The car was in for some repairs which they had to remove both heads and replace gaskets. After picking her up i notice the acceleration was not there and the fuel consumption is high also difficulty in starting. They ran it on the computer and the following error codes appeared:
Error codes
P0341
P0070
P0017
P0016
P0018

What could be the problem? Im suspecting they didnt do a proper timing of aligning everything right.

 

Except for the P0070 (Ambient air temp sensor) the others are cam and crankshaft sensor errors.. You can Google these codes. Why did they have to do the head gaskets? Take it back to them and tell them to fix the thing right. You're probably right that they didn't get the timing just right on it. And, most importantly, don't pay them a dime to re-do it because THEY messed up, not you.

 

They did the gasket after i notices low coolant warning and discovered 'mayonnaise' on the oil cap! Yes i already took the car back to them, and they confirmed that its the timing thats off, and they ordered some timing tool to fix it!

How do you get this engine to be properly timed?

 

There is a process you must follow in order to get it right. The gears on the cam that are driven by the timing belt are not "keyed'. They are on a tapered surface and must be loosened to allow for minute movements when tensioning the belt. The bolt that holds the gear on must be loosened a few turns and a puller is used to unseat the cam gear on that tapered surface. Installing a crank lock pin into the side of the block (there is a removable plug covering the hole) will verify the crank is in the proper TDC position. There are alignment marks on the cam chain gears that must align with marks cast into the cam bearing caps. There is a keyed plate on the cam belt gears that accepts a bar that spans the two sides of the engine. This bar goes on to hold the cams on their prospective marks. (Sidenote: If the cams have been removed for a chain or tensioner replacment, there is a certain number of links of the chain, 15 on one side, 16 on the other, that is the proper spacing)

With all of these marks aligned and the cam belt gears loose enough on the cam to allow it to rotate freely, you install the timing belt in a certain order starting with the crankshaft. I forget the specific order but is is spelled out in the manual and should be followed exactly to insure the belt goes on properly. Leaving the cam belt gears loose during the tensioning procedure of the belt, allows for any slack to be taken out of the belt that may turn the gears ever so slightly during the process but since the cams are locked into the proper timing with the cam lock bar, the cams will not move. Just the belt gear will move. Once the belt is tensioned properly, you THEN tighten down the cam belt gear bolts to basically lock them into position. Once you get them torqued, you remove the cam lock bar and crank lock pin from the block. Turn the engine over two full revolutions bringing it back up to TDC. Re-insert the crank lock pin (it should go in easily) and then slip the cam lock bar back on. If the cam lock bar goes on without complaining (not having to rotate ANYTHING), you have properly timed the engine. If not you'll need to pop the cam belt gears back loose and re-tension the belt with the cam lock installed.

This is the baseline timing for the engine. The ECU will then use the hydraulic chain tensioners between the cams to vary the timing depending on demand. If the cam belt gears are off a degree or so, the engine will still run fine but not perform like it should until you get that baseline timing exact. Frankly I was kind of skeptical of the non-keyed cam belt gears because of devastating potential of one of those things slipping. But now that I see that it allows for very very precise setting of the baseline timing, coupled with the fact when those things are torqued down (55nm or 40ft/lbs), the things are NOT going to move barring something else really bad happening. I recently had to change the cam chain tensioners on my 03 A8 4.2 and had some issues with carbon build up dropping down into the cylinders causing a binding with turning the engine over by hand which I finally resolved without having to remove the heads so basically I had to set the timing on the thing twice during this ordeal.. LOL But practice makes perfect and now I fully understand how it supposed to be done. While at first I thought the process seemed unnecessarily complicated, it really wasn't after doing it a couple of times. My car now runs great and will be even better when I get the new arms for the intake crossover flaps installed. While I had it apart, I went ahead and cleaned the pivots for the flaps on the front of the intake. They had seized up and snapped the little plastic arms at some point a while back. Got them freed up and working again.

What I bet has happened in your case is that they didn't loosen the cam gears to allow for the slight movement will occur when tensioning the belts on the V-6 and V-8 engines, it's just enough to affect the performance as you have noted.

 

Thanx for the reply! i actually saw a video on youtube. My suspicions is that they didn't have the cam lockers, cause they told me they were waiting for 'timing tools'! But i saw the car today they say they done timing the motor, they putting everything back together again!

 

I picked up a cam lock bar and the crank locking pin on ebay a while back. $50 maybe... Essential to doing it right though.