter, the DNWA the later one with a GPF. Mechanically they are closely related, but the exhaust side and the software differ. Always check the engine code on the timing chain cover before ordering parts.
Which oil and which service intervals apply to the DAZA?
Audi specifies 0W-30 to standard VW 504 00, and 7,1 litres including the filter. The oil change interval is between 15 000 km/1 year and 30 000 km/2 years depending on how it is driven, a service inspection at 30 000 km/2 years, air filter at 90 000 km and spark plugs at 60 000 km or 6 years. The timing chain and the ribbed belt are rated for the life of the engine according to Audi. Our experience with hard-driven and tuned cars is that it pays to stay at the short end of the oil interval.
Is the timing chain at the front or the rear on the DAZA?
At the rear, towards the gearbox. The drive is two-stage: the crankshaft drives the oil pump and intermediate shaft with an 8 mm toothed chain, and the intermediate shaft in turn drives the camshafts with an 8 mm roller chain. The intermediate shaft also drives the high-pressure pump and the vacuum pump via a three-lobe cam. The chain being on the gearbox side affects how much has to be removed when working on the cam drive.
What sets the DAZA apart from the older cast iron engine?
Almost everything at the bottom. The CEPA, CEPB and CZGB have cast iron blocks. The DAZA has an aluminium block with plasma-coated bores, a crankshaft with smaller main bearing journals (52 mm instead of 58 mm), fracture-split con-rods with no small-end bush and camshaft bearings machined straight into the cylinder head. Parts and working methods are not interchangeable between the generations.
Can a DAZA be tuned?
Yes, and it responds well. Software gives a clear lift, and with freer flow you get a fair bit over 500 hp. If you want more than that, the bottom end needs strengthening and the fuel system building out. We always tune with a margin, because on an engine that already sits high from the factory it is durability that sets the limit, not how much boost you can wind up.
Should you rebuild or replace the engine?
It depends entirely on what is damaged. If the cylinder head's camshaft bearings are damaged it gets expensive, because Audi states that the whole cylinder head must be replaced. If it is the bottom end or a bore that has failed, a rebuild is often the right call, especially as a used DAZA has an unknown history and the same weak points. We strip it, measure it and give a verdict before the work begins. We ship worldwide.
See also: our other engine guides under Engine types. The DAZA shares its bore and stroke with the VW Group's 2.0 TFSI, and anyone who likes inline-fives will also find Volvo's D5 and T5 in the catalogue.
Have an RS3 or TT RS that needs looking at?
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