Hi I own a Audi s3 2002 model I have just overhauled the engine the new parts I bought were new cylinder head,cylinder head gasket,head set,tappet cover gasket,water pump,cam belt with tensioner,venthose ,tube,housing,flange,stretch bolts,oil filter,exhaust gasket,flash,coolant,ignition oil,plugs and after all this my car is smoking so now I'm told my turbo has packed up.so my question is is it smoking because of the turbo and am I being guided in the right direction because all of this has cost me a lot of money and I don't want to spending anymore unnecessary money? Thanks

What exactly do you mean by an "overhaul"? More information please. Which diesel engine is this? The 2.5 litre or the 2.6 litre? What year is your vehicle? Some engines can be different settings depending on the size it is.
I'm assuming this is for the clearance between the valve rockers and the spring end of the valves?
If you're breaking rockers your mechanical timing might not be set correctly risking bent valves or the valves are already bent. Even One tooth out on the timing belt/chain can cause problems. You might need to take the cylinder head off to check the valves.
When you set the clearances the engine needs to be Cold and the cylinder you're working on needs to be at Top Dead Centre (TDC) to make sure the valves are closed. On an inline 4 cylinder engine the cylinders work as pairs, 1 and 4, 2 and 3.
Set cylinder number 1 to TDC. Set the clearances for only cylinders 1 and 4. Using the crank pulley bolt turn cylinder 1 to Bottom Dead Centre, (180' turn clockwise). This should bring cylinders 2 and 3 to TDC so you can set those clearances.
Is the engine burning the oil? (a thicker, more blue exhaust smoke than normal). Burning oil can also be a sign of a blown head gasket or badly worn piston rings.

The Chilton and Haynes manuals are your best bet. Order it at your local Autozone or goto the Library and research them online fro free.

If you havent fixed it yet then .
Then either your distributor cap is cracked/points set to 012" /lead no good/plug no good/tappet totight set tappets to 012" [No 4] cylinder/burnt out exhaust valve/ worn or broken piston rings [No 4 ]or a leaking inlet manifold gasket.,,or sometimes burnt or blown head gasket

if the cylinder head is the problem just replace it, but the leaking could just be from faulty head gasket you dont need it overhauled, all it needs to be done is take the cylinder head out put new head gasket

Hi Adrian, I'm not very clear on the nature of your problem. I'm guessing that your vehicle is a four cylinder in line engine. To replace the cylinder head gasket is rated as a major job and requires the following work to be carried out. The engine must be completely cold before starting any work. Disconnect the battery, drain the coolant and engine oil. Remove the fuel, coolant and all electrical connections to the carburation and ignition system. Remove the intake and exhaust manifolds followed by the tappet cover. It is also required to remove the fan belts, the crankshaft pulley and the front timing cover, Under the tappet cover is the valve assembly, which needs to be removed. The cylinder head bolts need removing in a strict sequential order, beginning from either end and spiralling in so that the last bolts loosened are those at the centre. Once the head is unbolted it should be measured to make sure that the face is not distorted in any way. Assembly is three times more complicated, requiring the correct torquing settings and the correct sequence of tightening, (beginning at the centre and spiralling outwards). You will also need to set the valve timing and clearances. If you would like to tackle the job after reading this, let me know and maybe I can give you pointers while you're on it. Coincidently we do not have that particular vehicle here so I have not had hands on experience with it. The information I have given refers to all four stroke internal combustion engines. The gasket appears as a very basic replacement, but fitting it is far from basic. Regards John

air trapped in engine let it run with cap off it will burp a few times then it should be good

Sounds to me like the head gasket is blown, but there may be sealant in the system which is making it intermittently leak antifreeze into the cylinders.

A bad cylinder head gasket will also cause a compromise in compression, which will cause a lack of power.

Time to overhaul or replace the engine's head gasket, or replace the engine with one that doesn't have a blown head gasket.

Good luck on this repair.

Sounds like coolant ports in the engine block is gunked up. Did you maybe notice the coolant ports when you changed the head gaskets? And, or, change the radiator cap,if you haven't already done so, I've seen them heat up over that too.

Hi,

In its simplest terms, the head gasket is the spacer/insulator between the cylinder head and the engine block. When the piston (in the block) moves upward to compress the air/fuel mixture (against the cylinder head), tremendous pressure develops inside the combustion chamber. The pressure will find any easy means of escape to expand. If the gasket is defective, the pressure will pass through that gasket and enter the water jackets (where the collant flows through). The pressure/air bubbles will ride the coolant flow and eventually end up inside the radiator and would then be visible as you have posted.

Incidentally, the gasket may be OK but the cylinder head could be warped and the same fault would also be exhibited. This is especially more so on aluminum heads.

Both the gasket problem and/or the warped cylinder head could have resulted from a prior overheating problem.

Corrective procedure on the air bubbles would require top overhauling wherein only the cylnder head is removed. Of course once removed, your mechanic would be able to inspect the pistons and its sleeves and could decide if a general overhaul is required or stick to the cylinder head work. A top overhaul also requires cylinder head gasket replacement.

Unto the overheating problem, you may want to check the water pump, thermostat, fan, fan relay and fan clutch. It may also be to your added advantage if you would have the radiator flushed/cleaned as well as the water jackets. Some mechanics especially in warmer regions opt to completely remove the thermostat and permanently wire the fan to always be on.

Hope this be of initial help/idea. Pls post back how things turned up or should you need additional information.

Good luck and kind regards.

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