Engine rebuild

Stuson

Stuson

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Could anyone give me rough idea of what rebuilding a 1.8T engine could involve please?


By this I mean best case scenario parts and cost and worst case scenario parts and cost. And this is based on an engine that is healthy.
I would go for forged rods no doubt there an obviously a damn good internal clean.

Thanks.
 
Depends what you mean by actual rebuild... and if you are doing it yourself.. I have an engine build pretty much detailed in my thread (from page 53)...

2k-5k is a ball park

<tuffty/>
 
Thanks for the reply Tuffty. I'll have a look at your thread.

Well I see a lot of people on here rebuilding engines because they want forged rods or because they blew an engine.

Assuming the engine is in good health, what kind of things need changing? Piston rings, valve stem seals...........
 
audi upgrades
Common things that might need replacing are oil pump and pick up, rings, bearings, gaskets & seals, valve guides, lifters, chain tensioner, timing belt kit
 
Do a compression and leak down test on the engine to get an idea of its state... once apart check bores for ovality and wear...

If the compression/leak down tests go ok and bores check out then you should theoretically get away with a light hone and new rings otherwise its advisable to go for a rebore and new oversize pistons... in which case you may as well consider a full rebuild then...

Heads suffer from worn guides, hardened stem seals and on occasion weak springs (older large port heads seem prone)... check valve and valve seats for pitting... lapping them in is a must but excessive pitting may require a light recut

Followers can wear or go sticky, cam tensioner chain can stretch, cam tensioner pads wear... change as required

Bottom end wise new shells (big ends and mains), thrust bearings, new mains bolts although its worth considering ARP studs as the price difference is negligible but the extra strength/reliability afforded is well worth the investment... you should also look at a new oil pump and oil pump chain+tensioner... the tensioner is plastic... the go brittle and can break apart...

On top of that you will need front and rear crank seals, head bolts, head gasket, timing belt kit, water pump and a new crank pulley bolt... plus new flywheel bolts...

<tuffty/>
 
If you're doing the work your self, I've just rebuilt my bottom end with IE rods, race bearing etc etc for under a grand (couldn't give you an exact figure)... Helps I saved 150 quid getting a mate to bring me some rods back from the states!

The only other thing I might like to do is a head rebuild (guides, stem seals, reseat valves), I'm gonna see how it performs on the dyno first though... But I've got 3 spare heads here anyway so might just keep one aside and rebuild it at some point.
 
VAG-Slag said:
...But I've got 3 spare heads here anyway so might just keep one aside and rebuild it at some point.
Click to expand...

Saw this... thought of you
Spareheads



..nerdy Red Dwarf thing... sorry :)

<tuffty/>
 
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Are these engines usually good for 200k before they need rebuilding? I appreciate every engine is different.

Mine is on 140k.
 
Stuson said:
Are these engines usually good for 200k before they need rebuilding? I appreciate every engine is different.

Mine is on 140k.
Click to expand...

You just answered your own question there... A thorough compression and leak down test will give you a good indication of the health of the engine

Really it is so subjective though, there's no golden rule...
 
This whole 'good for 200k' thing is a massively subjective discussion in its own right... really does depend on your definition of 'good'... I've seen peoples definition of 'good' and it really isn't...

A std engine that has regular oil changes and isn't modded, driven sensibly with the occasional blast will last decent mileage... have seen cars with 150k on them make better power than others with half the mileage...

Engine wear rate is hugely subjective... the best you can hope for is that a compression and leak down test gives good results as thats a fair indicator as to how tired your engine will be..

Bill had an S3 in for 'just rods' a while back... 130 odd k on the clock and the engine was the most worn out he had seen... basically needed a full rebuild... by full this typically means rebore and new pistons....

<tuffty/>
 
<tuffty/> said:
This whole 'good for 200k' thing is a massively subjective discussion in its own right... really does depend on your definition of 'good'... I've seen peoples definition of 'good' and it really isn't...

A std engine that has regular oil changes and isn't modded, driven sensibly with the occasional blast will last decent mileage... have seen cars with 150k on them make better power than others with half the mileage...

Engine wear rate is hugely subjective... the best you can hope for is that a compression and leak down test gives good results as thats a fair indicator as to how tired your engine will be..

Bill had an S3 in for 'just rods' a while back... 130 odd k on the clock and the engine was the most worn out he had seen... basically needed a full rebuild... by full this typically means rebore and new pistons....

<tuffty/>
Click to expand...

Octavia in today. 127K miles
hybrid k03.
barely made just over std 180bh power.
took no timing, made no power/torque, one older guy previous owner,. Unknown to existing owner it had been jabba mapped for probably years. Tow bar on back..
Car was clean.. was cheap.. but unfortunately engine is very tired. flowed 240bhp if air from 1.1bar boost, but made only 180bhp odd.. 60bhp of "missing in action" airflows internally.

Some high milers make awesome power..

Random as a random thing
 
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Thank you for your input Tuffty and Bill, much appreciated.

I hear what your saying, mine has regular oil changes, previous owner had it serviced at an Audi dealership.

Made good power on you're rollers Bill, 257bhp bbt K250, but I will get a compression test done to see how it fairs up.
 
Does anyone know the compression tolerance's for these engines?
Am I right to assume all Mk IV chassis 1.8T blocks are the same reguardless of engine code?
Mine is AUM.
 
Stuson said:
Does anyone know the compression tolerance's for these engines?
Am I right to assume all Mk IV chassis 1.8T blocks are the same reguardless of engine code?
Mine is AUM.
Click to expand...
Yes they're all the same.
What do you mean? As in what is the minimum you should be getting on a compression test?
 
Well I have the spec's for the Ibiza equivalent engine.
New is between 145-188psi and maximum wear limit is 101psi. With maximum difference between between the cylinders is 43psi.
If the compression ratio is the same on all 1.8T blocks I should be able to use this as a guide right?
 
Stuson said:
Well I have the spec's for the Ibiza equivalent engine.
New is between 145-188psi and maximum wear limit is 101psi. With maximum difference between between the cylinders is 43psi.
If the compression ratio is the same on all 1.8T blocks I should be able to use this as a guide right?
Click to expand...
The compression ratio varies by .5 on the more powerful 1.8t, I.e. TT, S3, lcr have lower.
 
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